US3448802A - Apparatus for well completion,cementing,circulating and production - Google Patents

Description

June 10, 1969 S. PAGE L COMPLETION, CEMENTING, CIRCULATING AND PRODUCTION Maa' Sheet La lq.

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United States Patent Office 3,448,802 Patented June 10, 1969 3,448,802 APPARATUS FOR WELL COMPLETION, CEMENT- ING, CIRCULATING AND PRODUCTION John S. Page, Lakewood, Calif., assignor, by mesne assignments, to Cook Testing Co., Long Beach, Calif., a

corporation of California Filed Mar. 30, 1967, Ser. No. 627,263 Int. Cl. E21b 33/03 U.S. Cl. 166--67 12 Claims ABSTRACT OF THE DISCLOSURE The disclosure concerns apparatus and method for controllably cementing a well during completion, and for controllably heating sub-surface equipment in a p roducing well. Multiple concentric pipe strings are installed in the well and utilized to flow cement flushing liquid in opposite vertical directions during completion, and to flow heating liquid in opposite vertical directions for heating sub-surface equipment during production of the well. The method and apparatus associated with use of such strings involve particularly advantageous and unusual steps and structure.

BACKGROUND OF THE INVENTION This invention relates -generally to oil and gas well completion and operation, and more particularly concerns apparatus and method for controllably cementing a well during completion and for controllably heating sub-surface equipment in a producing well.

During well completion it may become necessary to seal off against water leakage into casing, as for example from the underwater formation at the bottom or side of the casing during off-shore well completion, or during completion on land. In such event it is desirable to minimize the height of vthe cement column which must be subsequently drilled through, during well completion, while at the same time applying suiiicient cement throughout a vertical extent in the well as to assure against leakage; however, these objectives are difficult to realize simultaneously as they tend to become mutually exclusive.

Also, during production of certain wells, as for example gas wells, it is desirable to flow the fgas or well fluid through a sub-surface safety valve, or control valve, which will decrease the upward flow either automatically in the event of damage to the string above the valve, or under the control of a surface operator. Such valves include ow restrictions which produce throttling and consequent cooling in the case of pressurized gas flow. Prolonged cooling may result in ice formation at the valve and consequent malfunctioning.

SUMMARY OF THE INVENTION Major objects of the invention include the provision of method and apparatus to overcome the above problems. Basically, and as regard the problem of cementing control, the method steps of the invention include introducing cement slurry to the interior of a pipe string contained within the casing; introducing mud to the interior of the pipe string above the cement and traveling the mud downwardly therein for transmitting force driving the cement to flow downwardly to predetermined lower level within the pipe string and also to ow upwardly within the annulus between the pipe string and the well bore; and circulating flushing liquid in opposite vertical directions within the interiors of the pipe string and the annulus and also laterally between those interiors at predetermined upper level in the well, thereby to llush cement slurry from the annulus above the upper level. Additionally, the method may typically include the steps of establishing a solid barrier between the mud and cement in the pipe string as when mud is introduced into the string, so that the barrier may travel downwardly in the string in response to mud travel; interrupting mud travel downwardly in the string by landing the barrier within the string at the above-mentioned lower level; and blocking upward displacement of the landed barrier during the circulation step, whereby the cement upper limits are maintained at lower level in the pipe string and at upper level in the annulus.

Further steps may include introducing a check valve unit into the interior of the pipe string above the barrier and oriented to pass mud downwardly while blocking mud flow upwardly therethrough; traveling the check valve downwardly in the string in response to mud travel; and landing and locking the check valve proximate the above-mentioned upper level prior to landing of the barrier at predetermined lower level, whereby the landed check valve unit may pass mud downwardly therethrough to facilitate landing of the barrier while blocking upward displacement of the barrier and of mud below the check valve during the circulation step. After the cement hardens, drilling may be effected downwardly through the check valve, mud, barrier and cement therebelow, to open up the pipe string interior.

The check valve unit itself may typically comprise a tubular body sized to travel downwardly in the string, the body having -a downwardly facing annular seat and forming a vertical passage to pass well Huid downwardly through the body; outwardly urged latch means on 'the body for latching reception in annular grooving formed in the pipe string bore when the body arrives at landing position proximate the string side porting; a check valve carried by the body to move vertically relatively toward and away from the seat for passing uid downwardly through the passage lbut blocking fluid ow upwardly therethrough; and other valving means such as an elastomer sleeve supported by the body to control fluid ilow through the string side porting when the body is landed.

