适用于塔中区块碳酸盐岩缝洞型异常高温高压储集层的钻井液承压堵漏材料

Lost circulation material for abnormally high temperature and pressure fractured-vuggy carbonate reservoirs in Tazhong block,Tarim Basin,NW China

为了有效地解决塔中区块碳酸盐岩缝洞型异常高温高压储集层在钻完井过程中井漏、溢流频发的问题,在对该区块目标储集层地质特征和漏失情况进行统计分析的基础上,引入抗高温、高承压和研磨性好的刚性堵漏材料GZD,通过静态承压封堵实验对单剂加量及其与木质素纤维、弹性材料SQD-98和碳酸钙的复配加量进行了优化,形成了抗高温、高承压的新型复合堵漏材料SXM-I并通过钻井液配伍性实验、裂缝静态封堵承压实验和岩屑砂床实验对其性能进行了评价。实验结果表明,该新型复合堵漏材料与现场钻井液体系具有较好的配伍性,形成的堵漏钻井液既能封缝又能堵洞,裂缝静态承压9 MPa以上,累计漏失量仅13.4 mL;大孔径岩屑砂床30 min内侵入深度仅为2.5 cm,表现出较好的高温高压封堵性能,为该区块的顺利钻进提供了技术支撑。

To effectively solve the problem of lost circulation and well kick frequently occurring during the drilling of abnormally high temperature and pressure fractured-vuggy reservoirs in the Tazhong block,a rigid particle material,GZD,with high temperature tolerance,high rigidity(>8 MPa)and low abrasiveness has been selected based on geological characteristics of the theft zones in the reservoirs.Through static pressure sealing experiments,its dosage when used alone and when used in combination with lignin fiber,elastic material SQD-98 and calcium carbonate were optimized,and the formula of a new type(SXM-I)of compound lost circulation material with high temperature tolerance and high strength was formed.Its performance was evaluated by compatibility test,static sealing experiment and sand bed plugging experiment.The test results show that it has good compatibility with drilling fluid used commonly and is able to plug fractures and vugs,the sealed fractures are able to withstand the static pressure of more than 9 MPa and the cumulative leakage is 13.4 mL.The mud filtrate invasion depth is only 2.5 cm/30 min when the sand bed is made of particles with sizes between 10 mesh and 20 mesh.Overall,with good sealing property and high temperature and high pressure tolerance,the lost circulation material provides strong technical support for the safety drilling in the block.