鄂尔多斯盆地延长组长7_(3)亚段泥页岩层系岩石类型特征及勘探意义  

Characteristics of rock types and exploration significance of the shale strata in the Chang 7_(3) sub-member of Yanchang Formation,Ordos Basin

作　　者：刘显阳[1,2] 李士祥[1,3] 郭芪恒 周新平[1,3] 刘江艳 LIU Xianyang;LI Shixiang;GUO Qiheng;ZHOU Xinping;LIU Jiangyan(National Engineering Laboratory for Exploration and Development of Low-Permeability Oil&Gas Fields,Xi'an 710018,China;PetroChina Changqing Oilfield Company,Xi'an 710018,China;Exploration and Development Research Institute of PetroChina Changqing Oilfield Company,Xi'an 710018,China)

机构地区：[1]低渗透油气田勘探开发国家工程实验室,陕西西安710018 [2]中国石油长庆油田公司,陕西西安710018 [3]中国石油长庆油田公司勘探开发研究院,陕西西安710018

出　　处：《天然气地球科学》2021年第8期1177-1189,共13页Natural Gas Geoscience

基　　金：国家重点基础研究发展计划(973计划)项目“淡水湖盆细粒沉积与富有机质页岩形成机理”(编号:2014CB239003)资助。

摘　　要：长期以来,鄂尔多斯盆地长73亚段主要被作为单一烃源岩进行研究,涉及到多种岩石类型特征及源储一体方面的研究相对比较薄弱。基于岩性、物性相关分析资料结合测井精细解释,详细论述了长73亚段岩石类型特征,并分析了不同类型岩石储集特征及勘探意义。结果表明:(1)长73亚段发育黑色页岩、暗色泥岩、细砂岩、粉砂岩、凝灰岩共5类岩性;(2)砂质岩类的储集空间主要为长石溶蚀孔和刚性颗粒支撑的残余粒间孔,高长石和石英矿物含量、低碳酸盐胶结、低黏土矿物含量、较大累计厚度的砂岩是长73亚段最优的页岩油储层;(3)富有机质泥页岩是长73亚段发育规模最大的岩石类型,储集空间主要为黏土矿物晶间孔、黄铁矿晶间孔及碎屑颗粒粒间孔,有机质孔基本不发育,但常见有机质收缩缝,虽然长73亚段泥页岩的孔隙度和孔径都非常小,但也具备一定的储集性能和烃类流体可动性,初步估算长7泥页岩中滞留烃总资源量约为150×^(108)t,可动烃资源量约为60×^(108)t;(4)长73亚段砂质岩类和泥页岩含油饱和度普遍高于长71、长72亚段,进一步优化砂体纵向分布及平面展布特征,提高水平井砂岩钻遇率,加强试采方案研究,确保油水渗吸置换充分,是长73亚段砂质岩类页岩油快速建产增产的重要方向;(5)优选脆性指数和含油量高的黑色页岩,研发高效渗吸改善剂,采用压驱采一体化设计,增加缝宽、缝高及提高人工裂缝的导流能力,是实现泥页岩型页岩油动用的重要技术手段。For a long time,the Chang 73 sub-member of the Ordos Basin has been studied mainly as a single source rock,and the research involving the characteristics of multiple rock types and the integration of source and reservoir is relatively weak.Based on the related analysis data of lithology and physical properties,combined with fine well logging interpretation,the characteristics of rock type in the Chang 73 sub-member are discussed in detail,and the characteristics of reservoir and exploration significance of different types of rocks are discussed.There are black shale,dark mudstone,fine sandstone,siltstone and tuff in the Chang 73 sub-member.The storage space of sandy rocks is mainly composed of feldspar dissolved pores and residual intergranular pores supported by rigid particles.The storage space of shale and mudstone are mainly composed of clay mineral intercrystalline pores,pyrite intercrystalline pores and clastic particles intergranular pores.Organic matter pores are basically not developed,but organic matter shrinkage cracks are common.The filling of pores and throats with clay minerals reduces the porosity and seepage capacity of sandy rocks.Carbonate minerals are mainly cemented,which reduces the porosity of sandy rocks.The high content of feldspar and quartz is not only conducive to the preservation of primary intergranular pores,but also conducive to the development of secondary dissolution pores of feldspar,forming a higher movable fluid saturation.There is a clear positive correlation between the reservoir properties and oil-bearing of sandy rocks in the Chang 73 sub-member.It is the key to improve the shale oil production of the Chang 73 sub-member to find sandstones with high feldspar and quartz mineral content,low carbonate cementation,and low clay mineral content.It is preliminarily estimated that the total amount of retained hydrocarbon resources in Chang 7 mud shale is about 15 billion tons,and the amount of movable hydrocarbon resources is about 6 billion tons.Black shale with high brittleness i

关 键 词：长7_(3)亚段 泥页岩层系 岩石类型 勘探意义 鄂尔多斯盆地 

分 类 号：TE122[石油与天然气工程—油气勘探]