Patent Grant
6997260
Not applicable
Not applicable
Not applicable
1. Field of the Invention
The present invention relates to a new method and apparatus that does not mandate the use of a drilling rig for repairing and structurally reinforcing tubular members that are next to a casing head assembly on an oil or gas well, and in one embodiment, casing string (or other conductors) contained inside of an outer drive pipe.
2. General Background of the Invention
In the oil and gas well drilling and production industry, casing arrangements are typically used as part of a well. These casing arrangements often include a smaller diameter inside production casing contained concentrically within the bore of a larger diameter surface casing string. There may be additional casing strings referred to as conductors. The outer most casing is referred to as a drive pipe. The production tube, surface casing, and conductors if present, are concentrically placed inside of an outermost drive pipe or like tubular member. A casing head assembly is provided at the top of the surface casing or conductor string. A grout filler often occupies the annulus that is in between the outer drive pipe and the inner casing strings to an elevation, if in a marine environment, somewhere in between the mud line and casing head assembly.
Such an assembly of drive pipe, casing strings, typically extend between the casing head assembly, which is what the wellhead or blow out preventor attaches to, and the oil or gas reservoir.
Moisture can accumulate from condensation, rain, etc. in between the outer drive pipe and inner casing string at the uppermost elevation. This creates a corrosion cell that can structurally weaken or perforate the conductor or surface casing. Often there are multiple conductors (in addition to the surface casing string) that are in between the outer drive pipe and the innermost production tubing. If there is only one conduit in between the outer drive pipe and the inner production tubing, it is typically referred to as the surface casing. Additional conduits in this area between outer drive pipe and surface casing are referred to as conductors. Historically, mobilization of a drilling rig has been required whenever repairs to one of the gas or oil well casing strings is needed.
Patents have issued that relate generally to the concept of a method and apparatus for protective encapsulation of structural members.
One early patent is the Papworth U.S. Pat. No. 4,068,483 entitled “Protective Sheath for Water-Eroded Wood Piling”. In the Papworth patent, the sheath is for a water-eroded wood piling. The sheath is a longitudinally split, flexible and resilient plastic casing with overlapping circumferentially end segments. The casing has a preformed, integral spout at its upper end into which wet concrete can be poured to fill the casing around the eroded section of the piling. Flexible bands clamp the casing tightly around the piling, and the spout has aligned openings in its opposite sides for passing the uppermost one of these bands. The casing may comprise two or more longitudinal sections in overlapped sealed engagement with each other end-to-end for enclosing a long eroded section of the piling.
In the Colbert U.S. Pat. No. 4,023,374, there is disclosed a repair sleeve for a marine pile and a method of applying same. The '374 patent discloses a preformed molded fiberglass resin plastic repair sleeve for use on a marine or other submerged concrete pile and a method of applying the same. The sleeve is provided with at least one vertical seam consisting of inside interlocking reentrant bends which together establish an interlocking tongue and groove joint. The joint is maintained effective by self-tapping screws which are in engaged relation with steel closure clips or strips. The sleeve after assembly is centered about the pile undergoing repair and the continuous space which exists between the sleeve and the pile is filled with a suitable grout which, when hardened, encompasses the internal or inside portions of the joint under pressure and prevents unfastening of the seam. The vertical longitudinal extend of the sleeve is somewhat greater than the water depth of the partially submerged pile to which it is applied and, where a cylindrical concrete pile is concerned, the sleeve is molded on an arcuate bias so as to present an open gap enabling the sleeve to be readily slipped sidewise onto the pile by one or more divers and the gap thereafter closed in order to effect the interlocked joint. Where a square pile is undergoing repair, the sleeve assumes a conformable four-sided shape or, alternatively, it may be formed of two mating right-angle sleeve sections having a pair of vertical inside interlocking joints or seams between their adjoining side margins.
The Straub U.S. Pat. No. 4,114,388 discloses a device for protecting a pile from ice formations collecting on it and subsequently abstracting the pile as a result of a variation of tide level including a tapered guard member secured to the pile. The guard member is firmly secured to the pile by interconnecting stiffening members, horizontal stiffening rings, vertical fin members and compression rings which also serve to prevent deformation of the guard member taper as a result of interaction with the ice formations. The guard member comprises two sections connected by vertically extending tongue and groove joints.
