Characteristics Of Reservoir Sedimentary Of Chang9Layer Of Yanchang Formation In Hongjingzi-luopangyuan Area, Ordos Basin

Upper Triassic Yanchang Formation in Ordos Basin is characteristized by deepthickness of sedimentation and abundant oil and gas resources,which is one of themost important target zones for oil and gas exploration in the basin.Hongjingzi-Luopangyuan area is located in southwestern Ordos Basin, drilling datashow that chang9reservoir in the area has the characteristics of wider distribution,greater potential, but because of large differences in productivity and complexrelationship between oil and water, the research on reservoir characteristics,hydrocarbon accumulation mechanism and enrichment rules are still significantly less.In this paper, according to the study of Chang9geology background and reservoircharacteristics, we comprehensively analyzed oil sources,sedimentary facies anddiagenesis sand body distribution, further more,we classified the reservoir,predictedthe advantage area and achieved several important research results as follows:1. Based on the core observation, drilling and logging data analysis,we researchon the color characteristics, rock structure characteristics, sedimentary structures,paleontology signs and determine that Chang9reservior in Hongjingzi-Luopangyuanarea in Ordos Basin developed shallow water delta.2. Through source analysis, we conclude that the study area is controlled bythe south and the north provenance system, which are main to the north and northwestprovenance, the mother rock is main to volcanic and plutonic rock, the study area islocated in the intersection with multi-material source.3. Hongjingzi-Luopangyuan area Chang9reservior overall presentate thecharacteristics that Chang9reservior was from Chang7organic hydrocarbon, Theporosity and permeability in Chang91are better than Chang92, low porosity-lowpermeability reservoir commonly developed in the three districts, reservoir propertiesof Hongjingzi area is best, in which developed cracks. In Chang9reservoir, thedifferentiate between oil and water in the vertical is well, but difficult in the sideway.4. According to studying Chang9reservoir sandstone diagenesis characteristicswe conclude that chlorite, laumontite, Illite smectite mixed layer cements have the greatest impact on Chang9reservoir, single chlorite rim cement mainly developed inthe west, while single Illite smectite mixed layer rim cement in the northern andeastern parts of the study area, the remaining area are the transition between thechlorite and Illite smectite mixed layer rim cement. All kins of clay minerals rimcement have a good protective effect on primary intergranular pore, but the exist ofIllite smectite mixed layer rim cement is disadvantage of waterflooding.