INSERTABLE SURFACE-DRIVEN PUMP

Abstract

Wellbore tubing having an annular seating member and an annular anti-rotation member can be used for one or more types of surface driven submersible pumps. In one embodiment, a stator and a rotor of a surface driven progressing cavity pump can be inserted into the tubing after the tubing is deployed. In one embodiment, a surface driven reciprocating pump can be inserted into the tubing, later withdrawn from the tubing, and then a progressing cavity pump can be inserted into the same tubing.

Description

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to provisional application 61/347,303, filed May 21, 2010, incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an apparatus and method for securing an insertable pump in a wellbore. More specifically, the invention relates to limiting axial and rotational movement of surface driven wellbore pumps.

2. Description of Related Art

Surface driven progressing cavity pumps employ a rotor and a stator to pump fluid from a wellbore. The stator is affixed to the wellbore tubing and deployed into the wellbore along with the tubing. After the tubing is deployed, the rotor is inserted through the tubing, on a drive rod, into the stator. A motor located on the surface of the earth rotates the drive rod, which in turn rotates the rotor within the stator. Cavities are formed between the rotor and stator, and as the stator rotates, fluid enters the cavities and is progressed toward the surface of the earth.

The stator can be a resilient material that is susceptible to heat damage. Therefore, it is not desirable to use the progressing cavity pump in high temperature environments, such as during steam flooding. Rather, surface driven reciprocating pumps are more suitable to operate in high temperature environments. Operators may want to use, for example, a progressing cavity pump when the field is relatively cool, and a reciprocating pump when the temperature increases. Therefore, it is desirable to be able to efficiently withdraw one type of pump and replace it with the other.

BRIEF DESCRIPTION OF THE DRAWINGS

So that the manner in which the above-recited features, aspects and advantages of the invention, as well as others that will become apparent, are attained and can be understood in detail, more particular description of the invention briefly summarized above may be had by reference to the embodiments thereof that are illustrated in the drawings that form a part of this specification. It is to be noted, however, that the appended drawings illustrate only preferred embodiments of the invention and are, therefore, not to be considered limiting of the invention's scope, for the invention may admit to other equally effective embodiments.

FIG. 1 is a partial side sectional view of an embodiment of an insertable rod driven pump latching device located in tubing.

FIG. 1A is a detailed and partial cutaway view of FIG. 1 of the insertable rod driven pump of FIG. 1.

FIG. 2 is a sectional view of the anti-rotation ring of the insertable rod driven pump of FIG. 1, taken along the 2-2 line.

FIG. 3 is a perspective view of anti-rotation mechanism fingers of the progressing cavity pump insert system of the insertable rod driven pump of FIG. 1.

FIG. 4 is a sectional view of the anti-rotation mechanism and anti-rotation nipple of the insertable rod driven pump of FIG. 1.

FIG. 4A is a sectional view of the anti-rotation mechanism and anti-rotation nipple of FIG. 4, taken along the 4A-4A line.

FIG. 5 is a side partial sectional view of an alternative embodiment of the insertable rod driven pump latching device of FIG. 1.

FIG. 6 is a side sectional view of an embodiment of an anti-rotation mechanism of the insertable rod driven pump of FIG. 5.

FIG. 7 is a side sectional view of a deployed anti-rotation nipple of the insertable rod driven pump latching device of FIG. 5.

FIG. 8 is a side sectional view of the anti-rotation latching device of FIG. 5 located in the anti-rotation nipple of FIG. 6.

FIG. 8A is a sectional view of the anti-rotation latching device and anti-rotation nipple of FIG. 8, taken along the 8A-8A line.

FIG. 9 is a side partial sectional view of a rod pump inserted into the seating nipple of the embodiment of FIG. 1.

DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS

Referring to FIGS. 1 and 1A, tubing 100 is suspended in a wellbore (not shown). Tubing 100 may be located within the inner diameter of wellbore casing (not shown) and may be filled or partially filled with wellbore fluid. Wellbore fluid may be any kind of fluid including, for example, crude oil, water, gas, liquids, other downhole fluids, or fluids such as water that may be injected into a rock formation for secondary recovery operations. Indeed, production fluid can include desired fluids produced from a well or by-product fluids that an operator desires to remove from a well. Segments of tubing 100 can have threads 102 for connecting to adjacent segments of tubing 100 or other members such as seating nipple 104.

