Air Drilling, Rock Mechanics And Drilling Process Simulation,

This thesis belongs to the part research contents of fund project which is supported by State Key Laboratory of Reservoir Geology and Development Engineering "Hole Deviation of Gas Drilling with Lithological Influence"(Project NO.:PLN0412)Firstly, this thesis carried on a great deal of investigation, collection, study on the air drilling technique of the domestic and international document. Analyzed and based on the formers' research findings, established a formation rock three-dimension model in air drilling and dynamic drilling procedure model of bit drilling formation rock with rock mechanics and newest rock plastic mechanics--generalized plastic mechanics. In addition, in detail analyzed the result of simulation. Finally, some regulation and suggestion was given. The contents and achievements include:1. According to rock mechanics and generalized plastic mechanics, established a finite element three-dimension model of isotropy and anisotropy of varies of angle of inclination formation rock between air drilling and mud drilling. Simulated the rock mechanics trait of bottom hole rock and sidewall rock between air drilling and mud drilling under 3000 meter. Moreover, in detail analyzed the result of simulation. Some rule of hole deviation and sidewall instability problem and some suggestion was given.2. Basing on former researcher findings, simplified and deduced the formulas of formation deflecting force and azimuth force of transverse isotropy formation under the condition of the anisotropy bit. Adopted the same parameter as finite element simulation and performed a comparative analysis between the result of analytic solution and result of the simulation. they were general equal.3. Adopted Pro/E software and drew an 8 1/2 inch PDC bit. The finite element software introduced the bit and established anisotropy of series of angle of inclination formation rock in air drilling. Investigate the mechanism of interaction between bit and formation rock and the procedure of PDC bit breaking rock.The innovation of this thesis:1., Established first time dynamic drilling procedure finite element three-dimension model of material non-linear of formation rock and contact non-linear between rock and bit It can really simulate the bit dynamic drilling procedure2. In the finite element model, the principle of judging whether the rock element is failure or not is the equivalent plastic strain value.