Research On The Reservoir Characteristic And Hydrocarbon Enrichment In Yan9of Zhongshanjian District, Jingbian Oilfield, Ordos Basin

The Ordos Basin is one of those where oilfields are discovered at the earliest time, also is the second largest hydrocarbon-bearing basin,the main oil-bearing formation are Triassic Yanchang formation and Jurassic Yan’an formation.Owing to the high production, and remarkable economic benefit,Jurassic Yan’an formation has been one of the important successor of oil-bearing formation in this area.In order to provide the scientific prediction of the geology on expanding exploration and forecasting oil favourable object, it is necessary to meticulously research the relationship between the reservoir characteristic and the oil enrichment of Zhongshanjian region in Jingbian oilfield. Based on the research and study of predecessors, In accordance with the combination of macro and micro research mentality, used sedimentology, reservoir geology,natural gas geology,petroleum entrapment geology and logging geology as the instruction.Using geological logging, property analysis,scanning electron microscopy, mercury intrusion and other information to study the sedimentary, characteristics, diagenesis, reservoir physical property and microscopic pore structure. We classified the reservoir and analyzed the reservoir’s control factors, and investigated the relationship between reservoir characteristics and gas enrichment.On the basic of observation drilling core, laboratory test datum, we studied the reservoir’s characteristic of Yan9formations, concluded that the reservoir rock is lithic arkose. According to the physical property of the reservoir and the pore structural character, we assort and appraise the reservoir of the Yan9oil-bearings. Meandering channel sand body is the facies belts that oil and gas accumulated in this district. And Oil and gas were enriched in the thicker side of the beach where the channel sand deposited.Synthetizing the reservoir quality, the sedimentary facies and the sealing ability of cap rock, etc. We get the factors that control the accumulation as follows:The deep—semi-deep lake mudstone of Chang7formation provided the high quality source rock for the oil accumulation; Fracture offered the migration pathway; The upper mud cap rock and side block of mudstone were essential to the accumulation; structure, the thickness of the sand body, source of oil are the main controlling factors of oil and gas accumulation in this district.