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近年来,在沙特阿拉伯,由于水平井的钻探,使产层的泄油面积明显增加,一些油气田的产量也在增长。在完井作业中,需要下入多级增产系统(MSS)完井管柱,但在致密气藏深水平井中,出现下入困难甚至管柱被卡现象。分析认为,井眼的完成、不同压力体系的多套地层、井眼的准备以及下入的技术和程序等因素,是影响管柱组合顺利下入的关键。实践证明,对于存在多套低压层的井眼,钻井设计时,技术套管应尽可能深下,封住上部低压非生产层,最好将套管鞋坐封在生产层内。应在井眼安全的情况下,将钻井液密度调低,以减轻低压层的过平衡压力;一旦发生黏卡,缓慢降低钻井液密度,并小幅活动管串,是解卡的唯一途径。在可能存在台阶的水平井段,用模拟完井管串结构的钻具组合(BHA)通井,可以消除机械卡钻风险,为大尺寸尾管顺利下入创造条件。
In recent years in Saudi Arabia, due to the drilling of horizontal wells, the drainage area of the pay zone has increased markedly, and the production of some oil and gas fields has also increased. In the completion operation, MSS completion string needs to be put into operation. However, in the deep horizontal well of tight gas reservoirs, there is a problem that the MSS well completion pipe is stuck down or the pipe string is stuck. The analysis shows that the key to the success of the well combination is the completion of the wellbore, multiple sets of different pressure systems, the preparation of the wellbore and the technical and procedural factors involved. Practice has proved that for the existence of multiple sets of low-pressure borehole, drilling design, the technical casing should be as deep as possible, sealing the upper part of the low-pressure non-production layer, it is best to set the casing shoes in the production layer. The drilling fluid density should be lowered in the wellbore safety case to relieve the overbalanced pressure in the lower pressure zone. Once sticking occurs, slowly lowering the drilling fluid density and moving the tube strings slightly will be the only way to relieve the pressure. In the possible horizontal section of the step, drilling a well assembly (BHA) through a simulated completion string structure can eliminate the risk of mechanical sticking and create conditions for the smooth running of a large tail pipe.