US2432028A - Insert apparatus for oil well casings - Google Patents

Description

Dec 2, 1947. R. F. MACKIN INSERT APPARATUS FOR OIL WELL CASINGS Filed June 2, 1943 INVENTOR the pump element.

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Patented Dec. 2, 1947 irao stares rem prince NSERT APPARATUS FOR OIL 'WELL CASINGS iReuel LFranc'is .Mackin. Wink, Tex., assignor to Lam'tex Equipment Corporation, Fort Worth, 'Tex.,-a corporation of Texas Application June #2, 1943,Serial No.'1189;328

'18 "Claims.

.An object of my inventionis'to provide a methd and apparatus which make it economical an practical to eliminate or salvage the tubing .of an oil well and to use the well casing forconducting oil to the ground surface without losing the advantages of conventional'installationsin which tubing is employed.

Another object of this .invention'is to provide a casing pump apparatus-for oil wells which enables thepumping element to he 'removed from the wellfor servicingrepair or other use, in the same manner as the pump elementof conventionaltubing pumps.

Another object is to provide acasing-pump apparatus which will hold a column of oil in the casing at all times and yet permit the'pump e'lement to be withdrawn from the well whenever desired without dumping the columno'f'oil above the apparatus back into the "GH -bearing "formation.

A further object of this invention isto provide a-method and apparatusbywhichto locate-and seal a casing pump .unit atiits pumping position in an oil welloasing bymanipulationsof a'string of sucker mods without danger-of dropping :the unit into the formation.

According to my invention ,1 "make a special casing pumpinstallation in a new way'and'then flow oil from the formation through the well casing by the operation :of this installation, in general as follows: -Iuse a-reciprocatingpump element of any suitable construction, such asa pl unger carrying a traveling valve of :the kind heretofore used with tubing ppump installations. I provide a-special casingmumpunit which is constructed; so as to-be located and sealed atapumping position .inthe wellcasing and thereafter to receivevand work with this pump element to force oil upwardly through the casing. .And I provide a new insert device which is used in combination with the pump unit and with-a string of sucker rods was .to locate and seal'th-e unit in place in the casing .andthen to disconnect the unitand make itready tol-receiveandworkwith After these operations, the rods and insert device are withdrawn from the Well, the insertdevice is removed from the rods and. replacedby the pump e1ement,,and the pump element is lowered Ehy the .rods to .its working position and then. operated insidethe sealed pump At any thereafter the pump element can be withdrawn for service disturbingthe casing pump unit .or affecting its except as may be required by a ting portions shown in or .repair without sealer dropping the oil in .the casing back .into

the well formation.

My invention therefore is particularly =valuable for the flowing of low volume or .low fluid ,level oil wells, whichheretoforehave hadtobe worked with internal tubing and tubin 112111111 5 tooavoid dumping the oilintotheformation wheneverthe .pump.reguired mechanical service ;ororepair.' BY

the use of this invention 'the tubing of existing well pumpiinstallationsimay'be salvaged and used for ,otherpurposes, and newly developed wells'may be pumped without the need. oftubing to conduct the oil tothe ground surface.

The foregoing and other objects, features and advantages of my invention will becomemore apparentyfrom the following detaileddesoription of an illustrative embodiment thereof, when considered in connection with the accompanying drawings. The new "features of constructionand operation which I claim -as "my invention are set forth particularly in" the 'appended claims, I which contemplate various modifications *ofthe illustrative embodiment and 'are not restricted thereto fair interpretation of their terms.

In the drawings:

Figures 1 and 1a are-longitudinal views -partly in cross-section, showing upper and lower portions, respectively, of an assembly of -a :oasing pump unit, an insertdevice'and'a string of sucker rods as theunit is located' inawll casing ready to be sealedto the easing;

Figures 2 and 2a are longitudinal views,':partly in cross-section, showing upper and lower portions, respectively, of the casing pump installation in its operating conditio Figure 3 is an enlarged longitudinal section through --a two part mandrel which forms part of the 'assemblyas the pumpunit is lowered into the casing and located and sealed in pumping position; and

.pump mechanism to new oil from the well. .It

will be understood that the oil-bearingjformation lies adjacentto the bottomiofthecasing portion shown in .Eigures laand 12a, .and that the .well casing extends far above the top ;of the easiEieures .1 and 2., to the ground surface where suitable machinery is provided to operate the pump.

The main elements of the assembly of Figures 1 and la comprise a casing pump unit C, a string of sucker rods A, and an insert device B which interconnects the pump unit with the sucker rods. The main elements of the operating assembly in Figures 2 and 2a comprise the same casing pump unit C, the sucker rods A and the reciprocating pump element which in Figure 2a i marked within the bracket D and is secured to the lower end of the rods.