Regarding the method of operating the well, the invention contemplates installation of a tubing string and a valve downwardly within the pipe string interior; owing well lluid upwardly within the pipe string and through the valve, the lluid including gas which expands and cools in flowing through the valve; and circulating hot heat transfer fluid in opposite vertical directions within the pipe string and within the annulus between the well bore and pipe string to bring the hot fluid in heat transfer contact with the exterior of the tubing string proximate the valve. Additional steps may typically include initially sealing o the annulus between the pipe string and the well bore below a predetermined level, as for eX- ample by the cementing operation described above; and packing off between the tubing string and pipe string, whereby heat transfer fluid vertical circulation may be confined above the packed o and sealed off locations in the well; and operating the sub-surface Valve by transmitting a change in control fluid pressure downwardly in one of a pair of concentric tubing strings, thereby to control production fluid ow upwardly through the valve into the other of the concentric tubing strings, both of which are installed within the pipe string.

These and other objects and advantages of the invention, as well as the details of illustrative embodiments, will be more fully understood from the following detailed description of the drawings, in which:

BRI-EF DESCRIPTION OF THE DRAWINGS IFIGS. l, la, lb, and 1c show vertical sections of the well during pipe string installation and cementing;

FIGS. 2, 2a, 2b and YZc show vertical sections of the well during well production through the tubing string installed within the pipe string; and

FIGS. 3 and 4 are horizontal section taken on lines 3-3 and y4-4 repectively of FIG. la.

Referring tirst to FIGS. 1, 1a, 1b and 1c, a well head is indicated `at above surface 11, which represents the water surface, or land, or other well head equipment. Projecting downwardly from the head is outer casing string 12 which in an off-shore installation would extend to and below the ocean iioor. Also projecting below the head 10 is an inner casing string 13, referred to later as the first pipe string, the string 13 being spaced from the string 12 to form an annulus or zone 14 therebetween. Well head equipment associated with the strings includes a tubular section 15 attached at 16 to string 12, and a tubular section 17 attached at 18 to string 13 and sealing off the top of annulus 14 at 19. The two sections have side ports indicated at 20 and 21 through which flow may be established, as will be described. Also, the string 13 has side porting 22 in the form of circularly spaced, annularly narrow, vertically :elongated slots, at a predetermined upper sub-surface level (seen in FIG. 1a) to communicate between the exterior and interior of string 13, to pass circulating ush liquid, or heat transfer liquid, as will be described.

Generally speaking, the pipe string or inner casing 13 is shown in FIGS. 1b and 1c to contain three elements, these being a plug or solid barrier 23, a check valve unit 24 above the plug, and other valving means indicated -at 25. In this regard, the plug 23 is inserted into the string 13 via the top 26 thereof, and is movable relatively downwardly to landed position as shown in FIG. 1c for displacing cement slurry downwardly in the string. The plug is urged downwardly by mud pumped into the string 13 above the plug via inlet port 21, a mud source, pump and control valve being indicated at 27, 28 and 29. Before the plug is thus driven downwardly, cement slurry is pumped into the string as via source 30, pump 31, control valve 32, and port 21. The plug may comprise a wooden body 33 sized to loosely it the bore of the string 13 to be landed on a baffle ring 34 at a predetermined lower elevation in the string. Ring 34 is retained between the terminals of two pipe sections interconnected by collar 35, the string including other collars as shown. A flexible elastomer cup 36 carried by the plug opens upwardly and has a skirt 36a sealing against the pipe bore 37 in response to down pressure exertion by mud indicated by arrow 38 in FIG. lc.

Mud introduced to the string 13 above the plug ltravels downwardly in response to pumping for transmitting force driving all the cement 39 to flow downwardly past a predetermined lower level (at ring 34) within the pipe. Cemen-t is thereby forced to flow upwardly within the annulus 14 as indicated at 39b in FIG. lc, along the path indicated by arrow 40 extending beneath the tapered lip or shoe 41 at the bottom of pipe 13. The shoe may typically be lowered into soft shale above sandstone in the well.

The check valve unit 24 is inserted into the string 13 via the top 26 thereof, after insertion of plug 23, and is movable relatively downwardly to landed position by mud pumped into the string. Unit 24 is oriented to pass mud relatively downwardly therethrough while blocking mud flow relatively upwardly particularly after the unit is landed. Such landing is effected by reception of outwardly urged latch dogs 44 on body section 45b into annular grooving 46 formed in thebore 47 of the tubular sub 48 connected in the string 13, the sub including interconnected sections 48a and 48b. Dogs 44 are carried peripherally of the body section 45b in radial guide recesses 49, and they are urged outwardly by springs 50.

