US3386515A - Well completion apparatus - Google Patents

Description

June 5 M. L. CROW ETAL 3,386,515

WELL COMPLETION APPARATUS 2 Sheets-Sheet l Filed Dec. 5, 1965 F/gJZ INVENTORS 4/0464 1. oeau/ 59 J05 0. FOJZE'R MAP/01V 0. 60kt" June 4, 1968 M. L. CROW ETAL WELL COMPLETI ON APPARATUS Filed Dec. 5, 1965 l K//////// //\f/// /V f I I I 2 Sheets-Sheet 2 INVENTORS MAR/0M 0. A71 6M5 v BYME-MM 3P United States Patent 3,386,515 WELL COMPLETION APPARATUS Morgan L. Crow, Joe D. Foster and Marion 1). Kilgore,

Dallas, Tex., assignors to Dresser Industries, Inc., Dallas, Tex., a corporation of Delaware Filed Dec. 3, 1965, Ser. No. 511,547 6 Claims. (Cl. 166-120) ABSTRACT 0F THE DISCLOSURE A casing packer assembly including a string of casing suspended in a well bore, a formation packer attached to the casing string and arranged to be set against the wall of the well bore, and a slip joint incorporated in the casing string above the packer whereby thermal changes in the casing are absorbed in the slip joint without disturbing the packer or imposing stresses on the casing.

This invention is concerned with a well completion method and apparatus and is particularly concerned with a well completion method and apparatus wherein an oil well may be completed and the casing set therein without the necessity of cementing or other means of rigidly supporting the casing with relation to the well bore so that a slip joint may be incorporated in the well casing to compensate for expansion thereof due to excessive temperature rise in the well bore.

Although useful in the completion of any well wherein temperature variations are encountered, the present invention is especially applicable in wells which are subjected to thermal recovery methods.

In recent years so-called thermal recovery has been widely resorted to wherein hot fluids or vapors are introduced from the surface into the producing formation to lower the viscosity of the oil therein, resulting in an increase in productivity of the formation.

This has been done by several methods. A common method is to inject saturated or super-saturated steam into the well bore at temperatures of 600 F. or greater. Another method is introduction of hot vapors or oil, products of combustion, or heated inert gases at a temperature up to 1000 F.

Such superheated fluids are usually injected into a selected injection well to supply the hot media to the formation, and the lowered viscosity of oil is produced from production wells in communication with the formation. In either event the problem to which this invention is addressed is present.

Another method of thermal recovery is that which is called in situ combustion.

In this method a fire is actually ignited in the producing formation and is sustained by an introduction of combustion-supporting fuel. The heat generated by the in situ combustion passes through the formation to raise the pressure thereof, lower the viscosity of the oil therein, and thereby increase the production therefrom. In the employment of this method excessive rise in temperature creates a problem of undue expansion of the casing.

The linear co-etficient of thermal expansion for steel is approximately 6.9 l0 -6 inches per degree Fahrenheit. Thus, for an average rise in temperature of 100, every 1000 ft. length of easing would undergo a thermal expansion or extension in length of approximately 8.3 inches. For a 500 F. increase in temperature over a length of 5000 it, this extension would amount to approximately 207 inches, or slightly over 17 ft. It will be apparent that the disruptive stresses to which the casing would be subjected, if rigidly cemented into the well bore, and no provision was made to compensate for ex- Patented June 4, 1968 pansion, would in many instances be more than the casing strength could withstand.

Therefore, strictly from a mechanical standpoint alone, assuming that the casing could be cemented in place, the present invention solves a great problem caused by the recent advent of thermal recovery.

However, the problem is accentuated by the fact that cements capable of withstanding the higher temperatures of thermal recovery processes have not been developed as yet, thereby placing an upper limit on the temperature which can be employed in such process.

Inasmuch as the present invention eliminates the necessity of cementing the casing in place and provides means for compensating for expansion of the casing, the thermal recovery process can be practiced to the fullest extent.

It is, therefore, a primary object of the invention to provide a method and apparatus of positioning and anchoring a casing in a well without cementing or otherwise rigidly securing it to the well bore.

Another object of the invention is to provide method and means for positioning a casing in a well bore in such a manner as to allow the casing to expand in response to temperature rise without placing undue stress on the casing.

A still further object of the invention is to provide a combination packer and slip joint positioned in the casing string wherein the packer may be set to provide a combination seal and anchor against the wall of the well bore, and wherein the casing is permitted to expand to compensate for excessive rise in temperature in the well bore without placing undue stress on the casing.

