Patent Application
20170167206
None.
1. Field of the Disclosure
This disclosure relates generally to arrangements and related methods for protecting oilfield downhole tools from mechanical wear.
2. Background of the Art
To obtain hydrocarbons such as oil and gas, boreholes or wellbores are drilled by rotating a drill bit attached to the bottom of a drilling assembly (also referred to herein as a “Bottom Hole Assembly” or (“BHA”). The drilling assembly is attached to tubing, which is usually either a jointed rigid pipe or flexible spoolable tubing commonly referred to in the art as “coiled tubing.” The string comprising the tubing and the drilling assembly is usually referred to as the “drill string.” When jointed pipe is utilized as the tubing, the drill bit is rotated by rotating the jointed pipe from the surface and/or by a mud motor contained in the drilling assembly. In the case of a coiled tubing, the drill bit is rotated by the mud motor. During drilling, a drilling fluid (also referred to as the “mud”) is supplied under pressure into the tubing. The drilling fluid passes through the drilling assembly and then discharges at the drill bit bottom. The drilling fluid provides lubrication to the drill bit and carries to the surface rock pieces disintegrated by the drill bit in drilling the wellbore. The mud motor is rotated by the drilling fluid passing through the drilling assembly. A drive shaft connected to the motor and the drill bit rotates the drill bit.
During wellbore operations, downhole tools with sensitive outer parts and/or equipment can be subjected to mechanical influences, such as abrasion, chipping and cuttings and chemical influences resulting from a direct contact with the mud flow. Prior to operation, downhole how tools may be subjected to electromagnetic radiation coming from tools storage and transportation on the ground. The present disclosure addresses the need to protect these sensitive parts and equipment.
In aspects, the present disclosure provides an apparatus for use in a wellbore. The apparatus may include a downhole tool configured to physically transform to execute a specified downhole operation and a protector at least partially enclosing the downhole tool. The protector may form a physical barrier between the downhole tool and a wellbore environment. The protector may include a sheath formed of a pliant material.
In aspects, the present disclosure also provides an apparatus that includes a downhole tool configured to be conveyed into a wellbore to perform a specified downhole function and a protector at least partially enclosing the downhole tool. The protector may form a physical barrier between the downhole tool and a wellbore environment. The protector may include a sheath formed at least partially of a textile.
In aspects, the present disclosure further provides a method for using a downhole tool in a wellbore. The method may include at least partially enclosing the downhole tool using a protector; conveying the downhole tool and the protector into the wellbore, and executing a specified downhole operation. The protector may form a physical barrier between the downhole tool and a wellbore environment and include a sheath formed of a pliant material or a textile. The specified downhole operation may be executed by physically transforming the downhole tool.
Examples of certain features of the disclosure have been summarized rather broadly in order that the detailed description thereof that follows may be better understood and in order that the contributions they represent to the art may be appreciated. There are, of course, additional features of the disclosure that will be described hereinafter and which will form the subject of the claims appended hereto.
For a detailed understanding of the present disclosure, reference should be made to the following detailed description of the embodiments, taken in conjunction with the accompanying drawings, in which like elements have been given like numerals, wherein:
As will be appreciated from the discussion below, aspects of the present disclosure provide protection arrangements that use a pliant material to protect downhole tools from mechanical wear. Mechanical wear includes, but is not limited to, abrasion, chipping, fracturing, cracking, cutting, etc. In some embodiments, the pliant material may be a textile, e.g., a braided, knitted or woven fabric with optional wear-resistant inserts. While the discussion below is set in the context of a drilling system, it should be understood that the teachings of the present disclosure may be used in all phases of well construction and production (e.g., drilling, completion, production, workover, etc.).
Referring now to
Some of the tooling and equipment of the drill string 18 and the BHA 12 do not change shape or dimensions in order to operate as intended. Other tools undergo a physical transformation as part of their intended operation. A physical transformation can include a change in shape, size, or dimensions. Illustrative transformations include, but are not limited to, expansion, contraction, twisting, shifting, etc. By way of illustration, there is shown a packer device 40 positioned along the drill string 18. The packer device 40 may include an expandable annular sealing element. When activated, the packer device 40 may radially expand into a sealing engagement with an adjacent surface, such as a borehole wall.
