山西兴县奥陶系碳酸盐岩岩溶储层特征

CHARACTERISTICS OF ORDOVICIAN CARBONATE KARST RESERVOIR IN XINGXIAN, SHANXI

山西省兴县奥陶系马家沟组第五段—亚段位于古风化壳的顶部，主要由泥晶石灰岩组成，有少量泥晶白云岩，夹层含有一定量的泥质岩。储集空间为孔洞和裂缝。原生孔隙以晶间孔为主，次生孔隙有晶问孔、溶蚀孔（洞）、鸟眼孔和砾间孔；裂缝为构造缝、成岩缝、岩溶缝和缝合线缝。属于低渗透的溶蚀裂缝—孔洞型储层。影响储层最重要的作用是岩溶作用。

The first submember of the fifth member of the Lower Ordovician Majiagou Formation in Xingkian, Shanxi Province is located at the top of a paleo-weathered crust and consists mainly of micrite and small amount of micritic dolomite. The intercalations in it contain some amountes of argillaceous rocks. The reservoir spaces are pores, caves and fractures. The primary POres are dominantly intercrystal pores; the secondary pores include intercrystal pores, solution pores and caves, bird's eye pores, intergtavel pores; the fractures consist of structural fratures, diagenetic fractures, karst fractures and suture fractures. It is suggested that the reservoir should belong to low Permeable solution fracture-cave reservoir. The fundamental factor to effect the reservoir property is karstification.