新型钻井液成膜剂的研制及其在埕海油田的应用

为了降低埕海油田钻井过程中外来流体对储层的损害,基于成膜钻井液技术的基本理论,以苯乙烯、丙烯酸丁酯单体为原料,采用乳液聚合的方法,以过硫酸铵为引发剂,合成了新型钻井液成膜剂LCM-8。室内试验表明:埕海油田上部钻井液中加入成膜剂LCM-8后,流变性能能够满足携岩要求;能在岩心污染端形成一个渗透率极低的封堵带,封堵率可达90%以上;返排渗透率恢复率大于90%。新型钻井液成膜剂LCM-8在埕海油田2口井的储层钻进过程中进行了应用,结果表明,上部钻井液加入该成膜剂后,其性能能满足钻井要求,2口井的表皮系数为-2.31和-3.11,而未用该成膜剂2口邻井的表皮系数为-0.27和0.23。这说明,成膜剂LCM-8能满足埕海油田钻井要求,实现钻井过程中的储层保护。 

Development of New Film-Forming Agent for Drilling Fluids and Application in Chenghai Oilfield

In order to reduce the reservoir damage caused by foreign fluid during drilling in Chenghai Oilfield,a new film-forming agent LCM-8 had been developed using styrene,butyl acrylate monomer and trigger ammonium persulfate,by emulsion polymerization method based on the film-forming technology.Laboratory tests showed that rheological properties of the drilling fluid could be gotten to carry cuttings after adding LCM-8,which could form a plugging area with low permeability at the polluted end of the core.The plugging rate and flowback permeability recovery rate could be higher than 90%.LCM-8 had been applied in two wells in Chenghai Oilfield,the results showed that the drilling fluid for the upper well section could meet the drilling demand after adding the film-forming agent,resulting in skin factors of-2.31 and-3.11 respectively,while the skin factors of two adjacent wells were-0.27 and 0.23 respectively without adding the film forming agent.It showed that LCM-8 could meet the demand of drilling and reservoir protection in Chenghai Oilfield.