The Study On Enrichment Regularity Of Chang 4+5 Reservoir In Qingpingchuan Oil Region

In this paper,with the qingpingchuan oil region in the Ordos Basin of Chang 4+5reservoir as the object of the research,the application of principle of sedimentary cycle and logging curve marker,the 4+5 formation from the bottom to the top is divided into 4+5₂²,4+5₂¹,4+5₁²,4+5₁¹.Studying the regularity of oil distribution focuses on the sedimentary facies and sand body distribution,reservoir characteristics and reservoir distribution characteristics and comprehensive evaluation.On the basis of the analysing core and logging facies,study area 4+5 mainly developed delta plain and front sub facies,distributary channel and distributary bay to the main microfacies.The results of the core test show that the main reservoir rock type is mainly feldspar sandstone,and diagenesis mainly includes compaction,cementation and dissolution,and main pore types are intergranular pore,intergranular pore and dissolution pore combination types;Pore constriction to fine pore fine throat.According to lithology,physical property and capillary pressure characteristics of Chang 4+5 reservoir parameter evaluation,reservoir will be stored into(class ?),(?),(?),(?).Qingpingchuan oil Chang 4+5 reservoir is mainly lithologic and structural lithologic reservoir,and the study area is located in the edge of hydrocarbon generation,so hydrocarbon supplying ability is insufficient.According to the study area of sand thickness and oil thickness composite map,tectonics and oil thick laminated composite graph,porosity and oil thick stack,the results make clear that the oil and gas enrichment is mainly affected by the sedimentary micro facies and tectonic control,so in the distributary channel sand body better development of the region is the main place of oil and gas accumulation;Finally,combined with the reservoir characteristics and oil enrichment controlling factors wereanalyzed,The results is that a total of 20 genes were favorable area,only 3 areas belong to?class oil enrichment area,10 areas belong to?class oil enrichment area,and7 areas belong to ?class oil enrichment area.