Seating nipple 104 can be an embodiment of an annular member that can restrict axial movement of, and can be used to form a seal with one or more types of submersible pumps. Seating nipple 104 can be deployed on tubing 100. Seating nipple 104 can include upper seating nipple 106. Upper seating nipple 106 can be connected to a segment of tubing 100 by, for example, threads 108 located at one end of upper seating nipple 106. The opposite end of upper seating nipple 106 can also have threads 110 for connecting to lower seating nipple 114.

Seating nipple 104 can also include lower seating nipple 114. Lower seating nipple 114 can have threads 116 for connecting to threads 110 of upper seating nipple 106. Similarly, lower seating nipple 114 can have threads 118 for connecting to another adjacent tubular member. Cup shoulder 120 is an upward facing shoulder on inner diameter 122 of lower seating nipple 114. Seating cup 126, also a part of seating nipple 104, is an annular member, or ring, that engages cup shoulder 120. The inner diameter of seating cup 126 is generally less than the minimum inner diameters of upper seating nipple 106 or lower seating nipple 114. Seating cup 126 can have upper tapered surface 128, which is a chamfer at the upper end of seating cup 126. Tapered surface 128 can have a generally smooth surface for forming a seal against another member. Seating cup 126 can also have lower tapered surface 130, which transitions the diameter from the inner diameter to lower face 132. Lower face 132 can be in a plane that is generally perpendicular to the bore axis.

Anti-rotation nipple 136 can be an embodiment of an annular member, which can also be deployed on tubing 100, that can be used to restrict the rotational movement of various types of submersible pumps. In one embodiment, anti-rotation nipple 136 is deployed just below, and connected to, seating nipple 104. Alternatively, anti-rotation nipple 136 could be above seating nipple 104, or a section of tubing 100 could be located between anti-rotation nipple 136 and seating nipple 104. In one embodiment, anti-rotation nipple 136 can include upper anti-rotation nipple 138, lower anti-rotation nipple 140, and anti-rotation ring 142.

In one embodiment, upper anti-rotation nipple 138 has threads 146 on its inner diameter at one end, for engaging threads 118 of lower seating nipple 114. Upper anti-rotation nipple 138 can also have threads 148 on its outer diameter at the other end. End face 150 can define the lower end of upper anti-rotation nipple 138. In one embodiment, end face 150 is a radial face in a plane that is generally perpendicular to the axis of upper anti-rotation nipple 138.

Like upper anti-rotation nipple 138, lower anti-rotation nipple 140 can have threads 152 on an inner diameter at one end, for engaging threads 148 of upper anti-rotation nipple 138, and lower anti-rotation nipple 140 can have threads 154 at the opposite end for engaging a subsequent tubular member such as, for example, tubing segment 156, or coupling 158. Recess 162 can be located on an inner diameter of lower anti-rotation nipple 140. In one embodiment, upward facing shoulder 164 is located at the lower end of recess 162.

Anti-rotation ring 142 can be an annular ring located in recess 162. Anti-rotation ring 142 can be placed in recess 162 before connecting upper anti-rotation nipple 138 to lower anti-rotation nipple 140. Anti-rotation ring 142 is then retained in the axial direction by upward facing shoulder 164 and end face 150.

Referring to FIG. 2, anti-rotation ring 142 can include ring body 168. One or more keys 170 protrude inwardly from inner diameter 172 of ring body 168 to form radial shoulders 174 for transferring torque. Keys 170 may extend axially along ring body 168. In one embodiment, eight keys 170 are used, but it can be any number of keys 170. In embodiments having more than one key 170, each key 170 is spaced apart from adjacent keys. The space between shoulders 174 of two adjacent keys 170 defines slot 176. Keys 170 may be spaced apart symmetrically or asymmetrically about inner diameter 172. Keys 170 may have a rectangular cross section or may have any other shape. Keys 170 define a circumferential opening within the center of ring body 168.

