CONTROL LINE ENCAPSULATOR AND FLAMMABLE CABLE

Abstract

FLAMMABLE CONTROL LINE AND CABLE ENCLOSORATOR The present invention relates to a flammable control line and cable encapsulator or flammable (thermally destructible) flat box that retains the characteristics of a conventional flat box, commonly used in well completion operations, containing cables and lines, but with the property of burning when ignited and reaching temperatures exceeding 600-800°C. With the flammable control line and cable encapsulator of the present invention, the melting of the column at a single point allows the destruction of this component to propagate over a sufficient cross-section to form a permanent abandonment barrier, thus enabling a faster abandonment process without the need to remove the production column.Furthermore, the self-destruction process of a well equipped with a control line encapsulator and flammable cable will be initiated by a localized and limited melting of the column. Since, in this case, the column melting is confined to a small area, this prevents more drastic consequences for the integrity of the barrier elements.

Description

Title of the invention: CONTROL LINE ENCAPSULATOR AND FLAMMABLE CABLE Scope of the invention

[0001] The present invention falls within the technical field of oil and gas, specifically relating to well drilling and completion, and concerns a control line encapsulator (flat pack) and flammable, or thermally destructible, cable, which are devices commonly used to hold and wrap cables and wires in operations carried out in oil wells. Background of the invention

[0002] In well abandonment, particularly in wet completion wells, the objective is to achieve, as far as possible, well isolation through the use of "through pipes", as this does not require removing the production column, making the operation much faster and less expensive.

[0003] However, the presence of cables and lines (confined in flat boxes) in the annular space of the well, in the region in which the abandonment plug will be placed, prevents this type of operation, because said accessories can constitute a leakage path through the cement plug, or any other material intended to constitute the permanent abandonment barrier.

[0004] Since most offshore wells contain such annular fittings along the upper completion, the abandonment of through pipes ends up having an extremely limited application scenario.

[0005] To be viable, said accessories must be removed or destroyed along a minimum section of 60 meters (or two sections of 30 m). There are studies for melting the column as well as the accessories, but melting 60 meters of column entails risks, due to the excess debris generated or the possible adverse consequences of excessive heat on the external barriers to the lining (cement and rock cover).

[0006] In view of the foregoing, in order to resolve the limitations and technical problems described above, the present invention describes a flammable control line and cable encapsulator or flammable flat housing (thermally destructible), containing cables and lines, but with the property of burning when ignited and reaching temperatures above 600-800°C.

[0007] The self-destruction process of a well equipped with the control line encapsulator and flammable cable of the present invention is initiated by means of a localized and limited melting of the column. Given that, in this case, the melting of the column is limited to a small extent, this helps to prevent more drastic consequences for the integrity of the barrier elements. State of the art

[0008] The article by Craddock et al. (2023), entitled "Survival of an Optical Fiber Flatpack Due to Perforation," is part of the general prior art and focuses more specifically on optical fiber flatpacks. In the article, the flatpack containing optical fibers is simulated for its survivability within the lining of a half-round wick system. The overall results of the comparative simulation show an optimal location and configuration for the flatpack and highlight several dos and don'ts for the system that can be field-tested, including not using clamps instead of concrete lining, placing the flatpack at approximately 90° to the conformed load, and decentralizing the loads.

[0009] In turn, US20010050111A1 describes a flat conduit housing for a well control cable. The control cables comprise fluid communication tubes and a layer of metallic reinforcement surrounding each of the fluid communication tubes. In one described embodiment, there are three fluid communication tubes arranged in a parallel relationship and held in contact with each other. The metallic reinforcement layer is in contact with the outer surface of each of the three tubes and is preferably formed by a spirally wound metal strip.

[0010] The document "Control Lines & Flatpacks" describes a kind of product catalog from an oil company (Prysmian Group), featuring different types of flat packs. The introduction describes how the flat packs are designed to simplify installation and reduce the number of installation reel units required during well completion, and are available in a wide variety of configurations with single-pass and double-pass encapsulation options for added protection.

