EP0450676B1 - Equipment for remote launching of cementing plugs into subsea drilled wells - Google Patents
Equipment for remote launching of cementing plugs into subsea drilled wells Download PDFInfo
- Publication number
- EP0450676B1 EP0450676B1 EP91200447A EP91200447A EP0450676B1 EP 0450676 B1 EP0450676 B1 EP 0450676B1 EP 91200447 A EP91200447 A EP 91200447A EP 91200447 A EP91200447 A EP 91200447A EP 0450676 B1 EP0450676 B1 EP 0450676B1
- Authority
- EP
- European Patent Office
- Prior art keywords
- plug
- dart
- casing
- launch tube
- launching
- 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 - Lifetime
Links
- 238000009434 installation Methods 0.000 claims description 12
- 230000002093 peripheral effect Effects 0.000 claims description 9
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 5
- 230000000295 complement effect Effects 0.000 claims description 3
- 230000000694 effects Effects 0.000 claims description 3
- 238000009527 percussion Methods 0.000 claims description 2
- 239000012530 fluid Substances 0.000 description 17
- 238000005553 drilling Methods 0.000 description 16
- 238000000034 method Methods 0.000 description 13
- 238000007789 sealing Methods 0.000 description 7
- 239000000872 buffer Substances 0.000 description 5
- 239000003129 oil well Substances 0.000 description 5
- 230000004323 axial length Effects 0.000 description 4
- 239000004568 cement Substances 0.000 description 4
- 239000000203 mixture Substances 0.000 description 3
- 239000002002 slurry Substances 0.000 description 3
- 238000004140 cleaning Methods 0.000 description 2
- 238000007667 floating Methods 0.000 description 2
- 238000010008 shearing Methods 0.000 description 2
- 238000011144 upstream manufacturing Methods 0.000 description 2
- 230000006978 adaptation Effects 0.000 description 1
- 230000000712 assembly Effects 0.000 description 1
- 238000000429 assembly Methods 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 239000011248 coating agent Substances 0.000 description 1
- 238000000576 coating method Methods 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 238000005755 formation reaction Methods 0.000 description 1
- 230000005484 gravity Effects 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 239000012528 membrane Substances 0.000 description 1
- 230000002035 prolonged effect Effects 0.000 description 1
- 230000000630 rising effect Effects 0.000 description 1
- 238000007790 scraping Methods 0.000 description 1
Images
Classifications
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B33/00—Sealing or packing boreholes or wells
- E21B33/02—Surface sealing or packing
- E21B33/03—Well heads; Setting-up thereof
- E21B33/04—Casing heads; Suspending casings or tubings in well heads
- E21B33/05—Cementing-heads, e.g. having provision for introducing cementing plugs
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21B—EARTH OR ROCK 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
- E21B33/13—Methods or devices for cementing, for plugging holes, crevices or the like
- E21B33/14—Methods or devices for cementing, for plugging holes, crevices or the like for cementing casings into boreholes
- E21B33/16—Methods or devices for cementing, for plugging holes, crevices or the like for cementing casings into boreholes using plugs for isolating cement charge; Plugs therefor
- E21B33/165—Cementing plugs specially adapted for being released down-hole
Definitions
- the present invention relates to the domain of sub-sea fields oil well drilling and similar, from a working structure or rig which can be a floating or fixed platform of any type.
- sub-sea well should be considered as including all the application cases wherein a well should be drilled starting from a surface covered with a salty, or not, stagnant, or not, water height.
- the more particular target of the invention comprises the supplies, installation or equipment to be operated to insure cementing of the internal casing of such a bore hole.
- This bottom plug launching relies on pressurized fluid means such as, in particular, cement slurry. After positioning, in a per so well known manner, the bottom plug on the "float collar” or similar, the generated overpressure perforates the bottom plug breakage membrane. In an equally known manner the so called top plug will be launched into the same casing to also be propelled by a pressurized fluid under an overflush during a subsequent distinct operation, generally after the cement slurry has been pumped downhole.
- pressurized fluid means such as, in particular, cement slurry.
- the top plug function is to deliver through the bottom plug the previously pumped cement or similar product so that it is pumped back up through the ring shaped gap or "annulus" between the internal casing and either the adjacent formations, or an external casing.
- the first, so called external, casing which equips the drill well emerges from the bottom and bears, by means of a casing hanger, an internal casing.
- the casing hanger also follows mounting an adapter, called “installation tool”, which is prolonged upwards by the drill pipe all through the water height, so as to be linked with the rig, on which such a tube bears a release system for one or several launchers or darts.
- the installation tool allows hanging, inside the internal casing, one or several mutually associated plugs, the lips of which are radially stressed to establish a seal with the peripheral wall of the internal casing.
- the release system or dart includes a number of darts equal to the number of plugs, and being able to be launched in succession to cause the plugs to successively be supported and launched by known mechanical action(s).
- the plugs/installation tool assembly must be threadedly mounted onto the casing hanger.
- the peripheral lips of the various plugs therefore are submitted to a friction which can damage them, possibly make them unable to exert their basic sealing function, and the mechanical stresses, additionnally, can rupture or distort the shear pins between the plugs.
- EP 0 167 285 pertains to that category, in that it describes a tubular section placed inside the casing. Two plugs are contained in it with a central hole in which darts travel and cooperate with sealing means.
- each dart remains adapted to the corresponding plug and constitutes a technical element with a relatively high cost, but with a single utilisation.
