CASING SYSTEM AND METHOD FOR PIPELINE REINFORCEMENT AND REPAIR

Abstract

A system for the repair or reinforcement of a pipeline includes a casing having a dimension to envelope a damaged portion of the pipeline, such that a space is defined between an inner surface of the casing and an outer periphery of the pipeline. An injection port is positioned along the casing and is in selective communication with the space. A cap assembly is frictionally attached to the casing and the pipeline, after which time an injectable material is selectively injected through the injection port until filling a substantial entirety of the space.

Claims

1. A method for the repair or reinforcement of a pipeline, said method comprising the steps of: forming an initial casing with at least first and second ends around a pipeline; forming at least one additional casing around said pipeline; joining the initial casing and at least one additional casing into an integrated casing with a first and second end the interior wall of which is opposite to the exterior surface of the pipeline defining an annular space therebetween; providing at least one injection port in the casing; securing caps to the first and second ends; and, injecting a material through said at least one injection port to substantially fill said annular space.

2. The method for the repair or reinforcement of a pipeline according to claim 1, further comprising the steps of: submerging at least one end of the initial casing below a waterline prior to joining the initial casing to the at least one additional casing.

3. The method for the repair or reinforcement of a pipeline according to claim 1, further comprising the steps of: flushing the annular space with an inert gas mixture thereby removing water from within the annular space.

4. The method for the repair or reinforcement of a pipeline according to claim 1, further comprising the steps of: conducting an inspection of the weld integrity of joining welds provided to form the integrated casing.

5. The method for the repair or reinforcement of a pipeline according to claim 4, further comprising: wherein the inspection technique conducted is at least one selected from the group of: ultrasonic, eddy current, x-ray, visual, and dye.

6. The method for the repair or reinforcement of a pipeline according to claim 1, further comprising the steps of: pressure-testing the integrity of the integrated casing.

7. The method for the repair or reinforcement of a pipeline according to claim 6, further comprising, wherein the pressure test technique is at least one selected from the group of: pneumatic and hydraulic.

8. The method for the repair or reinforcement of a pipeline according to claim 1, further comprising the steps of: providing a siphon vent; enabling the operation of said siphon vent when injecting material through the at least one injection port.

9. The method for the repair or reinforcement of a pipeline according to claim 1, further comprising the steps of: applying release agents to the interior wall surface of the integrated casing; removing the integrated casing after injecting a material through said at least one injection port.

10. The method for the repair or reinforcement of a pipeline according to claim 1, further comprising the steps of: applying an exterior coating to the completed repair.

11. The method for the repair or reinforcement of a pipeline according to claim 1, further comprising the steps of: removing and subsequently replacing pipeline support structures.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The invention will be better understood making reference to the drawings attached, in which:

[0036] FIG. 1 is a lateral view and a longitudinal section showing in a schematic form the pipeline, the resin and the casing or enveloping.

[0037] FIG. 2 is a lateral view of the casing and of the pipeline section.

[0038] FIG. 3 is a top view and cross section of the section formed by the pipeline, the resin and the enveloping of the casing.

[0039] FIG. 4 is a lateral and a section of the mechanical union element between the casing and the pipeline as well as a lateral view of the penetrators for the injection of the resin.

[0040] FIG. 5 is a top view of the casing with elbows in the pipelines.

[0041] FIG. 6 is a top view of the “T” casing on the pipelines.

[0042] FIG. 7 is a lateral view of the casing and the pipeline section.

[0043] FIG. 8 is a lateral view and longitudinal cross section showing in a schematic form the pipeline, the bolted clamp, the resin, the injection ports and the casing or enveloping.

[0044] FIG. 9 is a lateral view and longitudinal cross section showing in a schematic form the pipeline, a valve, the resin and the casing or enveloping.

[0045] FIG. 10 is a schematic view of a pipeline repair according to an embodiment of the invention.

[0046] FIG. 11 is a schematic view of a pipeline repair according to an embodiment of the invention.

[0047] FIG. 12 is a schematic view of a pipeline repair according to an embodiment of the invention.

[0048] FIG. 13 is a schematic view of a pipeline repair according to an embodiment of the invention.

[0049] FIG. 14 is a schematic view of a pipeline repair according to an embodiment of the invention.

[0050] FIG. 15 is a schematic view of a pipeline repair according to an embodiment of the invention.

[0051] FIG. 16 is a schematic view of a pipeline repair according to an embodiment of the invention.