Further, body is tubular and has a passage 51 to pass mud downwardly. Also on the body is a downwardly facing annular seat 52 for receiving a ball check valve Cit 53 `in up position as seen in FIG. la, closing olf upward flow of mud. Thus, the column of mud between closed ball check valve 53 and the plug 23 is trapped against either upward or downward displacement. Mud ows (as illustrated by arrow 55) into the trapping column zone vi'a the unit 24 with ball 53 in open or down position indicated by broken line position 53a. At that time, the ball is off the seat, but is retained by a pin 54 extending transversely across the passage enlargement 51a. To complete the description of unit 24, an elastomer wiper ring 56 is reta-ined on the body at 57, and opens downwardly to remove cement from the string bore during downward travel of the unit 24. A packer annulus 58 on the body seals against the string bore 13 to prevent leakage of mud downwardly past the unit 24.

The above referred to other valving means 25 is movable relatively downwardly in the pipe string 13 in chasing relation to the check valve unit to land at a position for controlling iiushing liquid flow through the string side porting. Assurance of correct landing position may be achieved by mounting the valving means 25 on the unit 24 at 60 as seen in FIG. 1a, wherein the valve 25 is seen to comprise an elastomeric sleeve 25a opening upwardly and loosely fitting the bore 61. The sleeve is adapted to flex away from and toward the side porting tov admit flushing liquid inflow to the pipe interior, and to block outflow through the side porting, respectively.

It will be noted that the cement upper level 65 in the annulus 14 in FIG. la is proximate the predetermined upper level defined by side porting 22. Any cement forced above that level by the plug 23, as well as any mud in pipe string 13 above the porting 22, is flushed out and removed from the pipe and casing in accordance with the method of the invention, as follows. Broadly, flushing liquid is circulated in opposite vertical directions within the interiors of the pipe string and annulus, and also between those interiors via porting 22, until the cement and mud above porting level 22 are removed. As a consequence, the pipe string is opened up and freed of excess mud above valve 25; also, and more importantly, a path is cleared for circulation of heat transfer uid, as will later be explained. In this regard, a source indicated at I66, supplies ilush liquid via pump 67 and valve 68 for entry at 20 into the annulus 14, downiiow in the annulus and iiow inwardly via porting and past sleeve 25a to the interior of pipe string 13, the sleeve deflecting inwardly as' indicated by broken lines 2517. The ilush liquid then flows upwardly in string 13 for removal via port. 21 to a receptacle 1-51 via valve 152.

Sleeve 25a in position seen in 1a prevents outflow of mud to the annulus 14 during mud pressurization to low downwardly through the check valve unit 24. Before the sleeve arrives at the position shown, i.e. while unit 24 is traveling downwardly to force cement down the pipe 13, cement can escape through porting 22 into annulus 14; however, any such excess cement is removed by the circulation of liushing liquid as described. As is clear, the down pressure of flush liquid in the annulus cannot displace cement to flow reversely below level 65, since the plug 23 is blocked against upward travel by the mud column trapped between the plug and the closed check valve unit 24.

Following the circulation step, the cement slurry is allowed to harden or set; thereafter a rotary drill indicated at 168 in FIG. 1 is lowered and operated to cut through the check valve unit, mud, plug and cement to open up the pipe string interior for well completion, including installation of a production tubing string in the well. Ususally, the cement zone is tested for leaks, as an auxiliary step, prior to drilling completely through the cement.

The method of operating the well in accordance with the invention basically includes installing a valve along with the tubing string downwardly within the pipe interior, then flowing well fluid upwardly within the pipe string and through the valve, the lluid including gas which expands and cools in flowing through the valve, and finally circulating hot heat transfer uid in opposite vertical directions within the pipe string 13 and within the annulus 14 to bring the hot fluid in heat transfer contact with the exterior of the tubing string proximate the valve to prevent valve freezing. Additionally, the space between the tubing string and piping 14 is packed olf, to facilitate such circulation.

With regard to the above method, reference is made to FIGS. 2, 2a, 2b and 2c showing a tubing string 80 installed within pipe string 13, a valve 81 being located in the tubing string proximate the level of side porting 22 in FIG. 2a. Hot heat transfer liquid circulating means is shown in FIG. 2 as including source liquid 84 owing through valve 85 and port 21 to the interior 86 of string 13, downwardly past the valve 81 and then outwardly through side porting 22, and then upwardly in the annulus 14 to exit at 87 via port 20 and valve 88. Note in FIG. 2b the provision of a packer 89 sealing off the annulus 90 between the tubing and the string 13, below side porting 22.