[0011] Finally, the document by Scott et al. (2023), entitled “New Technique to Plug and Abandon Intelligent Well Completions with Fiat Packs,” which is also part of the general prior art, describes a new technique for plugging and abandoning intelligent well completions with flat packs. The scope of the article is to highlight the complexities that arise when attempting to plug and abandon (P&A) intelligent well completions and when the upper well completion must be reclaimed. For reclamation, the production line and the flat pack must be cut or completely severed, and a cutting tool is used, which is inserted into the line and positioned to perform the cut through the pipe and flat pack with control lines.

[0012] Thus, in light of these documents, it is evident that the present invention differs from others in a fundamental technical aspect: only the control line and cable encapsulator proposed in the present invention can be thermally destructible or self-igniting. These documents do not include such a solution. In view of the foregoing, it is also possible to discern relevant differences in the solutions presented in the prior art compared to the present invention, and it is further possible to verify the presence of a differentiating technical effect in the present invention, taking into account the inherent advantages of the flammable control line and cable encapsulator.

[0013] Ultimately, none of the initiatives considered actually aims to make well abandonment possible without removing the column. It is known that there have been attempts in this direction which aim to interrupt the continuity of such annular fittings by means of multiple perforations (explosive perforations) in different directions, but it has even been observed that sizing the intensity of the explosion, in order to allow the complete severance of the fittings without damaging the casing, can prove difficult.

[0014] It is important to emphasize that the present invention offers advantages in terms of economic impact and productivity, which are associated with a simpler and faster abandonment process, without the need to remove the production column. Furthermore, the control line and cable encapsulator presented here has a direct impact on health and safety issues, as reducing vessel usage time for abandonment implies a substantial reduction in CO2 emissions. Brief description of the invention

[0015] The present invention relates to a flammable control line and cable encapsulator or flammable (thermally destructible) flat box that retains the characteristics of a conventional flat box, commonly used in well completion operations, containing cables and lines, but with the property of burning when ignited and reaching temperatures exceeding 600-800°C. With the flammable control line and cable encapsulator of the present invention, the melting of the column at a single point allows the destruction of this component to propagate over a cross-section sufficient to form a permanent abandonment barrier, thus enabling a faster abandonment process without the need to remove the production column.Furthermore, the self-destruction process of a well equipped with a control line encapsulator and flammable cable will be initiated by a localized and limited melting of the column. Since, in this case, the column melting is limited to a small area, This helps to prevent more drastic consequences for the integrity of the barrier elements. Brief description of the figures

[0016] To obtain a full and complete understanding of the object of the present invention, the figures below are presented.

[0017] Fig. 1 shows a schematic illustration of the process in which a localized melting of the production column starts the destruction of the TDF (thermally destructible flat box) over a larger area.

[0018] Fig. 2 schematically shows an isometric view of the control line encapsulator and flammable cable, emphasizing each of its main components, according to a preferred configuration.

[0019] Fig. 3 shows an isometric view of the control line encapsulator and flammable cable with a section of the conduit with its sheath. Detailed description of the invention

[0020] The present invention relates to a flammable control line and cable encapsulator or flammable flat box (thermally destructible), which is a completion component which retains the characteristics of a conventional flat box, containing cables and lines, but with the property of burning when ignited and reaching temperatures above 600-800°C.

[0021] The design of the control line encapsulator and flammable cable is based on the idea that melting the column at a single point allows the destruction of this component to spread over a section sufficient for the formation of a permanent abandonment barrier, thus allowing a faster abandonment process without the need to remove the production column.

[0022] This concept aligns with the future vision of wells regarding the design of an automatically abandoned oil well.

[0023] As shown in [Fig. 1], from the moment of initial combustion, the control line and cable encapsulator will ignite, self-destructing along the entire length programmed for the placement of the cement plug. It is not necessary to use this type of control line and cable encapsulator along the entire length of the well, only 150 to 200 meters above the production packer, in front of the cover rock and in a section that has been proven to be well cemented.

[0024] For the design of an alternative component, in this case the control line encapsulator and flammable cable, which would help to allow the abandonment of through pipes in wells with components in the annular space, the following premises were established.

