Title:
固体成分含有量の少ない高圧の液体を使用して穿孔するための方法及び装置
Document Type and Number:
Japanese Patent JP3589425
Kind Code:
B2
Abstract:
A drillstring terminating in a drill bit is run into a borehole. A reduced solid content drilling fluid is pumped through the drillstring and out the bit, wherein the drilling fluid impinges upon and disintegrates formation material in cooperation with the bit. An annulus fluid having a density greater than that of the drilling fluid is continuously pumped into the annulus between the borehole and drillstring, wherein the annulus fluid extends substantially from the surface to the bottom of the drillstring. Drilling fluid and cuttings resulting from disintegration of formation material are returned to the surface through a substantially unobstructed tubular passage in the drillstring. The annulus fluid is maintained under a selected and controlled pressure in the annulus, wherein an interface is formed at the drill bit at which annulus fluid mixes with the drilling fluid and is returned along with the drilling fluid and cuttings and drilling fluid is substantially prevented from entering the annulus.
Inventors:
Shoe, Frank Jay
Application Number:
JP51925896A
Publication Date:
November 17, 2004
Filing Date:
December 13, 1995
Export Citation:
Assignee:
Telejet Technologies, Inc.
International Classes:
E21B17/18; E21B21/10; E21B21/12; E21B7/18; E21B34/00; (IPC1-7): E21B21/12; E21B7/18; E21B17/18
Foreign References:
| WO1986002403A1 | ||||
| WO1991017339A1 | ||||
| FR2526853A1 | ||||
| US3075589 |
Attorney, Agent or Firm:
Akashi Masatake