Referring to FIGS. 2 and 2a, it will be noted that the tubing string 80 includes inner and outer concentric tubing strings 92 and 93 which extend above the level of the valve 81. The inner string 92 includes a head 94 which seals at 95 against a cap 96 at the well head. Likewise, the outer string 93 includes a head 97 which seals at 98 against an orifice plate 99 at the well head. A single string section 100 of the tubing string 80 extends below the valve 81, and it will be understood that the well is produced upwardly through the string 100 and into one of the concentric strings previously mentioned above the valve. In the form of the invention shown, the produced Iluid ows upwardly through the valve to the inner concentric string 92 and is discharged through a valve 101 at the well head. On the other hand, the safety valve 81 is operable in response to a change in control fluid pressure transmitted downwardly within the outer concentric string 93. Thus, for example, uid pressure is controlled from a source 102 through a valve 103 to the inlet port 104 of a head section 105 attached to the section 17 as indicated. Such control pressure enters the top of the outer concentric tubing at 106 for communication of control pressure changes to the valve.

The illustrated valve means includes a sub `body 119 having interiorly threaded pin and box ends 120 and 121 respectively connected to the lower and upper strings 100 and 92. The body itself includes interconnected tubular sections 11921, 119b and 119C, and the outer concentric string 93 is connected to the body at 122. Control pressure is applied from the interior 117 of the outer string, and via side port 123 in the body section 119b, to a chamber 124 formed by the body and an axially movable valve sleeve 125. Such pressure exerted on piston surface 126 tends to urge the sleeve downwardly in a direction to displace the sleeve skirt 127 from closed position to open position as seen in FIG. 2a. The skirt in up position closes olf across of production tiuid ow to a by-pass channel 129 via an entrance side port at 130, whereas when that port is open the flow passes upwardly in the channel 129, the ow re-entering the interior of the sub ybody at 131 above a plug 132, for upward ow in inner string 92.

Plug 132 seals at 133 against the bore 134 of the cylindrical insert 135 suitably attached to the sub as by circularly spaced vertical webs 136. In this regard, the plug may be introduced to the inner string 92 and lowered by wire line attached to plug nipple 137, for releasable attachment to the valve interior. Such attachment may be effected by reception of lugs 138 (on collect spring fingers 139) into the annular groove 140 formed by the insert 135. The plug is retrievable as by connection of a wireline lowered cup onto the spring nger serrated terminals 141, to collapse the fingers inwardly releasing the lugs from groove 140.

A helical spin 142 retained Iby sub section 119e urges the valve sleeve upwardly at 143, tending to maintain the port closed. Such closing action can be overcome by exertion of sulicient control fluid pressure downwardly in the outer concentric string 93, to open the valve; conversely, the valve can be closed by reducing the control fluid pressure exerted at 126.

Referring now to FIG. 2b, it will be seen that the packer 89 is carried by a tubular body 200 connected in the string 100 at upper and lower locations 201 and 202. The packer is expansible to seal off against the bore 203 of the pipe 13 in response to uid pressure operation of an actuator mechanism. The latter includes a piston 204 on a sleeve 205 carried by the body at 206 to receive application of uid pressure from within the string via side port 207. The piston moves upwardly to displace slips 208 upwardly, thereby urging the downwardly tapering cone 209 in an upward direction, the cone being mounted at 210 on the body. As the cone -moves upwardly, it displaces another sleeve 211 upwardly to urge the packer compressing ring 212 in an upward direction whereby the packer is com-,l pressed and expanded. At the same time, the slips 208 are urged outwardly by engagement with the cone surface 213, whereby the slip wickers 214 engage the pipe bore 203 for anchoring and supporting the string in the well. In this regard, inasmuch as the packer 89 seals olf the annulus 215 between the lower string 100 and the pipe 13, the heat transfer uid cannot drain below the packer in the well. Also, the heat transfer fluid cannot drain below the top level 217 of the cement as seen in FIG. 2a.

Finally, provision is also made for producing well uid upwardly through the annulus 215 and the annulus 86, and outwardly from the port 21. For this purpose, such flow may be caused to by-pass the packer 89 through ports 218 and 219 as seen in FIG. 2b', then upwardly through the channel 220 and outwardly through port 221 into the annulus 215. The channel 220 is formed between the body sleeve 222 and a sleeve valve 223 which may be shifted into and out of blanking relation to the port 219. As illustrated, the sleeve valve section 224 blanks the port 219 to prevent such flow; however, the valve may 'be shifted downwardly to open communication between the port 219 and channel 220, at which time the lugs 225 on the spring fingers 226 are receivable in grooving 227 in the body. When the valve sleeve is in up position as shown, the finger lugs are blocked at 228 against downward displacement. Shifting of the sleeve valve downwardly may be achieved by dropping a ball indicated at 230, into engagement with the top of the sleeve and pressuring down the string as from a pressure source indicated at 231 in FIG. 2, valve 101 then being closed. To raise the sleeve, a ball may be dropped in the inner string to land at shoulder 233 in the body 200V thereby closing the passage 234. Pressurization of the inner string then urges the sleeve valve upwardly to the position shown in FIG. 2b. See in this regard U.S. Patent No. 3,299,955.