In one embodiment, anti-rotation ring 142 is formed of an integral tubular member, wherein slots 176 are cut away to reveal keys 170. Alternatively, keys 170 may be welded or otherwise attached to ring body 168. Regardless of the technique used, keys 170 define slots 176.

Referring back to FIGS. 1 and 1A, progressing cavity pump (“PCP”) 180, is a pump for pumping wellbore fluid out of the well. PCP 180 can be inserted in tubing 100 and located in wellbore fluid. PCP 180 includes a stator 182 which is elastomeric and has undulations 184 in its interior. Stator 182 can be located within stator housing 186. Stator housing 186 can be metal or another material. Tag bar 188 can be a nipple or other structure connected to the lower end of stator housing 186.

A helical metal rotor 190 can be adapted to be located within stator 182. Rotor 190 and stator 182 can be of conventional design. Rotor 190 can have an any axial length, and can be longer or shorter than stator 182. The upper end of rotor 190 is secured to a drive rod (not shown), which may have a coupling for connecting the drive rod to rotor 190. The drive rod can extend to the surface and be used for raising or lowering rotor 190, and for rotating rotor 142. The drive rod can be connected to a motor, located on the surface of the earth or otherwise distant from rotor PCP 180. Rotor 190 may be lowered through stator 182 after stator 182 is set in place. Tag bar 188 can prevent the end of rotor 190 from descending too far past stator 182 when rotor 190 is lowered into position. Any device may be used to locate rotor 190 in stator 182.

Latching sealing tool (“LST”) 194 can be used to latch and seal PCP 180 into seating nipple 104. An embodiment of the latching sealing tool, and application thereof, is described in U.S. patent application Ser. No. 12/271,624, incorporated herein by reference. In one embodiment, LST 194 can be a bushing located on the outer diameter of stator housing 186, thus forming a part of PCP 180. A suitable commercial embodiment of LST 194 is a Hold-Down Seal Assembly manufactured by a variety of manufacturers and covered under API 11AX, but any type of latching-sealing tool may be used. The outer diameter of LST 194 is smaller than the inner diameter of seating cup 126. Threads 196 at one end of LST 194 may connect LST 194 to tool receptacle 198. Seating cone 200 may be located on the outer diameter of LST 194, in an annular recess defined by a lower end of tool receptacle 198 and LST shoulder 202. Seating cone 200 can be an annular seal, adapted to press against and form a seal with seating cup tapered surface 128 of seating cup 126. Seating cone 200 can be elastomeric or may be any other type of seal.

In one embodiment, a plurality of latch fingers 204 (FIG. 1A) protrude from the outer diameter of LST 194. In their relaxed position, the outer diameter defined by the outer edge of latch fingers 204 is greater than the inner diameter of seating cup 126. Latch fingers 204 are adapted to compress radially inwardly against seating cup 126 as LST 194 is inserted into seating nipple 104 and expand radially outwardly after clearing seating cup 126. When expanded, latch fingers 204 can engage lower tapered surface 130 or lower surface 132 of seating cup 126, thus providing resistance to upward movement of LST 194. PCP 180 may be inserted by a running tool (not shown) connected to tool receptacle 198, or by any other technique.

Referring to FIGS. 1A and 3, anti-rotation mechanism 208 can be a device to prevent or reduce the rotation on PCP 180 within tubing 100. In one embodiment, anti-rotation mechanism 208 can be a cylindrical bushing connected to stator housing 186. In one embodiment, anti-rotation mechanism 208 is connected to housing 186 below LST 194. In some embodiments, anti-rotation mechanism 208 may be in contact with or connected to LST 194. In one embodiment (not shown), anti-rotation mechanism 208 and LST 194 are integrally formed of the same cylindrical body. Anti-rotation mechanism 208 and LST 194 may be located in any axial position along stator 182. In one embodiment (not shown), for example, anti-rotation mechanism 208 and LST 194 may be attached near the bottom of stator 182, such that stator 182 and rotor 190 protrude above anti-rotation mechanism 208 and LST 194.

