MXPA06006689A

MXPA06006689A - Mass isolation joint for electrically isolating a downhole tool.

Info

Publication number: MXPA06006689A
Application number: MXPA06006689A
Authority: MX
Inventors: Scott S Chesser; Bulent Finci; Richard D Ward
Original assignee: Schlumberger Technology Bv
Priority date: 2005-06-14
Filing date: 2006-06-13
Publication date: 2007-01-23
Also published as: CA2549541C; CA2549541A1; GB0611301D0; GB2427218B; GB2427218A; US20070131412A1

Abstract

A mass isolation joint for electrically isolating a downhole tool includes a first joint section having a distal end in which a first thread is formed, a second joint section, and an insulating composite structure coupling the first joint section to the second joint section, wherein at least one of the first and second joint sections is adapted for coupling to the downhole tool. The insulating composite structure includes a first composite layer formed on the second joint section. The first composite layer has a second thread which engages the first thread on the distal end of the first joint section.

Description

CONNECTING MASS ISOLATION TO ELECTRICALLY INSULATE A DRILL TOOL BACKGROUND FIELD OF THE INVENTION The invention relates to a ground insulation connection for electrically insulating a tool from the bottom of a bore from adjacent tools. BACKGROUND OF THE INVENTION Drilling bottom tools used in the exploration and production of hydrocarbons are typically made of frames or metallic or conductive bodies. In the operations of graphing, it is common to use these frames or metal bodies as measuring electrodes. For example, a metal frame of a tool can be used to emit a current signal in a surrounding formation, where the velocity at which the current flows from the tool mount to the surrounding formation can be measured and related to the resistivity of the formation. In a chain of tools for drilling that includes several tools, it may be necessary to prevent the current generated within a tool that has a tool mount used as an electrode from its migration to adjacent tools, where the adjacent tools may or may not be used as electrodes Mass isolation connections are typically used for this electrical insulation. Typically a mass isolation connection includes threads in adjacent connecting sections and an insulating material between the threads. To be effective, the mass isolation connection must be able to maintain its integrity when subjected to cutting and bending forces when the tools are transported within a borehole. The techniques of art known in the art include wireline, logging during drilling (LWD), measurement during drilling (M D), and logging during disconnection (LWT). Wired logging involves lowering the instrument toward the borehole at the end of an electrical cable to obtain measurements of the subsoil when the instrument moves along the borehole. The LWD / MWD involves placing the instrument in a drill assembly to obtain measurements of the subsoil while drilling a hole through an underground formation. The LWT involves placing sources or sensors inside the drilling column to obtain measurements while extracting the drilling column from the hole. US Patent No. 6,116,337 discloses an articulated connector for connecting two adjacent diaphragm probes that include a ground insulation connection to avoid the electrical signals of migration between the diagnostic probes. The ground insulation connection includes a first section and a second section arranged coaxially and coupled together by a screw gear with a coaxial insulator. The first section, the second section, and the insulator are generally cylindrical, although the insulator includes a portion of elongated diameter which extends between the opposite end faces of the first section and the second section, thus electrically isolating the first section. of the second section. An insulating sleeve is placed over the first section and second section to protect the connections between the first and second sections and the insulator of the fluids from the borehole. The insulating sleeve may be formed of a non-conductive material such as glass fiber or an epoxy compound. There is a continuing need for a robust ground insulation connection for use electrically in a bottom tool of a bore, which can withstand the cutting and bending forces, typical of operations at the bottom of a bore. BRIEF DESCRIPTION OF THE INVENTION In one aspect, the invention relates to a ground insulation connection for electrically insulating a tool from the bottom of a bore comprising a first connection section having a distal end in which a first thread is formed, a second connection section, and an insulating composite structure that couples the first connection section to the second connection section, wherein at least one of the first and second connection sections is adapted to be coupled to the bottom tool a perforation. The insulating composite structure comprises a first composite layer formed in the second connection section. The first composite layer has a second thread engaging the first thread at the distal end of the first connection section. In another aspect, the invention relates to a string of tools for drilling for use in an auger that penetrates an underground formation comprising a plurality of bottom tools of a borehole and a ground insulation connection, as described above, coupled to at least one of the tools at the bottom of a hole. Other aspects and advantages of the invention will be apparent from the following description and the appended claims. BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, described below, illustrate typical embodiments of the invention and are not considered to limit the scope of the invention, given that the invention can accept other equally effective modalities. The figures are not necessarily to scale, and certain aspects and a certain view of the figures can be shown exaggerated to scale or in schematic representation for reasons of clarity and conciseness. FIG. 1 is a longitudinal cross section of a ground insulation connection for electrically insulating a tool from the bottom of a hole. FIG. 2 shows a chain of tools for drilling in a hole incorporating the ground insulation connection of FIG. 1. DETAILED DESCRIPTION OF THE INVENTION The invention will now be described in detail with reference to a few preferred embodiments, as illustrated in the accompanying drawings. In describing the preferred embodiments, numerous specific details are set forth to provide a total understanding of the invention. However, it will be apparent to one skilled in the art that the invention can be practiced without some or all of these specific details. In other cases, well-known aspects and / or steps of the process have not been described in detail so as not to obscure the invention unnecessarily. In addition, similar or identical reference numbers are used to identify common or similar elements.

