新型低伤害高性能微泡沫钻井液性能评价与现场应用*

Evaluation and Field Application of New Microfoam Drilling Fluid with Low-damage and High-performance

马腾飞 周 宇 李志勇 孙晗森 杨 刚

MA Tengfei ZHOU Yu LI Zhiyong SUN Hanseng YANG Gang

针对在煤层储层段钻井过程中出现的易伤害、易塌等技术难题，研发了新型低伤害高性能微泡沫钻井液体 系。将双子型阴离子起泡剂（LHPF-1）、两性离子起泡剂十二烷基二甲基甜菜碱（BS-12）和生物聚合物增黏剂 （XC）复配，利用响应曲面优化实验分析了3种处理剂间的交互作用对于泡沫综合指数的影响，在此基础上优选 了降滤失剂和抑制剂，确定微泡沫钻井液的最佳配方；研究了微泡沫钻井液的综合性能，并在滇东地区老厂勘探 区进行了现场应用。结果表明，微泡沫钻井液最佳配方为：0.25% LHPF-1+0.25% BS-12+0.25% XC+1%褐煤树 脂+1%聚丙烯腈胺+0.2%聚丙烯酸钾。钻井液密度为0.49 g/cm3，起泡量可达420 mL，泡沫半衰期可达33 h以 上。泡沫液膜厚度能达到泡沫尺寸的50%，对煤层岩心的封堵率和渗透率恢复值均在90%以上，同时可抗7%的 岩屑和煤粉污染。钻井液在现场应用中，钻进时间4 d，无任何井下复杂事故，全井段平均井径扩大率为5.9%，滤 失量小于5 mL。微泡沫钻井液具有良好的流变性、携岩性、抑制性、封堵性和储层保护效果。

Aiming at the technical problems such as damage tendency and collapse tendency during drilling process in coal bed reservoir section，a new microfoam drilling fluid system with low-damage and high-performance was developed. The gemini anionic foaming agent（LHPF-1），zwitterionic foaming agent dodecyl dimethyl betaine（BS-12）and biopolymer thickener（XC） were compounded. The interaction between the three treatment agents on the comprehensive foam index was analyzed by using response surface optimization experiments. On this basis，the filter loss reduction agent and inhibitor were selected to determine the best formula of microfoam drilling fluid. The comprehensive performance of microfoam drilling fluid was studied. Finally，it was applied on Laochang exploration area in east Yunnan. The results showed that the best formula of microfoam drilling fluid was obtained as follows：0.25% LHPF-1，0.25% BS-12，0.25% XC，1% brown coal resin，1% polyacrylonitrile，0.2% potassium polyacrylate. The density of drilling fluid was 0.49 g/cm3，the foaming volume could reach 420 mL，and the half-life of foam could reach more than 33 h. The thickness of foam film reached 50% of the foam size，and the sealing rate and permeability recovery value of the core of coal seam were above 90% ，while it could resist 7% of rock chips and coal dust pollution. In the field application of drilling fluid，the drilling time was 4 days without any downhole complications. The average enlargement rate of well diameter was 5.9% in the whole well section，and the filtration loss was less than 5 mL. The microfoam drilling fluid had good rheology，rock-carrying，inhibition，plugging and reservoir protection effects.

10.19346/j.cnki.1000-4092.2021.04.001