Research On Gas Reservoir Characteristics Of Q1 Period In Chs2 Wells Area Of Wangfu Area

Through comprehensive analysis to well data, seismic data and core data of 30 wells in chs2 well field of the first member of Quantou Formation in Wangfu area, it is divided into 6 sand groups and 18 sub-layers, and the sequence stratigraphic framework in the first member of Quantou Formation is established. According to exploration wells and seismic data, top structural feature in the first member of Quantou Formation is completed, which demonstrates that the fracture system is mainly in the direction of near north-south horizontally, and divided into 3 stages based on the duration of activity vertically. It is identified that the sedimentary system of the first member of Quantou Formation in Wangfu area was made up of Riverbed subfacies, Embankment subfacies and Floodplain subfacies.From the aspect of gas reservoir type, according to the anatomy of individual well profile and connecting-well section, and spatial relations of oil and water between them, it is finally comprehensive identified that the main gas reservoir types of research area were structure conglomerate gas reservoir and lithologic gas reservoir.From the aspect of gas reservoir distribution law, according to the interpretation results of each well and the gas and water distributed situation of each sand group, it can be summarized that gas reservoirs study area are widely distributed in Sand groupⅡ~Ⅳ with an unconspicuous gas and water distribution, which was controlled by lithologic gas reservoir. And Sand Group Ⅰand Ⅴ are mainly water layers and dry layers that have an effect of sealing for the middle sand groups. From the aspect of major control factors, the source rocks of Wangfu area were distributed in the northwest of Quantou formation, and according to the results of gas testing and interpretation, the distribution of source rock has not a conspicuous effect on the distribution of gas reservoir in Quantou formation. On the whole, the law of gas water distribution in Quantou Formation is not obvious, which belongs to typical lithologic gas reservoirs, and the accumulation of gas reservoirs is mainly controlled by lithology.The gas reservoir section is determined by seismic section, and gas and water distribution are determined by gas testing results and well logging interpretation.According to comprehensive analysis of the pattern of source-reservoir-cap assemblages, structures, traps and sedimentary facies features, it can be concluded that the first member of Quantou Formation belongs to secondary gas reservoir with complex distribution of gas and water, and lithology and favorable tectonic setting are the main controlling factors of gas reservoir.