A further object of the invention is to provide a com bination packer and anchor to be set against the wall of the well bore which may be expanded and set by hydraulic force admitted through a tool lowered on a tubing string into the casing.

Another object of the invention is to provide a combination formation packer and slip joint which may be lowered into the well in retracted, unexpanded position, and which has shear elements therein, which may be broken, to permit the packer to be set by hydraulic force injected from the surface, and the slip joint to be disengaged for expansion in response to temperature rise in the well bore.

A still further object of the invention is to provide a formation packer which may be anchored and sealed against the formation by hydraulic pressure injected from the surface, and which may be disengaged, retracted, and retrieved from the well when desired.

A general object of the invention is to provide method and apparatus which permits the maximum employment and benefits derived from the thermal recovery process.

Other and further objects of the invention will become apparent upon reading the detailed specification hereinafter following and by referring to the drawings annexed hereto.

A suitable embodiment of the invention is shown in the attached drawings, wherein,

FIGURE I is a schematic cross-sectional elevational view of the combination of elements making up the in vention, as it would appear when installed in an oil well bore,

FIGURE II is a cross-sectional elevational view of the expansion joint in telescoped position,

FIGURE III is a fragmentary cross-sectional elevational view showing the frangible connection between the mandrel and the external shell of the expansion joint in expanded position,

FIGURE IV is a cross-sectional elevational view of the packer in unexpanded position, showing the hydraulic setting tool positioned in the bore of the packer preparaa tory to applying hydraulic pressure to the packer to expand and set same; and

FIGURE V is a cross-sectional elevational view of the packing element employed with this invention, showing the details of construction thereof.

Numeral references are employed to indicate the various parts shown in the drawings and like numerals indicate like parts throughout the various figures of the drawings.

FIGURE I shows schematically a generalized layout of the various elements of this invention in a well bore 1, which is drilled through various sedimentary or unproductive earth strata, and a relatively compact, well consolidated and impervious caprock 2, into or through a producing formation 3. It is desirable that the packer P be set against a formation of type indicated at 2 in order to provide the best combination seal and anchor, as hereinafter indicated.

A surface string 4 is cemented in the upper portion of the well bore, as indicated at 5, to protect surface strata and fresh water producing strata.

The surface string 4 supports 'a casing head 6, which, in turn, supports at producing casing string 7, as by mating threads 8.

A- telescoping expansion joint I, described in detail in connection with FIGURES II and III, is attached to the lower end of the production casing 7 and positioned in such a telescoped relationship that increases in temperature, causing longitudinal expansion of the production string 7, can be absorbed therein to compensate for such expansion without undue stress to the casing.

A formation packer P, described in detail in connection with FIGURES IV and V, is positioned and set in the wall of the well bore through the impervious cap rock 2, and supports said expansion joint I in its expanded position.

In the event more than one producing zone, separated by impervious layers such as 2, are encountered, it is obvious that the combination of the present invention could be extended, and a like combination formation packer P and expansion joint I could be positioned and used for each of said production zones to compensate for thermal expansion of the casing between said zones.

Referring now to FIGURES II and III, the expansion joint I consists of an upper hollow connection 20, having threads 2% therein for connection to the casing string, and an external tubular shell 21, rigidly attached to said upper connection 26' by mating threads 22. The sealing rings 23 prevent fluid loss or pressure leaks between connection 20 and shell 21.

A lower stop 24 is attached to the exterior sleeve 21 by welding or other suitable means, as indicated at 25, and has an inwardly extending shoulder 26. Spaced keys 27 are carried by the lower stop 24 and are adapted to engage in spaced, downwardly facing slots 28 when the expansion joint is in fully extended position (FIGURE III) in order for torque or rotary motion to be applied therethrough.

The slots 28 are formed on the lower end of a support ring 29, which is attached to the tubular inner mandrel 30 as by welding shown at 31. There is a groove 32 machined in the exterior surface of support ring 29 which is positioned to engage shear screws 33 extending through the lower stop 24 to hold the expansion joint I in fully extended position while being run into the well, as shown in FIGURE III. A multiplicity of seal rings 34 are positioned between the upper end of the support ring 29 and the mandrel head ring 35, which is attached to the mandrel 30 by the mating threads 36.

Referring to the detail drawing of the formation packer P, shown in FIGURES IV and V, an upper connection 40 is adapted to receive in threaded and supporting engagement the mandrel 30 of expansion joint I by mating threads 30a.

