Chang6 Reservoir Characteristics And CO₂ Drive Analysis In Qiaojiawa Area, Jingbian

As the CO2 storage experimental area, qiaojiawa belongs to typical low porosity and low permeability reservoir, so it is necessary to understand reservoir characteristics of qiaojia wa area, with carbon dioxide storage project goes on, carbon dioxide can also enhanc oil recovery, it is a win-win outcome. At the same time, it has a contribution to improving green house effect and enhancing oil recovery.Based on those reasons, Chang6 of Qiaojiawa area became our target.reservoir, through the basic geological theory and logging data, this thesis did small layer division and correlation of Chang6 in QiaoJiawa area. Combined with sedimentary marks, Chang6 sedimentary facies was identified. With the help of sedimentary petrology, petroleum geology theory, combined with many physics analysis means such as scanning electron microscope、 fication of clay minerals、high pressure mercury to give a comprehensive analysis on petrology, pore structure, physical property, pore throat feature of Chang6.in Qiaojiawa area.,so as to understand the geological characteristics of the reservoir and evaluates the target reservoir.Based on the fact that Chang6 of Qiaojiawa area has low porosity,carring CO2-water alternative drive is an alternative way to enhance oil recovery.at the same time, there are some factors which affect the experiment called alternate proportion, alternating slug, injection rate and injection intensity. During the experiment,best injection parameters will be chosen by the breakthrough time of gas, the renew rate, the oil gas oil ratio of production, the ability of gas injection.Eventually,the paper has achieved some results and conclusions.(1)Chang6 reservoir mainly includes feldspar sandstone, feldspathic quartz sandstone also being regnized. Chang 62 provide the bigget part of oil and gas in chang 6.Reservoirs mainly experienced coppaction, pressolution, cementation, dissolution and metasomatism. reservoir rock has a low ratio of clay minral. By conducting nuclear magnetic resonance and high pressure experiments, reservoir was evaluated by the parameters.(2)Based on the fact that Chang6 reservoir has low permeability and low porosity.CO2-water alternative drive was used to enhance oil recovery.at the same time,there are some factors which affect the experiment called alternate proportion, alternating slug, injection rate and injection speed. During the experiment, best injection parameters will be chosen by the breakthrough time of gas, the renew rate, the oil gas oil ratio of production, the ability of gas injection. Experiment shows that when the injection rate stays 2:1, injection slug holds 0.1 PV, the speed of inject is 0.96cm3/min and earlier the CO2-water alternative drive,the recovery is remarkable. Compared to CO2 drive,CO2-water alternative drive has a better recovery efficiency. Therefore, CO2-water alternative drive should take the priority of conducting gas drive and water drive.