[0052] FIG. 17 is a schematic view of a pipeline repair according to an embodiment of the invention.

[0053] FIG. 18 is a schematic view of a pipeline repair according to an embodiment of the invention.

[0054] FIG. 19 is a flow chart for a method of implementation of an embodiment of the invention.

DETAILED DESCRIPTION OF THE INVENTION

[0055] Making now reference in particular to the previously mentioned figures, the present invention will be now described in detail.

[0056] FIG. 1 illustrates a longitudinal section view of the pipeline repair and reinforcement system, according to one embodiment of the present invention. As shown in FIG. 1, a conducting pipeline/conduit 1 is intended for repair with the envelope/casing 2, the mechanical union element head 3 and the O-ring type seal 5 which is housed between the mechanical union element and the conducting pipeline.

[0057] It will be readily appreciated that after the mounting of the mechanical head 3, and in connection with the placement of the o-ring seal 5, the annular space formed between the interior surface of the casing 2 and the exterior peripheral wall of the conducting pipeline will be effectively sealed.

[0058] Once the casing 2 has surrounded the damaged portion of the pipeline, and the head, or cap, 3 is fitted and secured thereto, the annular space formed between the interior surface of the casing 2 and the exterior peripheral wall of the conducting pipeline 1 is injected and filled with a suitable injectable material/resin 4 via the penetrators or couplings/ports 7. It should be noted that the number and the position of injection ports 7 is variable and they may be situated in any part of the body of the casing 2, in dependence upon the geometry and necessity of the pipeline to be repaired/replaced. Once the cap 3, has been so positioned, FIG. 2 also illustrates the welding of union 6 which permits the integration of the casing 2.

[0059] As will be appreciated, the specific resin chosen will be selected on the composition and environmental conditions of the pipeline to be repaired, without departing from the broader aspects of the present invention. Moreover, by filling in the annular space between the pipeline section to be repaired and the outer casing disposed therearound, the present invention ensures that the entirety of the inner surface of the casing assuredly contacts, via the injected resin, the entirety of the outer periphery of the pipeline in the area that is to be repaired.

[0060] As discussed previously, known pipeline repairs involve the necessity of welding directly on the pipeline itself, with all the inherent dangers associated with taking such actions on a vessel that is likely conducting hydrocarbon gas or liquid. It is therefore one important aspect of the present invention that a combination of the injected resin, and the mechanical caps, effectively avoids the potentially concerning pipeline welding that is a hallmark of pipeline repair systems known a priori.

[0061] Moreover, and as will be appreciated, known pipeline repairs have no way of ensuring that the entirety of the outer periphery of the damaged pipeline, or the periphery of any element, valve, flange or others installed in the area to be repaired, will be in contact with the repairing casing. Indeed, as the outer periphery of the pipeline is effectively never uniform in contour or diameter, it is axiomatic that known pipeline repair systems cannot provide supportive contact to the entirety of the outer periphery of the pipeline via the repairing shell of the casing.

[0062] Thus, it is another important aspect of the present invention to provide a means and method for the supportive nature of the casing 2 to be imparted to the entirety of the damaged portion of the pipeline. The present invention accomplishes this by injecting the resin, via ports 7, into the substantially annular space formed between the casing and the pipeline. In this manner, and regardless of changes in contour or diameter, the present invention ensures that the damaged portion of the pipeline contacts and enjoys the structural support of the casing over its entire outer periphery/surface.

[0063] In FIG. 2, which is a longitudinal lateral view, it is shown the outer appearance of casing 2 and of the pipeline 1. As shown, the main body of the casing 2 is preferably in two sections but may be of any number without departing from the broader aspects of the present invention. Indeed, and although not illustrated in FIG. 2, the present invention not only suggests the use of a two-piece casing that is to be welded to itself along dual axial lines, apart from the outer surface of the pipeline, but equally contemplates a since piece casing. With a single-piece casing, the casing is ‘slipped’ over the affected portion of the pipeline via a single, axial split line opening, and after suitable peripheral constriction, the single seam is welded in the same nature as when a two-piece casing is utilized.

[0064] Turning again to FIG. 2, it can be appreciated the joining element 3 between the casing 2 and the pipeline 1, the ports 7 for the injection of resin 4, as well as the joining welding 6 for integrating or forming the casing around the pipeline.

[0065] For its part, FIG. 3 is a cross section top view of the middle area of the casing. FIG. 3 therefore illustrates the three elements which essentially form a repaired pipeline, which are the pipeline 1, the resin 4, which is located in the space between the casing and the pipeline 1, and the main body of the casing 2.