By the term casing pump unit I refer to the structures which cooperate with the reciprocating pump element D. These may be of various forms, but essentially include a standing valve 20, a pump barrel 24 thereabove, and a casing pump head provided with means, such as an expansible packer 30 and a cooperating mandrel element 32, to be operated by the manipulation of rods A and insert device B to seal the pump unit in its working position. In addition, where the unit is not to be supported by structure provided for that purpose in the well formation, an anchoring means 40 of any suitable construction is provided as part of the pump unit for operation to anchor or locate the unit in place before flowing the Well.

The operation in general is as follows: At the top of the well the pump unit C is assembled with the sucker rods A through the insert device B, which is positively yet releasably connected at its lower end to the top of the unit, such as by a special construction of the mandrel hereinafter described, and which is secured at its upper end to the lowermost sucker rod. This assembly is then lowered into the well casing until the unit has reached the desired pumping position. The rods are then turned, usually in a counterclockwise direction, t set the anchoring device 40 against casing It in a well-known manner. At this stage the mandrel element 32 is spaced above the packer 30, by reason of an interconnection which permits a limited relative axial motion between these parts. When the unit has been located in place by the setting of the anchor, the rods A are further lowered until the mandrel element 32 moves into the packer 30, and the rods are then manipulated up and down to operate the insert device B and pound the mandrel element tightly into the packer, thus sealing the unit at the packer against the well casing. This manipulation is provided for by the construction of the insert device, which includes a plurality of parts interconnected through a slip joint for limited relative movement in axial direction. After the unit thus has been sealed, the sucker rods are again turned, but this time in a clockwise direction, so as to disconnect they insert device from the unit at the top of the mandrel element 32, whereupon the rods and the insert device are withdrawn from the well. The insert pump element D is then secured to the rods A in place of the insert device B, and the pump element and rods are lowered intothe well until the pump element has passed freely through the upper portion of the pump unit and reached its working position in the pump barrel 24. This is the operating condition depicted in Figures 2 and 2a. The rods are now reciprocated to operate the pump in its working barrel, with the efiect of raising oil through the standing valve 20 into the pump element within the barrel and then forcing the oil through the traveling valve of the pump element into the well casing and thence to the ground surface. The permanent standing valve 20 and the seal formed by packer 30 hold the column of oil in the easing In at all times, and the pump element D may be withdrawn from the unit at will without dumping this oil into the formation.

Referring more specifically to the illustrated form of construction, Figure 1a shows a nipple I4 at the bottom of the pump unit, through which oil is drawn from the formation, and the standing valve 20 is connected above this nipple. The pump barrel 24 extends above the standing valve and has between itself and the valve a seat 22 to limit the downward motion of the pump element D in its working barrel. The anchor 40 is secured to the top of the pump barrel through suitable tubular means, and similar means connect it rigidly with an outer or drain sleeve 26 of the casing pump head, shown in Figure 1. The annular expansible packer 30 is fastened to the top of the drain sleeve 26, and the mandrel element 32 is fixed to the top of a drain tube 28 that extends inside the drain sleeve and is connected therewith by suitable means, such as a tongue 29 working in a slot 21, for limited relative movement in axial direction.

It will be understood that when the casing pump unit as thus described is suspended in the casing from the mandrel element 32, the tongue 29 abuts against the top of slot 21 and the mandrel is located above the packer 30. In this condition of the unit, which exists before it is located or sealed in the well, a pin 4| of the anchoring device 40 will be located in a slot 42 so that the working elements of the anchor are retracted away from the well casing.

The mandrel of the assembly, as seen in Figures 1 and 3, is a novel two-part structure includ ing element 32 as the lower part and an upper disconnectable part or cap 38 which is also a part of the insert device B. The lower part 32 has a conical or tapered outer surface 34 adapted to fit into and expand the packer 30, and is secured by conventional screw threads to the top of the drain tube 28. This mandrel element is hollow and open or flared at its top 36 to permit free pasage therethrough of a pump element D fitting the pump barrel 24. The upper part or cap 38 is fitted to the lower part through mating means, such as a tongue 39 on the cap engaging in a notch 31 in the top part 36, to prevent relative turning motion but allow axial separation of the two mandrel parts. Both parts are threaded internally with registering left- hand screw threads 36a and 38a.

