US2582700A

US2582700A - Pipe suspending device

Info

Publication number: US2582700A
Application number: US69533A
Authority: US
Inventors: Marvin R Jones
Original assignee: Standard Oil Development Co
Current assignee: Standard Oil Development Co
Priority date: 1949-01-06
Filing date: 1949-01-06
Publication date: 1952-01-15
Anticipated expiration: 1969-01-15

Description

. M. R. JONES Jan. 15, 1952 PIPE SUSFENDING DEVICE 2 SHEETS-SHEET 1 Filed Jan. 6, 1949 DERRICK FLOOR FORMATION *SURFAGE CASING INCOMPETENT gin. B.

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SEA LEVEL COMPETENT 6 u a A 8 5 M 2??? a x/a w 7 2 H 2 SHEETS-SHEET 2 M. R. JONES PIPE SUSPENDING DEVICE Filed Jan. 6, 1949 FIG. 2.

Patented Jan. 15, 1952 PIPE SUSPENDING DEVICE Marvin R. Jones, Houston, Tex assignor, by

mesne assignments, to Standard Oil Development Company, Elizabe of Delaware th, N. 5., a corporation Application January 6, 1949, Serial No. 69,533

4 Claims. v 1

This invention relates to new and useful improvements in pipe-suspending devices and relates particularly to devices for suspending and supporting tubular conductors, such as casing and tubing, within a borehole.

In the drilling of wells for oil, gas and other fluids, it is the general practice to employ casing .or pipe to line the walls of the borehole, with successive inner casing strings of gradually diminishing diameter being run in as drilling pro.- ceeds. Ordinarily as in land drilling, the well bore initially traverses a competent formation having sufficient strength to give lateral support .to the outermost casingstring and, said outer casing is usually cemented within said formation. Because the competent formation extends substantially to the Surface, of the borehole and therefore, substantially to the upper end of the casing, said casing has sufiicient lateral reinforcement throughout its length to efiectively support the weight of the inner casing or pipe strings which are suspended from its upper end thereof through the usual casing and tubing head ar rangements at or near the derrick floor,

However, in the drilling of wells at sea or offshore, such as on the continental shelf in the Gulf of Mexico, off coastal Louisiana and Texas, the drilling operation is carried on over water of substantial depth. The borehole initially traverses the formation at the bottom of the ocean and this initial formation is largely of a mucky nature and of insufficient mechanical strength -to impart the necessary or required lateral reinforcement or support to the outer casing. Thus,

the first competent underground formation traversed by the borehole is located a considerable distance below thederrick floor and upper end of the outer casing so. that when the outer casing 'is cemented or anchored in s d comp ten f rmation, the point of anchorage of said casing is .ispaced well below the extreme upper end of the casing The upper portion of the casing which extending through the upper incompetent formation and through the water is substantially 2 tion, it is not practical to suspend or transfer the weight of the inner string of casing or pipe to the outer casing at the upper end of said outer casing through the usual casing and tubing head arrangements because of the instability, due'to lack of lateral support, of said outer casing.

To effectively transfer the weight of the inner pipe or casing string to the outer casingand then to the competent formation, it is necessary to locate the point of suspension of the inner string at an elevation within the outer casing where said outer casing has suflicient strength to transfer the load to the formation. In marine drilling the initial formation below the Ocean floor does not always impart the required lateral support although it may give some lateral reinforcement to that portion of the outer casingwhich extends therethrough. Thus, although it is prob: ably preferable to locate the point of suspension ofthe inner string substantially opposite the cornpetent formation to which the outer casing is anchored, said point of suspension may, in certain instances, be at an elevation above the competent formation. As the casing has sufficient strength at any selected point to efie'ctive'ly transfer the load to the competent formation, the inner pipe string may be suspended Within said casing at that point. Since the point or elevation of support or suspension of the inner string is variable, the suspending means or device for said; string must be capable of setting at a selected level; also, because the inner string is usually cemented or anchored at its lower end, the suspending device must be capable of being set without rotation or manipulation of the inner pipe string and for this reason, the usual hanger or slip-type supporting devices now in general use, are not applicable or satisfactory for supporing the inner string.

It is, therefore, one object of the present invention to provide an improved device for eff ciently suspending or supporting a pipe string within an outer pipe string at a desired level or elevation therein, which device is adapted to be actuated or moved into a set position without the necessity of rotating or otherwiselmanipulating ,the pipe string which it supports,

annular space between said pipe strinesflsaid device bein actuated by hydraulic meanscom trolled from the surface, whereby the device may beselectively set at any predetermined level or 3 elevation without manipulation or rotation of the inner pipe string.