[0066] FIG. 4 shows the union elements between the casing 2 and the pipeline 1, the couplings/ports 7, the welding between the main body of the casing 2 and the welded base as an integrated part of the casing for receiving the mechanical union element/cap 3 which, preferably, is installed with the use of screws. In certain other embodiments (not shown) cap 3 may be threaded into an interfacing end of casing 2 compressing an o-ring type seal 5.

[0067] FIG. 5 shows one embodiment of the invention of how the casing 2 can be formed by two or more semicircular sections enveloping the pipeline 1.

[0068] FIG. 6 illustrate the use of the present invention, with pipelines/casings having “T”, or angled, configurations. In other embodiments (not shown) casing 2 may be a unitary piece slip fit over a first pipe 1 that is connected to additional casing pieces to form the repair piece. In still other embodiments the unitary piece may further be integrated with a mating half of a casing piece for the perpendicular pipe, thus reducing the number of union welds 6 necessary to form the envelope 2.

[0069] In particular, FIG. 7 illustrates a lateral external view of the use of the present invention installed over a bolted clamp previously installed on the pipe. This shows how one embodiment of casing 2 can be shaped to allow encapsulate an element, valve, flange, that is part of the pipeline. FIG. 8, likewise, illustrates the cross-sectional view of FIG. 7. In some embodiments, ports 7 may be placed to target areas of particularly difficult flow geometry around an embedded fitting, thus ensuring full penetration of the resin 4 into the lateral space and full contact with the all surfaces of the conducting pipeline 1 and fitting. FIG. 9 is a lateral view and longitudinal cross section showing in a schematic form the pipeline 1, a valve, the resin 4 and the casing or envelope 2.

[0070] It is also noted that in the vertical (or horizontal) position it is oftentimes required to provide a siphoning action at the time when the injection of the injectable material is accomplished. That is, due to the fact that repairs may occur underwater, it is necessary to effect a siphon to guarantee the total saturation of the annular space between the casing and the tube, with the injected resin material.

[0071] Illustrated in FIGS. 10-18. An alternative embodiment and particular use of the present invention involves the repair/reinforcement of ascending pipelines 8 of marine platforms 9. Such environments are particularly of concern as ascending pipelines, typically carrying gas or liquid hydrocarbons, are subject to swells and tides and therefore suffer a high grade of corrosion due to the abrasive effect of these tides. Moreover, the content of chlorides and the high grade of oxygenation of the marine water in such areas, as well as the constant spray of salts in the non-submerged splatter area of the pipeline, can accelerate corrosion of such ascending pipelines.

[0072] Still further, when a pipeline works at a temperature of ˜50° C. or higher, the corrosive effects of the surrounding environment are highly increased, generating with this a phenomenon called accelerated corrosion.

[0073] Thus, one important application of the present invention is in the areas and conditions of just such aggressive environments, including when the pipelines are operated in the range of temperature of ˜0-200° C.

[0074] When working in such hostile environments and at such extreme temperatures, both internally with respect to the pipeline itself, as well as compared to the surrounding environment, the present system and method provide many advantages over known repair and reinforcement systems, especially in relation to ascending pipelines.

[0075] In particular, the present system and method will structurally reinforce any damaged portion of such an ascending pipeline, working as only one assembly. Moreover, the injected resin, or other isolating material, effectively and thermally separates the casing from the conducting pipeline, obtaining with this that the outer wall of the casing works at a temperature much lower than that of the pipeline.

[0076] The present invention also and equally contemplates electrically insolating a damaged pipeline through the use of dielectric materials for manufacturing the screwable head of union between the casing and the pipeline, effectively making the main body of the casing electrically isolated from the pipeline. In this manner, it is possible to ensure that materials can be selected with different cathode potentials for making the body of the casing and not generating a galvanic potential between the casing and the pipeline.

[0077] As will therefore be appreciated by review of the foregoing comments and associated drawings figures, the present invention utilizes a casing, preferably with the same general specifications as the pipeline to be repaired, of variable length and positioned so as to evidence an annular gap between the pipeline and the casing, and including a screwed head system at the ends of the casing, which serve for making a seal and sealing the annular gap between the pipeline and the casing and into which a resin or another material based on polymers, copolymers, or any type of material is injected.

[0078] Integrated as such in a single assembly, the pipeline and the casing thus obtained evidence very high structural mechanical properties as compared to that of the pipeline by itself, increasing the working pressure capacity of the pipeline in this section.

