US3299956A - Superposed well tubing assembly of separate tubing strings and method of supporting same - Google Patents

Description

3,299,956 UBING Jan. 24, 1967 c. P. HOWE SUPEHPOSED WELL TUBING ASSEMBLY OF SEPARATE T STRINGS AND METHOD OF SUPPORTING SAME Filed July 8, 1964 2 Sheets-Sheet 1 INVENTOR Char/es P Howe 7mdgm ATTORNEY Jan. 24, 1967 c. P. HOWE 3,299,956

SUPERPOSED WELL TUBING ASSEMBLY OF SEPARATE TUBING STRINGS AND METHOD OF SUPPORTING SAME 2 SheetsSheet 2 Filed July 8, 1964 INVENTOR Char/e5 P Howe ATTORNEY United States Patent Ofifice 3,299,956 Patented Jan. 24, 1967 This application is a continuation-in-part of application Serial No. 254,978 filed January 30, 1963, now Patent No. 3,105,719 of September 29, 1964.

This invention relates to a superposed well tubing string assembly in a well casing, and hook wall anchor means on string below the topmost string supporting the weight of the string thereabove.

A further object of this invention is to provide a well tubing string assembly wherein each string below the topmost string has mounted a 'well slip hook wall anchor mounted on its top and actuated by the weight of a string thereabove into anchoring position to support the weight of the actuating string thereabove.

A further object of this invention is to provide a well tubing string assembly, using the same hook wall anchor as that disclosed in the above identified patent, but wherein the string assembly is a plurality of separate strings, with each string above the lowermost string supported at its bottom on a wall anchor mounted at the top of the string therebelow, and the lowermost string supported by a mud anchor on the bottom of the well.

A further object of this invention is to provide a well tubing string assembly, wherein each string of the assembly is made of suitable length, possibly from 500 to 1,000 feet in length, and wherein the assembly may be 15,000 feet or more in length, wherein each string section is lowered or raised separately, and wherein the weight of each string assembly actuates a hook wall anchor mounted on the top of a previously positioned lower string section to support the weight of the actuating string on the well casing, thus preventing excessive weight loads on the string sections and transferring the load of the strings to the wall of the well casing.

A further object of this invention is to provide a methd of reducing the weight load on the tubing string by providing a plurality of separable and joinable string portions and supporting the weight of each separate section at its bottom, the bottom string on the well bottom and the upper strings on the well casing wall.

A further object of this invention is to provide a method of reducing the pumping load on the pumping equipment of a deep well by preserving the bottom hole pressure within the pay zone and causing such pressure to lift oil within the tubing string to pumping equipment at the top of the string.

A further object is to provide an improved well slip assembly and also to provide an improved book wall assembly for a tubing string in a well casing.

A further object of this invention is to provide a well slip assembly made in one piece thereby not only facilitating its manufacture, but greatly facilitating its use in a hook wall anchor for releasably anchoring a tubing string within a well casing so that it will support the weight of a pumping or tubing string thereabove, and which may readily be released from anchoring cooperation with the well casing when it is desired to remove the pump or tubing string on which it is secured from the well casing, and wherein the anchor is released from the well casing before the weight of the tubing string there below is picked up, thus facilitating the lifting of the tubing string and its removal from the well casing.

Still a further object of this invention is to provide an improved well slip assembly wherein there are a,

plurality of slip hooks, each integrally connected by a slip stem substantially narrower than the slip hook head, with the slip stems extending integrally from a single integral column member in the general direction of the axis of the integral collar.

Still a further object of this invention is to provide a well slip assembly and hook anchor particularly useful in supporting the weight of a tubing string supported thereabove.

Still a further object of this invention is to provide an improved well slip assembly and hook wall anchor, particularly useful in multiple completion wells, in preventing excessive weight loads on production equipment in deep wells and to assist in maintaining a controlled hydrostatic pressure and water flux as well as in other types of wells.

With the above and related objects in view, this invention consists in the details of construction and combination of par-ts, as will be more fully understood from the following description, when read in conjunction with the accompanying drawing in which:

FIG. '1 is an elevational view of the hook wall anchor assembly and tubing string assembly of this invention in operative position in a well casing.

FIG. 2 is an enlarged detailed section in wall hook anchoring position.

FIG. 3 is a sectional view on line 33 of FIG. 2, showing the slip hook heads in anchored position.

