摘要
中国高含硫天然气资源丰富,为了解决高含硫气藏开发过程中硫沉积对气井产量及气藏采收率的影响,全面梳理了高含硫天然气中单质硫析出、沉积和运移的主要机制,阐述了影响硫沉积的主要因素,总结了储层硫沉积预测技术,并结合硫沉积规律提出了防治储层硫沉积的措施,最后指出了储层硫沉积未来的研究方向及建议.研究结果表明:①高含硫气藏硫沉积主要发生在近井附近,可能会对气井产能、气井生产寿命和气藏最终采收率产生严重影响;②液硫沉积对高渗透储层的影响不大,但对低渗透致密储层有一定影响,固硫沉积则对储层影响较大,沉积一旦开始,可能会发生快速堵塞;③影响硫沉积过程的关键因素包括环境压力、温度、储层物性、混合气体单质硫含量、H2S气体含量和采气速度等;④通过梳理总结储层中硫沉积规律和特征,提出了"防—控—治—替"等多种手段相结合的治理硫沉积综合治理方法.结论认为,未来高含硫气藏储层硫沉积研究应聚焦高含硫气藏气水硫多相流动机理及模拟方法,射孔炮眼硫沉积堵塞机理,注CO2控硫机理、技术政策和配套工艺,储层—井筒一体化耦合模拟,增压开采对储层硫沉积影响等前沿科学问题研究和攻关,并形成"高含硫气田开发全流程数字孪生技术",以保障高含硫气田的规模安全绿色高效开发.
Abstract
There are abundant high-sulfur gas resources in China.During the development of high-sulfur gas reservoirs,sulfur deposition seriously affects the production of gas wells and the recovery factor of gas reservoirs.This paper systematically reviews the main mechanisms of elemental sulfur precipitation,deposition and migration in high-sulfur gas reservoirs,elaborates on the main factors controlling sulfur deposition,and summarizes the reservoir sulfur deposition prediction techniques.Moreover,this paper proposes measures to prevent and control sulfur deposition depending on sulfur deposition patterns.Finally,this paper presents the future research direction and suggestions of sulfur deposition.The following results are obtained.First,sulfur deposition in high-sulfur gas reservoirs mainly occurs near the wellbore,and it may have a serious impact on the well productivity,production life,and ultimate recovery factor.Second,liquid sulfur deposition has little effect on high-permeability reservoirs,but has some effect on low-permeability tight reservoirs.Solid sulfur deposition may significantly affect the reservoirs,possibly by rapidly generating a blockage therein.Third,the key factors that determine the sulfur deposition process include:environmental pressure and temperature,reservoir properties,elemental sulfur and H2S contents of mixed gases,and gas recovery rate.Fourth,depending on the identified patterns and characteristics of sulfur deposition,a comprehensive method is proposed to deal with sulfur depositionwith a combination of prevention,control,treatment and displacement.It is concluded that the future research on sulfur deposition in high-sulfur gas reservoirs will focus on some cutting-edge scientific issues,such as the multiphase flow mechanism and simulation method of gas,water,and sulfur,the blockage mechanism of sulfur deposition in perforation holes,the mechanism,strategy and process of CO2 injection for sulfur control,the reservoir-wellbore integrated coupling simulation,and the impact of pressurized production on sulfur deposition,and form the digital twin technology for the entire process of high-sulfur gas field development,in order to ensure an extensive,safe,green and efficient development of high-sulfur gas fields.
维普
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