[0079] Moreover, the present invention can effectively act as and produce a thermic isolation between the pipeline and the outer wall of the casing which is going to be in direct contact with the environment. As a result, the working temperatures are radically lowered and the corrosion rates are lowered in the system as a whole, besides permitting to carry out the work out of the outer coating in a suitable form.

[0080] Shown in FIGS. 10-18 is a schematic cross section of a marine platform 9 with an associated ascending pipeline 8. One of ordinary skill in the art can appreciate that ascending pipeline 8 is functionally similar to conducting pipeline 1 if not, in some instances, structurally similar. The ascending pipeline 8 transitions from an atmospheric zone above the waterline 10 to a submerged zone below the waterline. Due to the action of tides and waves, as described above, one of ordinary skill can readily appreciate that an area submerged at the time of repair may likewise be exposed to the atmosphere later and that an area exposed to the atmosphere may subsequently be submerged. Likewise, a repair according to embodiments herein described may be accomplished wholly above or below the waterline or may transition from one to the other.

[0081] Shown in FIG. 10, an initial casing 11 formed similarly to envelope 2 described above, with joining welding 6 is placed around ascending pipeline 8.

[0082] Shown in FIG. 11, initial casing 11 is moved below waterline 10 as second casing 12 with joining welding 6 is formed around ascending pipeline 8.

[0083] Shown in FIG. 12, initial casing 11 and second casing 12 are joined with another joining welding 6 to form a larger casing 2.

[0084] Shown in FIG. 13, a third casing 13 formed similarly to initial casing 11 and second casing 12 is formed around ascending pipeline 8 and directed towards the larger casing 2.

[0085] Turing to FIG. 14, third casing 13 is shown integrated with the initial and second casings to form the overall envelope 2 similar in construction as described above. In this embodiment, the casing is shown centered over a repair area that bridges above and below waterline 10.

[0086] FIG. 15 illustrates the installation of cap 3 at the top of casing 2. Port 7 may be formed and welded to casing 2 or pre-formed as part of the initial casing formation process as above described. Since casing 2 was assembled above the waterline and then submerged below before final integration into a single piece via joining welding 6, one of ordinary skill will appreciate that the annular space formed between the interior of the casing 2 and ascending pipeline 8 would potentially be filled with seawater.

[0087] As shown in FIG. 16, with the completion of the installation of cap 3 either with an o-ring type seal or as a screw-cap fitting, both as described above, pressurized gas is introduced into the annular space via port 7 to flush out the seawater and maintain a submerged water level 14. One of ordinary skill can readily appreciate that any pure or mixed inert gas supply, such as air, argon, or nitrogen is suitable for this purpose. The moisture content of the air may be further decreased in order to facilitate more rapid drying of the annular space.

[0088] Turning to FIG. 17, an additional cap 3 with o-ring type seal 5 is installed at the base of casing 2, thus preventing further intrusion of water into the annular space. In some embodiments the additional cap 3 is configured differently from the initial cap 3 (e.g., one may be threaded, the other a screw-type).

[0089] As shown in FIG. 18, resin 4 is injected into, and fills the annular space via port 7, thus completing the repair. Also, as shown in FIG. 18, one of ordinary skill in the art can readily appreciate one or more clamp/pipeline support structures (schematically shown) 15 may be present along ascending pipeline 8. In some embodiments, therefore, these claims may require removal and replacement and/or substitution upon initiation and completion of the repair process.