- the present invention aims at overcoming the above inconveniences by proposing a new launching equipment for cementing plugs in sub-sea oil wells or similar.
- the object of the invention is to propose an equipment which allows using standard plugs according to the surface drilling and cementing techniques.
- Another object of the invention is to propose a simple reliable and strong equipment, which can be operated with the commonly used technical means of sub-sea wells drilling and cementing.
- Another object of the invention is to propose an equipment which can be operated so as to recover the remote dart in order to sensibly reduce the operating cost of such an equipment and eliminate the subsequent plug drilling problems.
- the remote launching equipment of the type including a dart release system comprising at least one dart and assembled on a drill pipe rising from an installation tool mounted on the internal casing, including a remote launching head provided inside the internal casing characterized in that it comprises : a launch tube, partly communicating with the inside casing and extending, coaxially with the drill pipe, downwards from the installation tool, a basket secured at the launch tube bottom part, with a cross section smaller than that of the internal casing, open at its bottom end and containing at least one plug with peripheral lips, axially kept stationary inside the basket by its radially prestressed lips, a launching device, sliding inside the launch tube and including an axial push rod, which cooperates with the plug, and a piston integral with the rod, axially kept stationary in the tube by a limited strength stopping means and designed for an axial movement, caused by a pressure effect exerted by the arrival of the dart, coming from said release system, at the level of the sliding launching device
- Fig. 1 is a schematic view of the equipment according to the invention.
- Fig. 2 is a schematic longitudinal section illustrating one of the elements constituting the equipment.
- Fig. 3 is an axial cross section taken along line III-III of Fig. 1.
- Fig. 4 is a longitudinal section representing an enlarged view of a structure detail of Fig. 3.
- Fig. 5 is an enlarged partial longitudinal section along line V-V of Fig. 4.
- Figs. 6 to 9 are longitudinal sections showing, at a reduced scale, four particular operational phases of the equipment according to the invention.
- Fig. 1 schematically illustrates the application domain of the object of the invention.
- This domain includes drilling and cementing an oil well 1 or similar, starting from a surface S topped by a water height H .
- off-shore drilling from a rig 2 as illustrated in dot-dash lines, which can consist of a floating or a fixed platform, of any type, should be quoted.
- the object of the invention more particularly aims at allowing a remote control, from platform 2, of this cementing operation.
- the plug remote launching equipment includes a remote launching head 6 hanging, inside the internal casing 4, from an installation tool 7 mounted on a casing hanger 8 of the internal casing 4, from the external casing 3.
- the installation tool 7 consists of a ring shaped part which is adapted, by known means, at the end of a drill pipe 9 linked to its platform 2 in order to bear, at its portion emerging from the water height and inside platform 2, a release system for one or several darts.
- Fig. 2 illustrates an embodiment of system 10 comprising a body 11 limiting a cylindrical chamber 12 designed for being linked through several fittings with at least one pressurized fluid supply circuit 13.
- a circuit 13 can be connected, although not represented in Fig. 2, with several circuits supplying various fluids, which generally are used for oil wells cementing, as known in the art.
- each dart 14 includes a percussion head 17 and a sealing rear buffer 18.
- the darts 14 a and 14 b are axially kept stationary inside chamber 12 while being separated from one another by means of retractable stopping devices 19 a and 19 b which can be of any, hand or power operated, suitable type.
- fittings 20, 21, 22 are provided for connection with circuit 13 by means of three taps 23, 24 and 25.
- Fitting 20 opens into chamber 12, below dart 14 a , fitting 21 between the latter and dart 14 b , and fitting 22 on top of the latter.
- taps 24 and 25 are closed and tap 23 is open to allow introducing muds or similar inside the oil well through fitting 20.
- chamber 12 would include four connection fittings with circuit 13.
- Figs. 3 and 4 show the remote launching head, generally designated by numeral 6, in a more detailed manner.
- a head includes a launch tube 30 fixed on the installation tool 7 to extend downwards by being disposed coaxially with the drill pipe 9 inside the internal casing 4.
- the length of launch tube 30 is a multiple of the elementary length of the darts, which possibly can have mutually different lengths.
- the launch tube 30 bears, at its bottom end part, a preferably cylindrical basket 31, open downwards, with a diameter smaller than the cross section of the internal casing 4.
- Basket 31 can be permanently linked with casing 4, in particular by means of holes 32 provided at different levels inside the basket.
- Basket 31 which is coaxially disposed with casing 4, is designed to hold plugs 33, for instance two plugs, the bottom plug and the top plug, maintained superposed in contact while being kept stationary by radial stress.
- Plugs 33 are of a type used in the surface cementing techniques and generally include a body 34 provided with an external coating which forms resiliently deformable peripheral lips 35. The plugs are axially maintained in the basket by prestressing lips 35.
- Plugs 33 are of standard type, i.e. identical to those used in corresponding surface cementing techniques.
- the number of plugs 33 is related to the number of darts 14 and the axial length of each plug 33 is chosen in matching relation with the darts length.
- the plugs 33 all have the same axial length, which is equal to the length of the darts 14.
- Fig. 3 illustrates the operation of a basket 31 adapted to hold one bottom plug 33 a and one top plug 33 b .
- the basket 31 can be designed to include either one single plug 33, or, for instance, three plugs 33.
- the launching head 6 when operating a basket 33 designed to hold at least two plugs, as in the example illustrated in Figs. 3 and 4, the launching head 6 includes a remote launching device 36, telescopically mounted inside the launch tube 30.
