致密碳酸盐岩储集层特征与天然气勘探潜力——以鄂尔多斯盆地伊陕斜坡东部奥陶系马家沟组为例  

Gas exploration potential of tight carbonate reservoirs:A case study of Ordovician Majiagou Formation in the eastern Yi-Shan slope,Ordos Basin,NW China

作　　者：魏新善[1,2] 陈洪德[3] 张道锋[1,2] 代榕[4] 郭彦如[5] 陈娟萍[1] 任军峰[1,2] 柳娜[1,2] 罗顺社[4] 赵俊兴[3] 

机构地区：[1]中国石油长庆油田公司勘探开发研究院,西安710018 [2]低渗透油气田勘探开发国家工程实验室,西安710018 [3]成都理工大学,成都610059 [4]长江大学,武汉430100 [5]中国石油勘探开发研究院,北京100083

出　　处：《石油勘探与开发》2017年第3期319-329,共11页Petroleum Exploration and Development

基　　金：国家科技重大专项"大型油气田及煤层气开发"(2016ZX05044)

摘　　要：基于钻井、试气、分析化验等资料的综合分析,对鄂尔多斯盆地伊陕斜坡东部奥陶系马家沟组马五_(1+2)亚段致密碳酸盐岩储集层特征及其成因进行研究,并对天然气勘探潜力进行分析。研究提出致密碳酸盐岩储集层为孔隙度小于2%、渗透率小于0.1×10^(-3)mm^2的储集体。伊陕斜坡东部马五_(1+2)亚段致密碳酸盐岩储集层以含膏泥粉晶白云岩、泥粉晶白云岩及岩溶角砾白云岩为主,孔隙类型以裂缝-溶孔、裂缝-晶间孔为主,非均质性强,储集层呈薄层大面积展布。奥陶系顶部不整合面构造调整导致的储集层"造孔"与"填孔"作用,以及埋藏期溶蚀增孔与沉积充填减孔共同作用是储集层大面积致密化的主要原因。薄层白云岩致密储集层与上覆广覆式上古生界煤系烃源岩紧邻形成大面积致密碳酸盐岩气成藏组合,含气普遍,气藏埋深浅(1 900~2 500 m),与上古生界致密砂岩气组成立体含气模式,因此鄂尔多斯盆地伊陕斜坡东部勘探开发潜力大。On the basis of comprehensive analysis of drilling, gas testing, laboratory analysis and testing data, the characteristics and genesis of tight carbonate reservoirs in Ma51＋2 Member of Ordovician Majiagou Formation, eastern Yi-Shaan slope, Ordos Basin were examined, and the potential of natural gas exploration and development were analyzed. The tight carbonate reservoir is defined as the reservoir with a porosity of less than 2% and permeability of less than 0.1 x 10-3 pm2. The Ma5j＋2 reservoirs are dominantly gypsum mud dolomite, muddy dolomite and Karst-breccia dolomite and has strong heterogeneity, pore types being mainly composed of fracture-dissolution pores and fracture-intercrystalline pores, and thin reservoir layers are distributed in a large area. The unconformity structure adjustment at the top of the Ordovician caused pore creation and pore filling effects, and the joint effect of dissolution pore increase and pore reduction by filling is the major reason for extensive reservoir densification. The thin tight dolomite reservoirs and the overlying adjacent coal source rock in the Upper Paleozoic formed extensive tight carbonate gas with shallow depth （1 900-2 500 m） and formed a three-dimensional gas containing pattern combined with the Upper Paleozoic tight sandstone gas. The eastern Yi-shaan slope in the Ordos Basin has great exploration and development potential.

关 键 词：鄂尔多斯盆地 伊陕斜坡东部 致密碳酸盐岩储集层 致密气 勘探潜力 

分 类 号：TE122.2[石油与天然气工程—油气勘探]