Downhole motor and method for directional drilling of boreholes
Patent 4485879 Issued on December 4, 1984. Estimated Expiration Date: 
July 28, 2003. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
July 28, 2003. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.Patent ReferencesDownhole flexible drive system Dual-rotating eccentric drilling apparatus and method Patent #: 4267893 InventorsAssigneeApplicationNo. 06/518270 filed on 07/28/1983US Classes:175/61, Boring curved or redirected bores175/107, Fluid rotary type175/320WITH TOOL SHAFT DETAILExaminersPrimary: Novosad, Stephen J.Assistant: Starinsky, Michael International ClassesE21B 4/02 (20060101)E21B 4/20 (20060101) E21B 7/04 (20060101) E21B 7/06 (20060101) E21B 4/00 (20060101) Foreign Application Priority Data1982-08-25 GBAbstractThe invention relates to a downhole motor having a housing of which the resistance against bending in a predetermined longitudinal plane is smaller than in any other longitudinal plane. Directional drilling of boreholes is carried out by rotating the drill string simultaneously with the rotation of the drill bit driven by the downhole motor over periods preceded and followed by selected periods during which the drill string is not rotated simultaneously with the rotation of the drill bit driven by the downhole motor. | |
