CA1161748A - Ball switch device and method - Google Patents
Ball switch device and methodInfo
- Publication number
- CA1161748A CA1161748A CA000381025A CA381025A CA1161748A CA 1161748 A CA1161748 A CA 1161748A CA 000381025 A CA000381025 A CA 000381025A CA 381025 A CA381025 A CA 381025A CA 1161748 A CA1161748 A CA 1161748A
- Authority
- CA
- Canada
- Prior art keywords
- piston
- tubing string
- gun
- vent
- downhole
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
- 238000000034 method Methods 0.000 title claims abstract description 35
- 238000010304 firing Methods 0.000 claims abstract description 106
- 230000004087 circulation Effects 0.000 claims abstract description 39
- 239000012530 fluid Substances 0.000 claims description 53
- 230000015572 biosynthetic process Effects 0.000 claims description 33
- 229930195733 hydrocarbon Natural products 0.000 claims description 33
- 239000004215 Carbon black (E152) Substances 0.000 claims description 20
- 150000002430 hydrocarbons Chemical class 0.000 claims description 19
- 238000004519 manufacturing process Methods 0.000 claims description 15
- 125000001183 hydrocarbyl group Chemical group 0.000 claims description 14
- 230000003578 releasing effect Effects 0.000 claims description 8
- 238000007789 sealing Methods 0.000 claims description 5
- 238000005474 detonation Methods 0.000 claims description 4
- 230000003405 preventing effect Effects 0.000 claims description 4
- 239000000543 intermediate Substances 0.000 claims 13
- 230000004888 barrier function Effects 0.000 claims 2
- 238000012856 packing Methods 0.000 claims 2
- 238000003825 pressing Methods 0.000 claims 2
- 235000015277 pork Nutrition 0.000 claims 1
- 230000008878 coupling Effects 0.000 abstract description 12
- 238000010168 coupling process Methods 0.000 abstract description 12
- 238000005859 coupling reaction Methods 0.000 abstract description 12
- 238000005755 formation reaction Methods 0.000 description 10
- 230000009471 action Effects 0.000 description 4
- XQCFHQBGMWUEMY-ZPUQHVIOSA-N Nitrovin Chemical compound C=1C=C([N+]([O-])=O)OC=1\C=C\C(=NNC(=N)N)\C=C\C1=CC=C([N+]([O-])=O)O1 XQCFHQBGMWUEMY-ZPUQHVIOSA-N 0.000 description 3
- 230000009850 completed effect Effects 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 239000007789 gas Substances 0.000 description 3
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 2
- 230000002706 hydrostatic effect Effects 0.000 description 2
- 230000007257 malfunction Effects 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 208000036366 Sensation of pressure Diseases 0.000 description 1
- 230000000712 assembly Effects 0.000 description 1
- 238000000429 assembly Methods 0.000 description 1
- 238000004140 cleaning Methods 0.000 description 1
- 238000004891 communication Methods 0.000 description 1
- 239000000356 contaminant Substances 0.000 description 1
- 238000011109 contamination Methods 0.000 description 1
- 238000005553 drilling Methods 0.000 description 1
- 239000013505 freshwater Substances 0.000 description 1
- 230000005484 gravity Effects 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 230000007246 mechanism Effects 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- 230000000246 remedial effect Effects 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
Classifications
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH DRILLING; MINING
- E21B—EARTH DRILLING, e.g. DEEP DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B33/00—Sealing or packing boreholes or wells
- E21B33/10—Sealing or packing boreholes or wells in the borehole
- E21B33/12—Packers; Plugs
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH DRILLING; MINING
- E21B—EARTH DRILLING, e.g. DEEP DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B34/00—Valve arrangements for boreholes or wells
- E21B34/06—Valve arrangements for boreholes or wells in wells
- E21B34/14—Valve arrangements for boreholes or wells in wells operated by movement of tools, e.g. sleeve valves operated by pistons or wire line tools
- E21B34/142—Valve arrangements for boreholes or wells in wells operated by movement of tools, e.g. sleeve valves operated by pistons or wire line tools unsupported or free-falling elements, e.g. balls, plugs, darts or pistons
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH DRILLING; MINING
- E21B—EARTH DRILLING, e.g. DEEP DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B33/00—Sealing or packing boreholes or wells
- E21B33/10—Sealing or packing boreholes or wells in the borehole
- E21B33/12—Packers; Plugs
- E21B33/129—Packers; Plugs with mechanical slips for hooking into the casing
- E21B33/1294—Packers; Plugs with mechanical slips for hooking into the casing characterised by a valve, e.g. a by-pass valve
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH DRILLING; MINING
- E21B—EARTH DRILLING, e.g. DEEP DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B43/00—Methods or apparatus for obtaining oil, gas, water, soluble or meltable materials or a slurry of minerals from wells
- E21B43/11—Perforators; Permeators
- E21B43/116—Gun or shaped-charge perforators
- E21B43/1185—Ignition systems
- E21B43/11852—Ignition systems hydraulically actuated
Abstract
BALL SWITCH DEVICE AND METHOD
ABSTRACT OF THE INVENTION
A tubing string extends downhole in a cased borehole to a jet perforating gun. A packer device is located uphole of a releasable coupling apparatus. The coupling apparatus has an annular piston therein which is moved to release the lower string.
Two spaced apart movable annular pistons are series connected in the tubing string at a location below the packer and above the gun. Flow ports, formed in the tubing wall, are covered by the pistons. A ball of appropriate diameter can be circulated down-hole and seated upon either of the pistons, thereby forcing a selected piston in a downhole direction. Circulation ports are provided below the lower piston in proximity of a gun firing head. The lower piston includes a shaft depending axially there-from and into proximity of a detonator of the gun firing head, so that when the lower piston is forced downhole, the shaft con-tacts the firing head which detonates the shaped charges of the perforating gun. This assembly of elements enables many differ-ent options to be exercised prior to firing the gun.
ABSTRACT OF THE INVENTION
A tubing string extends downhole in a cased borehole to a jet perforating gun. A packer device is located uphole of a releasable coupling apparatus. The coupling apparatus has an annular piston therein which is moved to release the lower string.
Two spaced apart movable annular pistons are series connected in the tubing string at a location below the packer and above the gun. Flow ports, formed in the tubing wall, are covered by the pistons. A ball of appropriate diameter can be circulated down-hole and seated upon either of the pistons, thereby forcing a selected piston in a downhole direction. Circulation ports are provided below the lower piston in proximity of a gun firing head. The lower piston includes a shaft depending axially there-from and into proximity of a detonator of the gun firing head, so that when the lower piston is forced downhole, the shaft con-tacts the firing head which detonates the shaped charges of the perforating gun. This assembly of elements enables many differ-ent options to be exercised prior to firing the gun.
Description
174~
BACKGROUND OF THE INVENTION
In my previous U.S. Patent No. 3,706,344, -there is disclosed a perforating gun which is detonated by dropping a bar down the tubing string. The bar impacts against a firing head which detonates the shaped charges of the gun. Once the bar has been dropped down the tubing, the system is commit-ted to proceed with the final completion steps~
Often it is desirable to install the perforating gun while various workover equipment is on hand, and -to complete -the well at some subsequent date. This effects a considerable sav-ings in money and also provides a means for isolating the hydro-carbon containing zone so that the well can remain dormant until the subsequent completion date arrives. During this time, there is always a danger of some objects being accidently dropped downhole and inadverten-tly firing the gun and completing the well without the necessary surface equipment and technical people being on hand. Moreover, during a long ;'nterval of time, it is possible for debris to collect above the firing head so that when the bar is subsequently dropped in order to attemp-t complet-ing the well, the overlying debris prevents the bar from contact-ing the firing head, and the perforating gun cannot be fired.
There are many highly deviated boreholes slanted towards the horizontal to an extent which precludes -the use of gravity induced impact for firing a perforating gun. In this instance, some means, o-ther than a bar, must be employed for detonating the gun. ~his is especially so in offshore rigs where multiple boreholes are formed by slanting each of the wells away from a single drilling platform, -thereby radially spacing the wells respective to one another.
In my previous U. S. Patent ~os. 3,966,236 and 4,066, 282, it is pointed out that one can often foresee that a tool string located on the lower marginal end of a tubing string must 7~B
be subsequently disconnected from the remainder of the string and abandoned downhole in the wellbore. It is especlally im-portant when running tool strings into expensive offshore wells to be able to assure everyone concerned that should the string become stuck downhole, that provisions are included for releas-ing the stuck part of the tool string.
As pointed out in my previously issued U. S. Patent No.
3,706,344, it is advantageous to be able -to complete a wellwhile the tubing string is open to ambient so -that a maximum pressure differential is achieved across the production formation instan-taneous with the perforation thereof so that the debris is im-media-tely flushed out of the newly completed formation, thereby avoiding any contamination of the production zone with extraneous material.
It would be desirable to be able to circulate fluid downhole and across the firing head of a gun in order to wash debris therefrom. ~t would also be desirable to be able to open the main vent assembly of the tubing simultaneously with the actuation of the firing head. It would further be desirable to protect the firing head of the perforating gun prior to detona~
tion thereof. Moreover, several heretofore known advantages would be realized if one were able to increase and then decrease the circulation rate of the lower borehole annulus, and to be able to close off -the lower tubing string, or to open the lower tubing string at any time prior to detonation of -the gun. It would furthermore be desirable to be able to fire the gun while the tubing string is vented to ambient at -the surface of the ground.
Apparatus and me-thod Which enable the above desirable manipulations to be performed w~hile completing a cased wellbore is the subject of the present inven-tion.
~tii7 ~15 SUMMARY OF THE INVENTION
A ball switch device and method which enables a hydro-carbon bearing formation to be perforated and the borehole com-pleted in a new and unobvious ~anner so that unusual and unex-pected results are attained thereby. The apparatus of -the present invention includes a tubing string having the lower end thereof connected to a per~orating gun. A packer device is interposed between the casing and tubing to divide the casing annulus into an upper and lower annular area. The packer device is located uphole of a releasable coupling apparatus. An annu-lar piston is slidabl~ ~oved downhole to effect release of the releasable coupling apparatus so that the entire lower tool string can be abandoned downhole in the borehole. -The gun preferably is a large casing gun having afiring head arranged to be detonated by impac-t with an object which has been circulated downhole through the tubing string.
Two additional spaced apart movable annular piStOIlS
are series connected in the tubing string in underlying relation-ship respective to the releasable coupling. The perforating gun 2Q is disposed downhole of the lowermost piston, Elow ports, formed at spaced locations along the tubing ~all, are covered by the pistons. Each piston has an axial passageway formed there-through. The passage~ays of the three pistons diminish in diam-eter in a downhole direction. ~alls of selected diameters can therefore be circulated downhole into sea-ted rela-tionship respective to a specific piston. A large ball, for example, will become seated on the piston of the releasable coupling apparatus to effect release thereof, while a smaller ball can flow axially through both of the upper piston passageways and come to rest in sea-ted relationship on the lower piston- ~n intermediate size ball, on the other hand, will pass through the uppermost piston and become seated on the intermediate or second piston.
Circula-tion ports are proYided below the l~wermost piston in proximity of a gun firing head. The lowermost piston includes a shaft depending axially downhole therefrom and into proximity of a detonator of the gun firing head, so that when the lower piston is forced downhole, the shaft contacts the fir-ing head which detonates the shaped charges of -the perforating gun. This assembly of elements enables many different options to be exercised prior to the firing of the gun.
This invention enables a small outside diameter ball to be circulated down through the tubing string, through the upper passageway of the upper and intermediate pistons, and into seated position of the lowermost piston, Thereafter, fluid pres-sure is effected within the tubing string to force the lower piston to move in a downward direction and detonate the shaped charges of the perforating gun.