FIG. 1 shows a longitudinal cross section of a ground insulation connection 100 for electrically insulating a tool from the bottom of a hole. The ground insulation connection 100 includes a first connection section 102, a second connection section 104, and an insulating composite structure 106 which couples the first connection section 102 to the second connection section 104. The first section of connection 102 may be a reinforcement clamp, which may be coupled to the first tool mount or may be an integral part of the first tool mount. The first tool mount may be a diagnostic probe, for example, and the first connection section 102 may be coupled to the first tool mount via a rigid or flexible connection. The second connection section 104 may be a mandrel, which may be coupled to a second tool mount or may be an integral part of a second tool mount. The second tool mount may be a logging probe, for example, and the second connection section 104 may be coupled to the second tool mount through a rigid or flexible connection. The first and second connecting sections 102, 104 may be made of a conductive material, typically a metal or alloy, or a synthetic material. Preferably, the material of the first and second connection sections 102, 104 can withstand conditions in the holes for the exploration and production of hydrocarbons. The first and second connecting sections 102, 104 can generally be cylindrical (or tubular) and can be provided with holes or perforations 108, 110, which can be aligned for the passage of wires and tools. The insulating composite structure 106 includes an internal composite layer 112 formed on the outer surface 114 of the second connection section 104. The internal composite layer 112 also covers the external face 116 of the second connection section 104, i.e. , the end face opposite the first connection section 102. The formation of the internal composite layer 112 in the second connection section 104 may include winding a composite material in tension about the second connection section 104 manually or using a suitable winding device such as a turning machine. The composite layer 112, internal, may include one or more wraps of a composite material. The outer surface 114 of the second connecting section 104 can be textured to allow an increased bond between the inner, composite layer 112 and the second connecting section 104. The texturing can be provided by sand polishing the outer surface 114 of the second section is used as a gauge for the threads 124 in the first connection section 102 so that the first connection section 102 can engage the composite layer 112, internally through the threads 118, 124. An adhesive 126 of High temperature can be injected or inserted between the first connection section 102 and the internal composite layer 112. The high temperature adhesive may be a curable material such as epoxy. The curable material is allowed to cure, thereby providing a bond between the first connecting section 102 and the inner, composite layer 112 that can withstand high temperature conditions. The internal composite layer 112 provides an insulating layer between the second connection section 104 and the first connection section 102 and thus prevents the migration of currents from the second connection section 104 to the first connection section 102. The structure 106 composite, insulator, further includes a sealing layer 128 formed at the distal end 120 of the first connection section 102 and the internal composite layer 112 in the second connection section 104. An outer composite layer 130 is formed in the sealing layer 128. The sealing layer 128 and the composite layer 130, outer, protect the connection between the first connection section 102 and the internal composite layer 112 of the borehole fluids. The sealing layer 128 may be made of an elastomer or rubber material or other sealing material suitable for use in a borehole environment. Suitable materials for the sealant layer include, but are not limited to, Neoprene (RTM), Viton (RTM), and Nitrile (RTM). The outer composite layer 130 can also be made of any suitable composite material. For example, the. Composite layer 130, outer, could be made of a fiber-resin composite, fiberglass, or fabric impregnated with resin. The formation of the outer composite layer 130 in the sealing layer 128 may include winding a tensioned composite material around the sealing layer 128 manually or using a suitable winding device such as a turning machine. The outer, composite layer 130 may include one or more wrappings of the composite material. An outer projection 132 of the first connection section 102 that joins the outer composite layer 130, and the sealing layer 128 may be biased, as shown, or may be straight. A biased projection provides an increased surface area for sealing. In general, the thickness of the composite, insulating structure 106, or of the individual layers in the composite, insulating structure 106, is selected such that the composite, insulating structure 106 is encompassed with the outside diameter of the first section of insulation. connection 102.

