【作者】 陈修平； 邹德永； 汤晶； 王家骏；

【Author】 CHEN Xiu-ping;ZOU De-yong;Tang Jing;WANG Jia-jun;School of Petroleum Engineering in China University of Petroleum;

【机构】 中国石油大学(华东)石油工程学院； 中国石化西北油田分公司完井测试管理中心；

【摘要】 为量化分析PDC钻头水力因素对其水力性能的影响规律,利用UG软件建立典型PDC钻头井底及环空的三维流域模型,利用GAMBIT软件对流域模型进行网格划分,将岩屑假设为从井底面射入流场的球状颗粒,基于FLUEN软件中的DPM(离散相模型)对岩屑颗粒运动进行追踪,使用岩屑运载比(距离井底不同高度截面上的平均岩屑颗粒速度与平均环空流速之比)作为PDC钻头水力性能的评价参数,研究流量、岩屑尺寸、喷嘴尺寸、喷嘴数量、喷嘴布置方式等对钻头水力性能的影响规律。数值计算结果表明,其他水力条件不变情况下,岩屑运载比随着流量的增大而增大,随着岩屑尺寸及喷嘴尺寸的增大而减小;对于同一钻头,且喷嘴总出口面积相同时,与六喷嘴钻头相比,五喷嘴钻头的岩屑运载比值稍大;对于所研究的钻头,喷嘴布置方式对岩屑运载比影响很小。更多还原

【Abstract】 In order to analyse the effect of the hydraulic factors on the hydraulic performance of PDC bits, the three-dimensional fluid volume model which includs the bottomhole of PDC bit and the annulus was established using UG, and the mesh of the fluid volume model was generated using GAMBIT. Cuttings were modeled as spherical particles that were injected into the flow field from the bottom of hole, the discrete particle modeling(DPM) was used to track the cuttiings. The ratio of average particle velocity to average annulus fluid velocity, refered to as the cutting-transport ratio, was used to evaluate the hydraulic performance of PDC bits, the effects of flow rate, cutting size, nozzle size, nozzle number, nozzle-size arrangement on the hydraulic performance of drill bits were studied. The numerical calculation results showed that the cutting-transport ratio increased as flow rate increased and decreased as cutting size and nozzle size increased. The cutting-transport ratio increased slightly in a bit with five nozzles when compared with the same bit with six nozzles with the same total fow area. Also, the cutting-transport was found to be insensitive to the nozzle-size arrangement of the bit studied.更多还原