- the remote launching device 36 includes a piston 37 provided with a dart positionning boss and extending, opposite to the latter, by means of a push rod 38, the end part of which 39 cooperates with the top plug 33 b .
- the remote launching device 36 is axially kept stationary in a waiting position, inside the launch tube 30, by limited mechanical strength stopping means 40.
- These means 40 may consist of shearing type screws, passing across the wall of the launch tube 30 to cooperate with the peripheral groove 41 formed in piston 37.
- the position of the members 40 is so determined as to match the maximal retractable position of the push rod 38 in which the end part 39 cooperates with the plug 33 b arranged in axial contact with plug 33 a , totally retracted inside the basket 31.
- the launching device 36 is designed, as appears from the following explanation, to control the successive expulsion of plugs 33 a 33 b in relation to the basket 31.
- two limited strength stopping means 40 a and 40 b are provided on the launch tube to exert a function of keeping the rod 38 stationary in an initial operating position, as illustrated in Fig. 3, and in an intermediate position.
- a third stage 40 of limited strength stopping means is provided on tube 30.
- the end part 301 of tube 30 includes an internal rim 42 which forms an abutment for the end of run of piston 37.
- the axial interval between two stopping means stages 40 and/or the ring 42 is provided in relation with the axial length of the plugs 33.
- this length is equal to the length of the plugs 33, which in its turn equals that of darts 14.
- Passages 43 are formed in the launch tube 30, just above the top position of piston 37. Passages 43 are designed to allow fluids, pumped from the surface, the flow towards the inside of casing 4 by passing through the ring shaped gap or annulus between inside casing 4 and the outside of basket 31.
- Passages 43 are formed at the basis of a bore or chamber 45 with a carefully machined wall, formed in the top part of the launch tube 30 and designed for sealing with the seals or buffers 18 of darts 14.
- the diameter of the bore 45 is slightly smaller than all the diameters which can be met, starting from system 10 on, so that the buffers 18 only are really biased into bore 45 where they arrive in a perfect shape.
- the axial length of the bore 45 is, at least, equal to that of a dart 14.
- Pressure balancing holes 46 also are formed in the launch tube 30, between the basis of the latter and the passages 43, so that no strength is exerted on the launching device 36 except as caused by the thrust of darts 14 a and 14 b , as explained herebelow.
- Axial pressure balance grooves 47 also are provided for the same purpose in the ring 42.
- Such a member 50 includes a release rod 51, slidably mounted inside push rod 38.
- This release rod 51 is kept stationary in a stable position and includes a butt 52 engaged inside the end portion 39 to control the radial extension of the resiliently retractable locking fingers 53, housed in the end portion 39, which constitute the adaptation nose in the complementary housing 54 formed on the top of top plug 33 b .
- fingers 53 are engaged in a matching groove inside housing 54.
- the release rod 51 is kept stationary in a stable position, either simply by gravity or by means of a pin 55 passing through the launch tube 30, as appears from Fig. 5.
- Pin 55 is of the shearing pin type and has a smaller mechanical strength than the stopping means 40 b .
- the release rod 51 includes a head 56 with two pins 57 passing through axial oblong guiding holes 58 formed in the push rod 38.
- the pins 57 are externally projecting out of the push rod 38, so that they can cooperate with the abutment rim 42 as explained hereafter.
- the remote launching equipment described above is operated as follows.
- tap 23 is closed, tap 24 is open, so that circuit 13 supplies a pressurized fluid into that portion of chamber 12 limited by darts 14 a and 14 b .
- a fluid can be a cementing mixture of any known composition.
- the retractable stopping device 19 a is retractably controlled to release dart 14 a which is propelled inside the drill pipe 9 by the fluid pressure which insures its propagation. Dart 14 a is then lead to engage inside chamber 45 where a seal is established by the rear buffer 18.
- Dart 14 a is brought into contact with piston 37, so as to trigger the operation of the launching device 36. From that position, as illustrated in Fig. 6, the sealing buffer 18, which exerts its function with the chamber 45, blocks the circulation of the fluid through the holes 43, which creates a pression increase upstream of the dart. The fluid pressure inside the drill pipe 9 then rises until it reaches the triggering threshold of the limited strength stopping means 40 a .
- the dart 14 a When the triggering of means 40 a has been effected, the dart 14 a , under effect of the pressure developped upstream in the drill pipe, pushes the launching device 36.
- the rod 38 pushes top plug 33 b which expulses plug 33 a out of basket 31.
- the expulsion of bottom plug 33 a is effected when the launching device 36 reaches the intermediate stable position caused by the stopping means 40 b provided, by structure, to oppose a higher strength than the stopping means 40 a do, in order to allow differentiating at the time of surface pressure control. In this position, pins 57 are disposed close to the rim 42.
- bottom plug 33 a insures a tight closure, so that the fluid pressure in casing 4 increases until it causes a perforation of lid 60 which closes plug 33 a , as is well known in the art.
- dart 14 b uncovers the passages 43 of chamber 45, so that the fluid, transferred from the drill pipe and launch tube 30 towards internal casing 4, takes along top plug 33 b launched from internal casing 4.
- the equipment according to the invention allows a control of the launching of a plug, being in a waiting position at the entrance of the drill well, remotely from the rig from which the dart releasing system operates.
- a launching is performed in a precise manner for each plug, due to the controllability of an effective launching through an appreciation of the pressure peak corresponding to the ruptures in succession of stopping means 40 a and 40 b .
- An additional advantage of the invention resides in the fact that the plugs used are of the same design as those used in surface cementing techniques. cf EP-A-377 255.