Attached to the upper connection 40 by the mating threads 41, is a packer head 42. Also attached to upper connection 40 by mating threads 43 is a tubular mandrel 44 which extends internally and downwardly through the packer P.

Surrounding the mandrel 44 there is a movable head 45, slidably mounted thereon. Seal ring 46 establishes a fluid tight, slidable seal between head 45 and mandrel 44.

Also positioned around the mandrel 44, and between the head 42 and movable head 45, there is a packing memher, generally indicated at 47. The packing member 47 includes a steel spiral 43 of flat material (FIGURE IV) which has one end attached to the head 42 by the upper cap screw 49, and the other end attached to the movable head 45- by the cap screw 56. Between the convolutions of the spiral 48, there are positioned a multiplicity of packing rings 51 made of flexible, deformable material, and preferably impregnated with asbestos fibers or other heat resistant material.

The entire packing member 47 is enclosed in a boot 52 made of a flexible material, of asbestos braid or the like, which is suitably impervious to the action of temperature and well fluids. The boot 52 is attached to heads 42 and 45 at the upper and lower ends by the split rings 53 which are held in place to the head 42 and movable head 45, respectively, by the screws 54.

Attached to the movable head 45 by the mating threads 55, is a cylinder 56 which is supported in the unset position on cylinder support 57. The cylinder support 57 is attached about the mandrel 44 by means of snap rings 58 positioned in grooves provided in the wall of the mandrel.

Shear plugs '59 are carried by the cylinder 56 and are engaged in an external slot 60 provided in the support 57. The shear plugs 5% are adapted to hold the formation packer P in an extended position while running into the well bore. Shear plugs 59 have a predetermined shear value so that they will shear at a predetermined force and allow the setting of the packer after it has been run into the well.

A piston head 61 is positioned between the mandrel 44 and the cylinder 56 in slidable fluid tight relation to each by means of the seal rings 61a. The retracted, running position of the piston head 61 is maintained on the mandrel 44 by the shear plugs 63, which extend through head 61 and engage in a groove 64 cut into the outer surface of the mandrel 44-.

There is an upper frusto-conical surface 65 on the piston head 61 adapted to carry the toothed wedges 66 which are retained thereon by the snap ring 67, engaged in a groove about the head 61. Movement upwardly of the cylinder 56, with relation to head 61 is possible, but the toothed wedges 66, acting between the frusto-conical surface 65, and the inner wall of cylinder 56 effectively prohibits relative downward movement of the cylinder 56 in respect to piston head 61.

The mandrel 44 is further provided with pressure ports 68 through the wall thereof, which are positioned between the movable head 45 and the piston head 61 through which hydraulic pressure may be applied to the area between head 45 and piston head 61.

An hydraulic setting tool H is provided which is adapted to be run into the well on a relatively small, or macaroni, string of tubing 69 from the surface of the well. The setting tool H consists of a tubular mandrel 70 upon which is mounted an upper sealing cup 71, facing downwardly, and a lower sealing cup 72, facing upwardly. Said upper and lower sealing cups are adapted to contain an hydraulic pressure therebetween. Pressure ports 73 are provided through the wall of the tubular mandrel 70, which communicate with the port 68 in the formation packer P for the application of hydraulic pressure from the surface of the well through tubing 69 to set formation packer P in the manner hereinafter described.

In running the equipment described in connection with this invention, the expansion joint I is made up on the bottom of the production casing string 7 and the formation packer P is attached thereto.

The shear plugs 59 of the formation packer P are in place, the packing element 47, and its connected cylinder 56, are held in the extended position thereby, and running clearance is thus provided between the packer P, and the well bore 1.

The shear plugs 33 of the expansion joint I are engaged in the slot 32 (FIGURE III) of the support ring 29 and thereby holds the expansion joint in the fully extended position for running-in purposes.

It is important that the expansion joint be in this extended position while running, and immediately thereafter, inasmuch as the temperature in the well at that time is as low as will be met, and compensation for expansion of the casing string 7 must be provided for when subsequent thermal recovery processes are started to cause the temperature to which the casing string is exposed to increase. The length of the stroke provided by the expansion joint which is necessary to compensate for the expansion of the casing string can be precalculated by considering the'depth to which the equipment is to be run and the expected differential in temperature which the casing string will be subjected.

When the formation packer P has been positioned opposite the impervious cap rock formation 2, as determined by log readings or other well known procedures, the casing string 7 is hung in the well head 6 by conventional means.