Referring to FIG. 3, anti-rotation mechanism 208 may include anti-rotation mechanism body 210 and one or more anti-rotation fingers 212 axially protruding from the outer diameter of body 210. Fingers 212 may be spaced apart from each other around the circumference of body 210. In one embodiment, each finger 212 has a base 214 connected to body 210, and each finger 212 extends out to tip 216. Finger 212 can taper radially outward with distance from body 210, as best shown in FIG. 1A. Other finger configurations may be used. For example, in an alternative embodiment, a band or annular ring (not shown) may restrain tip 216 near body 210, such that finger 212 bows outward between base 214 and tip 216. In this embodiment, tip 216 may slide axially between body 210 and the band (not shown) as finger 212 flexes inwardly and outwardly.

Anti-rotation fingers 212 may be resilient and adapted to move inwardly to pass through seating cup 126. Alternatively, anti-rotation fingers 212 may be rigid and define an outer diameter that is smaller than the inner diameter defined by seating cup 126. Either way, anti-rotation mechanism 208 is able to pass through seating nipple 104 when PCP 180 is inserted.

Referring to FIG. 4, the outer diameter defined by fingers 212 is greater than the inner diameter defined by anti-rotation nipple keys 170. When fingers 212 are circumscribed by anti-rotation nipple 136, fingers 212 engage keys 170, such that torque associated with anti-rotation mechanism 208 is transferred to anti-rotation nipple 136. Sidewall 218 of fingers 212, thus, transfers torque from anti-rotation mechanism 208 to anti-rotation nipple keys 170. Anti-rotation nipple 136, thus, prevents anti-rotation mechanism 208 and PCP 180 (FIG. 1) from rotating with respect to tubing 100.

Referring back to FIGS. 1 and 1A, stator 182 of PCP 180 can be inserted through tubing 100 on a wire or running tool. In one embodiment, rotor 190 is not located in stator 182 when stator 182 is inserted. As stator 182 is inserted, anti-rotation mechanism fingers 212 may contact seating cup 126 of seating nipple 104. Fingers 212 can compress inward, allowing anti-rotation mechanism 208 to pass through nipple 104. When LST 194 reaches nipple 104, LST latch fingers 204 contact tapered surface 128, causing fingers 204 to compress inward, thus allowing fingers 204 to pass seating cup 126. Once clear of seating cup 126, fingers 204 spring outward engage lower face 132, thus resisting upward axial movement of LST 194 in relation to nipple 104. At approximately the same location that fingers 204 spring outward, anti-rotation mechanism 208 reaches anti-rotation nipple 136. Anti-rotation mechanism fingers 212 are, thus, radially located in slots 176, between keys 170 of anti-rotation nipple 136.

When stator 182 is set in position, and thus LST 194 is set in nipple 104, rotor 190 is inserted on a drive rod (not shown) through stator 182 until rotor 190 contacts tag bar 188. Rotor 190 may then be pulled back a predetermined distance such that there is clearance between rotor 190 and tag bar 188. As drive rod (not shown) begins to rotate rotor 190, stator 182 may rotate with rotor 190 until fingers 212 contact shoulder 174 of keys 170 (FIG. 2). Upon contact, fingers 212 transfer torque from stator 182 to anti-rotation nipple 136, thus preventing further rotation of stator 182. Other configurations of latching fingers and slots may be used. In one alternative embodiment (not shown), for example, latching fingers may deployed on tubing, such that they protrude from the inner diameter of a length of tubing and a slotted ring can be attached to a PCP. In this embodiment, the latching fingers can engage the slotted ring as the PCP, and hence the slotted ring, are inserted through the tubing.

PCP 180 can be withdrawn by first withdrawing rotor 190, and then exerting upward pressure on tool receptacle 180. Sufficient upward pressure can cause latch fingers 204 to compress inward as they engage lower face 132. Similarly, the upward pressure can cause latch fingers 212 to compress inward as fingers 212 clear slots 176. Tapered surface 216 can facilitate inward compression of the tips of fingers 212 as they encounter various narrow diameters as they are withdrawn through anti-rotation nipple 136 and sealing nipple 104.

