Patent Application
20180038217
This disclosure pertains generally to devices and methods for providing shock and vibration protection for borehole devices.
Exploration and production of hydrocarbons generally requires the use of various tools that are lowered into a borehole, such as drilling assemblies, measurement tools and production devices (e.g., fracturing tools). Electronic components may be disposed downhole for various purposes, such as control of downhole tools, communication with the surface and storage and analysis of data. Such electronic components typically include printed circuit boards (PCBs) that are packaged to provide protection from downhole conditions, including temperature, pressure, vibration and other thermo-mechanical stresses.
Some high temperature electronics are built using ceramic materials as the substrate on which individual electronic parts are attached. These ceramic materials can be damaged by bending moment acting on them. Such bending can occur when a drilling tool is used to drill a curved section of a borehole. Because the curvatures of the drilling tool and the bore hole can be substantially the same, the electronics inside the drilling tool may be forced to bend to accommodate the same curvature as well. During drilling, the drilling tool rotates inside the curved borehole section. Thus, the drilling tool and the electronics inside the drilling tool are subjected to undesirable cyclical bending.
In one aspect, the present disclosure addresses the need for enhanced electronic components and other bending moment sensitive devices used in a borehole.
In aspects, the present disclosure provides an apparatus for protecting an electronics module used in a borehole. The apparatus may include an enclosure disposed along a drill string. The electronics module may be attached to the enclosure by at least one joint. The at least one joint allows a predetermined bending between the electronics module and the enclosure that does not mechanically overload the electronics module. In some embodiments, the joint may be a ball joint.
In aspects, the present disclosure also provides a method for protecting an electronics module used in a borehole. The method may include forming a drill string; disposing an enclosure along the drill string, wherein the electronics module is attached to the enclosure by at least one joint; and protecting the electronics module by using the at least one joint to allow a predetermined bending between the electronics module and the enclosure without mechanically overloading the electronics module.
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.
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:
Directional drilling can result in a borehole having curvatures that impose significant bending moments on a drilling tool. These bending moments can damage certain brittle electronics in the devices and components used in a drill string. In aspects, the present disclosure provides mountings and related methods for protecting these components from mechanical overloading while being conveyed through the borehole. By mechanical overloading, it is meant bending, twisting, or otherwise deforming these components to the point that these components fracture, crack, disintegrate, or deform to a point where they become partially or completely non-functional.
Referring now to
One or more electronics modules 24 incorporated into the BHA 14 or other component of the borehole string 12 may include components as necessary to provide for data storage and processing, communication and/or control of the BHA 14. These components may be disposed in suitable compartments formed in or on the borehole string 12. Exemplary electronics in the electronics module include printed circuit board assemblies (PCBA) and multiple chip modules (MCM's).
Referring to
Generally, the joints 104 allow the section 102 and pressure barrel 103 to bend while preventing module 24 from encountering bending stresses. In one arrangement, the joints 104 may employ surfaces that allow relative rotation between the joint 104 and the ends 108. For example, the joint 104 may employ a ball-and-socket connection wherein the ends 108 have convex faces 110 that can slide inside concave supports 112. It should be noted that the concave surface member may be associated with the electronics module or the enclosure and the convex member may be associated with the electronics module or the enclosure. It should be understood that such an arrangement is merely illustrative. For example, the joint 104 may include both the ball and the socket and the ends 108 may be attached to the ball. In either case, the ball shape of such joints 104 ensures that housing bending is decoupled from the electronic component throughout the rotating bending cycle.
It should be further understood that ball-and-socket connection is only a non-limiting type of connection that may be used; e.g., a pinned joint may also be used. The socket may deviate from a spherical shape to e.g. a conical shape or only a hole, having an edge for the ball to slide on, which provides for simpler manufacturing but increases contact pressure. The ball, the socket or both may be made from a variety of materials in order to minimize friction and wear. Suitable materials include, but are not limited to steel, a copper alloy, a bronze, aluminum, ceramic, tungsten carbide or a polymer. The goal of minimizing friction and wear may be achieved by application of coatings to the members of joint 104. Such coatings include, but are not limited to PTFE, diamond, graphite and PEEK. In some embodiments, the ball joint may use a non-spherical socket, e.g., conical, oval, etc. Also the socket may be an edue of a suitably size hole.
In embodiments, the joints 104 may be configured to provide support for the mass of the electronic component under shock and vibration. The joints 104 may be mechanical preloaded, e.g., spring loaded, hydraulically pressurized, utilize elastomeric elasticity, and/or utilize metal spring force or a combination thereof in order to compensate for manufacturing tolerances and thermal expansion mismatches. The electronic component may be supported by additional members (not shown) to avoid rotation inside the enclosure, e.g., the pressure barrel 103.
In embodiments, the module 24 may be of a rectangular outer shape, positioned inside a larger rectangular section of the enclosure 103. The rectangular shape is only illustrative and other complementary shapes may be used. A gap between the module 24 and the wall of the enclosure 103 may be at least partially filled with elastomer elements 114. The elastomer elements 114 may also provide heat transfer away from the electronic component in order to limit self heating under electrical load. One non-limiting embodiment of elastomer elements 114 may be formed at least partially of a visco-elastic material. As used herein, a viscoelastic material is a material having both viscous and elastic characteristics when undergoing deformation.
In embodiments, the elastomer elements 114 of
Referring now to
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 be embraced by the foregoing disclosure.
