FAC tool flexible assembly and method

Abstract

A flexible assembly is provided for a fill-up and circulation (FAC) tool. The flexible assembly preferably comprises a flexible hose portion and a rigid tubular housing portion. The flexible assembly is attached to the tool body of the FAC tool below the casing seal of the FAC tool. The casing seal is utilized for sealing with an interior surface of an upper joint of a casing string. Preferably a tapered guide is provided at a lower end of the flexible assembly and a fluid outlet may preferably be formed in the tapered guide. The flexible assembly preferably has an overall length such that the tapered guide is positioned within the interior of the upper joint of the casing string when the fill-up and circulation tool is attached to a standard traveling block assembly and the elevator casing gripping slips attached to the traveling block assembly are engaged with the upper joint of the casing string.

Description

FIELD OF THE INVENTION

[0002] This invention relates to fill-up and circulating (FAC) tools utilized during completion of subterranean wells, and more specifically to a flexible assembly for a fill-up and circulation (FAC) tool.

BACKGROUND OF THE INVENTION

[0003] Fill-up and circulation tools are well known in the prior art. An exemplary fill-up and circulation (FAC) tool is described in U.S. Pat. No. 5,584,343, issued Dec. 17, 1996, to the present inventor Malcolm G. Coone of Davis-Lynch, Inc., Pearland, Tex., and is hereby incorporated herein by reference in its entirety. This FAC tool is provided in a unitary construction to thereby perform both fill-up and circulating functions whenever needed as is especially useful when running casing.

[0004] The procedure for drilling and completing subterranean wells to recover, for example, oil and gas from a reservoir, consists of boring a hole in the earth down to the reservoir of interest and installing pipe from the reservoir to the surface. Casing is used as a protective liner within the well bore that is cemented in place to insure a pressure-tight connection to the oil and gas reserve. The casing consists of lengths of tubulars, or joints. Casing is typically run into the well bore one joint at a time. Casing is lifted and lowered by the traveling block of the rig. As the casing is run into the well bore, it is often desirable to fill the casing with fluid. For example, drilling fluid may be added to the casing string to provide counter-pressure against the interior walls of the casing string to prevent the casing from being damaged by the high pressures encountered in the well bore and/or to aid the rig equipment in lowering or floating the casing string into the wellbore.

[0005] The fill-up and circulation tool is mounted to the traveling block for movement with the traveling block and is fluidly connected to the rig fluid pumps through a hose or other piping means. The fill-up and circulation tool must be positioned such that at any desired time, the fill-up and circulation tool can be used to fill the casing. However, the elevators will typically have a particular length of bails, which may typically vary, depending on the particular rig, and may also depend on dimensions, construction, and other casing running equipment such as spiders, various platforms, and the like. Thus, prior art fill-up and circulation (FAC) tools may provide means for adjusting the length of the FAC tool to position the FAC tool so as to be ready for filling the casing.

[0006] However, the FAC tool also provides fluid circulation functions. The unfinished well bore has rough sides of raw earth, and on occasion, the casing becomes stuck against irregularities in the sides of the well bore as it is lowered down. If this occurs, it may be desirable to circulate fluid through the well. The FAC tool provides this function without the need to threadably attach a circulating head to the top of the casing, thereby saving significant time and money. In this case, a seal on the FAC tool is then typically lowered into the uppermost casing joint by moving the traveling blocks while holding the uppermost casing joint in position, such as with a spider assembly. After insertion of the seal into the casing joint, circulation may begin whereby fluid is circulated down the casing string and out the lower end thereof. The fluid exits the casing and flows into the annular space between the external side of the casing and the sides of the well bore to wash material therefrom and free the casing from the well bore. The fluid then returns to the surface whereupon it is filtered after which the fluid may be pumped to circulate through the casing string again. The relative spacing of a fill-up and circulation tool should preferably be the same for both the fill-up function and the circulation functions.

[0007] Therefore, in the prior art, it was often necessary to adjust the length of each FAC tool for the particular spacing needed with a particular drilling/workover rig configuration. This may have required adding or removing extension sections and may also have been accomplished by other time consuming means which required measurements of rig equipment, extra mechanical connections, adjustments, and so forth.

