深部地热抗高温甲酸盐钻井液体系研究

Anti-High Temperature Formate Drilling Fluid System for Deep Geothermal Resources

为满足深部高温地热钻探需求,针对钻井液在高温作用下流变性能难以控制及重晶石等惰性材料堵塞地热储层等关键技术难题,开展抗温240℃水基钻井液技术研究。通过优选造浆材料、高温增黏剂及高温降滤失剂等抗高温材料,研发了一套具有良好的高温流变稳定性和储层保护特点的抗高温甲酸盐钻井液体系,对该钻井液体系的流变性能、滤失性能、悬浮稳定性、高温封堵性能及抗岩屑污染性能进行了评价。同时研发了一套抗高温甲酸盐钻井液与抗高温可循环泡沫钻井液之间相互转化的工艺方法,可实现在不同孔隙压力地层钻探施工中不同密度钻井液的相互转化。

In order to meet the drilling demand of deep high-temperature geothermal resources,this work focused on the key technical problems of drilling fluid rheology control under high temperature and geothermal reservoir block by inert sealing materials such as barite.In particular,water-based drilling fluid technology resisting high temperature of 240℃was tested and analyzed.Through optimizing mud-making materials,high-temperature viscosifiers,and high temperature filtrate reducer,etc.,a set of anti-high temperature formate drilling fluid system was developed with fine high-temperature rheological stability and reservoir protection.The rheological properties,filter loss performance,suspension stability,high temperature blocked performance and anti-cutting-contamination performance were evaluated,and a set of mutual transforming process between anti-high temperature formate drilling fluid and circulative foam drilling fluid was developed,which can achieve mutual conversion of drilling fluids of different densities during drilling different pore-pressure strata.