A coupling device 44 having external left-hand screw threads 44a is located inside the cap 38 with its threads in engagement with the threads 36a and 38a, as shown in Figure 1. The two mandrel parts thus are positively secured together during the lowering, location and sealing of the pump unit in the well. A stem 46 on coupling member 44 extends through and beyond the cap 38 and completes the lower part of the insert device B. This stem is tubular in form, and an upper tubular part 48 of the insert device is telescoped thereinto and connected therewith for limited relative axial movement, for example, through a tongue 49 on part 48 working in a slot 41 in part 46. The top of part 48 is secured to the lowermost sucker rod A.

The pump element D (Figure 2a) includes a suitable seating device 50 having rings to seal against the inside of theworking barrel andhaving a hollow stem 54 to rest in the seat 22 at the lower endof theworking barrel; together with a reciprocatory insert pump 56- of known construction above this seating device which pump has a part connected tothe seating device We tube-52 and has a traveling valve 58 at the top where the sucker rods A- areattached.

When the" insert device is disassembled from the pump unit and the sucker rods; as illustrated in Figurea, it comprises the upper and lower telescoped parts 48 and 45 connected together through the slip joint 4-! and 49; together with the coupling member it at the lower end 013 part 4'6 andthe upper'mandr-el part or can 38 threadedi thereon.

When the insert device is assembled in preparation for'locating and sealing the pump unit in the well casing, the cap 38 is fittedt'othe lower mandrel element 32 and the device isturned counterclockwise so as to engage the coupling member 44 with the screw threads 3612.

Upon lowering the assembly into the well, the pump unit and insert device are suspended from the sucker rods-A with tongue 49 of the slip-joint at the topof" its slot ll and with tongue 29 f the connection between the drain tubeand drain sleeve-at the top of its slot 261 The mandrel thus is located above the packer and pin 41 of the anchoring device 40 is held in its slot 62.

When the pump unit reachesthe desired pumping position. the rods A are first turned in a counterclockwise direction to free pin 41: from slot 42 and thus set the anchor against the well casing, which locates and: well; The rods are then lowered further to drop the tapered surface 3d of the mandrel" into the packer, and. are then reciprocated through the slip: joint 41-, 49 to pound the lower mandrel element into the pack-er and seal the unit against the casing. This having been done, the rods are now turned in a clockwise. direction, whereupon the coupling member M is screwed upwardlyint'o cap- 38, out of engagement withthe threads 33a on: mandrel element 32, sothatthe insert device and rods are disconnected from the" sealed pump unit and the latter is made ready to receive the pumpitself for-operation to flow'the well. When the? insert device has been withdrawn from: the well and replaced on the; rodsby the. pump element D: the pumpelement islowered: to its worling. position in pump barrel 24; and: then recip rorated to flowthe well.

I, claim:

1. Apparatus for flowing an. oil well through the well. casing: comprising a standing valve, a pump barrel therealoove,v av drain sleeve connect:- ed above; the barrel and having an annular expansible packer at, the top, a drain tube cons nected with the drain sleeve for limited. relative axial movement; a two-part mandrel-r includingzan upperpart, a lower'hollowpart, which is normally open. at the top, has a conical periphery and. is secured to the drain tube tomove therewith. and expand the pack and means operated by turning the upperpart: to discou nect the two; parts of theumandrel.

2; Oil well casing pump apparatus; comprising the combination of a casing pump unit. with an insert. device for. ositively yeti releasably conmeeting the unit with a; string of sucker rodsami operable by manipulation of the. rods to locate and; seal the unit at a pumping position in; the well casing, said device comprising aplurality of arts connected together for limited relative-axholds the unit in the 6 ial: motion; and said unit comprising an expane sible packer and a cooperating mandrel having-a releasable screw connection with the lowermost of sai'd parts;

3% Oil well casing pump apparatus comprising the combinationof acasing pump unit with an insert device for positively yet releasablyconnecting the unit with a-string of sucker rodsand operable by manipulation of the rods to: locate and seal the unit ata pumping position in the well casing, said device comprising a plurality of parts connected together for limited relative axi-ai motion, and said unit comprising an expans-ihle packer and a. cooperating: mandrel having' a reIeasabl'eleft-handscrew connection with thelowermostofsai'dparts.

4 "In: an apparatus; for flowing an oil well through; the weli casing, the combination of a casing pump unit including means to anchor the same at a pumping position inthe well casing and means to seal the samewithin the casing to hold acolumn of oil above the unit, an insert device connectable with said unit to be turned in one directionto operate said anchor means and movable axiallytooperate said sealing means, and complementary means on said device and said unit for disconnecting the same when the unit is anchored and sealed and the devi'ceis turned in the other direction.