[0025] The control line and flammable cable encapsulator must have functionalities and parameters compatible with a standard flat housing, without compromising its applicability and meeting the usual requirements for subsea wells for this type of equipment. This implies fulfilling its function of transmitting pressure, fluids, or signals, and its installation being perfectly feasible.

[0026] The control line and flammable cable encapsulator must retain its functionality even when exposed to the well environment for decades. More specifically, when exposed to completion fluid and its additives, as well as possible hydrocarbon contamination.

[0027] The flammability of the control line encapsulator and flammable cable must not be such that it is likely to be accidentally caused during transport, handling, or even during the productive life of the well. Therefore, it must require the application of a reasonably high level of energy to initiate its combustion.

[0028] Notwithstanding the previous requirement, the activation energy required must not be so high as to present a significant risk that the heat from a thermite applied inside the production column may not be sufficient to initiate its self-destruction process, in the event that the melting of the tube is not complete and / or that debris from this process prevents the effective transmission of heat to the annular space.

[0029] It must be an economically viable control line and cable encapsulator, constructed with readily available materials and, if possible, without the need for complex manufacturing processes.

[0030] It must be a compact control line and cable encapsulator, minimized as much as possible, taking into account the risk of incomplete combustion of the encapsulator, even in the case where it has been partially damaged during the deployment of the production column.

[0031] In other words, the control line and cable encapsulator must not have a matrix larger than necessary to minimize the material to be destroyed, which will depend on the design characteristics of each well, since the wells have different column and liner diameters and can be directional or vertical. Furthermore, its exothermic reaction must generate sufficient heat for self-destruction.

[0032] Its exothermic reaction must not generate enough heat to compromise the integrity of the well. Its self-destruction must only generate discontinuous, non-cohesive residues that naturally settle to the bottom of the borehole by gravity or can be easily removed by the movement of fluid or cement mud.

[0033] For the development of the control line encapsulator and flammable cable of the present invention, from the architecture of a conventional flat housing and with the aim of achieving the premises mentioned above, two essential aspects were addressed.

[0034] The first aspect relates to the incorporation of combustible material so that, from an initial energy application, the control line and cable encapsulator will burn, continuously self-destructing up to its interface with the standard control line and cable encapsulator.

[0035] The second aspect concerns the selection of components of the control line and cable encapsulator, choosing those with a lower melting point and / or higher flammability, where applicable.

[0036] In the example shown in [Fig.2], the control line and flammable cable encapsulator comprises at least one control line and one electrical cable encapsulator line (1), which may preferably be made of Super Duplex Steel (SDSS) or Inconel 825 steel. It should be noted that the number of control lines and / or electrical cables may vary according to the requirements of each well.

[0037] It further comprises a matrix (2), which can preferably be made of Santoprene or polypropylene, and is internally ventilated, but with a smooth external finish to prevent chemical attack.

[0038] An electrical cable core (3), made of conductive material, preferably copper. An electrical cable sheath A (4), which may be made of fluorinated ethylene propylene (FEP). An electrical cable sheath B (5), which may be made of polypropylene (PP).

[0039] The control line and cable encapsulator also includes at least two corrugated conduits (6), which may preferably be made of high-density polyethylene (HDPE), a pyrotechnic material (7), which may normally be a manganese aluminum oxide thermite, and a conduit jacket (8), which may be made of polyvinyl chloride (PVC). These conduits contain the pyrotechnic material, and their redundancy is necessary to minimize the risk of an interruption in combustion propagation.

[0040] Regarding the pyrotechnic material, it should be noted that three options were analyzed: thermite based on iron and aluminum oxides; thermite based on manganese and aluminum oxides; and nitrocellulose. Nitrocellulose was quickly abandoned when the risk of explosion caused by impact during transport or handling was verified.

[0041] With regard to thermite composition options, iron and aluminum oxide-based thermite is the most common and readily available, in addition to being less expensive. However, the energy required to initiate its combustion is more large (above 2000°C) and, once initiated, the energy generated is also greater.

[0042] In the search for a solution, thermite based on manganese and aluminum oxides (in some cases also molybdenum) was found, which, depending on its formula (proportion and particle size), can produce a compound capable of igniting at about 600 °C with reduced enthalpy and with exothermic potential compared to the first option.