At any time before the gun is fired, an intermediate size ball can be circulated downhole and into seated position on the second piston -to thereby obstruct the lower tubing string to prevent debris from accumulating therebelow, and wherein pressure effected above said ball and within said tubing string forces the second piston to move in a downward direc-tion, thereby opening the upper ports.
Should a malfunction occur, or should the lower part of the tool string become stuck downhole, a relatiye large ball can be circulated downhole to actuate the releasable coupling. This enables retrieval of all of the string located above the releas-able coupling.
Therefore, the aboYe well completion appa~atus enables 3~ the following method to be achieved.
~ 4 _ ~6~'7~
An appropria-te size ball can be placed on the second seat, thereby preventing access to the firing head of the perfo-rating gun. Reverse circulation thereafter removes -the ball along with any debris that may have accumula-ted about -the gun firing head.
I~ith the ball retrieved, circula-tion can occur down through the tubing string and through the lowermost ports, there by forcing any debris which may have accumulated about the gun head to be washed up the borehole annulus and to the surface of the ground.
The above ball can be circulated downhole onto -the second piston, and thereafter pressure effected on the tubing interior to move the piston in a downward direction, whereupon the upper ports are uncovered and circulation occurs through the uppermost ports. Thereafter reverse circulation retrieves the ball and the perforating gun can be detonated by driving the lower piston in a downward direction with a bar in order to deto-nate the gun if the hole is not unduly slanted.
With the second and third pistons covering their respective ports, a relatively small o,d. ball can be circulated downhole through the tubing, through the upper piston ? through the second piston, where the ball lands on the seat of the lower-most piston, thereby driving the lower piston in a downward direction to detonate the gun and simultaneously open additional vent or circulation ports so that production can occur back uphole to the surface of the ground. This last port can be eliminiated as another embodiment of this invention.
Accordingly, a primary object of the present invention is the provision of improvements in apparatus and method for com-3a pleting a hydrocarbon producing formation.
7 ~3 A further objec-t of this inyention is the provision of method and apparatus which enables -the firing head of a gun to be protected until a well is completed, and during completion of the well, the apparatus may be used to open additional circulat-ing ports while simultaneously detonating a perfora-ting gun.
A still further object of this invention is the provi-sion of method and apparatus for completing slanted boreholes by effecting fluid pressure internally of a tool string loca-ted within -the borehole.
Still another object of -this invention is the provision of method and apparatus by which objects may be circulated into and out of a tool string located in a slanted borehole so as -to complete the well and subsequently re-trieve the tubing along with part of the tool string.
The above objects are attained in accordance with the present inyention by the provision of a tubing string disposed within a cased borehole, with a perforating gun attached at the lower end of the tubing string, and two spaced annular pistons located above a gun firing head of the perforating gun, with each 2Q piston covering a vent, so that a ball of a small diame-ter can be circulated down through the tubing string -to open the lower piston and fire the gun, or a ball of a large diameter can be circulated downhole to open the upper piston, These and various other objects and advantages o~ the invention will become readily apparent -to those skilled in the art upon reading the following detailed description and claims and by referring to -the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 is a diagrammatical ? cross-section~l, hypothe-tical view of a wellbore extending downhole into the ground with 7 ~
apparatus made in accordance with the present invention ~eingdisclosed in conjunction therewith;
Figure 2 is a fragmentary, enlarged, part cross-sectional, schematical-type view of par-t of -the apparatus dis-closed in Figure l;
Figure 3 illustrates the apparatus of Figure 2 in an-other operative configuration;
Figure 4 illustrates the apparatus of Figure 2 in still another operative configuration;
Figure 5 sets forth an enlarged detail of part of the apparatus seen in the foregoing figures;
Figure 6 sets forth an enlarged de-tail of another part of the apparatus disclosed in the foregoing figures;
Figure 7 is a broken view of the presen-t invention dis-closed in conjunction with a slanted borehole;
Figure 8 is an enlarged view of par-t of the apparatus disclosed in Figures 1 and 7; and, Figure 9 is a cross-sectional view taken along line 9-9 of Figure 8.
DETAILED DESCRIPTION OF THE PREFE~RED EMBODI~ENTS
In Pigure 1, there is schema-tically illustrated a well-head 10 located at the upper end of a borehole having a casing 11 therewithin. Packer 12 separates the upper borehole annulus 14 from a lower borehole annulus 15. Tubing 16 extends from the wellhead, downhole -to a je-t perforating gun 18 located in proxi-mity of a hydrocarbon bearing forma-tion 17. The well may extend vertically downward into the ear-th as seen at 11, or the bore-hole can be slanted as indicated at 111 in Figures 1 and 7.
The perforating gun preferably is a large casing gun having shaped charges 19 which are detonated by a firing head 2a.
L6~
The firing head is responsive -to impact, and the de-tails -thereof are more fully set forth in my previously issued U. S. Patent No.
3,706,344. The -tubing string includes subs 21, 22~ 24, and 26, the details of which are more fully disclosed in other figures of the present drawings.
As seen illustrated in ~igures 2 and 4, a lower circu-lation port 28 of relatively small diameter is located in close proximity of the firing head of the gun so that circulation can be effected therethrough. This action removes debris from the upper end of the gun firing head. As seen in Figures 1-3, the tubing wall has a relatively large diameter upper port 30 which ..
is sealingly closed by an annular piston 21. The piston in-cludes spaced seals, 32 and 34, circumferentially extending there-about and sealing the interface formed between the exterior of the piston and the interior wall surface of the -tubing. An axial passageway 36 of a specific relative diameter extends longitu-dinally through the piston. The piston passageway is formed into a seat 38 at -the upper marginal end thereof against which a ball of a specific outside diameter can be seated so that the piston 21 can be circulated or forced to move in a downward direction in order to uncoYer the upper ports 30 in accordance with the present invention.
Radially spaced apart ports or vents 42 are of a speci-fic relative size respective to vents 30 and 28. The vents 42 are located below -the upper vents 30 and above the lower ve~ts 28. The middle yents are coyered by annulus piston 23, Circum-ferentially extending seals 44 and 46 seal the interface between the ex-terior of the lower piston and the interior o~ -the tubing string. Axial passageway 48 termina-tes in a lower seat 50 located at the upper end of the piston 23 and sealingly recei~es a relatively small o.d. ball 52 ~n seated relat~onship there-against.
~6~L~4~ ~
A firing rod 54 i6 axially aligned longi-tudinally with respect to -the tubing string and includes a fixed end 56 which is affixed to the lower end of piston 23. The firing rod down-wardly depends from the pis-ton and terminates at a free end 58.
Passageway 48 communicates with ports 28 by means of the radial passageways formed through the lower end of the annular piston.
Piston 23 can be forced to slide in a downward direc-tion relative to the tubing interior, whereupon -the free end of the firing rod impacts agains-t the trigger device 60 of the firing head. This action moves the trigger rod 62 in a downward direction, whereupon detona-tion of the perforating gun occurs.
The presence of intermedia-te ports 42 in Figures 1 and 2, and the absence of these ports from Figure 4 shows that different embodiments of the invention are illustrated herein.
In Figure 5, there is set forth the details of one of the subs. The sub 24 is provided with threads 64 and 66 at the opposite marginal ends thereof so that the sub can be threadedly made-up into the tubing string, The piston as an o.d. 68 which enables it to be slidably received in close tolerance relation-ship within the reduced inside diameter 70 of the sub. The i.d.of the sub increases at 71 from the nominal i.d. of the lower tubing string.
The lower end of the piston is provided with the before mentioned radially spaced apart circulation ports 72 which are arranged circumferentially about the longitudinal axial center-line of the sub, and parallel to the axial centerline of the -tubing string, with there being ample material at 74 for transfer of loads which may be imposed upon the before mentioned firing rod. Shear pin 76 is received within the illustra-ted groove 77 and rigidly captures the piston within the sub until sufficient ~L6~7~8 force is exerted upon the piston to shear the pins. The por-ts 42 are smaller than ports 30, or may be excluded from the apparatus.
In Figure 6, wherein the details of the sub 22 are more fully disclosed, the axial passageway 36 of piston 21 is unre-stricted to proyide for movement o:F the rela-tive small i.d. ball therethrough. The sub 22 is threaded at each marginal end 78 and 80 thereof for attachment in series relationship within the -tub-ing string. Shear pin 82 rigidly affixes the piston wi-thin the small i.d. portion 84 of the sub.
The interface between the piston and the inside surface 84 is sealed by -the o-rings 32. The lower circumferentially ex-tending edge 39 of the annular piston which is opposed to the seat 38 can be engaged by a fishing tool should it ever become necessary to move the piston in an uphole direction respective to the sub.
I,n Figure 7, the borehole is seYerely slanted as noted at 111. The tool string of Figure 7 is identical to the tool string illustrated in Figures 1-6.
In Figures 8 and 9, the details of the releasable coupling apparatus 21 is more fully disclosed. The coupling apparatus includes a pin end 86 opposed to a box end 87, An outer barrel 88 slidably receives an inner ~andrel 89 ln sealed, releasable relationship therewithin.
The barrel and mandrel are released from one another by movement of releasing annular piston 90, which is the uppe~-most piston of the tool str~ng. The barrel has one end 91 opposed to the pin end 86.
The releasing piston has a sea-t 92 which receives a relative large ball 93 in seated relationship thereon. A plural-ity of radially spaced releasing balls 94 are fi-tted into annular ~61~
groove 95 jointly formed within the wall of the ~andrel and barrel.
Seal 96 prevents fluid flow between the co-acting marginal end portions of -the mandrel and barrel, The mandrel includes a skirt which terminates at circumferentially extending edge portion 97, while -the releasing piston terminates at 98.
The skirt has an axial bore 90 which slidably receives piston 90, while the piston has an axial bore 100 which is of smaller diam-eter 101 as compared to the i.d. of the tubing string.
I`n operation, the gun is at-tached -to the end of tubing string 16, the packer is interposed in the tubing s-tring, and the subs 21, 22, 24, and 26 are series connected -therein. Care must be taken that sub 26 is arranged such that the small ports 28 are located to cause any accumulated debr~s to be washed from about the firing trigger rod 62, The location o~ sub 24 must be such that piston 23 is positioned to cause the depending end 58 of rod 54 to contact the firing head trigger enlargement 60 when the piston 23 is forced downhole.
The axial piston passageway~s 36, 48, and 100, and the balls 40, 52, and 93, must be of a size whereby balls 93, 40~
and 52, respectively, are seated on top of pistons 90 ? 21, and 23, respectlvely; while ball 52 can pass through passageway 36 and become seated on -top of piston 23; and ball 4 a can pass through passageway 100 and become seated on -top of piston 21.
The spaced distance between rod end 58 and trigger end 60 must be selected so -that there is no question of the gun improperly detonating when the lower piston is moyed in a downw~ard direction.
Assuming that the cased borehole extends yertically~ or horizontally through a pay zone 17, that packer 12 is set a and that gun 18 is properly positioned adjacent to the pay~ zone, and ~6:iL7~
that the subs 21, 22, 2~, and 26 are properly positioned wi-thin the tubing string; those skilled in the ar-t will now appreciate that an intermediate size ball 40, when circulated through -the cubing string, will pass through the annular piston of the re-leasable coupling and come to rest in the dot-dash position seen illustrated at 40 in Figures 2 or 3, The entire system is now in the standby configuration, ready for the gun -to be de-tona-ted, whenever it is desired to do so; but, at the same time, the gun firing mechanism is safe from inadYertently being Pired because of the presence of the large ball ~0 located on seat 38. More-over, debris which may inadvertently fall down tubing 16 is pre-cluded from lodging about -the firing head trigger device. The well can remain in this configuration until it is desired to complete the well and tie the production into a gathering system The task of completing the well at some subsequent date has been greatly simplified, and the wellbore and production apparatus is rendered safe during the intervenlng -time interval.