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Description
- The present invention relates to the domain of sub-sea fields oil well drilling and similar, from a working structure or rig which can be a floating or fixed platform of any type.
- If the more particulary concerned techniques are those related to off-shore drilling, the definition of sub-sea well should be considered as including all the application cases wherein a well should be drilled starting from a surface covered with a salty, or not, stagnant, or not, water height.
- The more particular target of the invention comprises the supplies, installation or equipment to be operated to insure cementing of the internal casing of such a bore hole.
- Although no very precise description of the cementing of the internal casing of a drilled well is needed, due to the knowledges of those familiar with the art, it however is appropriate to remind that these cementing techniques consist of launching, inside a casing, a sealed plug, called the bottom plug, designed for cleaning by scraping the internal surface of the casing to eliminate drilling mud traces and avoid any mud/cement slurry contact.
- This bottom plug launching relies on pressurized fluid means such as, in particular, cement slurry. After positioning, in a per so well known manner, the bottom plug on the "float collar" or similar, the generated overpressure perforates the bottom plug breakage membrane. In an equally known manner the so called top plug will be launched into the same casing to also be propelled by a pressurized fluid under an overflush during a subsequent distinct operation, generally after the cement slurry has been pumped downhole.
- The top plug function is to deliver through the bottom plug the previously pumped cement or similar product so that it is pumped back up through the ring shaped gap or "annulus" between the internal casing and either the adjacent formations, or an external casing.
- It will be understood that such a process is difficult to operate in a sub-sea drilling case, due to the fact that the usual cementing head, which bears the plugs, usually is adapted on the working structure or "rig". In the case of sub-sea drilling, such an approach would lead to both plugs moving along a long path between the rig and the sub-sea bottom, with all the inconveniences and problems which such techniques would induce.
- To reduce the inconveniences that would result from such an operation, the previous art has proposed solutions, of which one can be considered on the basis of application EP-A 0 167 285.
- According to these techniques, the first, so called external, casing which equips the drill well, emerges from the bottom and bears, by means of a casing hanger, an internal casing. The casing hanger also follows mounting an adapter, called "installation tool", which is prolonged upwards by the drill pipe all through the water height, so as to be linked with the rig, on which such a tube bears a release system for one or several launchers or darts.
- The installation tool allows hanging, inside the internal casing, one or several mutually associated plugs, the lips of which are radially stressed to establish a seal with the peripheral wall of the internal casing.
- The release system or dart, includes a number of darts equal to the number of plugs, and being able to be launched in succession to cause the plugs to successively be supported and launched by known mechanical action(s).
- Such techniques imply a certain number of inconveniences of which the main ones are as follows.
- The plugs/installation tool assembly must be threadedly mounted onto the casing hanger. The peripheral lips of the various plugs therefore are submitted to a friction which can damage them, possibly make them unable to exert their basic sealing function, and the mechanical stresses, additionnally, can rupture or distort the shear pins between the plugs.
- In order to allow the plugs launchings in succession, those plugs require a tubular construction so that the dart can successively pass through them. Such a conformation implies a delicate, highly expensive execution, which requires linking means between two successive plugs, sealing means between them, but also release or mutual unlocking means through a dart action. Furthermore, such plugs also have to bear such complementary linking and sealing means that each one of them builds up a sealed assembly, able to exert the initial plug function, with the corresponding dart.
- Above cited EP 0 167 285 pertains to that category, in that it describes a tubular section placed inside the casing. Two plugs are contained in it with a central hole in which darts travel and cooperate with sealing means.
- These various means are particularly complex, and furthermore are specific, so that standard plugs, generally operated in surface drilling techniques, cannot be used with a sub-sea head.
- In addition, each dart remains adapted to the corresponding plug and constitutes a technical element with a relatively high cost, but with a single utilisation.
- The presence of a dart on each plug, on the other hand, causes a problem for the subsequent drilling operation which necessarily has to be performed to start drilling again after the cementing operation.
- These various problems bear an economical aspect, in that they considerably increase the cost of a drill, and mostly generate drilling difficulties which sometimes cannot be solved.
- The present invention aims at overcoming the above inconveniences by proposing a new launching equipment for cementing plugs in sub-sea oil wells or similar.
- The object of the invention is to propose an equipment which allows using standard plugs according to the surface drilling and cementing techniques.
- Another object of the invention is to propose a simple reliable and strong equipment, which can be operated with the commonly used technical means of sub-sea wells drilling and cementing.
- Another object of the invention is to propose an equipment which can be operated so as to recover the remote dart in order to sensibly reduce the operating cost of such an equipment and eliminate the subsequent plug drilling problems.
- In order to reach the above objects, the remote launching equipment according to invention, of the type including a dart release system comprising at least one dart and assembled on a drill pipe rising from an installation tool mounted on the internal casing, including a remote launching head provided inside the internal casing characterized in that it comprises :
a launch tube, partly communicating with the inside casing and extending, coaxially with the drill pipe, downwards from the installation tool,
a basket secured at the launch tube bottom part, with a cross section smaller than that of the internal casing, open at its bottom end and containing at least one plug with peripheral lips, axially kept stationary inside the basket by its radially prestressed lips,
a launching device, sliding inside the launch tube and including an axial push rod, which cooperates with the plug, and a piston integral with the rod, axially kept stationary in the tube by a limited strength stopping means and designed for an axial movement, caused by a pressure effect exerted by the arrival of the dart, coming from said release system, at the level of the sliding launching device inside the tube on a limited axial run, to insure expulsion of the plug out of the basket. - Various other characteristics will appear from the above description when referring to the appended drawings illustrating embodiments of the object of the invention which should be taken as non limiting examples.
