黔南坳陷凯里油砂矿地质特征及成矿模式

Geological characteristics and forming pattern of Kaili oil sand in southern Guizhou Depression

 张海全¹ 孟万斌² 王鹤³

中国地质调查局成都地质调查中心，四川 成都 610083 成都理工大学油气藏地质与开发工程国家重点实验室，四川 成都 610059 成都北方石油勘探开发技术有限公司，四川 成都 610000）

Chengdu center, China Geological Survey, Chengdu 610083, China State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Chengdu University of Technology, Chengdu 610059, China Chengdu North Petroleum Exploration and Development Technology Co. Ltd., Chengdu 610000, China)

 基于前人的研究资料和对油砂钻孔岩心的详细观察及测试数据，对黔南坳陷凯里油砂矿进行了岩石学特征、储层特征及地球化学特征分析，探讨了油砂矿的成矿模式。研究认为：凯里油砂为多层分布，厚度变化大，砂岩以方解石胶结为主，有效面孔率为1.0%~8.0%，储集空间以原生粒间孔为主，孔隙度为1.0%~7.0%，渗透率为0.01×10-3~1.20×10-3 μm²，整体属低孔低渗储层；抽提物组分碳同位素具典型海相原油特征，局部倒转明显；油砂矿的成矿模式为加里东期形成的背斜型古油藏遭受改造，后期再次埋深再成藏，至燕山期强烈抬升剥蚀，储层中的油气遭受降解、氧化，形成“古油藏破坏型”沥青质油砂矿。

 According to previous research data and test data of the oil sand drill core, the characteristics of petrography, reservoir and geochemistry of Kaili oil sands are analyzed, and the oil sand metallogenic model is discussed. Result shows that kaili oil sands distribute in multi-layers with greatly variable thickness; the cements in the sandstone are dominated by calcite; the reservoir space is mainly primary pores with the effective area porosity 1.0%￣8.0%, porosity 1.0%￣7.0%, and permeability 0.01￣1.20 md, which shows that the reservoir has low permeability and low porosity on the whole; the carbon isotope of extract components has the characteristics of typical marine origin petroleum with obviously local inversion; the oil sands metallogenic model is a transformed anticlinal paleo-oil reservoir formed during the Caledonian, which late again was buried in depth and formed reservoir till the intense uplift and erosion during the Yanshanian; hydrocarbons in reservoirs suffered from degradation and oxidation, which formed the "damaged paleo-oil reservoir type" asphaltic oil sands.

10.6056/dkyqt201604003