Referring to FIG. 5, in an alternative embodiment, slotted anti-rotation nipple 230 and anti-rotation mechanism 232 prevent rotation of stator 233. Referring to FIG. 6, anti-rotation mechanism 232 includes anti-rotation mechanism body 234. Anti-rotation mechanism body 234 may be a tubular body for mounting on stator housing 235 (FIG. 5). Body 234 may have threads 236 located at either or both ends for engaging adjacent components such as, for example, LST 272 (FIG. 5). One or more recesses 238 may be located on the outer diameter of body 234. Each recess 238 may be an axial groove on the outer diameter that may extend a substantial portion of the axial length of body 234.

Spring loaded keys 242 may be located in each recess 238. Each key 242 can be, for example, a metal tab, but other materials may be used. In one embodiment, each key 242 has tapered surface 244 at each end. Tapered surface 244 slopes away from anti-rotation mechanism body 234 such that the overall length of key 242 becomes shorter as the radial distance from the center of anti-rotation mechanism 232 increases. Surface 248 may define a terminal radial surface of key 242. Surface 248 may be generally parallel to the axis of body 234, and have a length defined by the outer ends of tapered surface 244. Key tab 246 extending axially from each end of key 242, near the radially inward portion of key 242.

Key retainer 250 may be used to keep keys 242 in recess 238. In one embodiment, key retainer 250 is an annular ring located on an outer diameter of anti-rotation mechanism body 234. Key retainer may be connected to body 234 by, for example, threads, fasteners, or force fit. In an alternative embodiment, not shown, key retainer 250 can be a plate that is bolted or welded to the exterior of body 234. In one embodiment, upper and a lower key retainers 250 are located on body 234. The axial distance between the retainers 250 is greater than the axial length of the tapered portion of key 242, but less than the axial length of the tabbed portion of key 242. Thus, retainer 250 engages tabs 246 to retain key 242, but allows the face of key 242 to protrude from recess 238. Spring 252 may be located between key 242 and recess 238 to cause key 242 to protrude from body 234. In an alternative embodiment (not shown), spring 252 may be a leaf spring that protrudes from the outer diameter of body 234. In this embodiment, springs 252 may be used in place of keys 242.

Referring to FIG. 7, slotted anti-rotation nipple 230 may be a tubular body with threads 260 located on the inner or outer diameter of each end. Anti-rotation nipple 230 may be connected as a section of tubing in a length of tubing 100 (FIG. 5). In one embodiment, anti-rotation nipple 230 is located below seating nipple 270 (FIG. 5). Anti-rotation nipple 230 may have a plurality of slots 262 spaced apart around its inner diameter. Each slot 262 is shown as an elongated axial passage having a length and width greater than the length and width, respectively, of key 242 (FIG. 6). Alternatively, the axial length of slot 262 is at least greater than the axial length of surface 248. The radial spacing of slots 262 matches the radial spacing of recesses 238 on anti-rotation mechanism 232 (FIG. 6). In some embodiments, the number of slots 262 may be a multiple of the number of recesses 238. For example, anti-rotation mechanism 232 may have four recesses 238, and thus four keys 242, while anti-rotation nipple 230 has eight slots 262.

Referring back to FIG. 5, stator 233 is inserted through tubing 282 on a wire or running tool. As it is inserted, keys 242 may contact shoulder 268 of seating nipple 270. Keys 242 retract, allowing anti-rotation mechanism 232 to pass through nipple 270. When LST 272 reaches nipple 270, fingers 274 contact shoulder 268, causing fingers 274 to compress inward, thus allowing fingers 274 to pass shoulder 268. Once clear of shoulder 268, fingers 274 spring outward and thus resist upward movement of LST 272 in relation to nipple 270. At approximately the same location that fingers 274 spring outward, anti-rotation mechanism 232 reaches slotted anti-rotation nipple 230. Keys 242 may or may not immediately engage slots 262, depending on the radial alignment of keys 242 in relation to slots 262. The circumferential spacing of slots 262 may determine the rotational distance that anti-rotation mechanism 232 must be rotated for keys 242 to engage slots 262. For example, with four slots 262, anti-rotation mechanism 232 may rotate no more than ¼ turn before keys 242 engage slots 262. With eight slots 262, anti-rotation mechanism 232 may rotate no more than ⅛ turn. In embodiments having fewer keys 242 than slots 262, the number of slots still determines the rotational distance, and some slots 262 will remain empty after keys 242 engage other slots.

