水敏性地层钻探用接枝淀粉聚合物泥浆体系研究

Study of the Grafted Starch-polymer Mud System Used for Drilling in Water-sensitive Strata

以接枝淀粉共聚物为降失水剂,选择抑制剂、防塌剂、润滑剂、包被剂、膨润土等处理剂,优化设计了水敏性地层用接枝淀粉聚合物泥浆体系。经过测试,该体系的API失水为7ml,相对膨胀降低率84.2%,岩屑回收率92%,摩阻系数0.07。该体系在水敏性地层的钻探施工中取得了良好的使用效果。

In this study, we designed and optimized a starch graft polymers mud system used for drilling in water-sensitive strata, using the graft co- polymer of starch as filtrate reducer, selecting inhibitor, anti-sloughing agent, lubricant, encapsulating agent and bentonite as treating agents. Tests show that the system＇s API filtrate loss is 7ml; the reduction of relative expansion is 84.2% ; recovery of cuttings is 92% ; and the friction coefficient is 0.07. This mud system has achieved good results in real drilling in water-sensitive strata.