[0043] Although [Fig. 2] illustrates a configuration with an electrical cable, a control line, and two thermite conduits, other configurations are possible. However, a significant increase in the number of components can increase the rigidity of the cable and also require a higher thermal power of the compound to allow all the components to melt.

[0044] This increase in generated heat must be evaluated so as not to compromise the integrity of the other components of the well, in particular the cement casing.

[0045] The conduits with thermite or the corrugated conduits (6) are not continuous; they are profiled into sections of two or three feet each. This design facilitates construction and prevents any localized damage to the control line and cable encapsulator from preventing it from achieving its purpose.

[0046] Each section is completely enclosed at its top and bottom by the casing, as shown in [Fig. 3]. This encapsulation prevents any damage to the control line and cable encapsulator that exposes the thermite from causing complete degradation of the entire system over time, and also limits the loss of thermite through any opening.

[0047] The interruptions in each conduit are positioned out of phase ([Fig. 3]). The reason for this is to prevent the interruption from halting the propagation of combustion. If this occurs in the conduit where the interruption takes place, the other conduit(s), being intact, is / are responsible for propagating the burn and restarting combustion from the first one after the interruption.

[0048] The ducts are corrugated to increase the flexibility of the assembly, but this feature has an additional function. The duct cavities retain a small amount of air which contributes to the combustion process by supplying oxygen.

[0049] Although the benefits of a reduction in the cost of abandoning a well only occur several years after its construction, the addition of materials and components during the implementation of the proposed invention must not lead to a substantial increase in cost and must therefore present a return that justifies its adoption.

[0050] This assertion is based on the simplicity of the incorporated materials and their relatively low implementation complexity, which should not result in a final cost for the flammable control line and cable encapsulator that is significantly different from that of conventional encapsulators. It should be noted that it is not necessary to install the control line and cable encapsulator along the entire length of the well.

[0051] A person skilled in the art will appreciate the teachings presented in this document and will be able to reproduce the invention in the embodiments presented and their variants, which are covered by the scope of the following claims.

Claims

Demands

1. Control line and cable encapsulator, characterized in that it is flammable or thermally destructible and comprises at least two control lines (1), a matrix (2), an electrical cable core (3), an electrical cable sheath A (4), an electrical cable sheath B (5), at least two corrugated conduits (6), a pyrotechnic material (7), and a sheath (8).

2. Encapsulator, according to claim 1, characterized in that it is ignited and burned at between 600 and 800°C.

3. Encapsulator, according to claim 1 or 2, characterized in that it houses cables and lines.

4. Encapsulator, according to any one of claims 1-3, characterized in that it is used between 150 and 200 m above the production packer, in front of the cover rock.

5. Encapsulator, according to any one of claims 1-4, characterized in that the control lines are preferably made of Super Duplex steel (SDSS) or Inconel 825 steel.

6. Encapsulator, according to any one of claims 1-5, characterized in that the matrix (2) is preferably made of Santoprene or polypropylene.

7. Encapsulator, according to any one of claims 1-6, characterized in that the matrix (2) is internally ventilated and comprises a smooth outer finish.

8. Encapsulator, according to any one of claims 1-7, characterized in that the electrical cable core (3) is made of conductive material, preferably copper.

9. Encapsulator, according to any one of claims 1-8, characterized in that the electrical cable coating A (4) is made of fluorinated ethylene propylene (FEP).

10. Encapsulator, according to any one of claims 1-9, characterized in that the electrical cable coating B (5) is made of fluorinated ethylene propylene (FEP).

11. Encapsulator, according to any one of claims 1-10, characterized in that the corrugated conduits (6) are preferably made of high-density polyethylene (HDPE).

12. Encapsulator, according to any one of claims 1-11, characterized in that the pyrotechnic material (7) is manganese and aluminium oxide-based thermite.

13. Encapsulator, according to any one of claims 1-12, characterized in that the envelope (8) is preferably made of poly(vinyl chloride) (PVC).

14. Encapsulator, according to any one of claims 1-13, characterized in that the at least two corrugated conduits (6) are profiled into sections of two or three feet each.

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