[0008] Other factors which may complicate the length adjustment may include the need for occasionally adding weight to the casing string to force the casing down through rough spots in the wellbore while typically circulating fluid down the interior of the casing at the same time. Thus, the length adjustment should be built with such requirements in mind.

[0009] During circulation, the fill-up and circulation tool may experience high pressures from the wellbore. These pressures act to force the tool up and out of the casing. Traditionally, such tools are prevented from being pushed out of the casing merely by the traveling block to which the tool is attached and the hook or other assembly which attaches the tool to the traveling block. Sometimes the traveling block may have a push plate to push the tubular into the borehole. In accord with the patent application to this continuation-in-part, i.e., U.S. patent application Ser. No. 09/557,229, a “tie-down” is provided to prevent the tool from being ejected from the casing by down hole pressures. Thus, the length assembly of the present invention may therefore preferably operate with or without such a tie-down. The tie-down has many advantages as discussed in detail in the parent to this application.

[0010] Those skilled in the art will appreciate the present invention which addresses the above and other problems.

SUMMARY OF THE INVENTION

[0011] It is an object of the present invention to provide an improved FAC tool.

[0012] It is another object of the present invention to provide a flexible lower assembly for the FAC tool.

[0013] A feature of a preferred embodiment of the present invention is a lower assembly comprising a flexible hose.

[0014] Another feature of a preferred embodiment of the invention is a rigid tubular attached to the flexible hose.

[0015] It is an advantage of the present invention to utilize the flexible lower assembly of the present invention for a wide range of rig constructions including elevators with widely different bale lengths.

[0016] It is another advantage of the present invention to enable the flexible lower assembly to be easily stabbed into a casing joint that may be askew from the vertical.

[0017] These and other objects, and/or features, and/or advantages of the present invention will become apparent from the drawings, the descriptions given herein, and the appended claims. However, it will be understood that above listed objectives of the invention are intended only as an aid in understanding aspects of the invention, are not intended to limit the invention in any way, and do not form a comprehensive list of objectives, and/or features, and/or advantages of the invention.

[0018] In accordance with the present invention, an assembly for a fill-up and circulation tool is provided wherein the fill-up and circulation tool may be operable with a rig when inserting a casing string into a wellbore. The fill-up and circulation tool may comprise a tool body and a casing seal mounted to the tool body for sealing with an interior surface of an upper joint of the casing string. The rig may comprise a traveling block assembly to which the fill-up and circulation tool is attachable. Casing gripping slips may preferably be mounted to the traveling block assembly for engaging the upper joint of the casing string. The assembly may comprise one or more elements such as, for instance, a flexible hose secured to the tool body of the fill-up and circulation tool, and a rigid tubular housing secured to the flexible hose whereby the rigid tubular housing is insertable into the upper joint of the casing string.

[0019] The assembly may further comprise a guide forming a lower end of the rigid tubular housing. The guide may preferably be operable for guiding insertion of the FAC tool into the upper joint of the casing string. The guide may preferably have a tapered surface and/or the guide may define a fluid outlet.

[0020] Preferably, an overall length of the flexible hose and the rigid tubular housing is provided such that the guide is positioned within an interior of the upper joint of the casing string when the fill-up and circulation tool is attached to the traveling block assembly and the casing gripping slips are engaged with the upper joint of the casing string. In one preferred embodiment, the flexible hose supports a lower rigid tubular assembly. The casing seal of the FAC tool may be above the flexible hose. The rigid tubular housing may define a fluid outlet.

[0021] In one embodiment, an assembly is provided for use with a subterranean drilling rig when running a casing string into a wellbore and wherein the casing string may have an upper joint of casing. The assembly may comprise one or more elements such as, for instance, a rig with a traveling block, an elevator, elevator slips mounted to the elevator, and bails connecting the traveling block with respect to the elevator. A fill-up and circulation tool is attachable to the traveling block of the rig in accord with the present invention. The fill-up and circulation tool may comprise a tool body and a casing seal operable for sealing with the interior of the upper joint of casing and a flexible hose secured to the tool body for insertion into the upper joint of casing.

[0022] The assembly may further comprise a rigid tubular secured to the flexible hose at an opposite end thereof from the tool body. The tapered guide is preferably attached to a lower end of the rigid tubular. The flexible hose and the rigid tubular in combination have an overall length such that at least a portion of the flexible hose and an entire length of the rigid tubular is positioned within an interior of the upper joint of the casing string when the fill-up and circulation tool is attached to the traveling block assembly and the casing gripping slips are engaged with the upper joint of the casing string.