- Fig. 1 is a schematic view of the equipment according to the invention.
- Fig. 2 is a schematic longitudinal section illustrating one of the elements constituting the equipment.
- Fig. 3 is an axial cross section taken along line III-III of Fig. 1.
- Fig. 4 is a longitudinal section representing an enlarged view of a structure detail of Fig. 3.
- Fig. 5 is an enlarged partial longitudinal section along line V-V of Fig. 4.
- Figs. 6 to 9 are longitudinal sections showing, at a reduced scale, four particular operational phases of the equipment according to the invention.
- Fig. 1 schematically illustrates the application domain of the object of the invention. This domain includes drilling and cementing an oil well 1 or similar, starting from a surface S topped by a water height H. As a preferred application, off-shore drilling from a rig 2, as illustrated in dot-dash lines, which can consist of a floating or a fixed platform, of any type, should be quoted.
- The drilling phase of such a well 1, when a
first casing 3 generally called external casing has been positionned, implies aninternal casing 4 which limits, with the above and/or the well, a ring shaped gap or annulus 5 to be cemented. The object of the invention more particularly aims at allowing a remote control, from platform 2, of this cementing operation. - The plug remote launching equipment according to the invention includes a remote launching
head 6 hanging, inside theinternal casing 4, from aninstallation tool 7 mounted on a casing hanger 8 of theinternal casing 4, from theexternal casing 3. Theinstallation tool 7 consists of a ring shaped part which is adapted, by known means, at the end of adrill pipe 9 linked to its platform 2 in order to bear, at its portion emerging from the water height and inside platform 2, a release system for one or several darts. - Fig. 2 illustrates an embodiment of
system 10 comprising abody 11 limiting acylindrical chamber 12 designed for being linked through several fittings with at least one pressurizedfluid supply circuit 13. Such acircuit 13 can be connected, although not represented in Fig. 2, with several circuits supplying various fluids, which generally are used for oil wells cementing, as known in the art. - When the equipment is operated according to the invention to perform a cementing operation implying the launching of two successive plugs, generally named bottom plug and top plug, the
chamber 12 contains therein twodarts darts 14abody 15 with deformableperipheral lips 16 which are radially stressed to cooperate withchamber 12, in order to establish a peripheral seal between the latter and thebody 15. Preferably, each dart 14 includes apercussion head 17 and a sealingrear buffer 18. - The
darts chamber 12 while being separated from one another by means ofretractable stopping devices 19a and 19b which can be of any, hand or power operated, suitable type. - In the illustrated example according to which
chamber 12 includes two darts, threefittings circuit 13 by means of threetaps chamber 12, belowdart 14a, fitting 21 between the latter anddart 14b, and fitting 22 on top of the latter. - For the mud circulating operation,
taps tap 23 is open to allow introducing muds or similar inside the oil well through fitting 20. - Obviously, such cementing or drilling techniques could imply a
system 10 including a different number of darts, for instance one or three. In the latter case,chamber 12 would include four connection fittings withcircuit 13. - Figs. 3 and 4 show the remote launching head, generally designated by
numeral 6, in a more detailed manner. Such a head includes alaunch tube 30 fixed on theinstallation tool 7 to extend downwards by being disposed coaxially with thedrill pipe 9 inside theinternal casing 4. The length oflaunch tube 30 is a multiple of the elementary length of the darts, which possibly can have mutually different lengths. - The
launch tube 30 bears, at its bottom end part, a preferablycylindrical basket 31, open downwards, with a diameter smaller than the cross section of theinternal casing 4.Basket 31 can be permanently linked withcasing 4, in particular by means ofholes 32 provided at different levels inside the basket. -
Basket 31, which is coaxially disposed withcasing 4, is designed to hold plugs 33, for instance two plugs, the bottom plug and the top plug, maintained superposed in contact while being kept stationary by radial stress. Plugs 33 are of a type used in the surface cementing techniques and generally include abody 34 provided with an external coating which forms resiliently deformableperipheral lips 35. The plugs are axially maintained in the basket by prestressinglips 35. - Plugs 33 are of standard type, i.e. identical to those used in corresponding surface cementing techniques.
- The number of plugs 33 is related to the number of darts 14 and the axial length of each plug 33 is chosen in matching relation with the darts length. Preferably, the plugs 33 all have the same axial length, which is equal to the length of the darts 14.