After running the packer and expansion joint in the well the hydraulic setting tool H is run inside of the casing string 7 on a relatively small or macaroni tubing string 69 and positioned with the hydraulic ports 73 in the running tool mandrel 70 opposite the ports 68 in the packer mandrel 44 and with the upper and lower sealing cups 71 and 72, respectively, bridging said ports 68 in the packer mandrel.

Hydraulic pressure is then applied from the surface through the macaroni string 69 and acts between heads 45 and 61 to cause the movable head 45 to move upwardly relative to the mandrel 44 and thereby compress the packing element 47 into sealing and supporting engagement with the impervious formation 2 (FIGURE I). It should be noted that the steel spiral plate 48, which was originally in an extended position, will increase diametrically as the sealing element 47 is compressed axially and will bite into said impervious formation 2 to aiford mechanical support to the packer P.

As the hydraulic force is applied through the ports 68, the shear plugs 59 shear at a predetermined shear value, but the shear plugs 63, which have a predetermined shear value relatively higher than the plugs 59, are not sheared.

Shear plugs 63, with their higher shear value, are adapted to shear only when the entire mechanism of this combination is retrieved. Plugs 63 may be sheared by upward pull on the casing string when it is desired to retrieve the packer.

When shear plugs 63 shear, the piston head 61 is released to allow cylinder '56 to move downwardly thereby permitting packing element 47 to extend axially and decrease diametrically so the packer can be retrieved from the well on the casing string 7.

In the original unset position of the packer P the shear plugs 33 in the expansion joint are in place and unsheared. However, after the packer is set, and the thermal cycle has begun, either due to injection of steam, hot vapors, or the production of hot fluids in the formation in a production well, the relatively long length of the casing string 7 will increase in temperature, its length will increase enormously, and the shear plugs 33 will shear, allowing the shell 21 to telescope downwardly over the mandrel 30 of the expansion joint and compensate for the expansion of the casing string, as shown in FIGURE II.

It should be noted that this invention can be practiced with or without additional well tools inside of the production casing string 7, such as packers, valves, tubing,

CIC.

As shown in the schematic drawing of FIGURE I an additional string of pipe 73 may be run into casing 7 and suspended from well head 6 by mating threads 74, and may 'be sealed to the casing 7 by a packer 75.

It should be further emphasized that in wells containing two or more productive zones separated by impervious and well consolidated strata, the invention can be practiced by the addition of an expansion joint and formation packer for each such production zone. In these cases, the stroke of the expansion joints would be calculated according to the length of each additional assembly, including said expansion joint and packer and necessary casing.

It will be obvious that other and further embodiments of the invention may be devised without departing from the spirit and scope of the appended claims.

Having described our invention we claim:

1. In a well packer useful in a well bore, a head; a tubular mandrel attached to the head; a support ring slidably and sealing disposed about the mandrel in Spaced relationship to the head; a spirally arranged deformable packing element disposed about the mandrel between the head and the support ring; a spirally arranged metal wall gripping member disposed in the convolutions of said packing element having one end connected to said head and another end connected to said support ring; a cylinder attached to the support ring and extending downwardly about the mandrel, there being an annular space between the cylinder and the mandrel; anchoring means between the cylinder and the mandrel and being arranged to permit upward movement of the cylinder with relation to the mandrel but preventing downward movement thereof; frangible means connecting the cylinder to the mandrel arranged to be broken upon application of hydraulic pressure between the ring and the anchoring means; and means to admit hydraulic pressure from the mandrel to the area between the ring and the anchoring means to move said cylinder upwardly to deform said packing element into sealing engagement with the wall of the well bore.

2. Means for completing a well, having a well bore with a producing formation communicating therewith, comprising, a well head attached at the upper end of the well bore; a string of casing suspended to the well head and extending downwardly in the bore; a formation packer attached to the casing string arranged to be set against the wall of the well bore above the producing formation; first shearable means holding the packer in retracted position; an hydraulically actuated means to break the said first shearable means and expand the packer into sealing and anchoring engagement with the wall of the Well bore; second shearable means to hold the packer in expanded poistion, said second shearable means being of higher shear value than said first shearable means; and a slip joint incorporated in the casing string above the packer comprising telescoping members arranged to move longitudinally with relationship to each other in response to thermal expansion of the casing.