FIG. 4 is a sectional view on line 44 of FIG. 2.

FIG. 5 is a partly sectional and partly elevational view of the hook assembly on the tubing string in non-anchoring position.

FIG. 6 is a continuation of the bottom of FIG. 5 on line A-A.

There is shown at 10 the well slip assembly which is used as a wall hook anchor on the top end of a tubing string 13 for supporting the weight of a tubing string 13 or a topmost pumping string 12 on the wall of a well casing 16. Mounted on the top of each tubing string 13 is a mandrel 14, and this mandrel 14 is provided at its top with a beveled surface 17 having a sealing O- ring 19 inserted therein. This beveled surface 17 and O-ring 19 form a sealed joint with beveledsurface 21 on the bottom of a coupling 15 which is secured to the bottom tubing piece 65 of the string thereabove. When the coupling 15 rests on the mandrel 14, the weight of the string thereabove actuates the well slip assembly 10 into securing position with the inside wall of the well casing 16 to support the weight of the string thereon on the wall of the well casing 16, as will hereinafter become apparent.

The well slip assembly 10 per se consists of an integral collar 18 of suitable circumference from which integrally extends a plurality, here shown as four, of slip stems 20 spaced from each other by spaces 22, the width of the spaces 22 being greater than the said circumferential width of the stem 20, and at the upper end of each slip 20 there is provided a slip hook head 24.

Each hook slip head 24 is spaced from each adjacent hook head 24 by a comparatively narrow space 26 sufficient to permit the hook heads 24 to approach each other when in non-holding position, and also permit oil to flow thereby when in holding position. As will be apparent from FIGS. 3 and 4, the slip stems 20 and hook heads 24 are annular in cross section, generally having the same circumference, when in relaxed nonholding position, as the slip assembly collar 18.

On the inner surface of each hook head 24, a tapering surface 28 is provided from a point 30 intermediate the attached end 32 and free end 34 of each hook head, this surface 28 tapering outwardly. The outer surface of each hook head 24 is provided with a plurality of parallel circumferential hook ridges 36 shaped approximately as shown. It will be observed that each hook ridge 36 has a long surface 38 approximately at right angles with a short surface 40, thus providing a sharp edge 42 which provides the gripping hook portion thereof in cooperating with the well casing 16 when the hook head 24 is forced or wedged into contact therewith by a complementary tapered surface 44 on the mandrel 14.

In operation, when the mandrel 14 has its tapered surface 44 pushed downwardly by the weight of the string 12 or 13 thereabove into wedging action within the hook heads 24, the hook heads 24 are wedged outwardly into anchoring position with the well casing 16, as clearly illustrated in FIG. 2 and FIG. 3.

The coupling 15 is connected in a conventional manner =by threads to the bottom end piece 65 of pumping string 12 or tubing string 13. The pumping string 12 is of conventional construction in which there is located the usual pump head 23 and packing assembly 25 and to which there extends the pumping rod 27 connected thereabove to the usual sucker rod, the same being of conventional details, one illustration of which is shown in applicants prior patents, Numbered 2,674,- 198 and 2,674,200, and copending and now issued Patents 3,150,605 and 3,150,606 of September 29, 1964.

Depending from the mandrel 14 is an assembly tube 48 forming part of the tubing string 13, the assembly tube 48 extending slidably down through the packing collar 50 and the packing assembly 52 with its packing 54, the assembly tube 48 terminating in an enlarged shouldered end 56 having a shoulder 58, the shoulder 58 being of a size to abut against the bottom of the packing assembly 52, as shown in FIG. 6, while the shouldered end 56 can slide down or up freely in an assembly tubing 60. As will be observed in FIGS. and 6, the well slip assembly slides free on the assembly tube 50 between the bottom of the tapered end 44 of mandrel 14 and the top of packing assembly 52.