The Moore U.S. Pat. No. 4,306,821 discloses a system for the restoring and reconditioning of structural piling. The system provides an outer form which is attachable to a portion of the piling which has been eroded or corroded and has lost some of is thickness and thus its overall strength. A diameter building filler is placed into the intraform space between the form and the piling, the filler providing a protective and structural coating to that portion of the piling where corrosion or damage has taken place. In the preferred embodiment, the filler is a setting material such as a suitable epoxy.
Three patents have issued to Richard Snow and Milton Ellisor. These patents include U.S. Pat. Nos. 4,876,896; 4,892,410; and 4,993,876. The '896 and '410 patents discloses a method and apparatus for forming an encapsulation or encasement about a structural member that is said to be suited for use in a marine environment. A two-component polymer system for protective and repair encapsulation is pumpable in two separate strings to the location of the structural member to be encapsulated. The two reactive components are combined in a static mixer immediately prior to be injected within the surrounding translucent jacket. By combining the reactive components immediately prior to use, premature setup is avoided and the resulting grout may be directed to flow upwardly in the jacket for enhancing final properties. By suitable coloring of the components, visual monitoring of the final mixing and distribution in the translucent form or jacket of the encapsulation material may be monitored. A field test for determining bond strength of the encapsulation polymer to the structural member is also disclosed in the '876 patent and in the '410 patent. The '896 patent discloses a method of testing protective encapsulation of structural members.
The above discussed patents all relate primarily to coatings for protecting against corrosive effects of the surrounding marine environment. However, the prior art fails to address a problem of structural reinforcement for structural members that have become weak because of the corrosive and/or mechanical effects of the surrounding environment. Further, these patented prior art systems do not address concentric, pipe within pipe configurations.
Other patents that discuss repair methods are the Fox U.S. Pat. No. 4,091,301 and the Moran U.S. Pat. No. 967,952, both references cited in U.S. Pat. No. 6,536,991 naming applicants herein as inventors. U.S. Pat. No. 6,536,991 is incorporated herein by reference.
The present invention provides a method of repairing an oil or gas well having a platform that has an outer drive pipe, an inner production flow line, and one or more intermediate conductors or surface casing strings that are concentrically positioned in between the inner production flow line and the outer drive pipe.
The repair method of the present invention identifies a corroded or other damaged portion of the intermediate conductor or conductors or casings. As part of the method of the present invention, a section of the drive pipe is removed to provide an upper cut edge.
A sleeve or other repair member (e.g. half sleeve, quarter sleeve, curved plate) is installed that spans between upper and lower positions that are above and below the damaged section of the surface casing string (or conductor). The sleeve that is installed over the damaged section can have a longitudinal slot or slots that enable it to be open for installation on the casing string. The sleeve can be metallic or non-metallic (e.g., composite).
If the sleeve is metallic, it can be welded to the selected casing or conductor with preferably upper and lower girth welds. The sleeve slots are then closed with longitudinally extending welds or connections. If the sleeve is of a precured composite material, it can be secured about the damaged section using an adhesive. Additionally, the composite repair may be formed in place where the reinforcement material and resin are combined on site. In this case, the resin that makes the composite rigid is also the adhesive.
The sleeve can be comprised of two sleeve sections, each having a transverse semicircular shape. When two metallic sleeve sections are used, there are two slots and each of the slots is closed with a longitudinal weld or connection.
In one embodiment, there are two sleeves, an inner sleeve that is connected to or welded to the surface casing or conductor and an outer sleeve that is connected to or welded to the outer drive pipe.
A grout product (e.g., epoxy, polymeric, or cement grout) can be added to the annulus between outer drive pipe and inner conductor or casing string. Multiple embodiments of the method of the present invention are disclosed. In keeping with the method of the present invention, a repair could include any figure shown and described herein of
For a further understanding of the nature, objects, and advantages of the present invention, reference should be had to the following detailed description, read in conjunction with the following drawings, wherein like reference numerals denote like elements and wherein:
A fourth embodiment of the method and apparatus of the present invention is shown in
In
Surrounding casing string 3 is an outer drive pipe 8. An annulus 9 is provided in between outer drive pipe 8 and casing string 3. The bore 5 of casing string 3 defines an annulus in between the production tubing or flow line 6 and surface casing string 3. This assembly of tube shaped members 3, 6, 8 can include additional cylindrically shaped conductors that are positioned in between the outer drive pipe 8 and casing string 3.
This assembly shown in
Outer drive pipe 8 has an upper end 11 and an open top 12 that could have a trash cover in place. If grout 10 becomes damaged, or was never installed to an uppermost elevation next to casing head assembly 2, water can collect in the annulus 9 just below casing head assembly 2. It should be understood that in general, such a wellhead area 1 having casing head assembly 2, casing string 3, production tubing 7 and outer drive pipe 8 is an assembly that is well known in the art.