Prior to perforating casing 11, ball 40 is circulated out of the tubing string by means of reverse circulation through small ports 28. At this time, several options are available to the technician as follows:
(1) Circulation down through the tubing string may be effected to clean debris from the borehole.
BACKGROUND OF THE INVENTION
In my previous U.S. Patent No. 3,706,344, -there is disclosed a perforating gun which is detonated by dropping a bar down the tubing string. The bar impacts against a firing head which detonates the shaped charges of the gun. Once the bar has been dropped down the tubing, the system is commit-ted to proceed with the final completion steps~
Often it is desirable to install the perforating gun while various workover equipment is on hand, and -to complete -the well at some subsequent date. This effects a considerable sav-ings in money and also provides a means for isolating the hydro-carbon containing zone so that the well can remain dormant until the subsequent completion date arrives. During this time, there is always a danger of some objects being accidently dropped downhole and inadverten-tly firing the gun and completing the well without the necessary surface equipment and technical people being on hand. Moreover, during a long ;'nterval of time, it is possible for debris to collect above the firing head so that when the bar is subsequently dropped in order to attemp-t complet-ing the well, the overlying debris prevents the bar from contact-ing the firing head, and the perforating gun cannot be fired.
There are many highly deviated boreholes slanted towards the horizontal to an extent which precludes -the use of gravity induced impact for firing a perforating gun. In this instance, some means, o-ther than a bar, must be employed for detonating the gun. ~his is especially so in offshore rigs where multiple boreholes are formed by slanting each of the wells away from a single drilling platform, -thereby radially spacing the wells respective to one another.
In my previous U. S. Patent ~os. 3,966,236 and 4,066, 282, it is pointed out that one can often foresee that a tool string located on the lower marginal end of a tubing string must 7~B
be subsequently disconnected from the remainder of the string and abandoned downhole in the wellbore. It is especlally im-portant when running tool strings into expensive offshore wells to be able to assure everyone concerned that should the string become stuck downhole, that provisions are included for releas-ing the stuck part of the tool string.
As pointed out in my previously issued U. S. Patent No.
3,706,344, it is advantageous to be able -to complete a wellwhile the tubing string is open to ambient so -that a maximum pressure differential is achieved across the production formation instan-taneous with the perforation thereof so that the debris is im-media-tely flushed out of the newly completed formation, thereby avoiding any contamination of the production zone with extraneous material.
It would be desirable to be able to circulate fluid downhole and across the firing head of a gun in order to wash debris therefrom. ~t would also be desirable to be able to open the main vent assembly of the tubing simultaneously with the actuation of the firing head. It would further be desirable to protect the firing head of the perforating gun prior to detona~
tion thereof. Moreover, several heretofore known advantages would be realized if one were able to increase and then decrease the circulation rate of the lower borehole annulus, and to be able to close off -the lower tubing string, or to open the lower tubing string at any time prior to detonation of -the gun. It would furthermore be desirable to be able to fire the gun while the tubing string is vented to ambient at -the surface of the ground.
Apparatus and me-thod Which enable the above desirable manipulations to be performed w~hile completing a cased wellbore is the subject of the present inven-tion.
~tii7 ~15 SUMMARY OF THE INVENTION
A ball switch device and method which enables a hydro-carbon bearing formation to be perforated and the borehole com-pleted in a new and unobvious ~anner so that unusual and unex-pected results are attained thereby. The apparatus of -the present invention includes a tubing string having the lower end thereof connected to a per~orating gun. A packer device is interposed between the casing and tubing to divide the casing annulus into an upper and lower annular area. The packer device is located uphole of a releasable coupling apparatus. An annu-lar piston is slidabl~ ~oved downhole to effect release of the releasable coupling apparatus so that the entire lower tool string can be abandoned downhole in the borehole. -The gun preferably is a large casing gun having afiring head arranged to be detonated by impac-t with an object which has been circulated downhole through the tubing string.
Two additional spaced apart movable annular piStOIlS
are series connected in the tubing string in underlying relation-ship respective to the releasable coupling. The perforating gun 2Q is disposed downhole of the lowermost piston, Elow ports, formed at spaced locations along the tubing ~all, are covered by the pistons. Each piston has an axial passageway formed there-through. The passage~ays of the three pistons diminish in diam-eter in a downhole direction. ~alls of selected diameters can therefore be circulated downhole into sea-ted rela-tionship respective to a specific piston. A large ball, for example, will become seated on the piston of the releasable coupling apparatus to effect release thereof, while a smaller ball can flow axially through both of the upper piston passageways and come to rest in sea-ted relationship on the lower piston- ~n intermediate size ball, on the other hand, will pass through the uppermost piston and become seated on the intermediate or second piston.
Circula-tion ports are proYided below the l~wermost piston in proximity of a gun firing head. The lowermost piston includes a shaft depending axially downhole therefrom and into proximity of a detonator of the gun firing head, so that when the lower piston is forced downhole, the shaft contacts the fir-ing head which detonates the shaped charges of -the perforating gun. This assembly of elements enables many different options to be exercised prior to the firing of the gun.
This invention enables a small outside diameter ball to be circulated down through the tubing string, through the upper passageway of the upper and intermediate pistons, and into seated position of the lowermost piston, Thereafter, fluid pres-sure is effected within the tubing string to force the lower piston to move in a downward direction and detonate the shaped charges of the perforating gun.
At any time before the gun is fired, an intermediate size ball can be circulated downhole and into seated position on the second piston -to thereby obstruct the lower tubing string to prevent debris from accumulating therebelow, and wherein pressure effected above said ball and within said tubing string forces the second piston to move in a downward direc-tion, thereby opening the upper ports.
Should a malfunction occur, or should the lower part of the tool string become stuck downhole, a relatiye large ball can be circulated downhole to actuate the releasable coupling. This enables retrieval of all of the string located above the releas-able coupling.
Therefore, the aboYe well completion appa~atus enables 3~ the following method to be achieved.
~ 4 _ ~6~'7~
An appropria-te size ball can be placed on the second seat, thereby preventing access to the firing head of the perfo-rating gun. Reverse circulation thereafter removes -the ball along with any debris that may have accumula-ted about -the gun firing head.
I~ith the ball retrieved, circula-tion can occur down through the tubing string and through the lowermost ports, there by forcing any debris which may have accumulated about the gun head to be washed up the borehole annulus and to the surface of the ground.
The above ball can be circulated downhole onto -the second piston, and thereafter pressure effected on the tubing interior to move the piston in a downward direction, whereupon the upper ports are uncovered and circulation occurs through the uppermost ports. Thereafter reverse circulation retrieves the ball and the perforating gun can be detonated by driving the lower piston in a downward direction with a bar in order to deto-nate the gun if the hole is not unduly slanted.
With the second and third pistons covering their respective ports, a relatively small o,d. ball can be circulated downhole through the tubing, through the upper piston ? through the second piston, where the ball lands on the seat of the lower-most piston, thereby driving the lower piston in a downward direction to detonate the gun and simultaneously open additional vent or circulation ports so that production can occur back uphole to the surface of the ground. This last port can be eliminiated as another embodiment of this invention.
Accordingly, a primary object of the present invention is the provision of improvements in apparatus and method for com-3a pleting a hydrocarbon producing formation.
7 ~3 A further objec-t of this inyention is the provision of method and apparatus which enables -the firing head of a gun to be protected until a well is completed, and during completion of the well, the apparatus may be used to open additional circulat-ing ports while simultaneously detonating a perfora-ting gun.
A still further object of this invention is the provi-sion of method and apparatus for completing slanted boreholes by effecting fluid pressure internally of a tool string loca-ted within -the borehole.
Still another object of -this invention is the provision of method and apparatus by which objects may be circulated into and out of a tool string located in a slanted borehole so as -to complete the well and subsequently re-trieve the tubing along with part of the tool string.
The above objects are attained in accordance with the present inyention by the provision of a tubing string disposed within a cased borehole, with a perforating gun attached at the lower end of the tubing string, and two spaced annular pistons located above a gun firing head of the perforating gun, with each 2Q piston covering a vent, so that a ball of a small diame-ter can be circulated down through the tubing string -to open the lower piston and fire the gun, or a ball of a large diameter can be circulated downhole to open the upper piston, These and various other objects and advantages o~ the invention will become readily apparent -to those skilled in the art upon reading the following detailed description and claims and by referring to -the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 is a diagrammatical ? cross-section~l, hypothe-tical view of a wellbore extending downhole into the ground with 7 ~
apparatus made in accordance with the present invention ~eingdisclosed in conjunction therewith;
Figure 2 is a fragmentary, enlarged, part cross-sectional, schematical-type view of par-t of -the apparatus dis-closed in Figure l;
Figure 3 illustrates the apparatus of Figure 2 in an-other operative configuration;
Figure 4 illustrates the apparatus of Figure 2 in still another operative configuration;
Figure 5 sets forth an enlarged detail of part of the apparatus seen in the foregoing figures;
Figure 6 sets forth an enlarged de-tail of another part of the apparatus disclosed in the foregoing figures;
Figure 7 is a broken view of the presen-t invention dis-closed in conjunction with a slanted borehole;
Figure 8 is an enlarged view of par-t of the apparatus disclosed in Figures 1 and 7; and, Figure 9 is a cross-sectional view taken along line 9-9 of Figure 8.
DETAILED DESCRIPTION OF THE PREFE~RED EMBODI~ENTS
In Pigure 1, there is schema-tically illustrated a well-head 10 located at the upper end of a borehole having a casing 11 therewithin. Packer 12 separates the upper borehole annulus 14 from a lower borehole annulus 15. Tubing 16 extends from the wellhead, downhole -to a je-t perforating gun 18 located in proxi-mity of a hydrocarbon bearing forma-tion 17. The well may extend vertically downward into the ear-th as seen at 11, or the bore-hole can be slanted as indicated at 111 in Figures 1 and 7.
The perforating gun preferably is a large casing gun having shaped charges 19 which are detonated by a firing head 2a.
L6~
The firing head is responsive -to impact, and the de-tails -thereof are more fully set forth in my previously issued U. S. Patent No.
3,706,344. The -tubing string includes subs 21, 22~ 24, and 26, the details of which are more fully disclosed in other figures of the present drawings.
As seen illustrated in ~igures 2 and 4, a lower circu-lation port 28 of relatively small diameter is located in close proximity of the firing head of the gun so that circulation can be effected therethrough. This action removes debris from the upper end of the gun firing head. As seen in Figures 1-3, the tubing wall has a relatively large diameter upper port 30 which ..
is sealingly closed by an annular piston 21. The piston in-cludes spaced seals, 32 and 34, circumferentially extending there-about and sealing the interface formed between the exterior of the piston and the interior wall surface of the -tubing. An axial passageway 36 of a specific relative diameter extends longitu-dinally through the piston. The piston passageway is formed into a seat 38 at -the upper marginal end thereof against which a ball of a specific outside diameter can be seated so that the piston 21 can be circulated or forced to move in a downward direction in order to uncoYer the upper ports 30 in accordance with the present invention.
Radially spaced apart ports or vents 42 are of a speci-fic relative size respective to vents 30 and 28. The vents 42 are located below -the upper vents 30 and above the lower ve~ts 28. The middle yents are coyered by annulus piston 23, Circum-ferentially extending seals 44 and 46 seal the interface between the ex-terior of the lower piston and the interior o~ -the tubing string. Axial passageway 48 termina-tes in a lower seat 50 located at the upper end of the piston 23 and sealingly recei~es a relatively small o.d. ball 52 ~n seated relat~onship there-against.
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A firing rod 54 i6 axially aligned longi-tudinally with respect to -the tubing string and includes a fixed end 56 which is affixed to the lower end of piston 23. The firing rod down-wardly depends from the pis-ton and terminates at a free end 58.
Passageway 48 communicates with ports 28 by means of the radial passageways formed through the lower end of the annular piston.