After stator 233 is installed, rotor 278 is inserted on drive rod 280 through stator 233 of PCP 266 until rotor 278 contacts tag bar 284. Rotor 278 may then be pulled back a predetermined distance such that there is clearance between rotor 278 and tag bar 284. As drive rod 280 begins to rotate rotor 278, stator 233 may rotate with rotor 278. Referring to FIG. 8, stator 233 can rotate until keys 242 become axially aligned with slots 262, at which time springs 252 cause keys 242 to move radially outward into slots 262. Referring back to FIG. 5, keys 242, thus, transfer torque from stator 233 to slotted anti-rotation nipple 230 to stop rotational movement of PCP 266.

Referring to FIG. 9, in one embodiment, a different type of pump may be inserted into the same seating nipple as described in FIG. 1. In this embodiment, tubing 288 is located in a wellbore (not shown). Seating nipple 290 is a seating and sealing surface deployed on tubing 288. Seating nipple 290 may be attached to tubing 288 by any technique including, for example, welding, threaded connections, or force fit. Tubing 288 can be attached to either or both ends of seating nipple 290. Seating nipple shoulder 292 is an annular shoulder that protrudes inwardly from seating nipple 290. The inner diameter of shoulder 292, thus, is smaller than inner diameter 294 of seating nipple 290. Sealing surface 296 may be a tapered surface that slopes downward inward from inner diameter 294 to shoulder 292. The face of sealing surface 296 may be generally smooth or otherwise adapted for forming a seal. Lower tapered surface 298 slopes downward and outward from shoulder 292 to outer diameter 298 of seating nipple 290. In some embodiments, a portion of inner diameter 294 may be generally smooth for forming a seal.

Anti-rotation nipple 302 is also deployed on tubing 288. Anti-rotation nipple 302 may be located below seating nipple 290. Anti-rotation nipple 302 may be attached to tubing 288 by any technique including, for example, welding, threaded connections, or force fit. Tubing 288 can be attached to either or both ends of anti-rotation nipple 302. As shown in FIG. 9, a length of tubing 288 can be connected between anti-rotation nipple 302 and seating nipple 290. Tubing 288 may extend below anti-rotation nipple 302. In one embodiment (not shown), the upper end of anti-rotation nipple 302 is attached to the lower edge of seating nipple 290. In another alternative embodiment (not shown), anti-rotation nipple 302 may be located above seating nipple 290, wherein the lower end of anti-rotation nipple 302 is attached to the upper end of seating nipple 302.

One or more keys 304 protrude inwardly from inner diameter 306 of anti-rotation nipple 302 to form radial shoulders for transferring torque. As described above, keys 304 may extend axially along anti-rotation nipple 302. Alternatively, a slotted nipple, such as nipple 230 of FIG. 5, may be used.

Reciprocating pump 312, which is conventional, may be inserted through tubing 288 to seating nipple 290. Reciprocating pump 312 does not use, nor does it interfere with, anti rotation nipple 302. Latching sealing tool (“LST”) 314 is a bushing located on the outer diameter of reciprocating pump 312. A suitable commercial embodiment of LST 314 is a Latching/Sealing Tool manufactured by various manufacturers according to API 11AX, but any type of latching-sealing tool may be used. The outer diameter of LST 314 is smaller than the inner diameter defined by seating nipple shoulder 292. Seal 316 is a tapered annular seal that may be located on an outer diameter or downward facing tapered surface of LST 314. Seal 316 is adapted to press against and form a seal with sealing surface 296 of seating nipple 290. Seal 316 may be elastomeric or may be any other type of seal.

