川中地区侏罗系适合页岩油气藏开采的地质依据  

Geologic evidences of the Jurassic reservoirs for the shale oil/gas recovery in the central Sichuan Basin

作　　者：张闻林[1] 周肖[1] 严玉霞[1] 何绪全[1] 

机构地区：[1]中国石油西南油气田公司勘探开发研究院

出　　处：《天然气工业》2012年第8期117-124,138,共8页Natural Gas Industry

摘　　要：四川盆地川中地区中、下侏罗统油气藏包括大安寨段、马鞍山段、珍珠冲组(段)、凉高山组、下沙溪庙组底部油气藏。对于大安寨段油气藏的储层类型,传统观点公认为是裂缝型,并且得到了井筒的相关资料证实,但是随着该区页岩气的开采成功,又开拓了新的认识起点:随着远离井筒,不少证据显示出大安寨段油气藏储集层具有裂缝—孔隙型特征,而这些孔隙似乎更可能是存在于页岩当中的,后续产出的油气很可能还有页岩当中游离油气的供给。通过对油气显示、储层特征以及生产动态等资料的分析,认为该区大安寨段油气藏由页岩中的油气补给而形成目前的生产状况更为合理;裂缝更多起的是一种疏导通道作用——当然并不排除介壳灰岩中可能存在孔隙的可能性,只是认为石灰岩中的孔隙不应该是唯一的储集空间,甚至可能不是其最为重要的储集空间;中国石油化工股份有限公司在元坝区块已经做出了有关尝试,并取得成效。结论认为:如果页岩中的油气是该区侏罗系油气藏重要的补给源,那么,应用页岩油气(致密油)的开采思路和技术将有可能是更为有效的手段和方式。The Middle and Lower Jurassic reservoirs in the central Sichuan Basin include Da'anzhai member,Ma'anshan member,Zhenzhuchong Formation,Lianggaoshan Formation and Lower Shaximiao Formation.The reservoir in the Da'anzhai member was previously believed to be the fractured type,which was verified by relevant well data.However,some new understandings were also obtained from the successful recovery of shale gas in this study area.The reservoir in the Da'anzhai member appears to be the fractured-porous type away from the wellbores.These pores possibly occur in shales and may contribute free oil/gas to the production at the late stage of this reservoir.The analysis of oil/gas shows,reservoir characteristics,and production performance data show that the production of the Da'anzhai reservoirs is more possibly from the shales,while the fractures possibly act as flow pathways.On the other hand,although the possibility that pores occur in the shelly limestones still exists,the pores in the limestone are neither the exclusive nor the most important reservoir space.Sinopec has successfully introduced these study results into gas development in the YB area.It is concluded that if oil/gas in the shale are an important source of supply for the Jurassic reservoirs in this area,recovery techniques of shale oil/gas may be more effective in the development of these reservoirs.

关 键 词：四川盆地 川中地区 早-中侏罗世 储集层类型 页岩油气 致密油 “连续型”油气藏 地质依据 

分 类 号：P618.13[天文地球—矿床学]