[0090] In light of the above, an example method of pipeline repair in a marine platform environment, shown in FIG. 19, may comprise the following steps: [0091] A. Position a support vessel in a work zone. [0092] B. Send divers to inspect the work zone submerged below the waterline and/or workers to inspect the work zone above the water line. [0093] C. Remove any obstacles, such as clamps or pipeline support structures as needed. Supply any temporary support structures as needed. [0094] D. Clean and prepare the pipeline above and below the repair zone. In some instances, the cleaning and preparation may be as large as 20 feet above or below the waterline. One of ordinary skill in the art would readily recognize this cleaning and preparative area is variable in size and scaled as necessary to the conditions at hand (e.g., size of repair, splash zone size, tidal swell, overall pipeline condition, etc.). [0095] E. Install any support equipment for maneuvering materiel and manpower throughout the work zone (e.g., winches, baskets, positioners, scaffolds, cranes, etc.). [0096] F. Locate and mark the middle point of the repair zone. [0097] G. Locate and mark the superior and inferior extremes of the envelope/casing/sleeve system. [0098] H. Conduct an inspection of the pipeline at the location of the mechanical interface of the caps. Visual and ultrasonic inspections may be conducted at points 0°, 90°, 180°, and 270° relative to each other in a 6 in band around the circumference of the pipeline. [0099] I. Position the first envelope/casing pieces around the pipeline in the atmospheric zone. [0100] J. Spot weld the casing pieces into place. [0101] K. Form the join weld, integrating the pieces into an initial casing piece. [0102] L. Perform a weld quality inspection of the joining welding. Weld quality inspection may be accomplished using x-rays, penetrating liquids, dyes, ultrasonics, eddy currents, or any other means of assuring weld quality. Weld inspections may be performed after each casing piece is integrated. Weld inspections may also additionally be conducted when the unitary casing is completely formed. [0103] M. Slide the initial casing piece down the pipeline; this frees room for formation of a second casing. [0104] N. Perform steps I-M as needed to form additional casing pieces around the pipeline, integrating each subsequent casing piece with the others forming a unitary envelope/casing. [0105] O. Position the assembled casing into final position. In the final position the casing may extend above and below the area requiring repair. One end of the casing may be submerged in water or open to the air. [0106] P. Install cap and seal at upper end of casing. [0107] Q. Install cap at lower end of casing. If casing is submerged, leave cap loose and able to vent, perform step R otherwise skip to step S. [0108] R. Inject inert gas mixture into annular space formed between envelope and pipeline. [0109] S. Seal cap at lower end of casing. [0110] T. Pressure test the sealed system. This may be accomplished using known pneumatic or hydraulic protocols. [0111] U. Inject resin via ports into the annular space formed between the pipeline surface and envelope. [0112] V. Install closing caps on injection ports. Caps may be welded into place, or installed as screw caps, plugs, etc. [0113] W. Apply exterior coating as required. Coating may be applied in submerged and atmospheric conditions. [0114] X. Re-install any clamps/pipeline support structures as needed. Substitute new and/or modified structures as necessary. [0115] Y. Clear worker and material support equipment from job site.

[0116] One of ordinary skill in the art can readily appreciate that some of these steps may be conducted in alternative orders or eliminated altogether without departing from the broader aspects of the disclosed method and invention. For example, where repairs are conducted solely in an atmospheric environment (i.e., not submerged) the steps of purging the annular space with inert gas may potentially be eliminated. Likewise, exterior coatings may be pre-applied to casing pieces before assembly or before the system is pressure-tested. In certain embodiments the initial, second, and third casings may thread together forming a unitary casing.

[0117] In still other embodiments the casing may form a removable mould that is removed after resin cure. In said embodiments, the wall of the casing facing the annular space and the surface of the pipeline may be pre-coated with a release compound enabling mould removal after resin hardening.

[0118] As will be appreciated by one of ordinary skill, the present invention offers a range of benefits, including but not limited to: [0119] Accommodating the repair/reinforcement of a pipeline having any specification and variations in dimension, with or without bezels for welding at the ends; [0120] Existing pipeline sections can be retrofitted to enjoy superior nominal dimensions via the applied casing, or during initial manufacture of the pipeline it can be made also as a concentric rolled section to the conducting pipeline as an enveloping casing and with any dimension; [0121] The utilization of screwable/torsion caps as a joining means between the conducting pipeline and the enveloping casing. While a screw-based system has been primarily described, it will be readily appreciated that any constricting or friction-based securing methodology may be employed to secure the cap and associated seal to both the casing and pipeline, without departing from the broader aspects of the present invention; [0122] Due to the substantially annular space formed between the casing and pipeline, the present invention enables an unending choice of resins that may be injected therein, including those manufactured from polymers, copolymers or any material which is insolating or with other physical properties and which has or not mechanical properties for complying a structural function, without reservation; [0123] One or more injection ports in the enveloping casing for the efficient injection of the resin or insulating material; [0124] An outer coating of the casing may be applied, which can be of any type. That can be among others without limitation to: the use of epoxy resins, elastomers based on natural or synthetic rubber, polyurethane elastomers, anticorrosive paints, etc.;

[0125] Lastly it is necessary to note as it has been previously indicated that the geometry of union/cap 3 can be varied according to the needs of the design which the case requires.

[0126] Although the invention has been described in relation to specific embodiments it is obvious that other embodiments are included within the object and the scope of the invention, being this invention only limited by the claims that follow.