Another object of the invention is to provide an improved hanger device of the slip-type, which will effectively transfer the weight of an inner pipe string to an outer pipe string, whereby said outer string may transfer the load to a competent sub-surface formation to which said outer string is anchored.

A particular object of the invention is to provide a hanger device, of the character described, which is so constructed that normal circulation downwardly through the inner string and upwardly through the annular space exteriorly of said strings may be carried out past the device, whereby a reversal of the circulation downwardly through the annulus functions to actuate the device to suspend or support the inner string within an outer pipe string.

Still another object of the invention is to provide an improved hanger device which is directly connected in the inner pipe string and which has its gripping members normally restrained from movement into actuating position, together with hydraulically operated means for releasing the restraining means, whereby said gripping members may be operated and moved into actuating position to support or suspend the inner pipe string.

The construction designed to carry out the invention will be hereinafter described together with other features of the invention.

The invention will be more readily understood from a reading of the following specification and by reference to the accompanying drawings, '0

wherein an example of the invention is shown, and wherein:

Figure l is a longitudinal sectional view of a "well bore drilled under the ocean and illustrating the improved hanger device supporting an inner pipe string,

Figure 2 is a view, partly in section and partly in elevation of the hanger device and showing the gripping slips in a retracted position,

, Figure 3 is a similar view, with the slips in their expanded or gripping position,

v Figure 4 is a horizontal, cross-sectional view,

taken on the line 44 of Figure 2,

Figure 5 is an enlarged, sectional detail, taken on the line 5-5 of Figure 2, and

Figure 6 is an enlarged sectional detail, taken on the line 65 of Figure 2.

In the drawings, the numeral I0 designates a well bore which has been drilled below the ocean floor and which, as illustrated, first traverses an incompetent structure or sub-surface formation A and then traverses a competent structure or formation B. The outer or surface casing I I extends downwardly from the derrick floor I2 and obviously extends through the water and then through the incompetent structure A, with its lower end projecting into the competent formation B and being cemented therein as'indicated at I3. Obviously, the upper portion of the casing which extends through the water is subjected'to lateral stresses occasioned by the wave action, and this portion of the casing is com- 'pletely without lateral support. The incompetent structure A is usually of a mucky formation and B, and this point is a considerable distance from the extreme upper end of said casing, with the result that the entire upper portion of the casing above the competent structure does not have any appreciable lateral support. For this reason, it is not practical to attempt to suspend an inner casing :from the extreme upper end of the casing I I as is the usual practice in land drilling.

In carrying out the present invention, the improved hanger device indicated at H in Figure l is connected in the inner pipe or casing string I4 and, as will be explained, is adapted to be set at a desired point within the outer casing II to effectively support or suspend the inner string. As illustrated, the device H is locked at a level or elevation substantially opposite the competent formation so that the load or weight of the inner casing I4 is transferred through the device to the outer casing II at a point where said outer casing may effectively transfer that load to the formation B which is competent to carry the same. It is pointed out that the device H may be selectively set at any desired point or elevation within the outer string, provided that the casing at such point has sufficient strength to elfectively transfer the load to the competent formation. The annular space between the inner and outer casings is sealed off or closed at the surface by a suitable sealing means which is shown schematically and indicated at I5 in Figure 1. a

The improved device comprises an elongated tubular mandrel 20 having an axial bore 2| extending entirely therethrough. The mandrel has its upper and lower ends externally threaded whereby it may be connected by means of coupling collars 22 in the inner pipe string I4. The coupling collars are preferably provided with radial projections or guide wings 23 which function to center the mandrel within the outer string and the vertical spaces 24 between the projections 01' wings form fluid by-pass channels to permit passage of fluid past said couplings. The intermediate portion of the exterior surface of the mandrel 20 is formed with a plurality of tapered expanding surfaces or cones 25. Above the uppermost expanding surfaces 25, the exterior surface of the mandrel is reduced as indicated at 26 whereby an external annular shoulder 21' is formed on said mandrel. Above the surface 26, the mandrel is further reduced as indicated at 26.

A plurality of arcuate slip segments 28' are mounted on the mandrel and are adapted to coact with the slip expanding cones. Any desired number of segments may be employed and four of such segments are shown. Each segment is of sufiicient length to extend throughout theexpanding surfaces 25 of the mandrel and said segment has its rear surface provided with tapered sections 29 which are complementary to the tapered expanding surfaces 25. The segments are retained in position on the mandrel by flanged retaining clamps 30 which are secured to the mandrel between the longitudinal edges of adjacent slip members by cap screws 3|. As is clearly shown in Figure 4, the flanges of the clamps overlie longitudinal ribs or projections formed at each longitudinal edge of each slip segment. The clamps are so positioned that the slip segments or members may undergo a limited outward or radial movement when said segments are moved longitudinally with respect to the expanding surfaces 25 of the mandrel; howeventit will be evident that the clamps prevent complete outward displacement of the slip segments from aseegvoo 5. the mandrel. Each slip segment is provided-with longitudinal-grooves or recesses 33 which permit a b'y-pass of-fiuid past the segments. When the slip segments or members 28 are moved upwardly with respect to the mandrel,

the rear inclined surfaces 29 of the segments coact with the-expanding surfaces of the mandrel and move the slips outwardly, whereby gripping teeth 280. on the external surface of the slip segments may engage the-wall of the outer casing l. The slip segments or members are constantly urged toward an upper position with .respect to the mandrel by a coiled spring 34 which surrounds the mandrel beneath the slip segments.