In one embodiment, a plurality of latch fingers 318 protrude from the outer diameter of LST 314. In their relaxed position, the other diameter defined by the outer edge of latch fingers 318 is greater than the inner diameter of seating nipple shoulder 292. Latch fingers 318 are adapted to compress radially inwardly against shoulder 292 as LST 314 is lowered into seating nipple 290 and expand radially outwardly after clearing seating nipple shoulder 292, thus providing resistance to upward movement of LST 314. Reciprocating pump 312 may be concentrically located with anti-rotation nipple 302 when LST 314 is latched into seating nipple 290, but reciprocating pump 312 generally does not contact or engage anti-rotation nipple 302.

Fishing neck 320 may be connected to reciprocating pump 312. Fishing neck 320 is conventional, and may used to lower and raise reciprocating pump 312. Sucker rod 322 may be connected to one end of reciprocating pump 312. In operation, sucker rod 322, or a plurality of connected sucker rods 322, are connected to a reciprocating surface pump such as, for example, a walking beam pump (not shown) located on the surface. The reciprocating surface pump (not shown) causes sucker rod 322 to move up and down, thus operating reciprocating pump 312. Fluid intake and discharge of reciprocating pump 312 is conventional. During operation, latch fingers 318 engage lower tapered surface 298 to prevent upward axial movement of reciprocating pump 312. Seal 316 engages sealing surface 296 to form a seal and to prevent downward axial movement of reciprocating pump 312. Reciprocating pump 312 can later be withdrawn by exerting sufficient upward axial pressure on sucker rod 322 to cause latch fingers 318 to compress inward against tapered surface 298 as pump 312 moves upward.

In one embodiment, reciprocating pump 312 may be used with tubing 288, seating nipple 290, and anti-rotation nipple 302. This configuration could be used, for example, during a steam flooding operation because reciprocating pump 312 may be less likely to be damaged by heat than other types of pumps. At a later time, such as at the conclusion of steam flooding operations, reciprocating pump 312 can be withdrawn from tubing 288, and, for example, PCP 180 (FIG. 1A) could be inserted into the same tubing 288. PCP 180 may have LST 194 (FIG. 1A) and anti-rotation mechanism 208 (FIG. 1A) for engaging seating nipple 290 and anti-rotation nipple 302, respectively. PCP 180, thus, can be used for additional pumping in a lower temperature wellbore environment. Reciprocating pump 312 can be withdrawn and PCP 180 can be inserted through tubing 100 without withdrawing tubing 100. Similarly, the PCP 180 can be used when the wellbore is relatively cool, and then, if the wellbore is going to reach a higher temperature, PCP 180 can be withdrawn and replaced with reciprocating pump 312. Tubing 288 and anti-rotation nipple 302 need not be removed prior to inserting reciprocating pump 312.

Claims

1. A system for pumping wellbore fluids, the system comprising:

a wellbore tubing;

a seating nipple located on the wellbore tubing;

an anti-rotation nipple located on the wellbore tubing;

a surface driven pump having a pump outer diameter and a latch seal, the latch seal sealingly engaging the seating nipple and resisting axial movement in at least one direction when the latch-seal is concentrically located within the seating nipple; and

wherein the surface driven pump can be deployed through tubing and at least a portion of the outer diameter can pass through the anti-rotation nipple.

2. The system of claim 1, wherein the surface driven pump is a reciprocating pump.

3. The system of claim 2, wherein the reciprocating pump is concentrically located within the anti-rotation nipple.

4. The system of claim 1, wherein the surface driven pump is a progressing cavity pump, the progressing cavity pump comprising a rotor and a stator.

5. The system of claim 4, wherein the system further comprises an anti-rotation mechanism connected to the progressing cavity pump, the anti-rotation mechanism engaging the anti-rotation nipple when the anti-rotation mechanism is concentrically located within the anti-rotation nipple.

6. The system of claim 4, wherein the anti-rotation mechanism comprises cantilevered latching fingers, the latching fingers being resilient, each having a base connected to the pump outer diameter and extending to a tip, the tips defining an anti-rotation mechanism outer diameter, the anti-rotation mechanism outer diameter being greater than an inner diameter of the seating nipple wherein the latching fingers are compressible to allow the anti-rotation mechanism to pass through an inner diameter of the seating nipple.

