Title:
DOWNHOLE CIRCULATION APPARATUS
Document Type and Number:
WIPO Patent Application WO/2011/061239
Kind Code:
A3
Abstract:
A downhole circulation apparatus 2 comprises at least one tubular body portion 4 defining a first through-flow passage 6 through which drilling fluid can pass along the drill string. A first sleeve 10 is slidably mounted in the tubular body portion 4 and is biased into a position in which the first port means 8 is closed by a biasing means such as a spring 12. Second port means 18 is formed through the tubular body portion 4 at a location below the first port means 8 in the drill string. The second port means 18 may comprise a plurality of second nozzles, wherein each of the second nozzles has a diameter greater than the diameter of each of the first nozzles of the first port means 8. Larger nozzles enable large particle size drilling fluid to be bypassed. A second sleeve 20 is slidably mounted inside the tubular body portion 4.
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Inventors:
LEE PAUL BERNARD (CA)
Application Number:
PCT/EP2010/067712
Publication Date:
October 27, 2011
Filing Date:
November 17, 2010
Export Citation:
Assignee:
SCHOELLER BLECKMANN OILFIELD EQUIPMENT AG (AT)
LEE PAUL BERNARD (CA)
LEE PAUL BERNARD (CA)
International Classes:
E21B21/10; E21B37/08
Domestic Patent References:
| WO2002075104A1 | 2002-09-26 | |||
| WO2003087526A1 | 2003-10-23 | |||
| WO2004088091A1 | 2004-10-14 |
Foreign References:
| US3503445A | 1970-03-31 | |||
| GB2360802A | 2001-10-03 |
Attorney, Agent or Firm:
DILG, HAEUSLER, SCHINDELMANN PATENTANWALTSGESELLSCHAFT MBH (Munich, DE)
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