钻头钻削桥塞过程受力分析与试验研究

为了定量分析和控制连续油管钻头钻削桥塞过程中的钻压和扭矩，预防钻屑过大，返屑困难，对复合桥塞钻削过程进行了力学分析。通过建立连续油管钻头钻削桥塞过程力学分析模型，分析了钻头钻压与压入深度和扭矩与切屑之间的力学关系，得到了钻压、扭矩与切削深度的力学方程。为验证该力学方程计算结果的准确性，在2口井进行了现场试验，共钻掉9个桥塞。试验显示，计算结果与现场试验结果的最大相对误差为15%，可满足预测实际钻塞深度的精度需求。研究结果表明，建立的连续油管钻头钻削桥塞过程力学分析模型可以描述钻压、扭矩与切削深度之间的力学关系，对桥塞钻削施工中钻压与扭矩的控制具有指导意义。 

Force Analysis and Test of Bridge Plug Drilling

To quantitatively control weights on bit(WOBs) and torques of the coiled tubing bit in the drilling of a bridge plug,and to eliminate problems related to oversize cuttings during the process,mechanical analyses were performed for the cutting of the compound bridge plug.By constructing the mechanical model for the cutting of bridge plug by the coiled tubing bit,the relationships among WOBs,drilling depths,torques and cutting volumes were analyzed to derive the dynamic equation for WOBs,torques and cutting depths.To confirm the accuracy of relevant calculation results,field tests were conducted in two wells to drill 9 bridge plugs.Test results showed the maximum relative error between calculation result and field application result was 15%,which was sufficient to satisfy accuracy demands at the expected plug-drilling depths.Research results showed the newly derived mechanical analyzing model for coil tubing bit to cut bridge plug could accurately high light correlation among WOBs,torques and cutting depths.The model is great significance to control the WOBs and torques in bridge plug drilling.