I claim:

1. In combination in a well having a bore,

a pipe string having side porting to communicate between the exterior and interior of the string,

a plug movable relatively downwardly in the pipe string below mud introduced therein for displacing cement slurry downwardly in the string,

means for landing said plug at a lower landed position in said pipe string,

a check valve .unit positioned in the pipe string above said plug and movable relatively downwardly in the pipe string in chasing relation to the plug and means for landing said valve unit in the pipe string at an upper landed position below and proximate said pipe string side porting, the check valve unit -being operable to pass mud downwardly therethrough but to block upward flow of mud therethrough,

and other valving means positioned in said pipe string above said check valve unit and movable relatively downwardly in the pipe string in chasing relation to the check valve unit, said other valving means having means for permitting ushing fluid ow through said string side porting into said pipe string while preventing fluid ow from said pipe string through said porting when said check valve unit is landed in said pipe string and said other valve means is landed above said check valve unit.

2. The combination of claim 1, wherein the check valve unit has latching interengagement with the pipe string at said upper landed position.

3. The combination of claim 2, wherein the check valve unit includes a tubular body, outwardly urged latch means on the body for latching reception in annular grooving formed in the pipe string bore, the body having a downwardly facing annular seat and forming a vertical passage to pass mud downwardly therethrough, and a check valve retained by the unit for vertical movement relatively toward and away from the seat.

4. The combination of claim 3, in which said other valving means comprising an elastomeric sleeve mounted on said -body to flex toward and away from said string side porting to admit flushing liquid viniow to the pipe interior and to block outflow through said side porting.

5. The combination of claim 1, in which said other valving means is mounted on the check valve unit.

6. The combination of claim 1, including a landing shoulder on the string exposed interiorly thereof at said lower landed position to interrupt downward movement of the plug.

7. The combination of claim 1, including means at the well head to circulate llushing liquid in opposite vertical directions in the well at the exterior and interior of the pipe string with ow through said side porting.

8. The combination of claim 7, including cement positioned in the annulus between said pipe string and the well bore below said porting which also seals off between the pipe string and the well bore.

9. The combination of claim 1 including a string of A conductor pipe forming said well bore.

10. Por use in a well pipe string having side porting to communicate between the exterior and interior of the string, a valve unit movable relatively downwardly in the string in chasing relation to a plug, comprising a tubular body sized to travel downwardly in the string,

the body having a downwardly facing annular seat and forming a vertical passage to pass well fluid downwardly therethrough,

outwardly urged latch means on the body for latching reception in annular grooving formed in the pipe string bore when the body arrives at landing position proximate said string side porting,

a check valve carried by said body to move vertically relatively toward and away from said seat for passing fluid downwardly through the passage but blocking fluid upwardly therethrough,

and other valving means supported by said body above said check valve, said other valving means having means to permit fluid flow into said pipe string through said string side porting and to prevent uid How from said pipe string through said porting when the body is landed at said position.

11. The valve unit as dened in claim 10, wherein said latch means comprise latch dogs carried peripherally of the body and springs urging the dogs radially outwardly relative to the body.

12. The valve unit as defined in claim 10, in which said other valving means comprises an elastomer sleeve mounted on the body to ex toward and away from said string side porting to admit flushing liquid inflow to the pipe interior and to block outflow through said side porting.

References Cited UNITED STATES PATENTS 2,058,688 10/1936 Halliburton 166-155 X l 2,223,442 12/ 1940 Crowell 166-26 2,762,440 9/1956 Reed 166 21 X 2,859,826 11/1958 Eckel 166-224 X 2,864,449 12/1958 Tausch 166-224 X 3,159,219 12/1964 Scott 166-156 3,213,940 10/1965 Wood 166-28 X 3,276,523 10/1966 Oliver 166-224 X 3,332,498 7/1967 Page 166-224 3,364,996 1/1968 Brown 166-155 X CHARLES E. OCONNELL, Primary Examiner.

IAN A. CALVERT, Assistant Examiner.

U.S. Cl. X.R.

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