5. In an apparatus for flowing an oil well through the well casing, the combination of a casing pump unit including means to anchor the same at a pumping position in the well casing and means to seal the same within the casing to hold acolumn of oil above the unit, an insert device connectable with said unit to be turned in one direct-ion to operate said anchor means and movable axially to operate said sealing means; and complementary means on said device andsaid unit for disconnecting the same when the unit is" anchored and sealed and the device is turneclin the other direction, the complementary means on said unit comprising a part mating with apart of said sealing means.

6-. m an apparatus for flowing an oil well through the well casing, the comb nation of a casing pump unit including a standing valve, a pumpbarrelthereabo-ve and a pump head above the barrel including an expansible packer and a tapered hollow mandrel to expand and seal the packer, a string of rods, an insert device interconnecting themandrel with the string of rods and movable with the rods to position and thereafter sea-l the unit in the casing, and complementary screwmeans respectively on said device and said mandrel'for disconnecting the rods and insert device from theunit when the unit has been positioned and sealed in the casing.

7; Inan apparatus for flowing an oil well through the well casing, the, combination of a casingpump unit including a standing valve, a pump barrel thereabove and a pump head above the barrel including an expansible packer and a tapered; hollow mandrel. to expand and seal the Packen. a. string of rods, an insert device interconnecting. the, mandrel with the string of rods and movable with the rodsto position and thereafter seal the unit in the casing, and complementary left-hand screw means respectively on said device.- and said mandrel for disconnecting the rods. and insert device from the unit when the unit has; been positioned and sealed in the casing, said device comprising; an upper part secured to one; or; the rods, a lower part carry ng, the screw 7 means and a slip joint permitting limited relative axial motion between said parts.

8. In an apparatus for flowing an oil well through the well casing, the combination of a casing pump unit including a standing valve, a pump barrel thereabove and a pump head above the barrel including an expansible packer and a tapered hollow mandrel to expand and seal the packer, a string of rods, an insert device interconnecting the mandrel with the string of rods and movable with the rods to position and thereafter seal the unit in the casing, said insert device comprising telescoping tubular members having a tongue and slot connection for limited relative axial motion, and complementary screw means respectively on the lowermost member of said device and on said mandrel for disconnecting the rods and insert device from the unit when the unit has been sealed in the casing.

9. In an apparatus for flowing an oil well through the well casing, a well casing, a nipple through which oil is drawn into the casing, a standing valve connected above this nipple, a pump barrel extending above said standing valve, a pump element attached to a string of rods and carrying a suitable traveling valve and fitting the barrel, a drain sleeve connected with the top of the barrel having an annular expansible packer at its top and a drain tube extending inside the drain sleeve and connected therewith for relative axial movement, and a mandrel element secured to the top of the drain tube having a tapered surface to expand the packer against the well casing, said mandrel being hollow and open at the top to permit free passage therethrough of said pump element.

10. Apparatus for insertion in an oil well casing comprising the combination of tubing having a tubular anchor, packer and mandrel element, the mandrel element movable axially relative to the packer, with an insert device separably connected with said mandrel element and adapted for lowering and fixing said tubing in the well casing, said device having relatively reciprocable parts, means respectively operable by turning said device in one direction and by relatively reciprocating said parts to activate said anchor and to seat said mandrel element into said packer so as to seal the latter at a desired position against the well casing, and means responsive to turning of said device in the other direction when the tubing has been so fixed for disconnecting the device from said tubing at said mandrel element.

11. Apparatus for inserting and sealing in an oil well casing tubing means having an annular expansible packer at its upper end, comprising interconnected upper and lower parts adapted to pass freely through the casing, a slip joint between said parts permitting axial reciprocation of one part relative to the other, means on said upper part for securing it to a string of rods, complementary separable upper and IOWer elements carried by said lower part, said lower element being hollow and having a tapered outer surface to serve as a mandrel for expanding said packer, mating means on said elements to prevent relative turning but allow relative axial motion therebetween, and screw-threaded means on said lower part and said elements separably interconmeeting said elements.

12. Apparatus for inserting and sealing in an oil well casing tubing means having an annular expansible packer at its upper end, comprising interconnected upper and lower par-ts adapted to pass freely through the casing, a slip joint between said parts permitting axial reciprocation of one part relative to the other, means on said upper part for securing it to a string of rods, complementary separable upper and lower elements carried by said lower part, said lower element being hollow and having a tapered outer surface to serve as a mandrel for expanding said packer, mating means on said elements to prevent rela tive turning but allow relative axial motion there between, and screw-threaded means on said lower part and said elements separably interconnecting said elements, said upper element comprising a hollow cap, the end of said lower part extending freely through an opening in said cap, and said screw-threaded means comprising registering internal screw threads inside said mandrel element and said cap and a coupling member inside the same on said end having external screw threads engaging said internal threads, said cap receiving said coupling member upon rotation thereof with said parts so as to disconnect said mandrel element.