The coiled spring is confined within a-sleeve 35 which sleeve is slidable on the mandrel. The lower end of the spring engagesa followerring 36 which rests upon the upper end of the lower coupling member 22. It will be apparent that the coil spring 34 constantly-exerts its pressure in a direction tending to move the slip segments or members 28 upwardly with respect to the expanding surfaces 25 of the mandrel.

For restraining the slip segments against ".up-

ward movement on the mandrel to hold said slips against movement into a set position, a retaining collar 31 engages the upper end of the-slip segments. The upper portion of the collar encircles the 'lower portion of :an annular piston 38 and is connected to said piston, as well as to the man-.

drel by means of a plurality of shear pins 38. Obviously, with the restraining collar 31 in engagement with the upper end of the slip segments, as shown in .Figure '2, and with said collar fastened to the mandrel by the :shear pins -39,-the slip segments 28 are restrained against upward movement with respect to said mandrel.

The piston 38 which mounted between the restraining collar 31 and the mandrel is slidable on the reduced portion 26 of said mandrel and has its upper end enlarged and encircling the upper reduced portion 26 of said mandrel. This upper enlarged :end 20f the piston .is formed with an annular recess or seat 4|],within which the lower portion of an annular sealing element 4| is mounted. Suitable screws 42 fasten the sealing member 4| to the piston. The sealing member is constructed of rubber 'or other deformable maiterial and includes an inner lip 4|a which engages thesurface 21 of the mandrel and an outer lip 4|.b which is adapted to engage the wall of the outer casing H as the device jis ilowered therethrough. For limiting the upward travel .of the ,piston 38 on the mandrel after the shear pins 39 have been fractured, said piston is formed with a plurality of slots 43 within which screws 44 xtend; the screws are threaded into the mandrel and have their outer portions disposed within said slots. For receiving the fractured shear pins 39 after said shear pins are broken, the outer surface of the piston 38 is formed with vertically extending recesses 45, each recess being in alignment with one of the shear pins (Figure 6).

In the operation of the device, the parts are assembled as shown in Figure 2 with the slip segments or members 28 being in their lowered or retracted position with respect to the expanding surfaces 25 of the mandrel. The segments are locked in this lowered position by means of the restraining collar 31 which, as explained, is fastened to the mandrel by the shear pins 38. The lower end of the piston 38 is also connected to the shear pin between the collar 31 and the mandrel and at this time, the coiled spring 34 beneath the slip segments is inits compressed-position.

. The device is assembled inthe inner or pipe string 14 by means of the coupling colllars .22 and is lowered-with. the inner. strinz through the outercasing. I 4. During such low!- ering, circulation downwardly through them-r her string and upwardly throughrthe annular space between the inner andouter strings is pos- .sible, for obviously; upward circulation the annular space will merely -Icy-pass the outer lip seal'Mb. Itis noted that the extemaldiam eter of the guide wings 230i thescouplingcolilars'zrisslightly larger than thesouter diameter of the retracted slip segments 28-." whereby said-wings prevent the teeth .of said :slip semments from striking orengaging the inner-surface or bore :of' the casing mi l as the deviceishee ing lowered 'therethrough.

When'zi-t is desired to settheldevice, it'ris onl necessary to reverse circulationandpump fluid downwardly through the annular space between the pipe strings 'I I and I4. This fluid pressure will act upon the annular sealing element 41 and will urge the piston 38 downwardly. When the pressure reaches a point suflicient to-fracture the shear pins 39,, said piston 38 moves downwardly into engagement withtheshoulder 21 on the exterior of the mandrelwhich limits down.- ward movement of the piston. Upon fracturing of the shear pins 38., the coil spring acting below the slip segments 28 will immediate- 1y move saidslip segments upwardly onthe expanding surfaces 25 of the mandrel whereby teeth 28a of said slips are moved into gripping enga ement with the inner wall of the outer casing ll. As the slips move upwardly to an expanded position, the restraining collar 31. which is now disconnected from the piston 38 slides upwardly with respect thereto, and-the inner fractured ends of the shear pins 39 .move upwardly within the recesses 45 which areprcvided for this purpose in :the outer surface of the piston. After the slips are :SBt it will-be evident that the weight of the inner string l4 will be transferred through the slips directlyto the outer casing H and said outer casingwill function to transfer the load directly to the competent formation B. After the pins .38 .have been fractured, upward movement of the piston 38 .and its :sealingelement 4| .is by thelimit screws 44 which ride withinthe .slots 43 in the piston.