Because of the accumulation of or exposure to water in part of the annulus 9 that could be filled with grout 10, corrosion can produce a damaged portion 13 to casing string 3 (or to other conductor pipes) over a period of time. For example, this damaged portion 13 can be in the form of rust or corrosion on the outer surface 14 of the casing string 3.
As part of the method, in
In
Upper girth weld 23 and lower girth weld 24 are used to attach the sleeve 18 to casing string 3 at the position shown in
Longitudinal welds 25 are used to connect the edges 26, 28 of half section 20 to edges 27, 29 of half section 22. This combination of girth welds 23, 24 and longitudinal welds 25 secures the sleeve 18 to the surface 14 of casing string 3.
Grout 10, if present below edge 16 is removed to provide a cavity 30 that communicates with the lower end portion of sleeve 18 as shown in
In
Each half section 32, 33 is preferably provided with a pair of longitudinally extending flanges. The first half section 32 has longitudinally extending, opposed flanges 34, 35. The second half section 33 has longitudinally extending flanges 46, 47. Each half section 32, 33 includes a curved portion. The half section 32 has curved portion 36. The half section 33 has curved portion 42.
A lower most flange 37 is an arc shaped flange fastened to the bottom of half section 32. Each of the longitudinally extending flanges 34, 35 is provided with a plurality of openings 50 that can receive bolted fasteners 51. Likewise, the longitudinally extending flanges 46, 47 of half section 33 provide openings 55 that can receive bolted fasteners 51.
The lower end portion of half section 33 has a curved or arc shaped flange 43. Each of the curved or arc shaped flanges 37, 43 can have inner and outer parts such as the inner part 44 and the outer part 45 shown in
A plurality of injection ports 39, 40, 41 are provided on sleeve 31 half sections 32, 33. The sleeve half section 32 has injection ports 39, 40. The sleeve half section 33 has an injection port 41.
In
In the embodiment of
In
In
In
In
The following is a list of suitable parts and corresponding parts descriptions for the various parts used in this specification.
PART NO. DESCRIPTION
The foregoing embodiments are presented by way of example only; the scope of the present invention is to be limited only the following claims.
| Number | Name | Date | Kind |
|---|---|---|---|
| 967952 | Moran | Aug 1910 | A |
| 1198649 | Moser | Sep 1916 | A |
| 1947413 | Hay | Feb 1934 | A |
| 2373885 | Gast et al. | Apr 1945 | A |
| 2593725 | Brown | Apr 1952 | A |
| 2687177 | De Camp | Aug 1954 | A |
| 2889885 | Hildebrandt | Jun 1959 | A |
| 2907351 | Rohrback et al. | Oct 1959 | A |
| 3316963 | Boldrick et al. | May 1967 | A |
| 3611736 | Goodman | Oct 1971 | A |
| 3736759 | Blose | Jun 1973 | A |
| 4019301 | Fox | Apr 1977 | A |
| 4023374 | Colbert et al. | May 1977 | A |
| 4068483 | Papworth | Jan 1978 | A |
| 4114388 | Straub | Sep 1978 | A |
| 4116013 | Hellmers | Sep 1978 | A |
| 4306821 | Moore | Dec 1981 | A |
| 4439070 | Dimmick | Mar 1984 | A |
| 4644722 | Phillips | Feb 1987 | A |
| 4779389 | Landers | Oct 1988 | A |
| 4876896 | Snow et al. | Oct 1989 | A |
| 4892410 | Snow et al. | Jan 1990 | A |
| 4941775 | Benedict | Jul 1990 | A |
| 4993876 | Snow et al. | Feb 1991 | A |
| 5345972 | Goglio et al. | Sep 1994 | A |
| 5380131 | Crawford | Jan 1995 | A |
| 5388317 | Johansen et al. | Feb 1995 | A |
| 5591265 | Tusch | Jan 1997 | A |
| 5722463 | Smyth et al. | Mar 1998 | A |
| 6536991 | Trader et al. | Mar 2003 | B1 |
| Number | Date | Country |
|---|---|---|
| 0480686 | Apr 1992 | EP |
| 2255583 | Nov 1992 | GB |
| 61-10634 | Jan 1986 | JP |
| 61-155521 | Jul 1986 | JP |
| 2-140322 | May 1990 | JP |
