摘要
岩性及沉积环境的差异是鄂尔多斯盆地下奥陶统马家沟组马五5亚段储层非均质性的重要因素,根据岩石类型、沉积构造及颜色等特征及其与沉积微相的关系,研究区马五5亚段可分为盆缘坪和台内盆地两个亚相及缘内(膏)云质洼地、缘内云坪、缘内灰坪、缘内云灰–灰云坪、盆地(膏)云质洼地、灰云–云灰质盆地及灰质盆地等微相。沉积微相平面上表现为,马五52时期,鄂尔多斯盆地基底抬升,中央古隆起带露出水面;北部地区发育缘内云坪–云质洼地、缘内灰云–云灰坪和灰质盆地;西部地区为缘内云坪–云质洼地、缘内灰云–云灰坪;中部地区为灰质盆地,间夹云灰盆地及盆内云质洼地;马五51时期,北部地区主要发育缘内云坪–云质洼地;西部地区为缘内云坪–云质洼地;中部地区为灰质盆地及盆内云质洼地。盆缘坪和台内盆地的低洼处有利于发生同生期后回流渗透白云化作用,对生成较大规模的泥粉晶白云岩具有重要的意义。
The difference between lithology and depositional environment is the main cause of reservoir heterogeneityin submember 5 Majiagou Formation of Lower Ordovician in the Ordos basin. According rock types, sedimentarystructures, color and its relationship with sedimentary environment, two subfacies and seven microfaciesin submember 5 Majiagou Formation are classified. subfacies include basin-marginal tidal flat and intra-platformbasin. The former can be furtherly divided into four types microfacies, such as intra-platform margin （gypsum）dolomite depression, intra-platform margin dolomite tidal flat, intra-platform margin calcitic tidal flat and intra-platform margin dolomite calcitic–calcitic dolomite tidal flat. The latter can be furtherly divided into three typesmicrofacies, such as basin （gypsum） dolomite depression, dolomite calcitic–calcitic dolomite basin and calcitic basin.In the stage of submember 5-1 Majiagou Formation, Ordos basin basement uplift, the ancient land expand, reducesea level, shallow sea, the ancient central uplift belt out of the water are the performance of sedimentary microfaciesplane. North area is mainly developing intra-platform margin dolomite tidal flat-dolomite depression, intra-platform margin dolomite calcitic-calcitic dolomite tidal flat and calcitic basin. West area develop intra-platform margin dolomite tidal flat-dolomite depression, intra-platform margin dolomite calcitic-calcitic dolomitetidal flat. Center area develop calcitic basin, and mix dolomite calcitic basin and basin dolomite depression.In the stage of submember 5-2 Majiagou Formation, north area mainly developing intra-platform margin dolomitetidal flat and dolomite depression. Secondary microfacies include dolomite calcitic–calcitic dolomite tidal flat, cal citic tidal flat. In western area, the main microfacies include intra-platform margin dolomite tidal flat and dolomitedepression. In center area, the main microfacies include calcitic basin and basin dolomite depression.
作者
包洪平
张云峰
王前平
董兆雄
武春英
杨西燕
BAO Hongping ZHANG Yunfeng WANG Qianping DONG Zhaoxiong WU Chunying YANG Xiyan(Research Institute of Exploration and Development, Petro China Changqing Oilfield Company, Xi凷an 710018, China School of Geoscience and Technology, Southwest Petroleum University, Chengdu 610500, China)
出处
《煤田地质与勘探》
CAS
CSCD
北大核心
2016年第5期16-21,共6页
Coal Geology & Exploration
基金
国家科技重大专项课题(2011ZX05004-006)
四川省重点学科建设项目(SZD0414)~~
关键词
沉积微相
沉积演化
碳酸盐岩
马五5亚段
鄂尔多斯盆地
sedimentary microfacies
sedimentary evolution
carbonate
submember 5 Majiagou Formation
Ordos basin
