低渗致密裂缝发育气藏衰竭开采底水水侵规律OA
Bottom-water invasion behavior during depletion of fractured tight gas reservoirs with low permeability
DX气藏具有超高压、特低孔渗、裂缝发育及强底水驱等特征,在开发过程中,随着地层压力下降,底水通过裂缝快速侵入气藏,降低气藏产能并导致大量天然气被水封存于微裂缝和孔隙中,严重影响气藏的开采效益.针对DX气藏开发过程中存在的底水活跃问题,开展低渗致密裂缝发育气藏衰竭期底水水侵规律的研究.通过模拟高温超高压(136℃和106 MPa)地层条件,进行全直径裂缝岩心的气藏衰竭水侵物理模拟实验,研究不同衰竭速度和水体大小对气藏采收率、水气比、无水采气期和单位压降产气量等关键指标的影响.结果表明,水体倍数的增加和衰竭速度的加快均会导致气藏产水量升高,水气比增大,无水采气期变短,采收率降低,且水体倍数增加的影响明显强于衰竭速度加快的影响.水体从4.5倍烃孔隙体积增大至20.0倍,累计产水量增加近10倍,见水压力提高18 MPa,天然气采出程度降低21.61%;而衰竭速度提升2倍,累计产水量增加近1倍,见水压力提高6 MPa,天然气采出程度降低10.97%.因此,合理的衰竭速度控制和控水方案是提高气藏经济效益的关键策略,本研究为裂缝发育气藏的水侵管理和防治提供了重要的理论和实验依据,对优化气藏开发策略具有重要的实际应用价值.
The DX gas reservoir is characterized by ultra-high pressure,extremely low porosity and permeability,well-developed fractures,and a strong bottom-water drive.During depletion,the decline in formation pressure intrudes rapid bottom-water invasion through fracture networks,resulting in early water breakthrough and significant trapping of natural gas within micro-fractures and pore spaces,thereby reducing overall recovery.To investigate the bottom-water invasion behavior in fractured tight gas reservoirs,physical simulation experiments were conducted under high-temperature and ultra-high-pressure conditions(136℃and 106 MPa)using full-diameter fractured core samples.The effects of depletion rate and aquifer sizes on key indicators,including recovery factor,water-gas ratio,water-free production period,and gas production per unit pressure drop,were systematically analyzed.Results indicate that both increasing aquifer size and accelerating depletion rate lead to higher water production,increased water-gas ratio,shortened water-free period,and reduced gas recovery.Aquifer size exerts a significantly stronger influence than the depletion rate.Specifically,increasing the aquifer size from 4.5 to 20.0 times the hydrocarbon pore volume results in a nearly tenfold increase in cumulative water production,an rise in water breakthrough pressure by 18 MPa,and a value of 21.61%reduction in gas recovery.In contrast,doubling the depletion rate results in approximately a twofold increase in cumulative water production,a 6 MPa increase in breakthrough pressure,and a 10.97%reduction in recovery.These findings indicate that appropriate control of rational depletion rate and effective water management strategies are critical for improving economic performance of fractured tight gas reservoirs.This research provides a crucial theoretical and experimental basis for understanding and managing bottom-water invasion and offers significant practical guidance for optimizing development strategies in fractured gas reservoirs.
杜建芬;王家树;郭平;田浩;王恒;陈啸博
西南石油大学石油与天然气工程学院,四川 成都 610500中海油田股份有限公司一体化和新能源事业部,天津 300450西南石油大学石油与天然气工程学院,四川 成都 610500西南石油大学石油与天然气工程学院,四川 成都 610500西南石油大学石油与天然气工程学院,四川 成都 610500中国石油天然气股份有限公司塔里木油田分公司,新疆库尔勒 841000
能源科技
油气田开发超高压衰竭开采衰竭速度水体大小水侵规律裂缝发育气藏
oil-gas field developmentultra-high pressuredepletion developmentdepletion rateaquifer sizewater invasion behaviorfractured gas reservoir
《深圳大学学报（理工版）》 2026 (3)
273-280,8
Natural Science Foundation of Sichuan Province(2024NSFSC2012)China National Petroleum Corporation"the 14th Five-Year Plan"Prospective Fundamental Major Science and Technology Project(2021DJ3301) 四川省自然科学基金资助项目(2024NSFSC2012)中国石油集团公司"十四五"前瞻性基础性重大科技资助项目(2021DJ3301)
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