强抑制钻井液体系研究及现场应用

水平井裸眼完井方式是降低开发成本的有效途径。为满足裸眼完井对井壁稳定的更高要求，通过水化机理分析研选出能够在岩心表面形成疏水膜、改变储层润湿性的抑制剂，对其改变润湿性能、相对抑制率、岩屑滚动回收率等进行了评价，并对钻井液性能进行了优化。实验结果表明:该抑制剂能有效抑制黏土表面水化，与钻井液配伍性好，优化后的钻井液岩屑滚动回收率从73.2%提升至92.42%。现场应用后钻井液抑制能力明显提高，抗污染能力强，有利于井壁稳定和机械钻速的提高。 

Study and Field Application of a Highly Inhibited Drilling Fluid

Open hole completion of horizontal wells is an effective way of reducing development cost. Based on the analysis of clay hydration mechanisms, an inhibitor able to form a hydrophobic film on the surfaces of a core and to change the wettability of the surfaces of a reservoir has been selected to satisfy a higher requirement for borehole stabilization in open hole completion. The inhibitor was evaluated in laboratory for its ability to change wettability, its relative rate of inhibition and percent recovery of shale cuttings in hot rolling test. A drilling fluid formulated with this inhibitor was optimized. Laboratory experiment results showed that the inhibitor can effectively inhibit surface hydration of clays, and is well compatible with other drilling fluid additives. Percent recovery of cuttings in hot rolling test was increased from 73.2% to 92.42% after optimization. Field practice showed that the inhibitive capacity of the drilling fluid was remarkably improved, and the drilling fluid showed very good resistance to cutting contamination, all of which were beneficial to borehole stabilization and increasing of rate of penetration.