摘要
大古3井是塔里木盆地库车山前地区的一口重点探井。该井四开φ215.9 mm裸眼井段压差卡钻风险大,白垩系舒善河组地层具有极强的水化能力和一定的硬脆性,极易水化掉块造成硬卡,现场采用强抑制强封堵KCl-阳离子乳液聚磺钻井液仍无法满足钻井要求,复杂处理时间长达60.93 d。通过室内实验研制了一套密度为1.63 g/cm3、油水比为80∶20的油包水钻井液,该体系的抑制性强,抗高温、抗水和抗土污染的能力强,且塑性黏度高、沉降稳定性好,通过强化抑制和减弱冲刷2方面作用来稳定地层,解决了大古3井的泥岩掉块问题,同时较水基钻井液钻时更快,为优化库车山前地区钻井工艺奠定了坚实基础。
Well Dagu-3 is a key exploration well in the Tarim Basin,which is characterized by a high risk of differential sticking in the215.9 mm open hole section.This hole section penetrates the Shushanhe Formation(Cretaceous System),a strongly water hydratable and brittle formation that sloughs easily during drilling.A well was drilled in the area with a highly inhibitive KCl-cationic emulsion containing polymers and sulfonates,which cannot suffice the success of drilling.Time spent dealing with downhole troubles was60.93 days.A new invert emulsion(W/O) drilling fluid was developed through laboratory experiment.It has a density of 1.63 g/cm^3and a oil/water ratio of 80/20,and is highly inhibitive.It is also contamination tolerant and high-temperature resistant.The problematic formations are stabilized through strong inhibition of the drilling fluid and weak erosion of mud flow.Field application also shows that the ROP is higher than the well drilled previously.
出处
《钻井液与完井液》
CAS
北大核心
2014年第2期35-38,97-98,共4页
Drilling Fluid & Completion Fluid
