吉木萨尔页岩油微观产出机理与提高采收率方法探讨

Micro-Mechanism of Production and Method of Enhanced Oil Recovery for Jimsar Shale Oil

吉木萨尔页岩油产量递减快,采收率低,研究吉木萨尔页岩油提高采收率机理与方法具有重要意义。研究了吉木萨尔页岩油产出的微观机理及可动性主控因素,提出了吉木萨尔页岩油的提采方法与对策。得出流体压差和渗吸驱油是吉木萨尔页岩油的主要产出机理,低界面张力表活剂、CO_(2)吞吐可提高原油可动性,裂缝密度与均匀度、地层能量、介质与原油相互作用是影响页岩油采收率的主要因素。建议针对新井与老井、单井与井组制订不同的提采措施,通过压裂与提采一体化、注入介质优选、一次井网同步压裂,提高原油可动性,实现均衡动用来提高总体采收率。

Jimsar shale oil has rapid production decline and low recovery factor.It is of great significance to study the EOR mechanism and method for Jimsar shale oil.In this paper,the micro-mechanism of production and the main controlling factors for Jimsar shale oil is studied,and an EOR method and countermeasures are proposed.It is found that the differential pressure of fluid and oil displacement by imbibition are the main production mechanism of Jimusar shale oil.Low interfacial tension surfactant and huff-n-puff CO_(2) injection can improve the mobility of crude oil.Hydraulic fracture density and uniformity,formation fluid pressure,as well as the interaction between EOR medium and crude oil are the main factors affecting the recovery factor of shale oil.It is suggested that different EOR measures should be developed targeting new wells and old wells,single wells and well groups,respectively;and oil mobility could be improved,and reservoirs should be produced in a balanced way to enhance the overall recovery factor by integrating fracturing and EOR,optimizing injection medium and conducting simultaneous fracturing for primary well pattern.