Characteristics and reservoir performance of continental organic-rich shale laminae: A Case Study of the Chang-7 member of Yanchang Formation in the southeast of the Ordos Basin

Key words: 
• ordos basin /
• organic-rich shale /
• laminae /
• laminae combination /
• reservoir performance /
• oiliness

Abstract: [Objective] With the continuous breakthrough of oil and gas exploration and development technology, shale oil has become an important replacement field for petroleum resources in the future. At present, the exploration and development of shale oil in Chang 7 Member of Ordos Basin has made important progress, but the reservoir performance of laminae shale oil is rarely studied. [Methods] Taking the organic-rich shale of Changchang 7 member of Yanchang Chang in the southeast of Ordos Basin as the research object, the development characteristics, reservoir performance and oiliness of different shale types in the Changchang 7 member shale formation were studied by means of thin section observation, scanning electron microscopy, high-pressure mercury intrusion and nitrogen adsorption, so as to classify the types of shale laminae and clarify the occurrence characteristics of shale oil. [Results and Discussions] Laminae is developed in silty mudstone, argillaceous siltstone, siltstone, black shale and tuff in Chang 7 member of the study area, which can be macroscopically divided into three types: thick laminated shale (1cm