13. In an apparatus for flowing an oil well through the well casing, comprising a standing valve, a pump barrel extending thereabove, a drain sleeve connected with the top of the barrel having an annular expansible packer at its top and a drain tube extending inside the drain sleeve and connected therewith for limited relative axial movement, a mandrel element secured to the top of the drain tube having a tapered surface to expand the packer against the well casing and being hollow and open at the top to provide passageway for a pump element fitting the pump barrel, and means including screw threads and an axial abutment on said element at its top for separably connecting it with an insert device.

14. Oil well casing pump apparatus comprising the combination of a tubing unit having an anchor, a mandrel and a packer with an insert device separably connected with the mandrel and adapted for positively connecting the unit with a string of rods, said device having relatively reciprocable parts, means respectively operable by turning said device in one direction and by relatively reciprocating said parts to locate and anchor the unit in the well and to set the mandrel into the packer so as to seal the latter at a desired position in a well casing, and means responsive to turning of the device in the other direction when the unit has been so located and sealed for disconnecting the device from the unit.

15. In apparatus for flowing an oil well through the well casing, the combination of a casing pump unit including a standing valve, a pump seat thereabove, a pump barrel above the seat, means to anchor the unit at a pumping position in the well casing, and means to seal the casing to hold a column of oil in the casing, an insert device connectable with the unit adapted to be turned in one direction to operate the anchoring means and to be moved axially thereafter to operate the sealing means, and complementary means on said device and said unit for disconnecting the same when the unit is anchored and sealed and the device is turned in the opposite direction, said unit when the device is disconnected being open at the top and providing an axial passageway therethrough.

16. In combination with a casing pump apparatus including a pump barrel having a standing valve therebelow, a drain sleeve having an expansible packer at the top, tubular means including a pump anchoring device connecting the drain sleeve with the top of the barrel, and a drain tube extending inside the drai sleeve and connected therewith for limited axial movement, a mandrel element secured to the top of the drain tube having a tapered surface to expand and seal the packer against the wall casing and being hollow and open at the top to provide passageway, a cap for said element, cooperating means on said element and said cap to prevent relative turning motion yet permit relative axial motion therebetween, registering female screw threads inside said element and said cap, and an external y threaded coupling member inside said cap engaging said screw threads and having a stem extending through and beyond said cap.

17. In combination with a casing pump apparatus including a pump barrel having a standing valve therebelow, a drain sleeve having an expansible packer at the top, tubular means including a pump anchoring device connecting the drain sleeve with the top of the barrel, and a drain tube extending inside the drain sleeve and connected therewith for limited axial movement, a mandrel element secured to the top of the drain tube having a tapered surface to expand and seal the packer against the well casing and being hollow and open at the top to provide passageway, a cap for said element, cooperating means on said element and said cap to prevent relative turning motion yet permit relative axial motion therebetween, registering female screw threads inside said element and said cap, an externally threaded coupling member inside said cap engaging said screw threads and having a stem extending through and beyond said cap, and an operating member connected with said stem for limited axial movement, with respect thereto and adapted to be secured to a string of sucker rods.

18. A mandrel for locating and sealing in an oil well casing tubing means having an annular expansible packer at its upper end, comprising a lower element having a tapered outer surface adapted to move into and expand the packer against the well casing and being hollow and open at the top to provide a passageway, a hollow cap fitting the top of said element, mating means on said cap and said element to prevent turning but allowing axial motion of the cap relative to said element, registering left hand internal screw threads inside said element and said cap, and a coupling member inside the same having external screw threads engaging said internal screw threads to connect the cap and element separably together, said coupling member carried on a stem extending freely through an opening in the cap and said cap formed to receive said coupling member upon turning said stem so as to disconnect said lower element.

REUEL FRANCIS MACKIN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 211,230 Downing Jan. 7, 1879 1,451,784 Olsen Apr. 17, 1923 1,535,141 Wade Apr. 28, 1925 1,578,720 Derby Mar. 30, 1926 2,074,912 Hutto Mar. 23, 1937 2,111,177 Cox Mar. 15, 1938 2,244,051 Collins June 3, 1941 2,253,776 Gaunt Aug. 26, 1941

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