潜山油藏开发后期驱油、储气及地热利用协同联动探索

Research on Synergy of Oil Displacement,Gas Storage and Geothermal Utilization in Later-on Development Stage of Buried-hill Oil Reservoir

针对潜山油藏开发后期剩余油潜力不明、注气提高采收率难度大、采出高温水处理难、地热资源未有效利用等问题,开展理论与技术探索,根据油藏型地下储气库驱油储气地热协同联动一体化建设实践,取得以下成果及认识:(1)潜山油藏具有得天独厚的建库优势;(2)通过调控注气速度控制油气界面缓慢推进,保持油水界面稳定,有望实现潜山油藏大幅提高采收率与调峰供气一体化;(3)结合油田现有规划,将地热井、换热站、油田管线进行区域整合,建立了潜山油藏注气开采—余热利用—回注闭环模式,实现多套地热资源和油田集输余热综合利用;(4)开展驱油储气地热协同联动一体化建设试验,取得良好效果,预测提高采收率20%以上。潜山地热开发利用推广以来,已在冀中地区建成205×10^(4)m^(2)/a供暖能力,利用地热能折合标准煤5.11×10^(4)t,减排CO_(2)达14.15×10^(4)t,提高了清洁能源综合利用能力,缓解了供暖压力。

The theoretical and technology study was made for the purpose to solve the issues related to the later-on development stage of the buried-hill oil reservoir,such as unclear remaining oil potential,difficult EOR by means of gas injection,difficult treatment of the produced high-temperature water,and failure for effective use of geothermal resources.A series of achievements were made in the practice from synergy among underground gas storage,oil displacement and geothermal utilization.(1)The buried-hill oil reservoir has a unique advantage for construction of gas storage depot.(2)The adjustment and control technology of the gas-injection speed can slowly expand the oil-gas interface and keep the oil-water interface stable,thus hopefully bringing about integration of EOR with peak-adjusting gas supply for the buried-hill reservoir.(3)Based on the existing plan of the oilfield,the geothermal wells,heat-exchanging stations and oilfield pipelines in the area are integrated to establish the closed-loop model of gas-injection development,residual heat recovery and re-injection for the buried-hill reservoir and make comprehensive use of multiple sets of geothermal resources and residual heat from the oilfield gathering and transferring facility.(4)Integrated construction of oil displacement,gas storage and geothermal synergy is experimented with the good results achieved.The predicted EOR is raised by more than 20 percent.The heat-supplying capacity of 205×10^(4)m^(2)/a has been established in the central area of Hebei Province since the buried-hill geothermal energy was brought under development and utilization.The applied geothermal energy was equal to 5.11×10^(4)t of standard coal,reduced 14.15×10^(4)t of carbon dioxide,improved the abilities for comprehensive use of clean energy,and alleviated the heat-supply pressure.