地质科学2026，Vol.61Issue(1)：82-99,18.DOI:10.12017/dzkx.2026.007
鄂尔多斯盆地奥陶系盐下马家沟组四段云斑灰岩储层的非均质性特征及优质储层的发育环境
Heterogeneity of dolomite-spotted limestone reservoirs of the sub-salt fourth member of the Ordovician Majiagou Formation in the Ordos Basin and development environment of high-quality reservoirs
摘要
Abstract
The sub-salt fourth member of the Ordovician Majiagou Formation in the Ordos Basin is a regional exploration hotspot,and dolomite-spotted limestones form important petroleum reservoirs.Currently,reservoir heterogeneity,high-quality reservoirs and their controlling factors have been poorly understood,limiting in-depth comprehensive evaluation and exploration and development in future.Therefore,with an integrated method of petrography,sedimentology,ichnology and reservoir geology,this paper studies heterogeneity characteristics of the reservoirs and reveal high-quality reservoir types and development environments.The results show that dolomite-spotted limestones in the study area can be classified into two types:three-dimensional box structure with Glossifungites ichnofacies and two-dimensional horizontal maze structure with Cruziana ichnofacies.Six types of reservoir spaces develop in the dolomite-spotted limestone:matrix micro-pores,residual mud micro-pores,dolomite intercrystalline pores,dolomite intracrystalline micro-pores,dissolution pores and fractures.The effective reservoir space is dolomite intercrystalline pores inside burrows and matrix pores are isolated,these lead to strong heterogeneity of dolomite-spotted limestones and sample size dependence of physical property measurement.Modeling analysis of full-size samples reveals that porosity and permeability of the dolomite-spotted limestone with three-dimensional box structure are 3.20％and 1.03 mD,respectively,while those with two-dimensional maze structure are 0.55％and 0.18 mD,respectively.The former has better physical properties and pores are well connected in all directions,making it a high-quality reservoir type.Further comprehensive analyses of ichnofacies and depositional sequences indicate that the depositional environment where this high-quality reservoir develops is the high-energy intertidal to shallow subtidal zone.关键词
鄂尔多斯盆地/马家沟组/云斑灰岩/储层非均质性/优质储层Key words
Ordos Basin/Majiagou Formation/Dolomite-spotted limestones/Reservoir heterogeneity/High-quality reservoirs分类
天文与地球科学引用本文复制引用
袁子彧,王爱国,王前平,罗晓容,魏柳斌,郭玮,曹斌风..鄂尔多斯盆地奥陶系盐下马家沟组四段云斑灰岩储层的非均质性特征及优质储层的发育环境[J].地质科学,2026,61(1):82-99,18.基金项目
中国石油长庆油田公司重大科技专项"鄂尔多斯盆地深部层系构造—沉积环境、成藏条件与有利勘探区带研究"(编号:2024D1JC06)资助 （编号:2024D1JC06）