, FIG. 2 shows a chain 200 of tools for drilling in a hole 202 that penetrates an underground formation 204. The chain 200 for drilling tools includes tools 206, 208, 210 of the bottom of a hole, for example. In one example, the tools 206, 208, 210 of the bottom of a perforation, are tools of diagrafia, such as tools for measurement of density, porosity, depth and / or intermediate and / or surface resistivity, natural gamma radiation, and size of the hole in a hole that penetrates an underground formation. As an example, which is not intended to be limiting, the tool 208 of the bottom of a hole may be an inductive resistivity tool having a tool mount 208a for use as a current emitting electrode. The ground insulation connections 100, as described above, are positioned between the tool mount 208a and the adjacent tools 206, 210 in the drill string 2 (30) The ground insulation connections 100 may be coupled to the tools 206, 210 through a rigid connection, as shown at 212, or through a flexible connection, as shown at 214. A rigid connection 212 may be a welded or threaded connection, for example. flexible ones may include a ball joint and for example, the mass isolation connection 100 prevents currents from migrating from the tool mount 208a to the adjacent tools 206, 210 in the drill string 200 and vice versa. of mass insulation does not always need to be between two tools at the bottom of a hole. a at the free end of a tool at the bottom of a hole, for example, to prevent currents from migrating to the tool at the bottom of a hole from that free end. The drill string 200 is supported on the bore 202 on the end of a cable drill 216 in a manner well known in the art. Alternatively, the drill string 200 may be supported on bore 202 on the end of a drill string (not shown) that includes a drill head (not shown), also in a manner well known in the art. Those skilled in the art will appreciate that embodiments of the invention can be implemented in any type of tool or instrument of the bottom of a hole that is known in the art or that is subsequently developed. The disclosed invention provides advantages over conventional structures, including reduced manufacturing costs, compatibility with smaller design circles, and lower failure rates during manufacturing. Although the invention has been described with respect to a limited number of embodiments, those skilled in the art who benefit from this disclosure will appreciate that other embodiments may be designed which do not depart from the scope of the invention as described in the present.

Claims

CLAIMS 1. - A ground insulation connection for electrically isolating a tool from the bottom of a hole, characterized in that it comprises: a first connection section having a distal end in which a first thread is formed; a second connection section, and a composite insulating structure that couples the first connection section to the second connection section, the insulating composite structure comprises a first composite layer formed in the second connection section, the first composite layer has a second thread which engages the first thread on the distal end of the first connection section; wherein at least one of the first and second connection sections is adapted to be coupled to the bottom tool of a hole.
2. - The ground insulation connection of claim 1, characterized in that the second thread is formed in a portion of the internal composite layer formed at a distal end of the second connection section, and the distal end of the first The connection section includes a slot for receiving the distal end of the second connection section and the internal composite layer formed therein.
3. - The ground insulation connection of claim 2, characterized in that the first thread is formed in a wall of the groove.
4. - The ground insulation connection of claim 1, characterized in that the insulating composite structure further includes a sealing layer formed in the first composite layer and the distal end of the first connection section.
5. - The ground insulation connection of claim 4, characterized in that the sealing layer comprises an elastomeric material.
6. - The ground insulation connection of claim 4, characterized in that the insulating composite structure further includes a second composite layer formed in the sealing layer.
7. - The ground insulation connection of claim 1, characterized in that it further comprises a high temperature adhesive placed between the first composite layer and the first connection section.
8. - The ground insulation connection of claim 7, characterized in that the high temperature adhesive is a curable material.
9. - The ground insulation connection of claim 1, characterized in that the first and second connection sections are made of a conductive material.
10. - The ground insulation connection of claim 1, characterized in that the first and second threads have a low separation.
11. - A chain of tools for drilling for use in a hole penetrating an underground formation, characterized in that it comprises: a plurality of tools from the bottom of a hole; and a ground insulation connection for at least one of the bottom tools of a bore comprising: a first connection section having a distal end in which a first thread is formed; a second connection section; and an insulating composite structure which couples the first connection section to the second connection section, the composite insulating structure comprises a first composite layer formed in the second connection section, the first composite layer having a second thread engaging the first thread.
12. - The string of tools for drilling of claim 11, characterized in that the ground insulation connection is placed between the adjacent tools of the bottom of a hole and coupled thereto.
13. - The drilling tool chain of claim 12, characterized in that the ground insulation connection is coupled to the adjacent tools of the bottom of a hole through a rigid or flexible connection.
14. - The chain of tools for drilling according to claim 11, characterized by the tools of the bottom of a hole comprise tools of diag- nosis.
15. - The chain of tools for drilling of claim 11, characterized in that the second thread is formed in a portion of the inner composite layer formed at a distal end and the second connection section, and the distal end of the first connection section includes a slot for receiving the distal end of the second connection section and the composite, internal layer formed in it.
16. The drilling tool chain of claim 11, characterized in that the first thread is formed in a wall of the groove.
17. The drilling tool chain of claim 11, characterized in that the insulating composite structure further includes a sealing layer in the first composite layer and the distal end of the first connection section.
18. The drilling tool chain of claim 17, characterized in that the insulating composite structure further includes a second composite layer formed in the sealing layer.
19. - The drilling tool chain of claim 18, characterized in that the sealing layer comprises an elastomeric material and the second composite layer comprises a composite resin.
20. - The drilling tool chain of claim 11, characterized in that it further comprises a high temperature adhesive placed between the first composite layer and the first connection section. SUMMARY OF THE INVENTION A mass isolation connection for electrically isolating a tool from the bottom of a bore includes a first connection section having a distal end in which a first thread is formed, a second connection section, and a structure insulating composite that couples the first connection section to the second connection section, wherein at least one of the first and second connection sections is adapted to be coupled to the tool of the bottom of a bore. The insulating composite structure includes a first composite layer formed in the second connection section. The first composite layer has a second thread engaging the first thread at the distal end of the first connection section. 106 FiG. 1