The strings 12 and 13 each includes as many couplings and/or adapters 62 and 64 and as many tubing pieces 65 as necessary to make up the desired length of each pump or tubing string 12 or 13. In the pumping string 12, the pumping barrel 66, containing the usual working barrel, pump valve and standing valve, such as more particularly illustrated in the aforementioned Howe Patents Nos. 2,674,198 and 2,674,200, is dependent from the pump head 23 which is sealed by the packing 25 to the inside wall of the well casing so that no fluid may pass in either direction between the well casing and the pump head, as shown in these latter mentioned Howe patents. The string sealing coupling is secured on the bottom end of the lowermost string piece 65, except for the lowermost string 13 at the bottom of the well. The bottom tubing piece 65 of this lowermost string is provided with a perforated mud anchor 68 connected thereto by suitable couplings 70. The length of the lowermost string 13 may be fairly short of small weight and the mud anchor is of sufficient length to guarantee that enough of its perforations 72 will always remain above the well bottom 74 so that oil which has entered through the perforations 76 in casing 16 located above the pay zone or oil sand of the well may enter the mud anchor perforations and ascend within the tubing strings 13 to the pumping string 12 and be pumped therefrom by the pump therewithin. Oil and gas pressure from the pay zone may ascend within the casing 16 about the strings 12 and 13 until it reaches a height to counterbalance the gas pressure of the well against the packing 25. This oil and gas pressure forces oil through the mud anchor perforations 72 into the inside of the tubing strings 13 and pumping string 12 to be pumped therefrom by the pump therein to the top of the well.

The lowermost string 13 of suitable short length, with its mud anchor 68 is first inserted in the casing 16 until it rests on the bottom 74 of the well, the string 13 being lowered on a fish, as usual, the fish being temporarily secured to the internal threads. Then the next string is inserted in the same manner, and the coupling 15 on the bottom of the next string has its beveled bottom 17 squeeze the O-ring 19 into a sealing contact with the top beveled surface of the mandrel 14 thus providing a mating, sealed joint that is readily and non-rotatably makable and separable in a vertical direction, as it forces the mandrel 14 downwardly into the well slip assembly 10 to cause the well slip anchor hook heads 24 to secure themselves firmly to the inside wall of the well casing 16 as set forth in detail above, and thus support the weight of the string 13 thereabove. This is repeated with each successive string 13 so that the weight of the strings above the lowest one is carried by the well casing. Then, the topmost string, the pumping string 12, is placed in position, and the packing assembly 25 is sealed against the casing, as described in the aforementioned Howe patents.

If it is necessary to remove the pumping string and/ or the tubing strings, the oil and sand above the pumping head is released through the drain valve forming :part of the pump head 23, as described in the latter mentioned Howe patents, then the packing 25 is released, as in these same patents, whereupon the pumping string 12 may be readily lifted from the well casing 16. A- fish is placed into the threads '78 of the mandrel 14, permitting it to be raised to first release the hook heads 24 from the well casing 16, and then to raise the string 13, and the same procedure is repeated with each lower string until all have been removed if desired.

This invention serves to prevent excessive weight loads on production equipment in deep wells. Some deep wells are skimmed from a point up the hole to prevent excessive weight loads on the production equipment. When this is accomplished with conventional equipment, water accumulates in the bottom of the well, restricting the produc tion. When this restriction in production occurs, it becomes necessary to pull the well and swab or bail the water from the well bore. By running tubing to the bottom and setting the hook wall to support each string thereon on the casing wall, excessive weight loads on the production equipment and accumulation of water in the bottom of the well are prevented.

This equipment, as described, also serves to maintain a controlled hydrostatic pressure in water floods. In some water flood projects, it is necessary to maintain certain hydrostatic back pressure on the formation to force the water through the less permeable portion of the sand, or to prevent it from channeling through previously flooded areas of the reservoir.

With the strings and wall anchor hooks of this equipment, this is acomplished by sealing the pumping tubing to the well casing at a calculated point in the well to maintain the desired back pressure.

This invention has thus provided both an improved slip assembly and an improved hook wall anchor utilizing such Islip assembly and usea'ble in solving different Well probems.

In the drawings, like numbers refer to like parts, and for the purposes of explication, set forth below are the numbered parts of the improved 'Superposed Well Tubing Assembly, and the like:

well slip assembly 12 pumping string 13 tubing string 14 mandrel 15 coupling at bottom of strings 16 well casing 17 bevel on top of 14 a 18 slip assembly collar 19 O-ring in 17 20 slip stem 21 bevel on bottom of 15 22 spaces between stems 20 23 pump head I 24 slip hook head 25 packing assembly 26 spaces between hook heads 24 27 pump rod 28 internal taper on hook head 24 30 point where taper 28 begins 32 attached end of hook head 24 34 free end of hook head 24 36 hook ridges 38 long side of ridges 36 40 short side of ridges 36 42 hook point or edge of ridges '36 44 external taper on mandrel 14 46 coupling between mandrel 14 and pumping string piece 65 48 assembly tube threadedly secured to bottom of mandrel 14 50 packing collar of packing assembly 52 52 packing assembly 54 packing in assembly 52 56 shouldered end of assembly tube 50 58 shoulder on end 56 '60 assembly barrel secured to packing assembly 52 62 coupling for barrel 60 to adapter 64 64 adapter 65 tubing pieces 66 pump barrel in pumping string 12 68 mud anchor at bottom 70 couplings between mud anchor 68 and lowermost string tubing piece 65 72 perforations in mud anchor 68 74 oil well bottom 76 oil entrance perforations in well casing 16 78 fish receiving threads in mandrel 14 Although this invention has been described in considerable detail, such description is intended as being illustrative rather than limiting, since the invention may .be variously embodied, and the scope of the invention is to be determined as claimed.

Having thus set forth and disclosed the nature of this invention, what is claimed is:

1. A well pumping assembly comprising a well casing, a plurality of superposed individually separate strings of tubing sealingly engaging each other inside said casing, the joining ends of said strings providing a mating sealed joint readily and non-rotatably separable in a vertical direction, and means for supporting each tubing string at its bottom, said means including means on each string, except the topmost string, engageable with the well casing for supporting the weight of the individual string thereabove.

2. The assembly of claim 1, said string supporting means for the lowermost string comprising a mud anchor on the bottom end of said lowermost string arranged to be supported on the bottom of the well and thus carry the weight of the lowermost string.

3. The assembly of claim 1, said string supporting 6 means for each superposed string comprising a hook wall anchor mounted on the top end of each string below the topmost string and arranged to be activated into anchoring position by the weight of the string thereabove resting thereon to thereby support the weight of the string thereabove, said topmost string being a pump string.

4. The assembly of claim 2, said string supporting means for each superposed string comprising a hook wall anchor mounted on the top end of each string below the topmost string and arranged to be activated into anchoring position by the weight of the string thereabove resting thereon to thereby support the weight of the string thereabove, said topmost string being a pump string.

5. The assembly of claim 4 in combination with a pumping barrel and standing valve, said barrel and standing valve being located in said topmost pump string and above the topmost hook wall anchor.

6. The assembly of claim 5, each said hook wall anchor comprising a well slip assembly collar, a plurality of circumferentially spaced apart slip stems integrally extending at one end from said collar in the general direction of the axis of said collar, and a slip hook head integrally extending from the other end of said slip stem, the inner surface of each said hook head tapering toward its unattached end, in combination with a mandrel mounted in the tubing string adjacent to the tapered ends of each said slip hook heads, said mandrel being externally tapered complementary to the internal taper on said hook heads, each said mandrel being manipulable by the weight of the string thereabove to insert its externally tapered surface against the internal tapered surfaces of said slip hook heads to wedge said slip hook heads into anchoring position into the inner surface of the well casing to thus support the weight of the string thereabove on the well casing.

7. A superposed well tubing string assembly comprising a plurality of individual separate superposed tubing strings having their joining ends providing a mating sealed joint readily and non-rotatably separable in a vertical direction, and well casing wall anchor means mounted on the top of each separate tubing string below the topmost pump string, each said well casing wall anchor means being engageable with a well casing for supporting the weight of the individual separate tubing string thereabove.

8. The method of reducing the pumping load in a deep well comprising extending a well casing to below the pay zone, the casing having oil entrance perforations below the pay zone, vertically and non-rotatably inserting separate, joinable tubing strings having contacting and sealing mating string ends into the inserted wall casing, resting the lowermost string on the well bottom, the lowermost string having oil entrance perforation means adjacent its bottom, anchoring the top of each string except the topmost string to the well casing to thereby support the separate string thereabove on the well casing wall, providing a pumping string as the topmost string, and sealing the topmost string to the well casing Wall at -a point adjacent the top of such topmost string, thereby preserving the bottom hole pressure in the well to build up pressure between the well casing and the tubing and thus cause such pressure to lift oil within the tubing to the pumping string tubing.