[0023] A method for constructing the flexible lower assembly of a fill-up and circulation tool for use in a subterranean well may comprise one or more steps such as, for instance, mounting a flexible hose to the tool body; and mounting a rigid tubular to the flexible hose on an opposite side of the flexible hose from the tool body.

[0024] The method of claim may further comprise other steps such as providing a guide at a lower end of the rigid tubular wherein the guide may be insertable into the upper joint of the casing string. Additional method steps may comprise providing a tapered exterior surface on the guide and/or forming a fluid outlet adjacent the rigid tubular and/or providing an overall length of the flexible hose and the rigid tubular such that rigid tubular is completely contained within an interior of the upper joint of the casing string when the fill-up and circulation tool is attached to the traveling block assembly and the casing gripping slips are engaged with the upper joint of the casing string.

[0025] The invention is best understood by the following detailed description taken in conjunction with the drawings. These are intended as only illustrative and not limitative, as the invention may admit to other embodiments to these of skill in the art.

BRIEF DESCRIPTION OF THE DRAWINGS

[0026] A more complete understanding of the invention and many of the attendant advantages thereto will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in conjunction with the accompanying drawing wherein corresponding reference characters indicate corresponding parts throughout several views of the drawings and wherein:

[0027] FIG. 1 is a front view of a FAC tool rig assembly shown in partial cross section and showing the present tie-down tool;

[0028] FIG. 2 is a top view of a tie-down tool sub assembly of the present invention; and

[0029] FIG. 3 is a detail of FIG. 1 showing a tie-down connection to the lower eye of the bails.

[0030] While the present invention will be described in connection with presently preferred embodiments, it will be understood that it is not intended to limit the invention to those embodiments. On the contrary, it is intended to cover all alternatives, modifications, and equivalents included within the spirit of the invention and as defined in the appended claims.

PREFERRED EMBODIMENTS OF THE INVENTION

[0031] Referring now to the drawings and, more particularly to FIG. 1, a fill-up and circulating (FAC) tool 1 is shown as an example to illustrate the present tool tie-down. FAC tool 1, in many ways, is substantially similar to the FAC tool described in U.S. Pat. No. 5,584,343. FAC tool 1 includes a radially expandable sealing or packer section 2, a flexible hose 3, non-flexible and typically metallic tubular sub 4, and guide cone 4A. The valve, as contained by FAC tools, may preferably be included in sub 4 or guide cone 4A. However, the valve could be located elsewhere as desired. A typical valve assembly that may be used with the present invention is shown and discussed in some detail in U.S. Pat. No. 5,584,343. Other valve assemblies could also be utilized which preferably shut off fluid flow after the pumps stop to avoid drainage onto the rig floor and provide a relief valve to relieve pressure below the valve after circulation.

[0032] Essentially, flexible hose 3 and sub 4 form the flexible assembly of the present invention in conjunction with FAC tool 1. Flexible hose 3 permits the flexible assembly of the present invention to be easily stabbed (inserted) into any joint of casing, such as casing joint 26, during the casing running process even if the casing joint is askew from the vertical as may often occur when stabbing. Thus, the necessary length is not constrained by the particular rig configuration and/or angle at which FAC tool 1 is stabbed into casing joint 26. On the other hand, flexible hose 3 and sub 4 are provided to be sufficiently long so that with virtually any standard length of bales 30, outlet 10 remains inside of casing joint 26. Thus, in accord with the present invention, a standard assembly of flexible hose 3 and sub 4 can be used with virtually any oil well rig configuration. The assembly therefore saves the time and cost of utilizing well experts to calculate the necessary length of FAC tool 1 and the time and cost of extending/reducing the length thereof. Moreover, no additional or alternative assembly components are needed or required for various rig configurations. Therefore, the flexible length assembly of the present invention substantially reduces costs for each use due to a more simplified operation.

[0033] Sub 4 will typically be a metallic cylindrical housing and preferably has a length and weight sufficient to prevent, under any circumstances, outlet 10 pointing upwardly or being able to whip out of the interior of casing joint 26. Sub 4 will typically be greater than one foot long and may preferably be constructed to be in the range of from about two to ten feet in length. Flexible hose 3 may be approximately in the same range of length of sub 4. However, flexible hose 3 may be shorter than sub 4 or could be longer than sub 4, if desired.