7. The system of claim 6, wherein the anti-rotation nipple comprises a plurality of keys, the keys defining slots therebetween.

8. The system of claim 7, wherein the latching fingers are adapted to compress inwardly upon engaging the keys to allow the anti-rotation mechanism to be concentrically located within the anti-rotation nipple when the fingers are radially aligned with the keys.

9. A method for pumping wellbore fluid, the method comprising the steps of:

a wellbore tubing;

connecting a seating nipple to a wellbore tubing;

connecting an anti-rotation nipple to the wellbore tubing;

deploying the seating nipple, anti-rotation nipple, and wellbore tubing into a wellbore;

inserting a surface driven pump through the tubing into the wellbore, the surface driven pump having a latch seal;

latching the latch seal to the seating nipple, thereby preventing axial movement in at least one direction;

sealingly engaging the seating nipple with the latch seal; and

driving the surface driven pump with a motor located on the surface of the earth.

10. The method of claim 9, wherein the step of inserting the surface driven pump further comprises passing at least a portion of the surface driven pump through the anti-rotation nipple.

11. The method of claim 10, wherein the surface driven pump comprises a progressing cavity pump having a stator and a rotor, the stator having a stator housing, and wherein the step of inserting the surface driven pump through the tubing comprises inserting the stator through the tubing after the tubing is inserted into the wellbore.

12. The method of claim 11, wherein the progressing cavity pump comprises an anti-rotation mechanism, the anti-rotation mechanism engaging the anti-rotation nipple to prevent rotary movement of the stator.

13. The method of claim 12, wherein the anti-rotation mechanism comprises fingers, each having a base connected to the stator housing and extending to a tip, the tips defining an anti-rotation mechanism outer diameter, the anti-rotation mechanism outer diameter being greater than an inner diameter of the seating nipple when the fingers are in their natural state, and wherein the step of inserting the surface driven pump through the tubing further comprises the step of compressing the fingers to permit the anti-rotation mechanism to pass through the seating nipple.

14. The method of claim 11, wherein the anti-rotation mechanism comprises a latching finger and the anti-rotation nipple comprises a plurality of keys to define a plurality of slots therebetween, wherein the latching finger is radially located against a key when the progressing cavity pump is inserted and further comprising the step of rotating the rotor of the progressing cavity pump, thereby causing the stator and the anti-rotation mechanism to rotate until the latching finger is radially located within one of the plurality of slots, thereby preventing further rotation of the stator.

15. The method of claim 9 wherein the surface driven pump is a reciprocating pump, further comprising the steps of withdrawing the reciprocating pump and inserting a progressing cavity pump.

16. The method of claim 15 wherein the tubing remains in place while the reciprocating pump is withdrawn and the progressing cavity pump is inserted.

17. A system for pumping wellbore fluids, the system comprising:

a wellbore tubing;

a seating nipple located on the wellbore tubing;

an anti-rotation nipple located on the wellbore tubing;

a progressing cavity pump having a rotor and a stator, the stator located in a stator housing, a latch seal connected to the stator housing, the latch seal sealingly engaging the seating nipple and resisting axial movement in at least one direction when the latch-seal is concentrically located within the seating nipple, and an anti-rotation mechanism, the anti-rotation mechanism comprising a bushing connected to the stator housing and at least one anti-rotation finger connected to the bushing and protruding from a base to a tip, the tip defining an outer diameter of the anti-rotation mechanism; and

wherein the surface driven pump can be deployed through tubing and at least a portion of the outer diameter can pass through the anti-rotation nipple.

18. The system of claim 17, wherein the anti-rotation mechanism engages the anti-rotation nipple when the anti-rotation mechanism is concentrically located within the anti-rotation nipple.

19. The system of claim 17, wherein the anti-rotation nipple comprises a plurality of keys, the keys defining slots therebetween.

20. The system of claim 19, wherein the latching fingers are adapted to compress inwardly upon engaging the keys to allow the anti-rotation mechanism to be concentrically located within the anti-rotation nipple when the fingers are radially aligned with the keys.