The Research On Rock Breaking Mechanism Of Torsion Impacter And Its Field Application

At present,with the increasing of the drilling depth,the drilled formation becoming more and more complicated.the hardness of the underlying rock is great,and rate of penetration is high.These factors effect drilling cycle greatly,so the drilling speed needs to be improved.In addition,the PDC bit that breaks the rock by shearing always appears sliding clamp,which results in the decline of both drilling efficiency and the bit life.Therefore,it is the most important project to improve the rock-breaking efficiency of PDC bits.The thesis,which is based on the study on the stick-slip vibration phenomenon of PDC drill bit,studies the rock breaking mechanism of the torsion impacter,through the analysis of the influence of stick-slip vibration phenomenon on rate of penetration.The thesis includes the content of stick-slip vibration phenomenon of PDC drill,rock breaking mechanism of the torsion impacter and its case analysis in the district of Yuanba,Yubei 6A,Yashen 1 well,Xinken 8-H well and Fu 19 well.The thesis systematically analyses the influence of impulse load produced by torsion impacter on drilling rate under the conditions of deep and hard formation.And the results of theoretical analysis and case analysis show that: torsion impacter enables the energy of drilling fluid to shift to low-rising,high-frequency pulse torque,to not only obviously improve the drilling speed,but to effectively decrease or eliminate harmful vibration in the drilling process of hard formation in order to protect drill bit and extend the service life of drill bit.Torsion impact drilling is a rising technology in the high-speed rock breaking field.The thesis plays a significant and practical role in the popularity of the stick-slip vibration mechanism and improvement of torsion impact drilling technology.