Downhole combination tool

• US 5,064,006 A
• Filed: 10/28/1988
• Issued: 11/12/1991
• Est. Priority Date: 10/28/1988
• Status: Expired due to Term

• Current Assignee: Reuter-Stokes, Inc. (General Electric Company)
• Original Assignee: Magrange Incorporated
• Inventors: Waters, Robert L., Clark, Howard C., Stelly, Otis V. II, Fitzgerald, Don D., Roberts, George F., Walters, Philip H.
• Primary Examiner(s): Dang, Hoang C.
• Application Number:
  US07/264,445
• Time in Patent Office: 1,110 Days
• Field of Search: 175/45, 175/50, 175/61, 175/24, 324/346, 324/367, 324/369, 324/326, 33/313, 33/355 R
• US Class Current: 175/45
• CPC Class Codes: E21B 47/0228 using electromagnetic energy or detectors therefor
• CPC Class Codes: E21B 47/092 by detecting magnetic anomalies
• CPC Class Codes: E21B 7/068 drilled by a down-hole drilling motor down-hole drives per se E21B4/00, E21B7/067 takes precedence
• CPC Class Codes: G01V 3/26 operating with magnetic or electric fields produced or modified either by the surrounding earth formation or by the detecting device with electromagnetic waves G01V3/30

Abstract

A directional drilling downhole steering and survey tool for detecting ferromagnetic bodies from an off vertical borehole, transmitting the signals from the downhole sensors to surface equipment while drilling, and for calculation of the range and direction to the detected ferromagnetic body for the use of the directional driller in intercepting or avoiding the ferromagnetic body. In combination with the steering and range and direction to ferromagnetic body capabilities, the downhole tool may also include sensors for detecting formation bed interface, apparatus for electric or gamma ray or radioactive logging, neutron density sensor apparatus and other formation evaluation or correlation apparatus. The downhole tools may be packaged in either an electric line transmitted tool of MWD transmitted tool.

Claims

1. A system for guiding and drilling a subterranean borehole to intercept a subterranean ferromagnetic body exhibiting target magnetic field comprising:

(1) a subsurface tool comprising a non-magnetic housing, a first sensing means within said housing for continuously measuring the earth'"'"'s gravity field, a second sensing means within said housing for continuously measuring the components of a magnetic field along mutually orthogonal axes simultaneously at two locations in said borehole;

said tool further comprising means for transferring electrical current from a location inside said drill string into the earth formation being drilled, said tool being installed in a drill string proximate a drill collar wherein said means for transferring electrical current from an electrical supply conductor comprises;

(a) at least one current conducting pin extending through and electrically insulated from said drill string;

(b) formation contactor means extending from said current conducting pin for electrically transmitting current into the wall of the borehole drilled; and

(c) guide and latch means comprising a pair of elongated guide legs formed at a juncture with a pin latch receptacle depending downwardly from said guide leg juncture, said guide and latch means being connected to said electrical supply conductor and supported by said wireline and being disposed to establish guiding and releasable latching relation with said current conducting pin as said guide and latch means is moved downwardly by said wireline;

(2) transmission and receiving means mounted in said housing and operatively connected to first and second sensing means for transmitting said gravity and magnetic field measurements to the surface while drilling and for receiving guidance control information transmitted to said tool; and

(3) surface equipment in communication with said housing transmission and receiving means comprising processing means for continuously calculating azimuth and inclination of said borehole and position of said borehole relative to said subterranean body using the measurements of said first and said second sensing means.

2. A system for guiding and drilling a subterranean borehole to intercept a subterranean ferromagnetic body exhibiting target magnetic field comprising:

(1) a subsurface tool comprising a non-magnetic housing, a first sensing means within said housing for continuously measuring the earth'"'"'s gravity field, a second sensing means within said housing for continuously measuring the components of a magnetic field along mutually orthogonal axes simultaneously at two locations in said borehole;

said tool further comprising means for transferring electrical current from a location inside said drill string into the earth formation being drilled, said tool being installed in a drill string proximate a collar wherein said means for transferring electrical current from an electrical supply conductor comprises;

(a) at least one current conducting pin extending in electrically insulated relation through said drill string;

(b) formation contactor means extending from said current conducting pin means for electrically transmitting current into the wall of the bore hole drilled; and

(c) guide and latch means comprising a pair of elongated guide legs formed at a juncture with a latch pin receptacle depending downwardly from said guide leg juncture, said guide and latch means being connected to said electrical supply conductor and supported by said wireline and disposed to establish guiding and releasable latching relation with said current conducting pin means as said guide and latch means is moved downwardly by said wireline;

said guide and latch means being of bifurcated form defining a pair of elongated depending guide legs disposed for guiding contact with current conducting pin means and an electrical contact latch receptacle receiving said current conducting pin means in electrically contacting releasable latched relation therein;

(2) transmission and receiving means mounted in said housing and operatively connected to said first and second sensing means for transmitting said gravity and magnetic field measurements to the surface while drilling and for receiving guidance control information transmitted to said tool; and

(3) surface equipment in communication with said housing transmission and receiving means comprising processing means for continuously calculating azimuth and inclination of said borehole and position of said borehole relative to said subterranean body using measurements of said first and said second sensing means.