9. The method of reducing the weight load of pumping equipment on the tubing string in a deep well comprising installing a well casing perforated below the pay zone, inserting a short tubing string having a mud anchor resting on the well bottom and having a well slip hook wall anchor and actuating mandrel at its top, the mandrel having a sealed joint forming surface at its top, successively vertically and non-rotatably inserting further separate strings, each further string having a mandrel actuating joint cooperating mating coupling at its bottom and a similar well slip and actuating mating mandrel at its top, and then a pumping string at the top with a similar bottom mating coupling, whereby each separate upper string actuates the well slip hook wall anchor of the string therebelow to support the weight of the separate upper string on the well casing, and then sealing the pumping string at its top to the well casing .to prevent oil flow thereby between the pumping string and the casing.

10. The method of reducing the weight load of pumping equipment on the tubing string in a deep well comprising providing a top pumping string and lower tubing strings in the form of a plurality of se arate joinable strings, supporting the bottom string on the Well bottom, providing a Well casing hook wall anchor and actuating mating mandrel at the top of each string except the top string and a scalable mating coupling at the bottom of each string except the bottom string, actuating each anchor by the Weight of the string thereabove by vertically and nonrotatably placing the sealable mating coupling of an upper string on the actuating mandrel of a lower string to simultaneously seal the upper string to the lower string and support the weight of the upper string through the actuated anchor on the well casing wall, and sealing the pumping string to the well casing wall adjacent the upper end of the pumping string.

References Cited by the Examiner UNITED STATES PATENTS 2,188,656 1/1940 Giberson 166216X 5 2,720,844 10/1955 Bodine 103 219 2,982,355 5/1961 Rodgers 166 105 3,119,450 1/1964 Evans 166-119 3,170,518 2/1965 Brown 166119 References Cited by the Applicant UNITED STATES PATENTS 2,345,888 4/1944 Scott. 2,674,198 4/1954 Howe. 2,675,200 4/1954 Howe. 15 2,708,001 5/1955 Reed.

2,982,355 5/1961 Rodgers. 3,097,697 7/1963 States.

CHARLES E. OCONNELL, Primary Examiner. 20 J. A. LEPPINK, Assistant Examiner.

Claims (2)

1. A WELL PUMPING ASSEMBLY COMPRISING A WELL CASING, A PLURALITY OF SUPERPOSED INDIVIDUALLY SEPARATE STRINGS OF TUBING SEALINGLY ENGAGING EACH OTHER INSIDE SAID CASING, THE JOINING ENDS OF SAID STRINGS PROVIDING A MATING SEALED JOINT READILY AND NON-ROTATABLY SEPARABLE IN A VERTICAL DIRECTION, AND MEANS FOR SUPPORTING EACH TUBING STRING AT ITS BOTTOM, SAID MEANS INCLUDING MEANS ON EACH STRING, EXCEPT THE TOPMOST STRING, ENGAGEABLE WITH THE WELL CASING FOR SUPPORTING THE WEIGHT OF THE INDIVIDUAL STRING THEREABOVE.

8. THE METHOD OF REDUCING THE PUMPING LOAD IN A DEEP WELL COMPRISING EXTENDING A WELL CASING TO BELOW THE PAY ZONE, THE CASING HAVING OIL ENTRANCE PERFORATIONS BELOW THE PAY ZONE, VERTICALLY AND NON-ROTATABLY INSERTING SEPARATE, JOINABLE TUBING STRINGS HAVING CONTACTING AND SEALING MATING STRING ENDS INTO THE INSERTED WALL CASING, RESTING THE LOWERMOST STRING ON THE WELL BOTTOM, THE LOWERMOST STRING HAVING OIL ENTRANCE PERFORATION MEANS ADJACENT ITS BOTTOM, ANCHORING THE TOP OF EACH STRING EXCEPT THE TOPMOST STRING TO THE WELL CASING TO THEREBY SUPPORT THE SEPARATE STRING THEREABOVE ON THE WELL CASING WALL, PROVIDING A PUMPING STRING AS THE TOPMOST STRING, AND SEALING THE TOPMOST STRING TO THE WELL CASING WALL AT A POINT ADJACENT THE TOP OF SUCH TOPMOST STRING, THEREBY PRESERVING THE BOTTOM HOLE PRESSURE IN THE WELL TO BUILD UP PRESSURE BETWEEN THE WELL CASING AND THE TUBING AND THUS CAUSE SUCH PRESSURE TO LIFT OIL WITHIN THE TUBING TO THE PUMPING STRING TUBING.

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