大庆油田萨中开发区二、三类油层同步挖潜补压结合射孔方法

Synchronous potential tapping method combining re⁃perforation and fracturing for ClassⅡand ClassⅢreservoirs in Sazhong development zone of Daqing Oilfield

大庆油田萨中开发区二类油层和三类油层平面、纵向交互分布,目前尚未形成同步开发方法。从射孔角度出发,通过分析油层特点,匹配射孔工艺方法,二类油层匹配深穿透(穿深为956 mm)射孔、三类油层匹配超深穿透(穿深为1 308 mm)射孔,建立单井“组合射孔”模式;针对大段三类油层,通过抽稀射孔数,提高单卡层段数,提高过孔压力,建立“组合射孔+限流法压裂”模式。数值模拟和现场分析结果表明:该方法在萨中开发区2个二、三类油层同步挖潜区块应用,“组合射孔”实施20口井,采出端单井含水率多降低2.0%、日产油量增加1.2 t;“组合射孔配套限流法压裂”实施6口井,实现了单孔排量0.6 m3/min以上,平均单井产液量增幅17.56%,含水率多降低0.94百分点。研究成果可有效指导投产设计,对二、三类油层的同步挖潜和提质增效具有重要意义。

ClassⅡand ClassⅢreservoirs in Daqing Oilfield Sazhong development zone are areally and vertically distributed interactively,and synchronous development method has not yet been formed.Research is conducted from the perspective of perforation by reservoir characteristics analysis matching perforation techniques to establish“combined perforation”mode for single well,with matching deep penetration of 956 mm perforation for ClassⅡreservoirs,and ultra-deep penetration of 1308 mm perforation for ClassⅢreservoirs.For large intervals of ClassⅢreservoirs,“combined perforation+limited entry fracturing”mode is established by sparsed perforation,increas-ing single-grip-intervals and increasing pressure across entry holes.Numerical simulation and field analysis of this method applied in 2 synchronous potential tapping blocks of ClassⅡand ClassⅢreservoirs in Sazhong develop-ment zone show that combined perforation is operated in 20 wells,with single-well water cut at production end de-creased by additional 2.0%and daily oil production increased by 1.2 t.“Combined perforation+limited entry fractur-ing”is implemented in 6 wells,achieving single-hole displacement of>0.6 m^(3)/min,with average single-well fluid production increase of 17.56%and additional 0.94 percentage point decrease in water cut.The research results can effectively guide production commencing design and have much significance for synchronous potential tapping,quality improving and efficiency enhancing in ClassⅡand ClassⅢreservoirs.