3. Means for completing a well, having a well bore with a producing formation communicating therewith, comprising, a wellhead attached at the upper end of the well bore; a string of casing suspended to the well head and extending downwardly in the bore; a formation packer attached to the casing string arranged to be set against the wall of the well bore above the producing formation; a slip joint incorporated in the casing string above the packer comprising telescoping members arranged to move longitudinally with relationship to each other in response to thermal expansion of the casing; and said packer including a head attached to one of the telescoping members of the slip joint, a tubular mandrel attached to the head, a support ring slidably and sealingly disposed about the mandrel in spaced relationship to the head, a spiral member disposed about the mandrel having one end attached to the head and the other end attached to the support ring, packing material disposed in the convolutions of the spiral, a sleeve secured to the support ring and extending downwardly about the mandrel, there being an annular space between the sleeve and the mandrel, an expander member disposed about the mandrel within said annular space, and being sealingly disposed with relation to the mandrel and the sleeve, anchor means between the expander member and the sleeve arranged to permit upward movement but not downward movement of the sleeve with relation to the mandrel, frangible means connecting the sleeve to the mandrel, frangible means connecting the expander to the mandrel, the last-named frangible means being shearable at a higher shear value than the first-named frangible means, and means to admit hydraulic pressure from the mandrel between the expander member and the support ring sufficient to shear the firstnamed frangible means and move the support ring and sleeve upwardly to expand the spiral member and packing material.

4. The combination called for in claim 3 wherein the means for admitting hydraulic pressure between the expander member and the support ring comprises at least one port through the wall of the mandrel communicating with the space between the expander member and the support ring and a hydraulic tool comprised of a support mandrel attachable to a tubing string arranged to be lowered into the well from the Surface, said support mandrel being closed at its lower end and having at least one passage through the wall thereof arranged to be positioned opposite the port; and spaced seal members on the support mandrel engageable with the wall of the tubular mandrel above and below the port and passage to confine and direct hydraulic pressure injected through the tubing string from the surface.

5. In a well packer, a head; a tubular mandrel attached to the head; a support ring slidably and sealingly disposed bout the mandrel in spaced relationship to the head; a deformable packing element disposed about the mandrel between the head and the support ring; a cylinder attached to the support ring and extending downwardly about the mandrel, there being an annular space between the cylinder and the mandrel; anchoring means between the cylinder and mandrel providing a seal between the cylinder and the mandrel and being arranged to permit upward movement of the cylinder with relation to the mandrel but preventing downward movement thereof; frangible means connecting the cylinder to the mandrel arranged to be broken upon application of hydraulic pressure between the ring and the anchoring means; shearable means conmeeting the anchoring means and the mandrel, which shearable means has a higher shear value than the frangible means connecting the cylinder to the mandrel; and means to admit hydraulic pressure from the mandrel to the area between the ring and the anchoring means.

6. In a well packer, a head; a tubular mandral attached to the head; a support ring slidably and sealingly disposed about the mandrel in spaced relationship to the head; a deformable packing element disposed about the mandrel between the head and the support ring; a cylinder attached to the support ring and extending downwardly about the mandrel, there being an annular space between the cylinder and the mandrel; anchoring means between the cylinder and the mandrel providing a seal between the cylinder and the mandrel and being arranged to permit upward movement of the cylinder with relation to the mandrel thus preventing downward movement thereof; frangible means connecting the cylinder to the mandrel arranged to be broken upon application of hydraulic pressure between the ring and the anchoring means; and means to admit hydraulic pressure from the mandrel to the area between the ring and the anchoring means, said means to admit hydraulic pressure to the area between the ring and shearable means including a hydraulic tool lowerable into the mandrel on a tubing string from the surface, said tool including a tubular Support, port means in the wall of the mandrel to admit hydraulic pressure to the said area, spaced seal members on the tubular support on opposite sides of the port means arranged to seal against the wall of the mandrel, and port means in the tubular support between the seal members arranged to admit hydraulic pressure from the surface through the tubing string between the seal members.

References Cited UNITED STATES PATENTS 2,275,935 3/1942 Baker 166l20 2,352,423 6/1944 Church 166179 X 2,834,415 5/1958 Boer 166-196 X 2,899,218 8/1959 Creighton 285302 3,181,614 5/1965 Brown 166--122 3,191,682 6/1965 Cochran 166l20 3,329,214 7/1967 Ehlert 166-226 3,330,357 7/1967 Elliston l66196 X CHARLES E. OCONNELL, Primary Examiner.

DAVID H. BROWN, Examiner.

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