复合钾盐聚合物钻井液的研制及应用

Study and application on compound potassium salt polymer drilling fluid

四川金秋区块深盆气资源丰富，但存在地层压力系数较高、气层活跃、CO2气侵严重、上部存在较厚的紫红色泥岩层极易造浆等难题，且甲方要求不能影响测井，这些均对钻井液提出了较高要求。针对以上问题，结合该地区特点，优选出复合钾盐抑制剂、降滤失剂等处理剂，研发出复合钾盐聚合物钻井液。该体系对泥岩岩屑一次回收率93％、抗CO2、钙镁离子污染能力强，密度最高可达2．20-2．30g／cm3。现场应用结果表明，该体系能够满足四川金秋区块的钻井需要。

Jinqiu block in Sichuan is rich in deepbasin gas, but has high pressure coefficient, active gas layer, and serious CO2 inva sion. The upper thick purple shale was easy to hydrate mudmaking formation and the logging was required to be not affected by slurry. These are high requirements for drilling fluid. Based on the existing technical difficulties of drilling fluid, the strong inhibition of potas sium salt polymer drilling fluid system was optimized. This system uses the preferred compound potassium salt as main inhibitors. The advantages of this system are strong inhibition, good temperature resistance ability, antipollution ability, and high density of 2.20 2.30 g/cm3, which can meet the drilling requirements in the region.