Directional and horizontal well drilling technology has significant meaning for shale gas exploration.The rock cutting process of a PDC bit in the directional and horizontal well drilling is very complex and it is remarkably different from that in vertical well. So the ordinary means of analyzing and predicting a PDC bit performance can't meet the needs of directional drill bit evaluation. In view of the weak points that exist in the reseach on directional and horizontal well bit technology in domestic PDC bit company and the practical demands of shale gas exploration,we developed systemic study on the PDC bit numerical experiment technology that is the key point of high-efficiency directional and horizontal well PDC bit design.
The contents and results obtained in this paper mainly include:
1.Developed study on the numerical bit ,well bottom and the borehole face modeling method for PDC bit numerical experiment system.
2.Through analysising the PDC bit kinematics of slide steering drilling, rotary steering drilling and combined drilling ,we established the PDC bit kinematics model of numerical experiment system.
3.Adopting the equal penetrate rate drilling process method,we emulated the PDC bit drilling process,analysised the contact between PDC cogging and rock and calculated the PDC cogging contact area and volume numerically.
4.Proposed a PDC cogging cutting angle calculation method that adapt to every complex movement condition.
5.Established the interaction model between PDC cogging and bottom rock , based on this caculate the cutting force of PDC cogging and the drilling force of PDC bit numerically.
6.Have a research on the basic principle and method of PDC bit rock-breaking efficiency,wornout mechanism,guide ability and the azimuthal stabilization.
7.Compiled “directional well and horizontal well PDC bit numerical experiment system software”that can develop drilling test numerically no matter what drilling mode,what formation character and what PDC bit cutting structure.get comprehensive numerical test results from each PDC cogging to integral bit.
8.Based on the”directional well and horizontal well PDC bit numerical experiment system software”,design and develop high-efficiency PDC bit that suit for directional and horizontal well,which obtained good result in field application.