Piston 23 can be forced to slide in a downward direc-tion relative to the tubing interior, whereupon -the free end of the firing rod impacts agains-t the trigger device 60 of the firing head. This action moves the trigger rod 62 in a downward direction, whereupon detona-tion of the perforating gun occurs.
The presence of intermedia-te ports 42 in Figures 1 and 2, and the absence of these ports from Figure 4 shows that different embodiments of the invention are illustrated herein.
In Figure 5, there is set forth the details of one of the subs. The sub 24 is provided with threads 64 and 66 at the opposite marginal ends thereof so that the sub can be threadedly made-up into the tubing string, The piston as an o.d. 68 which enables it to be slidably received in close tolerance relation-ship within the reduced inside diameter 70 of the sub. The i.d.of the sub increases at 71 from the nominal i.d. of the lower tubing string.
The lower end of the piston is provided with the before mentioned radially spaced apart circulation ports 72 which are arranged circumferentially about the longitudinal axial center-line of the sub, and parallel to the axial centerline of the -tubing string, with there being ample material at 74 for transfer of loads which may be imposed upon the before mentioned firing rod. Shear pin 76 is received within the illustra-ted groove 77 and rigidly captures the piston within the sub until sufficient ~L6~7~8 force is exerted upon the piston to shear the pins. The por-ts 42 are smaller than ports 30, or may be excluded from the apparatus.
In Figure 6, wherein the details of the sub 22 are more fully disclosed, the axial passageway 36 of piston 21 is unre-stricted to proyide for movement o:F the rela-tive small i.d. ball therethrough. The sub 22 is threaded at each marginal end 78 and 80 thereof for attachment in series relationship within the -tub-ing string. Shear pin 82 rigidly affixes the piston wi-thin the small i.d. portion 84 of the sub.
The interface between the piston and the inside surface 84 is sealed by -the o-rings 32. The lower circumferentially ex-tending edge 39 of the annular piston which is opposed to the seat 38 can be engaged by a fishing tool should it ever become necessary to move the piston in an uphole direction respective to the sub.
I,n Figure 7, the borehole is seYerely slanted as noted at 111. The tool string of Figure 7 is identical to the tool string illustrated in Figures 1-6.
In Figures 8 and 9, the details of the releasable coupling apparatus 21 is more fully disclosed. The coupling apparatus includes a pin end 86 opposed to a box end 87, An outer barrel 88 slidably receives an inner ~andrel 89 ln sealed, releasable relationship therewithin.
The barrel and mandrel are released from one another by movement of releasing annular piston 90, which is the uppe~-most piston of the tool str~ng. The barrel has one end 91 opposed to the pin end 86.
The releasing piston has a sea-t 92 which receives a relative large ball 93 in seated relationship thereon. A plural-ity of radially spaced releasing balls 94 are fi-tted into annular ~61~
groove 95 jointly formed within the wall of the ~andrel and barrel.
Seal 96 prevents fluid flow between the co-acting marginal end portions of -the mandrel and barrel, The mandrel includes a skirt which terminates at circumferentially extending edge portion 97, while -the releasing piston terminates at 98.
The skirt has an axial bore 90 which slidably receives piston 90, while the piston has an axial bore 100 which is of smaller diam-eter 101 as compared to the i.d. of the tubing string.
I`n operation, the gun is at-tached -to the end of tubing string 16, the packer is interposed in the tubing s-tring, and the subs 21, 22, 24, and 26 are series connected -therein. Care must be taken that sub 26 is arranged such that the small ports 28 are located to cause any accumulated debr~s to be washed from about the firing trigger rod 62, The location o~ sub 24 must be such that piston 23 is positioned to cause the depending end 58 of rod 54 to contact the firing head trigger enlargement 60 when the piston 23 is forced downhole.
The axial piston passageway~s 36, 48, and 100, and the balls 40, 52, and 93, must be of a size whereby balls 93, 40~
and 52, respectively, are seated on top of pistons 90 ? 21, and 23, respectlvely; while ball 52 can pass through passageway 36 and become seated on -top of piston 23; and ball 4 a can pass through passageway 100 and become seated on -top of piston 21.
The spaced distance between rod end 58 and trigger end 60 must be selected so -that there is no question of the gun improperly detonating when the lower piston is moyed in a downw~ard direction.
Assuming that the cased borehole extends yertically~ or horizontally through a pay zone 17, that packer 12 is set a and that gun 18 is properly positioned adjacent to the pay~ zone, and ~6:iL7~
that the subs 21, 22, 2~, and 26 are properly positioned wi-thin the tubing string; those skilled in the ar-t will now appreciate that an intermediate size ball 40, when circulated through -the cubing string, will pass through the annular piston of the re-leasable coupling and come to rest in the dot-dash position seen illustrated at 40 in Figures 2 or 3, The entire system is now in the standby configuration, ready for the gun -to be de-tona-ted, whenever it is desired to do so; but, at the same time, the gun firing mechanism is safe from inadYertently being Pired because of the presence of the large ball ~0 located on seat 38. More-over, debris which may inadvertently fall down tubing 16 is pre-cluded from lodging about -the firing head trigger device. The well can remain in this configuration until it is desired to complete the well and tie the production into a gathering system The task of completing the well at some subsequent date has been greatly simplified, and the wellbore and production apparatus is rendered safe during the intervenlng -time interval.
Prior to perforating casing 11, ball 40 is circulated out of the tubing string by means of reverse circulation through small ports 28. At this time, several options are available to the technician as follows:
(1) Circulation down through the tubing string may be effected to clean debris from the borehole.
(2) A small ball 52 can be dropped down the tub-ing string. Thereafter, small ball 52 can be retrieved by re-verse circulation; or alternatively~ the ball may beco~e seated on piston 23, and pressure applied to the -tubing interior where-upon the pin 76 is sheared, thereby moving piston 23 downhole to detonate the gun, thus completing the well.
(3) ~nstead of carry~ing out (2), the large ball ~0 can again be circulated downhole, the piston 21 engaged, the pins 82 sheared, and -the large ports 30 uncovered, -thereby en-abling a very large circula-tion in either direction to occur above the piston 21 and through the large ports 30.
t4) Af-ter the ball 40 has been dropped, and be-fore the piston 21 has been actuated, ball 40 can be retrieved by reverse circulation as pointed out above.
(5) Small ball 52 can be dropped onto seat 5a, thereafter large ball 40 can be dropped onto seat 38, pressure can be applied to the tubing interior, thereby simultaneously moving both pistons 21 and 23 downhole, de-tonating the casing gun, and completing the well with production simultaneously occurring through ports 28, 42, and 30, assuming ports 42 are selected to be formed within sub 24.
(6) Af-ter piston 21 has been moved downhole by ball 40, it is possible to retrieve the ball by reverse circula-tion and thereafter reposition piston 21 u~ing a ~ireline operated fishing -tool, so that either of steps (2) or (5) can thereafter be carried ou-t.
~ 7) Following step (3~, the gun can be detonated by dropping a bar down through the tuking string if the borehole is not unduly slanted.
At any time, should it become necessary to do so, the largest ball 93 can be circulated downhole onto seat 92 of piston 90, to force the annular piston downhole causing the releasing balls 94 to fall from the annular ball receiving groove 95, This action enables the mandrel to slidably part from the barrel, whereupon the tubing string and part of the tool string can be removed from the borehole, leaving the lower end of the tool string in the bo-ttom of the boreholet ~ence~ there is no danger of some unforeseen malfunction causing the hole to be abandoned.
The remainder of the -tool string can be removed by fishing e~-perts, if desired, or the lower forma-tion repene-trated using a whipstock.
Further details of apparatus similar to the releasable coupling 21 are found in my issued Patent Nos. 4,078,611; 4,066, 282; 3,990,507; 3,966,236; and 3,912,013 to which reference is made.
Further details of other vent assemblies and the pro-blems associated therewith are set forth in my issued U.S. Patent Nos. 4,151,880; 4,040,485; 3,~31,855; and 3,871,448.
Hence, the presen-t combination of elements enables a number of choices of downhole manipulations to be carried out in a low cost manner during the well completion operation, In the preferred method of completing a well, clean, clear water par*ially fills the lower annulus 15, wi-th there being compressible gas loca-ted under the seated packer 12, Ball 40 is seated on piston 21 unt~l it is desired to complete the well. At this time, the ball 40 is retrieved by reverse circu-la-tion after unlatching packer 12 so that fluid flow can occur in a reverse direction through small ports 28, thereby carrying ball 40 back to the surface and cleaning any debris from about the firing head of the gun. Ei-ther liquid or gas can be used for this operation. The packer 12 is reset, fresh water is pumped down tubing 16 to provide a hydrostatic head on the gun ?
and gas is again compressed under -the packer. The s~mall ball 52 is circulated or dropped downhole and becomes seated on top of piston 23, nitrogen or wa-ter is then pumped into tubing 16, causing shear pin 76 to fail, whereupon piston 23 moves downhole, engages and moves -the detonator rod 60~ 62; and a-t the same time intermediate ven-t 42 is opened. This enables the hydrocarbons to 748 ~
rush through the newly formed perfora~tions, into the lower bore-hole annulus, into vent por-ts 28 and 42, and uphole to the sur-face of -the ear-th.
By initially conducting the formation pressure across the minimum available pressure drop, that is, by flowing the new pay zone directly to ambient~ the perforations are cleaned up and all contaminants removed from the pay zone. This provides a superior production formation which is more economical to produce and which is subject to less remedial action a-t a subsequent time.
Proper adjustment of the relative posi-tions of the vent ports 42, piston 23, rod end 58, and trigger rod 60 will render the system such that it is impossible to fire -the gun until after the piston has commenced to move, with -these two actions occurring substantially simultaneously respective to one another.
In an extreme instance when a large circulation must be employed to clean out the borehole, the upper large vent 30 can be opened, and thereafter a bar used to force the piston 23 or both pistons 21 and 23 downward to detonate the gun.
After the shaped charges of the casing gun are deto-nated and the casing has been perforated, the pressure of the formation immediately flows inwardly against the gun, turns up-hole and then flows into the vents 28 and 42, where the flow is conducted uphole to the surface and into a pit where the hydro-carbons are flared until the well has been cleaned up. There-after, the well is tied into a gathering syst-em.
In the above examples, at any -time before the pins of -the lower piston have been sheared, any of the above recited options can be exercised, rather than going ahead and completing -the well by movement of -the lower piston.
3a The present ~nyentIon enables the simultaneo~s firing of the perforating gun, and communication of -the perfora-ted
t4) Af-ter the ball 40 has been dropped, and be-fore the piston 21 has been actuated, ball 40 can be retrieved by reverse circulation as pointed out above.
(5) Small ball 52 can be dropped onto seat 5a, thereafter large ball 40 can be dropped onto seat 38, pressure can be applied to the tubing interior, thereby simultaneously moving both pistons 21 and 23 downhole, de-tonating the casing gun, and completing the well with production simultaneously occurring through ports 28, 42, and 30, assuming ports 42 are selected to be formed within sub 24.
(6) Af-ter piston 21 has been moved downhole by ball 40, it is possible to retrieve the ball by reverse circula-tion and thereafter reposition piston 21 u~ing a ~ireline operated fishing -tool, so that either of steps (2) or (5) can thereafter be carried ou-t.
~ 7) Following step (3~, the gun can be detonated by dropping a bar down through the tuking string if the borehole is not unduly slanted.
At any time, should it become necessary to do so, the largest ball 93 can be circulated downhole onto seat 92 of piston 90, to force the annular piston downhole causing the releasing balls 94 to fall from the annular ball receiving groove 95, This action enables the mandrel to slidably part from the barrel, whereupon the tubing string and part of the tool string can be removed from the borehole, leaving the lower end of the tool string in the bo-ttom of the boreholet ~ence~ there is no danger of some unforeseen malfunction causing the hole to be abandoned.