[0034] Sub 4 and/or guide cone 4A may typically include a pressure operated valve with reverse flow check valves, which may be of a common type used in FAC tools such as the valve assembly, check valves, and so forth shown in the aforementioned U.S. Pat. No. 5,584,343. The valve assembly may be located in guide cone 4A, in the body of sub 4, or as desired. Thus, when filling the casing string, fluid will flow through FAC tool 1, through flexible hose 3, through sub 4, open the pressure operated valve wherever the valve is located, and flow out through outlet 10. Normally, packer 2 is outside of the top casing joint, such as casing joint 26, during filling.

[0035] When it is desired to circulate, the traveling block, bales 30, slips 20, and FAC tool 1, are lowered with respect to the top casing joint, such as casing joint 26, until packer 2 is inserted within the top casing joint. Fluid is pumped in the same way as explained above and packer 2 seals pressure therebelow. Packer 2 may be of many constructions and types of seals although details of a preferred packer assembly is disclosed in U.S. Pat. No. 5,584,343. Once circulation has been completed, then FAC tool 1 can be withdrawn, and the process of running the casing can continue, if it is not already complete.

[0036] The flexible length assembly of the present invention may be utilized with a tie-down assembly, if desired. Such a tie-down assembly is described hereinafter.

[0037] Upper mandrel 5 is connected to sealing section 2, which may not comprise a packer or other type of sealing assembly. Upper mandrel 5 comprises a threaded portion 6 distal to sealing section 2. The top end 7 of the tool is threadedly connected to threaded portion 6 of upper mandrel 5, comprises upper port 8, and is connected to a standard rig traveling block hook 51 by means of a U-bolt yoke mechanism 9. At the other end, guide cone 4A is equipped with a lower port or outlet 10. Fluid may be pumped downhole through ports 8 and 10. The FAC tool 1 may be a filling and circulating tool, depending on the position of sealing section 2, such as described in the '343 patent. Those skilled in the art, however, will appreciate that FAC tool is presented herein only as an example to illustrate the present tool tie-down, and that a variety of tools other than FAC tools will benefit from the present invention tie-down tool.

[0038] Elevator slips 20 grip casing 26 below casing collar 28. Slips 20 comprise slip eyes 22 and grippers 24. Bails 30 connect slips 20 to the traveling block as shown which supports the weight of the casing. Tie-down yoke mechanism 32 of the present invention, has an unthreaded bore 34 which slides over the upper threaded part of mandrel 5. The tie-down yoke 32 is limited in downward movement by vertical tightening sleeve 33 to secure tie-down yoke mechanism 32 in a desired vertical position on mandrel 5 and against upward movement by force from below. The sleeve 33 is threadedly attached to FAC tool mandrel 5. Typically, the tie-down yoke mechanism 32 maybe positioned with respect to mandrel 5 by sliding tie-down yoke mechanism 32 and screwing sleeve 33 down on mandrel 5 at threaded portion 6 prior to installing top sub 7. Then tightening sleeve 33 upwardly on mandrel 5 against the bottom of yoke 32 to secure yoke mechanism 32 in a desired vertical position on mandrel 5. Tie-down yoke mechanism 32 may be mounted with the ends surrounding bails 30 in a snug, but slideable relationship such that bails 30 prevent rotation of tie-down yoke mechanism 32. Tie-down yoke mechanism 32 may be frictionally engaged with bails 30 as controlled by horizontal tightening bolts 40. An outer arm portion 42 of yoke mechanism 32 may be formed to accommodate links 30. Horizontal tightening bolts 40 also frictionally secure tie-down connectors or eyes 44 to tie-down yoke mechanism 32.

[0039] Tie-down members 46 comprise cord members, fabricated, for example, a metal or metal alloy, a fiber, or combinations thereof, and connects tie-down yoke mechanism 32 to bails 30, which in turn are connected to elevator slips 20. Tie-down connector 44 may loop through upper (or top) tie-down eye 48 or eye 40 at one end, and lower tie-down eye 50 may loop through lower eye 52 of bail 30, at the other end. Other interconnections and variations, which may or may not include other clamps, u-connectors, and the like, may also be utilized depending on the rigsite situation.