Referring now to
In one embodiment, the protector 50 includes a sheath 56 that is formed of a pliant material. As used herein, a pliant material is a material that can physically transform or physically degrade. By physically transform, it is meant that the pliant material accommodates the physical transformation of the downhole tool 52 by also physically transforming (e.g., expanding, stretching, bending, etc.). Thus, in this arrangement, the sheath 56 is not damaged by the transformation. By physically degrade, it is meant the pliant material breaks up or otherwise structurally destabilizes while the downhole tools 52 physically transforms. In either case, the pliant material does not impede or prevent the physical transformation of the downhole tool 52.
A number of methodologies may be used to form the pliant material. For instance, a material having a modulus of elasticity that allows a preset amount of deformation and subsequent structural failure may be used. Alternatively or additionally, the sheath 56 may be formed with grooves, holes, or other features that initiate failure after a predetermined amount of deformation. In still other instances, the pliant material may be textile. As used herein, a textile may be structured as netting, knitting, braiding, weaving, meshing, lacing, or any other interconnection of fibers or strands. The material of the textile may be a mineral or synthetic. Illustrative mineral materials include, but are not limited to, glass fibers, metal fibers and metal wires. Synthetic textiles include, but are not limited to, polyester, aramid, acrylic, nylon, polyurethanes, olefins, and polylactides. Additionally, the material of the protector may include a coating of a secondary material to increase functionality.
In some embodiments, the sheath 56 may be constructed as a sacrificial layer that uses a material selected to resist wear long enough while being deployed downhole so that the underlying downhole tool is not physically compromised.
The sheath 56 may be formed as a sleeve that surrounds the downhole tool 52. In other embodiments, the sheath 56 may be wrapping that is layered around the downhole tool 52. In both instances, the sheath 56 is structurally separate from the underlying downhole tool 52.
Referring to
Referring now to
The inserts 60 may provide protection in two ways. First, the inserts 60 may provide better wear resistance than the base material. Second, the inserts 60 may act as a guard or shield for the base material. That is, the inserts 60 may protect against the mechanical influence resulting from a contact with the borehole wall while the sheath 56 protects against cuttings. Thus, if there are hook-like structure on the borehole wall, the pliant material making up the sheath 56 is protected from continuously tearing single fibers, which would weaken the entire protector 50 until failure.
The operating mode of the protector 50 depends, in part, on the behavior of the tool to be protected. Some non-limiting operating modes are discussed below with references to
In applications where the downhole tool 52 does not physically deform, the sheath 56 of the protector 50 may be formed using a textile, either with or without the inserts 60. At the surface, the sheath 56 may protect the downhole tool 52 during handling and transport, and possibly shield the downhole tool 52 from electromagnetic energy. Downhole, the sheath 56 may provide protection from mechanical wear. The sheath 56 may be structurally separate from or embedded in the downhole tool 52.
In applications where the downhole tool 52 does physically deform, the sheath 56 of the protector 50 may be formed using a pliant material, which may optionally be a textile and may optionally include the inserts 60. As before, the surface, the sheath 56 may protect the downhole tool 52 during handling and transport, and possibly from exposure to electromagnetic energy. Downhole, the sheath 56 may provide protection from mechanical wear. The sheath 56 may be structurally separate from or embedded in the downhole tool 52.
As noted above, the downhole tool 52, when activated, may physically transform (e.g., expand) in order to perform a specified downhole operation. By downhole operation, it is meant an act or process affecting the wellbore 14, the formation surrounding the wellbore 14, a fluid native to the formation, a fluid in the wellbore, and/or another downhole tool. For instance, a packer may be expanded to hydraulically isolate a portion of a wellbore. The protector 50 can have at least two distinct responses. The protector 50 may expand and fully accommodate the transformation of the downhole tool 52. In this response, the protector 50 retains structural integrity and continues to provide protection after the underlying tool changes shape or deforms. In another response, the protector 50 may partially or completely physically degrades to allow the underlying downhole tool 52 to transform (e.g., expand, twist, axially shift, etc.). For example, the protector 50 may fray, break, snap, etc.
As used above, the term “mechanical wear” or “mechanical influence” refers to a degradation of an object due principally to physical contact with another object. This is in contrast to chemical influence in which a chemical reaction principally causes the degradation or radiation influence wherein an energy wave or beam principally causes the degradation.
While the foregoing disclosure is directed to the one mode embodiments of the disclosure, various modifications will be apparent to those skilled in the art. It is intended that all variations within the scope of the appended claims be embraced by the foregoing disclosure.