The remainder of the -tool string can be removed by fishing e~-perts, if desired, or the lower forma-tion repene-trated using a whipstock.
Further details of apparatus similar to the releasable coupling 21 are found in my issued Patent Nos. 4,078,611; 4,066, 282; 3,990,507; 3,966,236; and 3,912,013 to which reference is made.
Further details of other vent assemblies and the pro-blems associated therewith are set forth in my issued U.S. Patent Nos. 4,151,880; 4,040,485; 3,~31,855; and 3,871,448.
Hence, the presen-t combination of elements enables a number of choices of downhole manipulations to be carried out in a low cost manner during the well completion operation, In the preferred method of completing a well, clean, clear water par*ially fills the lower annulus 15, wi-th there being compressible gas loca-ted under the seated packer 12, Ball 40 is seated on piston 21 unt~l it is desired to complete the well. At this time, the ball 40 is retrieved by reverse circu-la-tion after unlatching packer 12 so that fluid flow can occur in a reverse direction through small ports 28, thereby carrying ball 40 back to the surface and cleaning any debris from about the firing head of the gun. Ei-ther liquid or gas can be used for this operation. The packer 12 is reset, fresh water is pumped down tubing 16 to provide a hydrostatic head on the gun ?
and gas is again compressed under -the packer. The s~mall ball 52 is circulated or dropped downhole and becomes seated on top of piston 23, nitrogen or wa-ter is then pumped into tubing 16, causing shear pin 76 to fail, whereupon piston 23 moves downhole, engages and moves -the detonator rod 60~ 62; and a-t the same time intermediate ven-t 42 is opened. This enables the hydrocarbons to 748 ~
rush through the newly formed perfora~tions, into the lower bore-hole annulus, into vent por-ts 28 and 42, and uphole to the sur-face of -the ear-th.
By initially conducting the formation pressure across the minimum available pressure drop, that is, by flowing the new pay zone directly to ambient~ the perforations are cleaned up and all contaminants removed from the pay zone. This provides a superior production formation which is more economical to produce and which is subject to less remedial action a-t a subsequent time.
Proper adjustment of the relative posi-tions of the vent ports 42, piston 23, rod end 58, and trigger rod 60 will render the system such that it is impossible to fire -the gun until after the piston has commenced to move, with -these two actions occurring substantially simultaneously respective to one another.
In an extreme instance when a large circulation must be employed to clean out the borehole, the upper large vent 30 can be opened, and thereafter a bar used to force the piston 23 or both pistons 21 and 23 downward to detonate the gun.
After the shaped charges of the casing gun are deto-nated and the casing has been perforated, the pressure of the formation immediately flows inwardly against the gun, turns up-hole and then flows into the vents 28 and 42, where the flow is conducted uphole to the surface and into a pit where the hydro-carbons are flared until the well has been cleaned up. There-after, the well is tied into a gathering syst-em.
In the above examples, at any -time before the pins of -the lower piston have been sheared, any of the above recited options can be exercised, rather than going ahead and completing -the well by movement of -the lower piston.
3a The present ~nyentIon enables the simultaneo~s firing of the perforating gun, and communication of -the perfora-ted
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formation with ambien-t. The hydrostatic head o~ the fluids present in the lower annular area can be controlled to any pre-determined desired value.
The perforating ~un cannot inadvertently ~e fired by employing the present method, nor can debris accumulate above the firing head, thereby making the firing head inaccessible and necessitating the expensive employment of pulling equipmen-t.
The present apparatus and method provides a safe, re-liable and inexpensive means for completing a well in a manner which increases the well production as compared to other known well completion techniques.
formation with ambien-t. The hydrostatic head o~ the fluids present in the lower annular area can be controlled to any pre-determined desired value.
The perforating ~un cannot inadvertently ~e fired by employing the present method, nor can debris accumulate above the firing head, thereby making the firing head inaccessible and necessitating the expensive employment of pulling equipmen-t.
The present apparatus and method provides a safe, re-liable and inexpensive means for completing a well in a manner which increases the well production as compared to other known well completion techniques.
Claims (43)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. In a cased borehole having a packer device interposed between a tubing string and the casing to divide the casing annu-lus into an upper and a lower annular area, and a perforating gun having a firing head arranged to be detonated by impact of an object circulated downhole through a borehole; the combination with said tubing and gun of well completion apparatus;
said apparatus includes an upper piston, upper vent ports formed in said tubing string, seal means by which said up-per piston closes said upper port, an axial passageway formed through said upper piston, a large seat formed at the upper end of said upper piston;
a lower piston, an axial passageway formed through said lower piston and a small seat formed at the upper end of the axial passageway of said lower piston;
small circulation ports ports in proximity of said firing head and below said lower piston;
means connected to said lower piston for engaging and detonating said firing head when said lower piston is moved down-hole;
so that, a large ball can be circulated downhole into seated relationship with respect to said upper piston to thereby move said piston downhole and open said upper ports; and, a relatively small ball can be circulated down the tubing string, through the axial passageway of the upper piston, into seated engagement with the seat of said lower piston, to thereby move said lower piston downhole while concurrently en-gaging said firing head and detonating said perforating gun, whereupon formation fluid can immediately flow from the formation, into the tubing string, and uphole to the surface of the ground.
said apparatus includes an upper piston, upper vent ports formed in said tubing string, seal means by which said up-per piston closes said upper port, an axial passageway formed through said upper piston, a large seat formed at the upper end of said upper piston;
a lower piston, an axial passageway formed through said lower piston and a small seat formed at the upper end of the axial passageway of said lower piston;
small circulation ports ports in proximity of said firing head and below said lower piston;
means connected to said lower piston for engaging and detonating said firing head when said lower piston is moved down-hole;
so that, a large ball can be circulated downhole into seated relationship with respect to said upper piston to thereby move said piston downhole and open said upper ports; and, a relatively small ball can be circulated down the tubing string, through the axial passageway of the upper piston, into seated engagement with the seat of said lower piston, to thereby move said lower piston downhole while concurrently en-gaging said firing head and detonating said perforating gun, whereupon formation fluid can immediately flow from the formation, into the tubing string, and uphole to the surface of the ground.
2. The apparatus of Claim 1 wherein intermediate ports are formed in said tubing string, seal means by which said lower piston closes said intermediate ports; so that when said lower piston is moved downhole to fire the gun, the intermediate ports are simultaneously opened.
3. The apparatus of Claim 2 wherein said upper and lower pistons are held in fixed relationship respective to the tubing string by shear pins;
so that when either of said pistons are forced down-hole, the pins shear as the pistons are forced downhole within the tubing string.
so that when either of said pistons are forced down-hole, the pins shear as the pistons are forced downhole within the tubing string.
4. The apparatus of Claim 1 wherein said lower piston has a downwardly depending shaft attached thereto in axially aligned relationship respective to said tubing string; and, said firing head has an upwardly extending trigger shaft arranged along the axial centerline of the tubing string so that when said lower piston is forced in a downward direction, said shaft contacts said trigger means,
5. In a cased wellbore having a tubing string extending downhole to a perforating gun located adjacent to a hydrocarbon bearing formation, a packer means located uphole of the gun and dividing the casing annulus into an upper and lower annulus, the method of completing a well comprising forming upper, intermedi-ate, and lower ports in said tubing string so that fluid flow can occur down the tubing string and through either of the three re-cited ports, with the lowermost port being placed adjacent to the firing head of the perforating gun;
covering the uppermost ports with an upper piston and covering the intermediate ports with a lower piston and sealing the interface between the outside of the piston and the inside of the tubing to preclude flow of fluid through said upper and in-termediate ports;
forming an axial passageway through said upper piston and through said lower piston so that fluid flow can occur through said tubing string, through said upper and lower pistons, and through said lower ports, and into said lower casing annulus;
forming a ball seat on each of said pistons and making the upper passageway large in diameter respective to said lower passageaway;
dropping a large ball down the tubing string so that the ball comes to rest seated on the upper piston thereby pre-venting access to said gun firing head;
circulating said large ball out of the tubing string and circulating a small ball down the tubing string, through the passageway of the upper piston, into seated position on the lower piston;
and applying pressure to the tubing interior until the lower piston moves downward;
using the downward movement of the lower piston for actuating said gun firing head to thereby perforate said casing in proximity of said hydrocarbon bearing formation while simul-taneously opening said intermediate set of ports.
covering the uppermost ports with an upper piston and covering the intermediate ports with a lower piston and sealing the interface between the outside of the piston and the inside of the tubing to preclude flow of fluid through said upper and in-termediate ports;
forming an axial passageway through said upper piston and through said lower piston so that fluid flow can occur through said tubing string, through said upper and lower pistons, and through said lower ports, and into said lower casing annulus;
forming a ball seat on each of said pistons and making the upper passageway large in diameter respective to said lower passageaway;
dropping a large ball down the tubing string so that the ball comes to rest seated on the upper piston thereby pre-venting access to said gun firing head;
circulating said large ball out of the tubing string and circulating a small ball down the tubing string, through the passageway of the upper piston, into seated position on the lower piston;
and applying pressure to the tubing interior until the lower piston moves downward;
using the downward movement of the lower piston for actuating said gun firing head to thereby perforate said casing in proximity of said hydrocarbon bearing formation while simul-taneously opening said intermediate set of ports.
6. In a cased borehole having a casing gun located down-hole in proximity of a hydrocarbon bearing formation with there being a tubing string extending from a wellhead and connected to said gun; the method of completing the well according to the following steps;
1. providing said gun with a gun firing head which is detonated upon impact with an object circulated downhole through the tubing string;
2. forming circulating ports in proximity of said gun firing head so that fluid can be circulated downhole through the ports to clean out debris located in proximity of said gun firing head;
3. slidably positioning an annular piston within the tubing uphole of the circulating ports; and forming an axial passageway longitudinally through said piston;
4. circulating a ball downhole into sealed relation-ship respective to the passageway of said piston and using in-ternal tubing pressure to force said piston to move into engage-ment with said gun firing head to thereby detonate the gun and perforate the casing, and simultaneously permitting the hydro-carbons to flow from the perforations, into the circulating ports, and up through the tubing string, thereby completing the well.
1. providing said gun with a gun firing head which is detonated upon impact with an object circulated downhole through the tubing string;
2. forming circulating ports in proximity of said gun firing head so that fluid can be circulated downhole through the ports to clean out debris located in proximity of said gun firing head;
3. slidably positioning an annular piston within the tubing uphole of the circulating ports; and forming an axial passageway longitudinally through said piston;
4. circulating a ball downhole into sealed relation-ship respective to the passageway of said piston and using in-ternal tubing pressure to force said piston to move into engage-ment with said gun firing head to thereby detonate the gun and perforate the casing, and simultaneously permitting the hydro-carbons to flow from the perforations, into the circulating ports, and up through the tubing string, thereby completing the well.
7. The method of Claim 6 and further including the steps of: forming an upper port in said tubing string at a location spaced above said piston; slidably mounting a second annular piston about the first recited piston and closing said upper port with said second piston; forming an axial passsageway through the last said piston and making the last said passageway larger in diameter than the recited passageway formed through the lower piston so that a relatively large ball can be seated on the uppermost piston while a relatively small ball can be circulated downhole through the upper piston passageway and into sealed relationship with respect to the lower annular piston;
thereby enabling the upper passageway to be moved to the open position by a relatively large ball and for the gun to be fired by a relatively small ball.
thereby enabling the upper passageway to be moved to the open position by a relatively large ball and for the gun to be fired by a relatively small ball.
