Global Patent Index - EP 0996810 A1

EP 0996810 A1 2000-05-03 - REVERSE CIRCULATION DRILLING SYSTEM WITH BIT LOCKED UNDERREAMER ARMS

Title (en)

REVERSE CIRCULATION DRILLING SYSTEM WITH BIT LOCKED UNDERREAMER ARMS

Title (de)

UMKEHRSPULUNGSEINRICHTUNG MIT BOHRMEISSEL MIT VERRIEGELTEN ERWEITERUNGSARMEN

Title (fr)

SYSTEME DE FORAGE A INJECTION INVERSE DOTE DE BRAS ELARGISSEURS VERROUILLES PAR OUTIL

Publication

EP 0996810 A1 (EN)

Application

EP 98935684 A

Priority

  • US 9814651 W
  • US 89678797 A

Abstract (en)

[origin: WO9904130A1] An underreamer drill bit assembly including a pilot bit (82) and extendable underreaming arms (88) operatively connected to the pilot bit (82). The underreaming arms (88) have an extended position for underreaming, and a retracted position in which the overall diameter of the underreamer drill bit assembly is less than the inside diameter of the well casing, permitting the entire bit assembly to be withdrawn through the well casing. In another aspect of the invention, the bit assembly is operatively connected to a dual wall pipe assembly (12). A supply of compressed air is conducted through the annulus (24) of the dual wall pipe assembly (12) to a down hole pneumatic hammer (13). Exhaust air from the down hole hammer (13) is directed to the bit assembly for continuous removal of drilling debris through a central evacuation tube (43) of the dual wall pipe assembly.

IPC 1-7 (main, further and additional classification)

E21B 10/66

IPC 8 full level (invention and additional information)

E21B 10/32 (2006.01); E21B 10/66 (2006.01)

CPC (invention and additional information)

E21B 10/66 (2013.01); E21B 10/327 (2013.01)

Citation (search report)

See references of WO 9904130A1

Designated contracting state (EPC)

DE ES FI GB IT SE

EPO simple patent family

WO 9904130 A1 19990128; AU 755442 B2 20021212; AU 755442 C 20030612; AU 8487398 A 19990210; BR 9815553 A 20011211; CA 2296470 A1 19990128; CN 1263937 C 20060712; CN 1270655 A 20001018; EP 0996810 A1 20000503; HK 1030253 A1 20061117; JP 2001510256 A 20010731

INPADOC legal status


2007-02-23 [REG HK WD] APPLICATIONS WITHDRAWN, DEEMED TO BE WITHDRAWN, OR REFUSED AFTER PUBLICATION IN HONG KONG

- Document: HK 1028799

2004-09-01 [18D] DEEMED TO BE WITHDRAWN

- Effective date: 20040203

2000-05-03 [17P] REQUEST FOR EXAMINATION FILED

- Effective date: 20000119

2000-05-03 [AK] DESIGNATED CONTRACTING STATES:

- Kind Code of Ref Document: A1

- Designated State(s): DE ES FI GB IT SE