新型钻井液用成膜封堵剂CMF的研制及应用

针对渤海辽东湾某油田地层硬脆性泥页岩裂缝发育特点，笔者通过控制反应条件，制备了平均长径比在20～30之间的三水碳酸镁晶须和水合碱式碳酸镁晶片，并在此基础上与常用成膜剂LPF-H复配，研制了一种新型成膜封堵剂CMF，其中LPF-H∶晶须∶晶片的配比为7.0∶1.6∶0.4。室内实验结果表明，成膜封堵剂CMF与钻井液体系具有良好的配伍性，流变性能能够满足携岩屑要求，对不同渗透率砂盘的封堵能力优于常用成膜剂LPF-H。晶须、晶片与LPF-H这三种材料相互协同作用，在井壁形成一层致密、具有一定强度韧性的隔离膜，能有效封堵地层裂隙，稳定井壁，降低钻井液处理剂的损耗。该成膜封堵剂CMF在渤海辽东湾某油田X-1井进行了现场试验，结果表明，加入成膜封堵剂CMF后，钻井液性能满足要求，滤失量和表皮系数均低于采用成膜剂LPF-H的邻井X-2。这说明，成膜封堵剂CMF能够满足该油田钻井过程中储层保护的需要，具有推广应用前景。 

Development and Application of a Novel Filming Plugging Agent CMF

A new flming plugging agent, CMF, has been developed to deal with the problems encountered in drilling the brittle fractured shale formations in an oilfeld in the Liaodong Gulf area. CMF is formulated with nesquehonite whisker, hydrated basic magnesium carbonate wafer and a commonly used flming agent LPF-H. The nesquehonite whisker and the hydrated basic magnesium carbonate wafer, having length/diameter ratios of 20-30, were developed under controlled reaction conditions. The ratio of LPF-H, the whisker and the wafer is 7:1.6:0.4. Laboratory experimental results showed that CMF has good compatibility with the drilling fluid treated with it, and the rheology of the drilling fluid is able to satisfy the needs of cuttings carrying. Experiment on sand specimens of different porosity showed that CMF is superior to LPF-H in plugging the sand specimens. The synergism of the whisker, the wafer and LPF-H results in a dense and tough flm on the borehole wall, effectively plugging the formation fractures and stabilizing the borehole wall, and therefore reducing the consumption of drilling fluid additives. Application of CMF on the well X-1 in an oilfeld in Liaodong Gulf showed that the properties of the drilling fluid treated with CMF satisfed the needs of drilling operations. The fltration rate of the drilling fluid was lower than that of the drilling fluid (treated with LPF-H) used on the adjacent well X-2, indicating that CMF is able to protect the reservoir from being damaged, and is therefore worth spreading.