8. The method of Claim 6, and further including the step of:
releasably connecting the tubing string together at a location above said piston; slidably positioning an upper annu-lar piston within the tubing string and using the upper piston to hold the tubing string in the connected configuration;
forming an axial passageway through -the upper piston which is larger than the passageway formed through the piston located therebelow;
circulating a ball downhole into engagement with the upper piston, forcing the piston to move downhole, and using the downhole movement of the piston to release the lower tubing string at the recited location above the first recited piston.
releasably connecting the tubing string together at a location above said piston; slidably positioning an upper annu-lar piston within the tubing string and using the upper piston to hold the tubing string in the connected configuration;
forming an axial passageway through -the upper piston which is larger than the passageway formed through the piston located therebelow;
circulating a ball downhole into engagement with the upper piston, forcing the piston to move downhole, and using the downhole movement of the piston to release the lower tubing string at the recited location above the first recited piston.
9. The method of Claim 8, and further including the steps of:
packing off the annulus between the casing and the tubing by employment of a packer device to thereby provide an upper and lower well annulus, locating the packer device above the location where the tubing string is releasably connected together;
circulating a relatively small ball downhole and firing the gun, thus completing the well;
producing the well by flowing formation fluid from the perforations, into the circulating ports, up the tubing string, and to the surface of the ground.
packing off the annulus between the casing and the tubing by employment of a packer device to thereby provide an upper and lower well annulus, locating the packer device above the location where the tubing string is releasably connected together;
circulating a relatively small ball downhole and firing the gun, thus completing the well;
producing the well by flowing formation fluid from the perforations, into the circulating ports, up the tubing string, and to the surface of the ground.
10. In a cased borehole having a packer device interposed between a tubing string and the casing to divide the casing annulus into an upper and a lower annular area, and a perforating gun having a firing head arranged to be detonated by impact of an object circulated downhole through a borehole;
the combination with said tubing and gun of well completion apparatus;
said apparatus includes an upper piston, upper vent ports formed in said tubing string, seal means by which said upper piston closes said upper ports, an axial passageway formed through said upper piston, a relatively large seat formed at the upper end of said upper piston;
a lower piston, an axial passageway formed through said lower piston and a relatively small seat formed at the upper end of the axial passageway of said lower piston;
small circulation ports formed in proximity of said firing head and below said lower piston;
means connected to said lower piston for engaging and detonating said firing head when said lower piston is moved downhole;
so that, a relatively large ball can be circulated downhole into seated relationship with respect to said upper piston to thereby move said piston downhole and open said upper ports; and, a relatively small ball can be circulated down the tubing string, through the axial passageway of the upper piston, into seated engagement with the seat of said lower piston, to thereby move said lower piston downhole while concurrently engaging said firing head and detonating said perforating gun, whereupon formation fluid can immediately flow from the formation, into the tubing string, and uphole to the surface of the ground.
the combination with said tubing and gun of well completion apparatus;
said apparatus includes an upper piston, upper vent ports formed in said tubing string, seal means by which said upper piston closes said upper ports, an axial passageway formed through said upper piston, a relatively large seat formed at the upper end of said upper piston;
a lower piston, an axial passageway formed through said lower piston and a relatively small seat formed at the upper end of the axial passageway of said lower piston;
small circulation ports formed in proximity of said firing head and below said lower piston;
means connected to said lower piston for engaging and detonating said firing head when said lower piston is moved downhole;
so that, a relatively large ball can be circulated downhole into seated relationship with respect to said upper piston to thereby move said piston downhole and open said upper ports; and, a relatively small ball can be circulated down the tubing string, through the axial passageway of the upper piston, into seated engagement with the seat of said lower piston, to thereby move said lower piston downhole while concurrently engaging said firing head and detonating said perforating gun, whereupon formation fluid can immediately flow from the formation, into the tubing string, and uphole to the surface of the ground.
11. The apparatus of Claim 10 wherein intermediate ports are formed in said tubing string, seal means by which said lower piston closes said intermediate ports; so that when said lower piston is moved downhole to fire the gun, the intermediate ports are simultaneously opened.
12. The apparatus of Claim 11 wherein said upper and lower pistons are held in fixed relationship respective to the tubing string by shear pins;
so that when either of said pistons are forced downhole, the pins shear as the pistons are forced downhole within the tubing string.
so that when either of said pistons are forced downhole, the pins shear as the pistons are forced downhole within the tubing string.
13. The apparatus of Claim 10 wherein said means connected to said lower piston for engaging and detonating said firing head is a downwardly depending shaft attached thereto in axially aligned relationship respective to said tubing string;
and, said firing head has an upwardly extending trigger shaft arranged along the axial centerline of the tubing string so that when said lower piston is forced in a downward direction, the piston shaft contacts the trigger shaft which detonates the firing head.
and, said firing head has an upwardly extending trigger shaft arranged along the axial centerline of the tubing string so that when said lower piston is forced in a downward direction, the piston shaft contacts the trigger shaft which detonates the firing head.
14. In a cased wellbore having a tubing string extending downhole to a perforating gun located adjacent to a hydrocarbon bearing formation, said gun has a firing head which is denonated in response to impact, a packer means located uphole of the gun and dividing the casing annulus into an upper and lower annulus, the method of completing a well comprising forming upper, intermediate, and lower ports in said tubing string at a location below said packer means so that fluid flow can occur down the tubing string and through either of the three recited ports, when said ports are open; the lowermost port being placed adjacent to the firing head of the perforating gun;
covering the uppermost port with an upper piston and covering the intermediate port with a lower piston and sealing the interface between the outside of the piston and the inside of the tubing to preclude flow of fluid through said upper and intermediate ports;
forming an axial passageway through said upper piston and through said lower piston so that fluid flow can occur through said tubing string, through said upper and lower pistons, and through said lower port, and into said lower casing annulus;
forming a ball seat on each of said pistons at the upper end of each said axial passageway, and making the upper passageway relatively large in diameter respective to said lower passageway;
dropping a large ball down the tubing string so that the ball comes to rest seated on the upper piston thereby preventing access to said gun firing head;
circulating said large ball out of the tubing string and circulating a small ball down the tubing string, through the passageway of the upper piston, into seated position on the lower piston;
and applying pressure to the tubing interior until the lower piston moves downward;
using the downward movement of the lower piston for actuating said gun firing head to thereby detonate the gun and perforate said casing in proximity of said hydrocarbon bearing formation while simultaneously opening said intermediate set of ports.
covering the uppermost port with an upper piston and covering the intermediate port with a lower piston and sealing the interface between the outside of the piston and the inside of the tubing to preclude flow of fluid through said upper and intermediate ports;
forming an axial passageway through said upper piston and through said lower piston so that fluid flow can occur through said tubing string, through said upper and lower pistons, and through said lower port, and into said lower casing annulus;
forming a ball seat on each of said pistons at the upper end of each said axial passageway, and making the upper passageway relatively large in diameter respective to said lower passageway;
dropping a large ball down the tubing string so that the ball comes to rest seated on the upper piston thereby preventing access to said gun firing head;
circulating said large ball out of the tubing string and circulating a small ball down the tubing string, through the passageway of the upper piston, into seated position on the lower piston;
and applying pressure to the tubing interior until the lower piston moves downward;
using the downward movement of the lower piston for actuating said gun firing head to thereby detonate the gun and perforate said casing in proximity of said hydrocarbon bearing formation while simultaneously opening said intermediate set of ports.
15. In a slanted cased borehole having a casing gun located downhole in proximity of a hydrocarbon bearing formation with there being a tubing string extending from the surface to said gun; the method of completing the well according to the following steps:
providing the gun with a gun firing head which is detonated upon impact with an object moved downhole within the tubing string;
providing a tubing member series connected in the tubing string above the firing head;
deviating from vertical the longitudinal axis of the gun, firing head, and tubing member due to the slanted cased borehole so as to preclude dropping a weight through the tubing string to impact and actuate the firing head;
forming a circulating port in the tubing member so that fluid can be circulated downhole through the port to clean out debris located in proximity of the gun firing head;
slidably positioning a piston within the tubing member above the circulating port; and, forming an axial passageway longitudinally through the piston;
circulating fluid down through the tubing string, the axial passageway of the piston, and the circulating port to remove debris from about the firing head;
moving a ball downhole into sealed relationship respective to the passageway of the piston;
effecting internal tubing pressure at the surface of the ground to force said piston to move into engagement with the gun firing head to thereby detonate the gun and perforate the casing; and thereafter flowing hydrocarbons from the perforations, into the circulating port, and up through the tubing string, thereby completing the well.
providing the gun with a gun firing head which is detonated upon impact with an object moved downhole within the tubing string;
providing a tubing member series connected in the tubing string above the firing head;
deviating from vertical the longitudinal axis of the gun, firing head, and tubing member due to the slanted cased borehole so as to preclude dropping a weight through the tubing string to impact and actuate the firing head;
forming a circulating port in the tubing member so that fluid can be circulated downhole through the port to clean out debris located in proximity of the gun firing head;
slidably positioning a piston within the tubing member above the circulating port; and, forming an axial passageway longitudinally through the piston;
circulating fluid down through the tubing string, the axial passageway of the piston, and the circulating port to remove debris from about the firing head;
moving a ball downhole into sealed relationship respective to the passageway of the piston;
effecting internal tubing pressure at the surface of the ground to force said piston to move into engagement with the gun firing head to thereby detonate the gun and perforate the casing; and thereafter flowing hydrocarbons from the perforations, into the circulating port, and up through the tubing string, thereby completing the well.
16. In a cased borehole having a casing gun located downhole in proximity of a hydrocarbon bearing formation with there being a tubing string extending from a wellhead and connected to said gun; the method of completing the well according to the following steps:
providing said gun with a gun firing head which is detonated upon impact with an object forced downhole within the tubing string;
forming a circulating port in proximity of said gun firing head so that fluid can be circulated downhole through the port to clean out debris located in proximity of said gun firing head;
slidably positioning a piston within the tubing uphole of the circulating port; and, forming an axial passage-way longitudinally through said piston;
forming an upper port in said tubing string at a location spaced above said piston; slidably mounting a second piston above the first recited piston and closing said upper port with said second piston; forming an axial passageway through the last said piston and making the last said passage-way larger in diameter than the recited passageway formed through the lower piston so that a relatively large ball can be seated on the upper end of the uppermost piston, while a relatively small ball can be circulated downhole through the upper piston passageway and into sealed relationship with respect to the upper end of the passageway formed through the piston; thereby enabling the upper port to be uncovered by the use of a relatively large ball and for the gun to be fired by moving the lower piston with a relatively small ball;
circulating fluid down through the tubing string and through the axial passageways of the pistons to remove debris from about the firing head;
moving a ball downhole into sealed relationship respective to the passageway of said first recited piston and effecting internal tubing pressure at the surface of the ground to force said first recited piston to move into engage-ment with said gun firing head to thereby detonate the gun and perforate the casing, and thereafter flowing hydrocarbons from the perforations, into the circulating port, and up through the tubing string; thereby completing the well.
providing said gun with a gun firing head which is detonated upon impact with an object forced downhole within the tubing string;
forming a circulating port in proximity of said gun firing head so that fluid can be circulated downhole through the port to clean out debris located in proximity of said gun firing head;
slidably positioning a piston within the tubing uphole of the circulating port; and, forming an axial passage-way longitudinally through said piston;
forming an upper port in said tubing string at a location spaced above said piston; slidably mounting a second piston above the first recited piston and closing said upper port with said second piston; forming an axial passageway through the last said piston and making the last said passage-way larger in diameter than the recited passageway formed through the lower piston so that a relatively large ball can be seated on the upper end of the uppermost piston, while a relatively small ball can be circulated downhole through the upper piston passageway and into sealed relationship with respect to the upper end of the passageway formed through the piston; thereby enabling the upper port to be uncovered by the use of a relatively large ball and for the gun to be fired by moving the lower piston with a relatively small ball;
circulating fluid down through the tubing string and through the axial passageways of the pistons to remove debris from about the firing head;
moving a ball downhole into sealed relationship respective to the passageway of said first recited piston and effecting internal tubing pressure at the surface of the ground to force said first recited piston to move into engage-ment with said gun firing head to thereby detonate the gun and perforate the casing, and thereafter flowing hydrocarbons from the perforations, into the circulating port, and up through the tubing string; thereby completing the well.