From the foregoin it will be seen thatwa simple and eflicient hanger :device is provided for supporting an inner pipe or casing string-within an outer pipe or casing. Because the slipsare restrained from moving into an operating position until such time as sufficient fluid pressure is applied to the sealing element 4| and its piston, the device may be selectively set at any desired location within the outer casing. Also.

actuation is effected without the necessity of ward movement of the pipe would tend to cause the v expanding surfaces 25 of v the mandrel to move in a direction with respect to the slips which 7 woulda'llow said slips t'obe released from "gripping engagement-with the outer casing. The device operates entirely within the annulus between the two pipe strings andat all-time's allows an 'upiwardrfiow through the annulus even after the sliptse'gments have been moved to an engaged. or gripping position. The device is positively locked against actuation fduring. its,lowering and the coil spring-. 34 cannot function .to move theslip segments into gripping position untila suflicient pressurehasbeenapplied to the piston to .frac- 'ture the shear pins 39 and: thereby release the restrainingcollar 31. v --..zThe-jioregoing description of the invention is explanatory thereof andvarious changesinrthe size, shape and materials, as well as in -.the details of the ':il1ustrated, construction may be made. within the scope-of the appended claims,.without departing from the spirit'of the invention. xhHaving described the invention, I claim: .F'l. ,Ahangerdevice for supporting a string of .well' pipe including a. tubular mandrel defining with first and'second ends thereof threaded means'for connecting-same into a string of pipe .and-i'definin'g' an internal longitudinal passage- -way1 adapted to allowflow of fluid therethrough 'in' either direction, aplurality of segmental grip- .ping slips mounted on said mandrel and adapted 'to be expanded outwardly into gripping position upon a'longitudinal movementof the slips-relative- 'to-the' mandrel, a coiled spring surround- -in'gfithe .mandrel beneath the gripping slips= and urgingsaid slips upwardly on said mandrel to ward their expanded position, a restraining col-'- lar encircling the mandrel and enga'gingthe up.-';

-per- -endof the slips to maintain the same in'a lowered position against compression of the zsprin'g-fand a shear pin connecting the collar to -thel"niandrel in a position holding" the slips 1 against actuation, whereby the coiled spring can'- 'not function to expand saidslips until said shear pin'is fractured. 2:." A hanger device for supporting astring of "well pipe including a tubular mandreldefining =withfirst and second ends thereof external threads for connecting same into astring of pipe and defining an internal longitudinal passageway adapted to allow flow of fiuidtherethro'ugh' and urging. said slips upwardly on said mandrel toward their expanded" position, a restraining colla'r encircling the mandrel and engaging the upper end of the. slips to maintainthe, same in a lowered positionagainst compression of, the spring, a shear-pinconnecting the collar to the mandrel in a position holding the slips against actuation, :Whereby ,the coiled spring cannot function to expand'said slips until said shear pin is .fractured,; ,andQ-an annular piston slidably mountedon thejmandrel above the restraining collar and adaptedto fracture said shear pin upon downward movementof the collar, with re: spect to the mandrel, said piston being hydrau lically actuated to-fracture said pin and thereby release the slips foractuation.

A hanger, device-as set, forth in claim 2, wherein the piston'includes an annular lip-type sealing. member: which will allow flow upwardly thereby but will be actuated by a downward pressure exerted ,thereagainst. 7

= 4. A hanger device for supporting a string of well pipe including'a tubular mandrel defining with first and second ends thereof threaded means for connecting same into a string ofpipe and defining an internal longitudinal passageway adapted to allow flow of fiuid therethrough in either direction, a plurality, of segmental gripping slips mounted on said mandrel and adapted to be expanded outwardly into gripping position upon a longitudinal movement of the slips relative to the mandrel, spring means mounted on the exterior of the mandrel below the slips en;- gaging a lower end of said slips and urging the slips upwardly on said mandrel toward a gripping position, a restraining collar encircling the mandrel and engaging anupper end of the slips to maintain the same in a lowered position against compression of the spring, and a shear pin connecting the collar to the. mandrel in a position holding the slips against actuation, whereby thespring cannot function to expand said slips until said shear pin is, fractured.

' MARVIN R. JONES.

, REFERENCES CITED 7 The following referencesrare of record in the file of this patent: V

UNITED STATES PATENTS