- It obviously should be considered that the example according to Fig. 3 illustrates the operation of a
basket 31 adapted to hold onebottom plug 33a and onetop plug 33b. Obviously, according to the technique to be developped, thebasket 31 can be designed to include either one single plug 33, or, for instance, three plugs 33. - More particularly, when operating a basket 33 designed to hold at least two plugs, as in the example illustrated in Figs. 3 and 4, the launching
head 6 includes aremote launching device 36, telescopically mounted inside thelaunch tube 30. Theremote launching device 36 includes apiston 37 provided with a dart positionning boss and extending, opposite to the latter, by means of apush rod 38, the end part of which 39 cooperates with thetop plug 33b. - The
remote launching device 36 is axially kept stationary in a waiting position, inside thelaunch tube 30, by limited mechanical strength stopping means 40. These means 40 may consist of shearing type screws, passing across the wall of thelaunch tube 30 to cooperate with theperipheral groove 41 formed inpiston 37. The position of the members 40 is so determined as to match the maximal retractable position of thepush rod 38 in which theend part 39 cooperates with theplug 33b arranged in axial contact withplug 33a, totally retracted inside thebasket 31. - The launching
device 36 is designed, as appears from the following explanation, to control the successive expulsion ofplugs 33abasket 31. For this purpose, two limitedstrength stopping means rod 38 stationary in an initial operating position, as illustrated in Fig. 3, and in an intermediate position. Ifbasket 31 is designed to hold three plugs 33, a third stage 40 of limited strength stopping means is provided ontube 30. In all cases, theend part 30₁ oftube 30 includes aninternal rim 42 which forms an abutment for the end of run ofpiston 37. - The axial interval between two stopping means stages 40 and/or the
ring 42, is provided in relation with the axial length of the plugs 33. In the present case, this length is equal to the length of the plugs 33, which in its turn equals that of darts 14. -
Passages 43 are formed in thelaunch tube 30, just above the top position ofpiston 37.Passages 43 are designed to allow fluids, pumped from the surface, the flow towards the inside ofcasing 4 by passing through the ring shaped gap or annulus betweeninside casing 4 and the outside ofbasket 31. -
Passages 43 are formed at the basis of a bore orchamber 45 with a carefully machined wall, formed in the top part of thelaunch tube 30 and designed for sealing with the seals orbuffers 18 of darts 14. The diameter of thebore 45 is slightly smaller than all the diameters which can be met, starting fromsystem 10 on, so that thebuffers 18 only are really biased intobore 45 where they arrive in a perfect shape. The axial length of thebore 45 is, at least, equal to that of a dart 14. - Pressure balancing holes 46 also are formed in the
launch tube 30, between the basis of the latter and thepassages 43, so that no strength is exerted on thelaunching device 36 except as caused by the thrust ofdarts - Axial
pressure balance grooves 47 also are provided for the same purpose in thering 42. - When two plugs 33 are used, the cooperation between the
end portion 39 ofpush rod 38 and thetop plug 33b is insured by means of the self unlocking linking member 50 (Fig. 5). Such amember 50 includes arelease rod 51, slidably mounted insidepush rod 38. Thisrelease rod 51 is kept stationary in a stable position and includes abutt 52 engaged inside theend portion 39 to control the radial extension of the resilientlyretractable locking fingers 53, housed in theend portion 39, which constitute the adaptation nose in thecomplementary housing 54 formed on the top oftop plug 33b. In the radial extension position,fingers 53 are engaged in a matching groove insidehousing 54. - The
release rod 51 is kept stationary in a stable position, either simply by gravity or by means of apin 55 passing through thelaunch tube 30, as appears from Fig. 5.Pin 55 is of the shearing pin type and has a smaller mechanical strength than the stoppingmeans 40b. Preferably, therelease rod 51 includes ahead 56 with twopins 57 passing through axialoblong guiding holes 58 formed in thepush rod 38. Thepins 57 are externally projecting out of thepush rod 38, so that they can cooperate with theabutment rim 42 as explained hereafter. - For the purpose of a cementing operation, the remote launching equipment described above is operated as follows.
- When the
bottom plug 33a must be launched, starting with the conditions illustrated in Fig. 3, tap 23 is closed,tap 24 is open, so thatcircuit 13 supplies a pressurized fluid into that portion ofchamber 12 limited bydarts - The retractable stopping device 19a is retractably controlled to release
dart 14a which is propelled inside thedrill pipe 9 by the fluid pressure which insures its propagation.Dart 14a is then lead to engage insidechamber 45 where a seal is established by therear buffer 18. -
Dart 14a is brought into contact withpiston 37, so as to trigger the operation of thelaunching device 36. From that position, as illustrated in Fig. 6, the sealingbuffer 18, which exerts its function with thechamber 45, blocks the circulation of the fluid through theholes 43, which creates a pression increase upstream of the dart. The fluid pressure inside thedrill pipe 9 then rises until it reaches the triggering threshold of the limitedstrength stopping means 40a. - When the triggering of
means 40a has been effected, thedart 14a, under effect of the pressure developped upstream in the drill pipe, pushes the launchingdevice 36. Therod 38 pushestop plug 33b which expulses plug 33a out ofbasket 31. The expulsion ofbottom plug 33a, as illustrated in Fig. 7, is effected when thelaunching device 36 reaches the intermediate stable position caused by the stoppingmeans 40b provided, by structure, to oppose a higher strength than the stopping means 40a do, in order to allow differentiating at the time of surface pressure control. In this position, pins 57 are disposed close to therim 42. - As visible in Fig. 7, the expelling of the
bottom plug 33b out ofbasket 31 releases the prestress imposed upon theperipheral lips 35 which widen out to cooperate with the internal wall ofcasing 4. In this position, thedart 14a uncovers the transfer passages at the basis ofchamber 45, so that the pressurized fluid fills theinternal casing 4 and insures the launching and propulsion ofbottom plug 33a which has to scrape and clean the internal surface ofcasing 4 and prevent any mixture of the fluids. - At the end of the run inside
casing 4,bottom plug 33a insures a tight closure, so that the fluid pressure incasing 4 increases until it causes a perforation oflid 60 which closesplug 33a, as is well known in the art. - When the desired quantity of cementing fluid has been pumped, the operator closes