17. In a cased borehole having a casing gun located downhole in proximity of a hydrocarbon bearing formation with there being a tubing string extending from a wellhead and connected to said gun; the method of completing the well according to the following steps:
providing said gun with a gun firing head which is detonated upon impact with an object forced downhole within the tubing string;
forming a circulating pork in proximity of said gun firing head so that fluid can be circulated downhole through the port to clean out debris located in proximity of said gun firing head;
slidably positioning a piston within the tubing uphole of the circulating port; and, forming an axial passage-way longitudinally through said piston;
releasably connecting the tubing string together at a location above said piston; slidably positioning an upper annular piston within the tubing string and using the upper annular piston to hold the tubing string in the connected configuration;
said annular piston having an axial passageway which is larger than the passageway formed through the piston located therebelow;
circulating fluid down through the tubing string and through the axial passageways of the pistons to remove debris from about the firing head;
packing off the annulus between the casing and the tubing by employment of a packer device to thereby provide an upper and lower well annulus, locating the packer device above the location where the tubing string is releasably connected together;
circulating a relatively small ball downhole through the annular piston and into sealed relationship with the first recited piston passageway in order to carry out the step of firing the gun;
effecting internal tubing pressure at the surface of the ground to force said first recited piston to move into engagement with said gun firing head to thereby detonate the gun and perforate the casing, and thereafter flowing hydro-carbons from the perforations, into the circulating port, and up through the tubing string, thereby completing the well;
producing the well by flowing formation fluid from the formation, through the perforations, into the lower end of the tubing string, and to the surface of the ground;
circulating a ball downhole into engagement with the upper end of the passageway of the annular piston, forcing the annular piston to move downhole, and using the downhole movement of the annular piston to release the lower tubing string at the recited location above the first recited piston.
providing said gun with a gun firing head which is detonated upon impact with an object forced downhole within the tubing string;
forming a circulating pork in proximity of said gun firing head so that fluid can be circulated downhole through the port to clean out debris located in proximity of said gun firing head;
slidably positioning a piston within the tubing uphole of the circulating port; and, forming an axial passage-way longitudinally through said piston;
releasably connecting the tubing string together at a location above said piston; slidably positioning an upper annular piston within the tubing string and using the upper annular piston to hold the tubing string in the connected configuration;
said annular piston having an axial passageway which is larger than the passageway formed through the piston located therebelow;
circulating fluid down through the tubing string and through the axial passageways of the pistons to remove debris from about the firing head;
packing off the annulus between the casing and the tubing by employment of a packer device to thereby provide an upper and lower well annulus, locating the packer device above the location where the tubing string is releasably connected together;
circulating a relatively small ball downhole through the annular piston and into sealed relationship with the first recited piston passageway in order to carry out the step of firing the gun;
effecting internal tubing pressure at the surface of the ground to force said first recited piston to move into engagement with said gun firing head to thereby detonate the gun and perforate the casing, and thereafter flowing hydro-carbons from the perforations, into the circulating port, and up through the tubing string, thereby completing the well;
producing the well by flowing formation fluid from the formation, through the perforations, into the lower end of the tubing string, and to the surface of the ground;
circulating a ball downhole into engagement with the upper end of the passageway of the annular piston, forcing the annular piston to move downhole, and using the downhole movement of the annular piston to release the lower tubing string at the recited location above the first recited piston.
18. In a cased borehole having a casing gun located downhole in proximity of a hydrocarbon bearing formation with there being a tubing string extending from a wellhead and connected to said gun; the method of completing the well according to the following steps:
providing said gun with a gun firing head which is detonated upon impact with an object forced downhole within the tubing string;
forming a circulating port in proximity of said gun firing head so that fluid can be circulated downhole through the port to clean out debris located in proximity of said gun firing head;
slidably positioning a piston within the tubing up-hole of the circulating port; and, forming an axial passageway longitudinally through said piston;
placing a second piston above the first recited piston, forming a lateral flow port in the tubing and covering the port with the second piston; forming an axial passageway through said second piston which is larger than the passageway through the first piston;
circulating fluid down through the tubing string and through the axial passageway of the piston to remove debris from about the firing head;
moving a relatively large ball downhole into seated relationship respective to the upper end of the passageway of the second piston, thereby isolating the lower piston;
circulating the ball out of the hole, and moving another ball downhole into seated relationship respective to the upper end of the passageway of the lower piston;
increasing the tubing pressure, causing the lower piston to move downhole, thereby detonating the gun, and perforating the casing of the well bore.
providing said gun with a gun firing head which is detonated upon impact with an object forced downhole within the tubing string;
forming a circulating port in proximity of said gun firing head so that fluid can be circulated downhole through the port to clean out debris located in proximity of said gun firing head;
slidably positioning a piston within the tubing up-hole of the circulating port; and, forming an axial passageway longitudinally through said piston;
placing a second piston above the first recited piston, forming a lateral flow port in the tubing and covering the port with the second piston; forming an axial passageway through said second piston which is larger than the passageway through the first piston;
circulating fluid down through the tubing string and through the axial passageway of the piston to remove debris from about the firing head;
moving a relatively large ball downhole into seated relationship respective to the upper end of the passageway of the second piston, thereby isolating the lower piston;
circulating the ball out of the hole, and moving another ball downhole into seated relationship respective to the upper end of the passageway of the lower piston;
increasing the tubing pressure, causing the lower piston to move downhole, thereby detonating the gun, and perforating the casing of the well bore.
19. A well completion apparatus mounted on a pipe string extending into a slanted cased borehole, comprising:
a perforating gun having a firing head and disposed on the pipe string in proximity of a hydrocarbon formation;
a tubular member series connected in the pipe string above said firing head;
said tubular member, firing head and perforating gun having their longitudinal axis substantially deviated from vertical due to the slanted cased borehole so as to preclude dropping a weight through the pipe string to impact and actuate said firing head;
vent means in said tubular member for opening the tubing string to fluid flow prior to the detonation of the perforating gun;
a piston reciprocably mounted within said tubular member and having an axial flow passageway formed therethrough;
circulation ports formed in tubular member below said piston; and a ball circulated downhole through the pipe string for sealing said axial flow passageway whereby fluid pressure is applied to said piston causing said piston to engage said firing head and detonate said perforating gun.
a perforating gun having a firing head and disposed on the pipe string in proximity of a hydrocarbon formation;
a tubular member series connected in the pipe string above said firing head;
said tubular member, firing head and perforating gun having their longitudinal axis substantially deviated from vertical due to the slanted cased borehole so as to preclude dropping a weight through the pipe string to impact and actuate said firing head;
vent means in said tubular member for opening the tubing string to fluid flow prior to the detonation of the perforating gun;
a piston reciprocably mounted within said tubular member and having an axial flow passageway formed therethrough;
circulation ports formed in tubular member below said piston; and a ball circulated downhole through the pipe string for sealing said axial flow passageway whereby fluid pressure is applied to said piston causing said piston to engage said firing head and detonate said perforating gun.
20. The well completion apparatus of Claim 19 and further including means for sealing said piston with the interior of said tubular member.
21. The well completion apparatus of Claim 19 and further including shear means for supporting said piston within said tubular member in a predetermined position and being sheared upon the application of said fluid pressure.
22. The well completion apparatus of Claim 19 and further including projection means projecting from said piston for engagement with the firing head to move the firing head into detonating position.
23. The well completion apparatus of claim 19 wherein said vent means includes vent ports through said tubular member for permitting the flow of production fluids into the tubing string after detonation of the perforating gun, said vent ports being closed by said piston until said piston moves into engagement with said firing head.
24. The well completion apparatus of Claim 19 and further including release means for releasing the perforating gun from the pipe string.
25. The well completion apparatus of Claim 24 wherein said release means includes detent means connected the gun to the pipe string and a barrier actuated by fluid pressure for releasing said detent means.
26. The well completion apparatus of Claim 19 wherein said vent means includes a vent assembly disposed above said piston, said vent assembly having flow ports for fluid circulation between the interior of the pipe string and the annulus around the pipe string.
27. The well completion apparatus of Claim 26 wherein said vent assembly includes a barrier for closing said flow ports.
28. The well completion apparatus of Claim 19 and further including means disposed in the pipe string above said piston for preventing debris from falling through said tubular member to collect around the firing head.
29. The well completion apparatus of Claim 20 and further including;
release means for detaching the perforating gun from the pipe string; and, selective means for selectively actuating said vent means, said release means or said piston.
release means for detaching the perforating gun from the pipe string; and, selective means for selectively actuating said vent means, said release means or said piston.
30. The well completion apparatus of Claim 29 wherein said selective means includes a first sphere larger than said ball for closing an axial flow channel through said vent means and a second sphere larger than said first sphere for closing an axial flow passage through said release means.
31. In a cased wellbore having a tubing string extending from the surface downhole to a perforating gun located adjacent to a hydrocarbon bearing formation, the gun having a firing head which is detonated in response to impact, a packer means located uphole of the gun and dividing the casing annulus into an upper and lower annulus, the method of completing the well comprising:
forming a circulation port in proximity of the gun firing head so that fluid can be circulated downhole through the circulation port to flush out debris located in proximity of the gun firing head;
slidably positioning an actuator piston within the tubing string above the circulation port and forming an axial passageway longitudinally through the actuator piston so that fluid flow can occur through the actuator piston and circulation port;
forming a ball seat on the actuator piston at the upper end of the axial passageway for seating the actuator ball to seal that portion of the tubing string above the actuator piston to fluid flow;
forming a vent port in the tubing string at a location below the packer means and above the actuator piston so that fluid flow can occur between the tubing string and wellbore annulus;
covering the vent port with a slidable vent piston to preclude fluid flow through the vent port and forming an axial bore longitudinally through the vent piston with the axial bore being sized to pass the actuator ball there-through forming a ball seat on the vent piston at the upper end of the axial bore for seating a vent ball to seal that portion of the tubing string above the vent piston to fluid flow;
circulating fluid down through the tubing string, the axial bore, the axial passageway and the circulation port to remove debris located in proximity of the gun firing head;
moving the actuator ball downhole through the axial bore of the vent piston and into sealed relationship with the actuator piston at the ball seat;
effecting internal tubing pressure at the surface to force the actuator piston to move into engagement with the gun firing head;
detonating the perforating gun and perforating the cased borehole; and flowing hydrocarbons from the hydrocarbon producing formation, through the perforations, the circulation port and up the tubing string to the surface, thereby completing the well.
forming a circulation port in proximity of the gun firing head so that fluid can be circulated downhole through the circulation port to flush out debris located in proximity of the gun firing head;
slidably positioning an actuator piston within the tubing string above the circulation port and forming an axial passageway longitudinally through the actuator piston so that fluid flow can occur through the actuator piston and circulation port;
forming a ball seat on the actuator piston at the upper end of the axial passageway for seating the actuator ball to seal that portion of the tubing string above the actuator piston to fluid flow;
forming a vent port in the tubing string at a location below the packer means and above the actuator piston so that fluid flow can occur between the tubing string and wellbore annulus;
covering the vent port with a slidable vent piston to preclude fluid flow through the vent port and forming an axial bore longitudinally through the vent piston with the axial bore being sized to pass the actuator ball there-through forming a ball seat on the vent piston at the upper end of the axial bore for seating a vent ball to seal that portion of the tubing string above the vent piston to fluid flow;
circulating fluid down through the tubing string, the axial bore, the axial passageway and the circulation port to remove debris located in proximity of the gun firing head;
moving the actuator ball downhole through the axial bore of the vent piston and into sealed relationship with the actuator piston at the ball seat;
effecting internal tubing pressure at the surface to force the actuator piston to move into engagement with the gun firing head;
detonating the perforating gun and perforating the cased borehole; and flowing hydrocarbons from the hydrocarbon producing formation, through the perforations, the circulation port and up the tubing string to the surface, thereby completing the well.
