干热岩钻探高温可循环泡沫钻井液技术研究

Study on high-temperature recyclable foam drilling fluid system for HRD drilling

针对高温可循环泡沫存在的主要技术难点,优选了抗高温发泡剂GFJ,增黏剂GDRP,稳泡剂WPJ等关键处理剂,构建了高温可循环泡沫钻井液配方。结果表明,应用3%~4%钠膨润土、2%~3%SEP(海泡石绒)、0.5%~1.0%GDRP(增黏剂)、0.3%~0.5%WPJ(稳泡剂)、0.4%~0.8%GFJ(发泡剂)和水配成了钻井液体系。该体系在240℃下密度在0.6~0.9 g/cm3范围可调,半衰期>48 h,流变性好,具有较好的悬浮携带能力,可满足深部地热钻探施工需求。

Aiming at the main technical difficulties of high temperature circulating foam,the key treatment agents such as GFJ,GDRP,WPJ were selected,and the formula of high temperature circulating foam drilling fluid was constructed.The results showed that 3%~4%sodium bentonite,2%~3%SEP(sepiolite wool),0.5%~1.0%GDRP(viscosifier),0.3%~0.5%WPJ(foam stabilizer),0.4%~0.8%GFJ(foaming agent)and water were used to prepare the drilling fluid system.The system has an adjustable density in the range of 0.6~0.9 g/cm 3 at 240℃,a half-life>48 h,good rheology,good suspension carrying capacity,and can meet the requirements of deep geothermal DR2 drilling.