tap 24 and openstap 25 after he has released theretractable stopping device 19b. A propelling fluid is delivered intocircuit 13 to propeldart 14b, thetop lips 16 of which insure a cleaning ofchamber 12 anddrill pipe 9.Dart 14b then enterschamber 45 to contactdart 14a which has to trigger, for the second time, the operation of launchingdevice 36. The propelling fluid pressure increases until it causes the rupture of the second stage stopping means 40b to release the axial sliding ofdevice 36, as illustrated in Fig. 8. Pushrod 38 expels plug 33b out ofbasket 31, which causes, as illustrated in Fig. 9, the various lips to widen out in succession. - At the beginning of this axial movement, pins 57 abut against
rim 42. The axial sliding ofrod 38 causes the rupture ofpin 55 and is operated without the releasing rod, maintained in axial position, accompanying it. The axial movement ofpush rod 38 consequently causes the relative retraction ofbutt 52, so thatfingers 53 resiliently retract to cause automatic unlocking ofbutt 52 fromhousing 54. - At the end of the expulsion,
dart 14b uncovers thepassages 43 ofchamber 45, so that the fluid, transferred from the drill pipe and launchtube 30 towardsinternal casing 4, takes alongtop plug 33b launched frominternal casing 4. - As appears from above, the equipment according to the invention allows a control of the launching of a plug, being in a waiting position at the entrance of the drill well, remotely from the rig from which the dart releasing system operates. Such a launching is performed in a precise manner for each plug, due to the controllability of an effective launching through an appreciation of the pressure peak corresponding to the ruptures in succession of stopping
means - Another advantage of the equipment results from the simple production and assembling, resulting from the initial assembling under prestress of plugs 33 inside
basket 31, the diameter of which is smaller than that ofcasing 4. This allows eliminating the frictions imposed upon the lips in the traditional assemblies. - An additional advantage of the invention resides in the fact that the plugs used are of the same design as those used in surface cementing techniques. cf EP-A-377 255.
- An additional advantage resides in the fact that darts 14 remain included in
launch tube 30 and consequently can be recovered for a new use.
Claims (10)
- Equipment for remote launching of plugs (33) for cementing sub-sea drilled wells (1), of the type comprising, starting from the bottom, a first casing (3) sunk into the well to emerge from the bottom, a casing hanger (8) mounted on the first casing, an internal casing (4) hanging from the hanger,a ring shaped installation tool (7) mounted on the hanger, a drill pipe (9) extending upwards from the installation tool to emerge from the water and be attached to a working structure or rig (2), a launching system (10), mounted onto the drill pipe and containing at least one launcher or dart (14), axially held by a retractable stopping device (19) and at least one plug (33) kept stationary inside the internal casing while it waits for its percussion launching by the cementing head dart, including a remote launching head (6) provided inside the internal casing (4) and characterized in that it comprises:
a launch tube (30), partly communicating with the inside casing and extending, coaxially with the drill pipe, downwards from the installation tool,
a basket (31) secured at the launch tube bottom part, with a cross section smaller than that of the internal casing, open at its bottom end and containing at least one plug (33) with peripheral lips (35), axially kept stationary inside the basket by its radially prestressed lips,
a launching device (36), sliding inside the launch tube and including an axial push rod (38), which cooperates with the plug, and a piston (37) integral with the rod, axially kept stationary in the tube by a limited strength stopping means (40) and designed for an axial movement, caused by a pressure effect exerted by the arrival of the dart, coming from said release system, at the level of the sliding launching device inside the tube on a limited axial run, to insure expulsion of the plug out of the basket. - Equipement according to claim 1, characterized in that:- the dart release system (10) includes at least two darts (14a, 14b),- the basket (31) contains at least a bottom plug (33a) and a top plug (33b) kept stationary in mutual contact and being mutually superimposed,- the launching device (36):. is linked through a self unlocking linking system (39) with the top plug,. is associated with at least two stages (40a, 40b), of limited strength stopping means,- the launch tube (30) includes transfer passages (43) located just above the first stage.
- Equipment according to claim 2, characterized in that the limited strength stopping means stages (40) are mutually spaced by an axial distance equal to the respective length of the plugs (33), which in turn is related to the dart length (14).
- Equipment according to claim 2 or 3, characterized in that the stopping means, at each successive stage, exert a strength which grows from the launch tube top to its bottom.
- Equipment according to any of claims 2 to 4, characterized in that the first stopping means stage is located at an axial distance, from the launch tube top end, at least equal to a dart length.
- Equipment according to claim 5, characterized in that the launch tube comprises, between the top end and the transfer passages (43), an axial bore defining a sealed sliding chamber (45) for the dart(s).
- Equipment according to claim 2, characterized in that the self unlocking linking member (40) includes a release rod (51) slidably mounted inside the push rod (38), stationarily kept in position and externally forming a butt (52) controlling the extension of the resiliently retractable locking fingers (53) born by the assembling nose (40) which butt is mounted on the push rod (38) to cooperate with the complementary housing (54) formed in the top plug (33b).
- Equipment according to claim 7, characterized in that the releasing rod (51) includes, at its top part, projecting pins (57) guided in and passing through axial oblong holes (58) of the push rod (38) and able to butt cooperate with the rim of a ring (42) formed by the bottom end part of the launch tube (30).
- Equipment according to claim 1, characterized in that the tube (30) includes equal distribution holes formed between the passages (43) and the basket.
- Equipment according to claim 8 or 9, characterized in that the launch tube (30) includes, at its basis, axial equal distribution grooves formed in the ring (42).
