济阳坳陷古近系湖相生物礁油气藏研究

The Study on the Palaeogene Lacustrine Reefs in Jiyang Sag,Eastern Shandong Province

济阳坳陷局部地区古近系发育以藻礁为主的生物礁,作为一种高产油气的储集体,礁体呈复式,可分为礁核、礁前及礁后相。礁体在成分上以枝管藻、龙介虫等构成的藻白云岩为主,具有良好的储集性能。根据组成礁体的岩性特征,生物礁可分为藻礁、藻礁丘及藻生物层三种类型。其中藻礁储集性能最佳,对生物礁储层影响较大的成岩作用有白云岩化、同生胶结、大气渗流溶蚀及深埋藏溶蚀作用。生物礁油藏主要产于邻近洼陷的构造台地或边缘地区。根据构造、岩性及地层的匹配关系,可分为礁型地层、断块—岩性及岩性三种类型。

The reefs, mainly constructed by algae and with high production reservoir for oil and gas, are developed in several areas of Jiyang Sag in the form of composite deposition, that is, reef core, fore-reef and back reef. Taking into account of the biogenic components, the algal dolomite, the main component of algal reefs, consisted of Cladosiphonia sinensis, Serpula shandongensis etc. , and be of favorable storage capability. Based on the lithological characteristics of reef rocks, the reef types can be divided into algal reefs, algal reef mounds and algal biostromes, among which the algal reefs, are of the best reservoir property. Dolomitization, consortium cementation, atmosphere seepage corrosion and deep embedding effect have great influence on the property of reef reservoir. The reef reservoirs are developed mainly in the neighboring structural platform or brim, according to the matching relation of structure, lithology and stratum, reef reservoirs can be divided into reef stratum, fault block-lithology and lithology types.