[0040] Tie-down members 46 preferably comprise a material having high tensile strength. The tensile strength should be sufficient so that one or more tie-down members is able to secure a tool in a desired position in the casing against the back pressures and forces acting on the tool. A suitable material may be selected by estimating the forces that will be encountered, and selecting a material of known strength from which to fabricate tie-down members 46. The properties of a suitable material for tie-down 46 include a high strength to weight ratio, low stretch characteristics, i.e. inelastic, high wear and flex fatigue resistance, and low- to non-rotational characteristics. It would also be useful if the material could be spliced readily. The material should also tolerate the extreme temperature, acid, caustic, and corrosive conditions that maybe encountered in the field.

[0041] An example of a suitable tie-down material is Amsteel Blue™ (formerly Spectron 12 plus™), a commercially available synthetic fiber available from The American Group. Amsteel Blue™ has sufficient tensile strength, exceeding that of metallic steel, and also tolerates well the extreme temperature, acid, caustic, and corrosive environments that may be encountered at a drilling site or downhole. Amsteel Blue™ is recommended for a variety of applications, including mooring lines, tug assist lines, face and wing wires, seismic tow lines, winch lines, pulling lines, wire rope replacement, and of particular note for specialty rigging lines. Amsteel Blue™ also floats, a feature which may be useful for offshore operations.

[0042] In addition to synthetic or composite fibers, the material of tie-down member 46 may comprise a unitary metallic wire or metallic threads woven together. Tie-down member 46 may further comprise a composite of synthetic fibers and metallic wire woven together to form a cord. In short, the cords may be fabricated, for example from an elastomer, a metal or metal alloy, a fiber, or combinations thereof.

[0043] The material may be woven or braided, such as in a rope, to form upper and lower tie-down eyes, 48, 50, respectively. Braiding the material to form the eyes may be accomplished by providing a length of braided material, forming loops at either end of the length and then joining the ends to the body by splicing such as by braiding or weaving the ends into the body. Alternatively, the material may be formed to comprise loops or other suitable linkages.

[0044] FIG. 2 is a top view of tie-down yoke mechanism 32. Bails 30 are sandwiched by outer arms or plates 54 of yoke mechanism 32. Plates 54 can be tightened against bails 30 with shackle 40. Shackle 40 comprises a tightening bolt which connects opposing plates 54 whereby shackle 40 can be tightened against plates 54 to contain bails 30. Yoke mechanism 32 further comprises unthreaded bore 34 sized to receive mandrel 5.

[0045] FIG. 3 is a detail of lower tie-down connection 52. Tie-down eye 50 is looped through bail eye 52 in the same way a suitcase tag with an elastic loop is looped through the handle of a suitcase. In this way, tie-downs can be attached to a bail eye without any special subassembly or connectors. This is an advantage of using a cord over using steel links. Steel links are rigid, and require connecting hooks and blocks to attach to the rigid link eyes of steel links to the rig. The flexible tension member, or tie-down, of the present invention requires no additional equipment to connect the tie-down yoke mechanism 32 to the bails.

[0046] Thus, in operation the flexible length assembly of the present invention, which includes flexible hose 3 and non-flexible tubular section 4, may be stabbed into each joint of casing as slips 20 are lowered over the top of the joint of casing. When FAC tool 1 is connected to the traveling block, such as through traveling block hook 51, and slips 20 engage the top of upper casing joint 26 for gripping purposes, then the flexible length assembly comprising flexible hose 3 and non-flexible tubular section 4 has a combined length such that outlet 10 through which fluid exits FAC tool 1, is within the interior of upper casing joint 26 and preferably, such that packer 2 is above the top of upper casing joint 26. It is preferable, for the sake of avoiding wear on packer 2, that packer 2 be mounted so as to remain above the top of upper casing joint 26 during normal casing fill-up operation. If circulation is necessary, then spiders, slips, or other gripping means, are activated so that casing joint 26 is supported by the spiders and/or other gripping devices so as to be fixed in position. Traveling block hook 51, bales 30, slips 20, and FAC tool 1, may then be easily lowered with respect to casing joint 26 such that packer 2 engages and seals with the interior of casing joint 26. Circulation may then be instigated and continue so long as desired. After circulation is completed, traveling block hook 51, bales 30, slips 20, and FAC tool 1 may be raised with respect to casing joint 26. Slips 26 may then engage casing joint 26 and thereby lower the casing string into the wellbore as desired.

