泵注反循环钻井循环压耗实验研究

摘要

泵注反循环钻井是一种新型钻井方式，在钻复杂结构井时具有井眼清洁、机械钻速高等优点。循环压耗是泵注反循环钻井能否实现的关键问题。利用自行设计的泵注反循环模拟实验装置，进行了不同水眼个数、水眼布局以及钻井液参数下的循环压耗试验，根据试验结果对影响反循环循环压耗的主要因素进行分析。结果表明，最佳钻头水眼总面积为钻杆内截面积的50%，最佳钻头水眼布局方式为沿钻头边缘布局。同时，钻井液密度越高，循环压耗越大，但钻井液密度对最佳水眼面积和水眼的布局方式影响很小。研究结果为泵注反循环钻井钻头水眼优化设计提供了依据。%Pump-injected reverse circulation drilling is a new drilling method.It has lots of advantages (such as cleaned hole and high ROP)compared with previous method,which can be used in drilling complex structural well.As we all know,cyclic pressure loss is one of the most important topics in drilling.The laws of cyclic pressure loss in different nozzles or mud parameters are studied experimentally in lab.The paper analyses the major factors affected cyclic pressure loss,according to results of the simulated experiment.It comes to the conclusions that the area of the bit nozzles should be a half of the drilling stem.And the edge of the bit is the best position to place the bit nozzles.At the same time,the cyclic pressure loss can be higher while the density of drilling fluid increases.However,the density doesn’t seem to affect the best arrangement of bit nozzles.Theoretical basis is provided for optimized design of pump-injected reverse drilling bit nozzles.