公开(公告)号：CA2476370C

公开(公告)日：2009-06-09

申请号：CA2476370

申请日：2004-07-30

Applicant: WEATHERFORD LAMB

Inventor： CAMWELL PAUL ,  LOGAN DEREK ,  NERO MICHAEL ,  DOPF TONY ,  SMALLWOOD ROBERT E ,  HORST CLEMENS L

IPC: E21B17/00 ,  E21B47/01 ,  E21B47/12 ,  F16L25/02

Abstract: A compact, robust, wear resistant, and high performance electrically insulating gap sub for use with borehole EM Telemetry is disclosed. In one embodiment, the gap sub may include an externally threaded mandrel separated from an internally threaded housing by a dielectric material. Additionally, some embodiments may include an external gap ring for separating the upper and lower electrical halves of the sub which offers structural support, acts as the primary external seal, and provides an abrasion resistant non-conductive length on t he exterior. Some embodiments may include torsion bins to prevent the possible unscrewing of the dielectric filled threaded sections should the dielectric material become damaged or weakened.

公开(公告)号：CA2476370A1

公开(公告)日：2005-01-31

申请号：CA2476370

申请日：2004-07-30

Applicant: WEATHERFORD LAMB

Inventor： LOGAN DEREK ,  DOPF TONY ,  CAMWELL PAUL ,  NERO MICHAEL ,  HORST CLEMENS L ,  SMALLWOOD ROBERT E

IPC: E21B17/00 ,  F16L25/02 ,  E21B47/06

Abstract: A compact, robust, wear resistant, and high performance electrically insulating gap sub for use with borehole EM Telemetry is disclosed. In one embodiment, the gap sub may include an externally threaded mandrel separated from an internally threaded housing by a dielectric material. Additionally, some embodiments may include an external gap ring for separating the upper and lower electrical halves of the sub which offers structural support, acts as the primary external seal, and provides an abrasion resistant non-conductive length on t he exterior. Some embodiments may include torsion bins to prevent the possible unscrewing of the dielectric filled threaded sections should the dielectric material become damaged or weakened.

公开(公告)号：GB2404401B

公开(公告)日：2006-12-06

申请号：GB0417072

申请日：2004-07-30

Applicant: WEATHERFORD LAMB

Inventor： DOPF TONY ,  LOGAN DEREK ,  CAMWELL PAUL ,  NERO MICHAEL ,  HORST CLEMENS L

IPC: E21B47/12 ,  E21B17/00 ,  E21B47/00 ,  F16L25/02

公开(公告)号：GB2404401A

公开(公告)日：2005-02-02

申请号：GB0417072

申请日：2004-07-30

Applicant: WEATHERFORD LAMB

Inventor： DOPF TONY ,  LOGAN DEREK ,  CAMWELL PAUL ,  NERO MICHAEL ,  HORST CLEMENS L

IPC: E21B17/00 ,  F16L25/02 ,  E21B47/12 ,  E21B47/00

Abstract: A subsurface electromagnetic (EM) telemetry system 100 comprises a gap sub assembly 15 having a housing 103, a mandrel 104, a dielectric material (109, figure 2a) disposed between the mandrel 104 and the housing 103, and a first non conductive gap ring 105 disposed between the housing 103 and the mandrel 105. The dielectric material (109, figure 2a) and the first non conductive gap ring 105 create an electrical break between an upper section 10 and a lower section 20 of a drill string 60 to form a large antenna by energising the upper and lower sections 10, 20 with opposite polarity to provide EM waves 30. The EM waves 30 travel through the earth to the surface where a potential difference may be measured between a rig structure 40 and a point 50 on the surface at a predetermined distance away from the rig 40. In a further embodiment, the housing 103 and the mandrel 105 are attached by a threaded connection (107, figure 2a) which allows the housing 103 and the mandrel 105 to remain axially coupled together in the event of failure of the dielectric material (109, figure 2a).