[0047] The foregoing descriptions may make other variations or embodiments apparent to those of skill in the art. It is the aim of the appended claims to cover all such changes and modifications which fall within the true spirit and scope of the invention.

Claims

1. An assembly for a fill-up and circulation tool, said fill-up and circulation tool being operable with a rig when inserting a casing string into a wellbore, said fill-up and circulation tool comprising a tool body and a casing seal mounted to said tool body for sealing with an interior surface of an upper joint of said casing string, said rig comprising a traveling block assembly to which said fill-up and circulation tool is attachable, and casing gripping slips mounted to said traveling block assembly for engaging said upper joint of said casing string, said assembly comprising: a flexible hose secured to said tool body of said fill-up and circulation tool; and a rigid tubular housing secured to said flexible hose for insertion in said upper joint of said casing string.

2. The assembly of claim 1, further comprising a guide forming a lower end of said rigid tubular housing, said guide being operable for insertion into said upper joint of said casing string.

3. The assembly of claim 2, wherein said guide has a tapered surface.

4. The assembly of claim 2, wherein said guide defines a fluid outlet.

5. The assembly of claim 2, wherein an overall length of said flexible hose and said rigid tubular housing is such that said guide is positioned within an interior of said upper joint of said casing string when said fill-up and circulation tool is attached to said traveling block assembly and said casing gripping slips are engaged with said upper joint of said casing string.

6. The assembly of claim 1, wherein said flexible hose is attached secured between said rigid tubular assembly and said casing seal.

7. The assembly of claim 1, wherein said rigid tubular housing defines a fluid outlet.

8. An assembly for use with a subterranean drilling rig when running a casing string into a wellbore, said casing string having an upper joint of casing, said assembly comprising: a rig having a traveling block, an elevator, elevator slips mounted to said elevator, and bails connecting said traveling block with respect to said elevator; a fill-up and circulation tool attached to said traveling block of said rig, said fill-up and circulation tool comprising a tool body and a casing seal operable for sealing with an interior of said upper joint of casing, said fill-up and circulation tool being mounted to said traveling block for movement with said traveling block; and a flexible hose secured to said tool body for insertion into said upper joint of casing.

9. The assembly of claim 8, further comprising: a rigid tubular secured to said flexible hose at an opposite end thereof from said tool body.

10. The assembly of claim 9, further comprising: a tapered guide attached to a lower end of said rigid tubular.

11. The assembly of claim 9, wherein said flexible hose and said rigid tubular in combination have an overall length such that at least a portion of said flexible hose and an entire length of said rigid tubular is positioned within an interior of said upper joint of said casing string when said fill-up and circulation tool is attached to said traveling block assembly and said casing gripping slips are engaged with said upper joint of said casing string.

12. The assembly of claim 10, wherein said tapered guide defines a fluid outlet.

13. A method for constructing a flexible lower assembly of a fill-up and circulation tool for use in a subterranean well, said fill-up and circulation tool comprising a tool body and a casing seal mounted to said tool body operable for scaling with an interior surface of an upper joint of said casing string, said fill-up and circulation tool being operable for use with a rig comprising a traveling block assembly to which said fill-up and circulation tool is attachable, said rig further comprising casing gripping slips mounted to said traveling block assembly for engaging said upper joint of said casing string, said method comprising: mounting a flexible hose to said tool body; and mounting a rigid tubular to said flexible hose on an opposite side of said flexible hose from said tool body such that said rigid tubular is insertable into said upper joint of said casing string.

14. The method of claim 13, further comprising providing a guide at a lower end of said rigid tubular, said guide being insertable into said upper joint of said casing string.

15. The assembly of claim 14, further comprising providing a tapered exterior surface on said guide.

16. The assembly of claim 13, further comprising forming a fluid outlet adjacent said rigid tubular.

17. The assembly of claim 13, further comprising providing an overall length of said flexible hose and said rigid tubular such that rigid tubular is completely contained within an interior of said upper joint of said casing string when said fill-up and circulation tool is attached to said traveling block assembly and said casing gripping slips are engaged with said upper joint of said casing string.