印尼马都拉海峡A气田底流沉积-抱球虫灰岩储层特征

Characteristics of globigerinid limestone reservoirs of bottom current deposition in Gas Field A of Madura Strait,Indonesia

印尼马都拉海峡A气田抱球虫灰岩形成于底流沉积作用。从岩石学特征、储集空间特征以及测井和地震等方面对其沉积特征进行了研究。按沉积结构分类,研究区岩石包括颗粒岩、泥质颗粒岩和颗粒质泥岩。前两种岩性为颗粒支撑结构,分选较好。颗粒岩和泥质颗粒岩的储集空间以粒内孔为主,其次为粒间孔和孔洞,以及少量的铸模孔和裂缝。储层整体具有厚度大、物性好及净毛比高的特点,因此含油气潜能较大。针对研究区沉积环境存在的争议,提出形成抱球虫灰岩的三大类物源。

Globigerinid limestone in Gas Field A of Madura Strait in Indonesia might be deposited by bottom current in outer shelf to upper slope.Petrological and reservoir space characteristics as well as well logging and seismic data were integrated to describe its sedimentary characteristics.According to Dunham＇s classification,the reservoir consists of grainstone,packstone and wackestone.The former two lithologies are grain supported and well sorted,and the reservoir space was dominated by intragranular dissolved pore,followed by intergranular dissolved pore and vuggsand a small amount of moldic pores and fractures.The reservoirs feature in large thickness,good physical properties and high NTG,and have great petroleum-bearing potential.There has been much debate over the depositional environment of the Pliocene globigerinid limestone in the Madura Strait.We propose three provenances for the reservoir.