32. The method of Claim 31 and including after the step of moving the actuator ball downhole, the step of dropping the vent ball down the tubing string and into sealed relationship with the vent piston at the ball seat so that upon effecting tubing pressure at the surface, the vent piston also moves downwardly to open the vent port where, upon completion of the well, hydrocarbons can also flow into the tubing string through the vent port.
33. The method of Claim 32 and further including forming production ports in the tubing string which are covered by the actuator piston, opening the production ports upon the downward movement of the actuator piston, and flowing hydrocarbons through the production ports upon perforating the well.
34. The method of Claim 32 and further including the step of:
releasably connecting the tubing string together at a location above the vent piston; slidably positioning an upper annular piston within the tubing string and using the upper annular piston to hold the tubing string in the connected configuration:
forming an axial passageway in the annular piston which is larger than the axial bore formed through the vent piston located therebelow;
circulating a ball downhole into engagement with the upper end of the passageway of the annular piston, forcing the annular piston to move downhole, and using the downhole movement of the annular piston to release the lower tubing string at the recited location above the vent piston.
releasably connecting the tubing string together at a location above the vent piston; slidably positioning an upper annular piston within the tubing string and using the upper annular piston to hold the tubing string in the connected configuration:
forming an axial passageway in the annular piston which is larger than the axial bore formed through the vent piston located therebelow;
circulating a ball downhole into engagement with the upper end of the passageway of the annular piston, forcing the annular piston to move downhole, and using the downhole movement of the annular piston to release the lower tubing string at the recited location above the vent piston.
35. The method of Claim 31, further including prior to the step of circulating to remove debris, the steps of:
moving the vent ball downhole into sealed relation-ship with the vent piston at the ball seat; and maintaining the vent ball and piston in sealed relationship until it is desired to complete the well.
moving the vent ball downhole into sealed relation-ship with the vent piston at the ball seat; and maintaining the vent ball and piston in sealed relationship until it is desired to complete the well.
36. The method of Claim 35 and further including the steps of reverse circulating down the wellbore annulus and up the tubing string to carry the vent ball back to the surface.
37. The method of Claim 35 and further including the step of effecting internal tubing pressure at the surface to force the vent piston to open the vent port of fluid flow.
38. The method of Claim 37 and further including the steps of removing the vent ball from the tubing string and repositioning the vent piston with a fishing tool to close the vent port.
39. The method of Claim 38 and including after the step of moving the actuator ball downhole, the step of dropping the vent ball down the tubing string and into sealed relation-ship with the vent piston at the ball seat so that upon effecting tubing pressure at the surface, the vent piston also moves downwardly to open the vent port where, upon completion of the well, hydrocarbons can also flow into the tubing string through the vent port.
40. In a cased wellbore having a tubing string extending from the surface downhole to a perforating gun located adjacent to a hydrocarbon bearing formation, the gun having a firing head which is detonated in response to impact, a packer means located uphole of the gun and dividing the casing annulus into an upper and lower annulus, the method of completing the well comprising:
forming a circulation port in proximity of the gun firing head so that fluid can be circulated downhole through the circulation port to flush out debris located in proximity of the gun firing head;
slidably positioning an actuator piston within the tubing string above the circulation port and forming an axial passageway longitudinally through the actuator piston so that fluid flow can occur through the actuator piston and circulation port;
forming a ball seat on the actuator piston at the upper end of the axial passageway for seating an actuator ball to seal that portion of the tubing string above the actuator piston to fluid flow;
forming a vent port in the tubing string at a location below the packer means and above the actuator piston so that fluid flow can occur between the tubing string and wellbore annulus;
covering the vent port with a slidable vent piston to preclude fluid flow through the vent port and forming an axial bore longitudinally through the vent piston with the axial bore being sized to pass the actuator ball therethrough;
forming a ball seat on the vent piston at the upper end of the axial bore for seating a vent ball to seal that portion of the tubing string above the vent piston to fluid flow;
circulating fluid down through the tubing string, the axial bore, the axial passageway and the circulation port to remove debris located in proximity of the gun firing head;
moving the actuator ball downhole through the axial bore of the vent piston and into sealed relationship with the actuator piston at the ball seat;
moving the vent ball downhole into sealed relation-ship with the vent piston at the ball seat;
effecting internal tubing pressure at the surface to simultaneously force the vent and actuator pistons down-wardly to open the vent port and move the actuator piston into engagement with the gun firing head;
detonating the perforating gun and perforating the cased borehole; and flowing hydrocarbons from the hydrocarbon producing formation, through the perforations, the circulation and vent ports and up the tubing string to the surface, thereby completing the well.
forming a circulation port in proximity of the gun firing head so that fluid can be circulated downhole through the circulation port to flush out debris located in proximity of the gun firing head;
slidably positioning an actuator piston within the tubing string above the circulation port and forming an axial passageway longitudinally through the actuator piston so that fluid flow can occur through the actuator piston and circulation port;
forming a ball seat on the actuator piston at the upper end of the axial passageway for seating an actuator ball to seal that portion of the tubing string above the actuator piston to fluid flow;
forming a vent port in the tubing string at a location below the packer means and above the actuator piston so that fluid flow can occur between the tubing string and wellbore annulus;
covering the vent port with a slidable vent piston to preclude fluid flow through the vent port and forming an axial bore longitudinally through the vent piston with the axial bore being sized to pass the actuator ball therethrough;
forming a ball seat on the vent piston at the upper end of the axial bore for seating a vent ball to seal that portion of the tubing string above the vent piston to fluid flow;
circulating fluid down through the tubing string, the axial bore, the axial passageway and the circulation port to remove debris located in proximity of the gun firing head;
moving the actuator ball downhole through the axial bore of the vent piston and into sealed relationship with the actuator piston at the ball seat;
moving the vent ball downhole into sealed relation-ship with the vent piston at the ball seat;
effecting internal tubing pressure at the surface to simultaneously force the vent and actuator pistons down-wardly to open the vent port and move the actuator piston into engagement with the gun firing head;
detonating the perforating gun and perforating the cased borehole; and flowing hydrocarbons from the hydrocarbon producing formation, through the perforations, the circulation and vent ports and up the tubing string to the surface, thereby completing the well.
41. The method of Claim 40 and further including forming production ports in the tubing string which are covered by the actuator piston, opening the production ports upon the downward movement of the actuator piston, and flowing hydrocarbons through the production ports upon perforating the well.
42. The method of Claim 40 and further including the steps of:
releasably connecting the tubing string together at a location above the vent piston; slidably positioning an upper annular piston within the tubing string and using the upper annular piston to hold the tubing string in the connected configuration;
forming an axial passageway through the annular piston with the axial passageway being larger than the axial bore formed through the vent piston located therebelow; and circulating a ball downhole into engagement with the upper end of the passageway of the annular piston, forcing the annular piston to move downhole, and using the downhole movement of the annular piston to release the lower tubing string at the recited location above the vent piston.
releasably connecting the tubing string together at a location above the vent piston; slidably positioning an upper annular piston within the tubing string and using the upper annular piston to hold the tubing string in the connected configuration;
forming an axial passageway through the annular piston with the axial passageway being larger than the axial bore formed through the vent piston located therebelow; and circulating a ball downhole into engagement with the upper end of the passageway of the annular piston, forcing the annular piston to move downhole, and using the downhole movement of the annular piston to release the lower tubing string at the recited location above the vent piston.
43. In a cased wellbore having a tubing string extending from the surface downhole to a perforating gun located adjacent to a hydrocarbon bearing formation, the gun having a firing head which is detonated in response to impact, a packer means located uphole of the gun and dividing the casing annulus into an upper and lower annulus, the method of completing the well comprising:
forming a circulation port in proximity of the gun firing head so that fluid can be circulated downhole through the circulation port to flush out debris located in proximity of the open firing head;
slidably positioning an actuator piston within the tubing string above the circulation port and forming an axial passageway longitudinally through the actuator piston so that fluid flow can occur through the actuator piston and circulation port;
forming a ball seat on the actuator piston at the upper end of the axial passageway for seating an actuator ball to seal that portion of the tubing string above the actuator piston to fluid flow;
forming a vent port in the tubing string at a location below the packer means and above the actuator piston so that fluid flow can occur between the tubing string and wellbore annulus;
covering the vent port with a slidable vent piston to preclude fluid flow through the vent port and forming an axial bore longitudinally through the vent piston with the axial bore being sized to pass the actuator ball therethrough;
forming a ball seat on the vent piston at the upper end of the axial bore for seating a vent ball to seal that portion of the tubing string above the vent piston to fluid flow;
moving the vent ball downhole into sealed relation-ship with the vent piston at the ball seat;
effecting internal tubing pressure at the surface to force the vent piston to open the vent port to fluid flow;
dropping a bar down the tubing string to impact the vent piston which engages the actuator piston to move the actuator piston into engagement with the gun firing head;
detonating the perforating gun and perforating the cased borehole; and flowing hydrocarbons from the hydrocarbon producing formation, through the perforations, the circulation port and up the tubing string to the surface, thereby completing the well.
forming a circulation port in proximity of the gun firing head so that fluid can be circulated downhole through the circulation port to flush out debris located in proximity of the open firing head;
slidably positioning an actuator piston within the tubing string above the circulation port and forming an axial passageway longitudinally through the actuator piston so that fluid flow can occur through the actuator piston and circulation port;
forming a ball seat on the actuator piston at the upper end of the axial passageway for seating an actuator ball to seal that portion of the tubing string above the actuator piston to fluid flow;
forming a vent port in the tubing string at a location below the packer means and above the actuator piston so that fluid flow can occur between the tubing string and wellbore annulus;
covering the vent port with a slidable vent piston to preclude fluid flow through the vent port and forming an axial bore longitudinally through the vent piston with the axial bore being sized to pass the actuator ball therethrough;
forming a ball seat on the vent piston at the upper end of the axial bore for seating a vent ball to seal that portion of the tubing string above the vent piston to fluid flow;
moving the vent ball downhole into sealed relation-ship with the vent piston at the ball seat;
effecting internal tubing pressure at the surface to force the vent piston to open the vent port to fluid flow;
dropping a bar down the tubing string to impact the vent piston which engages the actuator piston to move the actuator piston into engagement with the gun firing head;
detonating the perforating gun and perforating the cased borehole; and flowing hydrocarbons from the hydrocarbon producing formation, through the perforations, the circulation port and up the tubing string to the surface, thereby completing the well.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US17551580A | 1980-08-05 | 1980-08-05 | |
| US175,515 | 1980-08-05 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1161748A true CA1161748A (en) | 1984-02-07 |
Family
ID=22640514
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000381025A Expired CA1161748A (en) | 1980-08-05 | 1981-07-02 | Ball switch device and method |
Country Status (2)
| Country | Link |
|---|---|
| CA (1) | CA1161748A (en) |
| GB (1) | GB2081344B (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4509604A (en) * | 1982-04-16 | 1985-04-09 | Schlumberger Technology Corporation | Pressure responsive perforating and testing system |
| CA1224139A (en) * | 1984-03-08 | 1987-07-14 | Flint R. George | Pressure responsive explosion initiator with time delay and method of use |
| US4510994A (en) * | 1984-04-06 | 1985-04-16 | Camco, Incorporated | Pump out sub |
| GB0108934D0 (en) * | 2001-04-10 | 2001-05-30 | Weatherford Lamb | Downhole Tool |
-
1981
- 1981-07-02 CA CA000381025A patent/CA1161748A/en not_active Expired
- 1981-07-17 GB GB8122208A patent/GB2081344B/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| GB2081344A (en) | 1982-02-17 |
| GB2081344B (en) | 1984-08-15 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |