摘要
鄂尔多斯盆地奥陶系发育岩溶风化壳储集层,气藏发育规律与沉积、成岩作用具有一定的内在联系。通过对苏里格地区S 20区块奥陶系储集层特征进行研究,分析储集层主控因素,结合勘探实践发现:白云石化与岩溶作用是储集层发育的关键因素。岩溶残丘、岩溶洼地及岩溶斜坡3类古地貌单元对气藏具有一定的控制作用。溶蚀孔洞较发育的斜坡至洼地成为最佳的成藏部位;沿斜坡向上至残丘部位孔隙度变差,孔隙度较差的顶部地层产生了有效的封堵作用。优质储集层主要集中在岩溶斜坡至洼地部位,岩溶残丘及洼地中心储集层较差。岩溶洼地为天然气成藏提供了运移通道。
Karst weathering crust reservoirs were developed in Ordovician of Ordos Basin.The gas reservoir development pattern has a certain intrinsic link with sedimentation and diagenesis.The characteristics of Ordovician reservoirs in block20 of Sulige area were studied.The analysis of main controlling factors of reservoirs and exploration practice indicated that the dolomitization and karstification were the key factors of reservoir development.The three types of Paleogeomorphic units such as karst hill,karst depression and karst slope control the gas reservoirs.The slopes and depressions where the denudation pores and cavities were developed are the best oil and gas accumulation parts.The porosity decreases from slope up to the hammock site.The top stratum with poor porosity provides an effective plugging action.The favorable reservoirs are mainly in karst slopes and depressions,reservoirs are poor at the centers of karst hills and depressions.The karst depressions provide a migration pathway for gas accumulation.
出处
《录井工程》
2014年第4期81-84,105,共4页
Mud Logging Engineering
关键词
苏里格
奥陶系
岩溶
古地貌
储集层
发育机理
天然气成藏
Sulige area,Ordovician,karst,Palaeogeomorphology,reservoir,development mechanism,gas accumulation
