一种生物合成基钻井液在长宁气田的应用

Application of a Biosynthesis-based Drilling Fluid in the Changning Gas Field

针对页岩气水平井用油基钻井液环境污染性强、废弃物处理难度大等缺点,开展了一种新型的页岩气井用环保型钻井液体系研究。通过生物合成基础油制备和系统配方性能实验评价,研发了一种以改性植物油为连续相,盐水为分散相的油包水乳化钻井液体系;该体系不含芳香烃等组分,易生物降解,废弃物满足环保标准。将生物合成基钻井液在长宁气田HA平台3口井中进行了应用,应用效果表明,该体系抑制性、封堵性和润滑性好,能保障钻井、电测和下套管等作业顺利施工,环保风险和废弃物处理成本低。

Oil-based drilling fluids used in horizontal shale gas wells,is of high risk of environmental pollution and is difficult dispose.To solve the problems,a novel and environmentally friendly drilling fluid system for shale gas wells was developed.Through the preparation of a biosynthesis-based oil and experimental evaluation of the performance of this formula,a waterin-oil emulsion drilling fluid system with modified vegetable oil as the continuous phase and brine as the dispersed phase was developed.The system,which does not contain aromatic hydrocarbon components,is biodegradable and meets environmental protection standards in wastes disposal.The biosynthesis-based drilling fluid was applied in three wells on the HA platform in Changning Gas Field.The results from this application show that the system possesses good inhibitive,sealing,and lubrication characteristics,ensureing smooth operations during drilling,electric logging and casing running,lowering environmental risks,and enabling low waste disposal costs.