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
FR9003129 | 1990-03-07 | ||
FR9003129A FR2659386B1 (en) | 1990-03-07 | 1990-03-07 | REMOTE LAUNCHING EQUIPMENT FOR CEMENTING SUBMARINE WELLS. |
Publications (2)
Publication Number | Publication Date |
---|---|
EP0450676A1 EP0450676A1 (en) | 1991-10-09 |
EP0450676B1 true EP0450676B1 (en) | 1995-06-07 |
Family
ID=9394634
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP91200447A Expired - Lifetime EP0450676B1 (en) | 1990-03-07 | 1991-03-02 | Equipment for remote launching of cementing plugs into subsea drilled wells |
Country Status (7)
Country | Link |
---|---|
EP (1) | EP0450676B1 (en) |
CN (2) | CN1054644A (en) |
CA (1) | CA2037681C (en) |
DE (1) | DE69110174T2 (en) |
FR (1) | FR2659386B1 (en) |
NO (1) | NO301658B1 (en) |
SA (1) | SA91110354B1 (en) |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5890537A (en) * | 1996-08-13 | 1999-04-06 | Schlumberger Technology Corporation | Wiper plug launching system for cementing casing and liners |
US6009944A (en) * | 1995-12-07 | 2000-01-04 | Weatherford/Lamb, Inc. | Plug launching device |
US6244350B1 (en) | 1996-12-06 | 2001-06-12 | Weatherford/Lamb, Inc. | Apparatus for launching at least one plug into a tubular in a wellbore |
Families Citing this family (11)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US7255162B2 (en) * | 2004-05-07 | 2007-08-14 | Halliburton Energy Services, Inc. | Methods and apparatus for use in subterranean cementing operations |
US7665521B2 (en) | 2007-04-11 | 2010-02-23 | Bj Services Company | Safety cement plug launch system |
EP2199537A1 (en) | 2008-12-22 | 2010-06-23 | Services Pétroliers Schlumberger | Apparatus and Method for Launching Plugs in Cementing Operations |
US8316931B2 (en) | 2009-09-03 | 2012-11-27 | Schlumberger Technology Corporation | Equipment for remote launching of cementing plugs |
US8327930B2 (en) | 2009-09-24 | 2012-12-11 | Schlumberger Technology Corporation | Equipment for remote launching of cementing plugs |
EP2317065A1 (en) * | 2009-10-30 | 2011-05-04 | Services Pétroliers Schlumberger | Equipment for remote launching of cementing plugs |
US8327937B2 (en) | 2009-12-17 | 2012-12-11 | Schlumberger Technology Corporation | Equipment for remote launching of cementing plugs |
US8789582B2 (en) | 2010-08-04 | 2014-07-29 | Schlumberger Technology Corporation | Apparatus and methods for well cementing |
WO2013133796A1 (en) * | 2012-03-06 | 2013-09-12 | Halliburton Energy Services, Inc. | Deactivation of packer with safety joint |
CN105294090A (en) * | 2015-10-28 | 2016-02-03 | 国家电网公司 | Special ceramic matrix of power cable clamp and production process of special ceramic matrix |
CN114155992A (en) * | 2021-11-29 | 2022-03-08 | 航天特种材料及工艺技术研究所 | High-adhesion conductive silver paste for ceramic matrix composite and preparation method thereof |
Family Cites Families (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
FR2641318B1 (en) * | 1989-01-02 | 1991-04-12 | Schlumberger Cie Dowell | OIL WELL CEMENTING HEAD |
-
1990
- 1990-03-07 FR FR9003129A patent/FR2659386B1/en not_active Expired - Fee Related
-
1991
- 1991-03-02 DE DE69110174T patent/DE69110174T2/en not_active Expired - Fee Related
- 1991-03-02 EP EP91200447A patent/EP0450676B1/en not_active Expired - Lifetime
- 1991-03-06 NO NO19910884A patent/NO301658B1/en not_active IP Right Cessation
- 1991-03-06 CA CA002037681A patent/CA2037681C/en not_active Expired - Lifetime
- 1991-03-07 CN CN91101384A patent/CN1054644A/en active Pending
- 1991-04-29 CN CN91102672A patent/CN1026351C/en not_active Expired - Fee Related
- 1991-05-14 SA SA91110354A patent/SA91110354B1/en unknown
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6009944A (en) * | 1995-12-07 | 2000-01-04 | Weatherford/Lamb, Inc. | Plug launching device |
US5890537A (en) * | 1996-08-13 | 1999-04-06 | Schlumberger Technology Corporation | Wiper plug launching system for cementing casing and liners |
US6244350B1 (en) | 1996-12-06 | 2001-06-12 | Weatherford/Lamb, Inc. | Apparatus for launching at least one plug into a tubular in a wellbore |
Also Published As
Publication number | Publication date |
---|---|
CA2037681A1 (en) | 1991-09-08 |
NO910884L (en) | 1991-09-09 |
DE69110174T2 (en) | 1996-02-01 |
DE69110174D1 (en) | 1995-07-13 |
CA2037681C (en) | 2001-09-04 |
SA91110354B1 (en) | 2004-09-04 |
FR2659386B1 (en) | 1992-06-26 |
EP0450676A1 (en) | 1991-10-09 |
NO910884D0 (en) | 1991-03-06 |
FR2659386A1 (en) | 1991-09-13 |
CN1054644A (en) | 1991-09-18 |
NO301658B1 (en) | 1997-11-24 |
CN1054824A (en) | 1991-09-25 |
CN1026351C (en) | 1994-10-26 |
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