高含硫气藏地层硫沉积研究进展及展望

Research progress and prospect of formation sulfur deposition in high sulfur gas reservoirs

地层硫沉积对高含硫气藏采收率及开发中后期稳产具有重要影响。文中通过梳理高含硫气藏天然气中硫溶解度、流体相态平衡、地层硫沉积伤害等方面的研究进展,提出了高含硫气藏地层硫沉积研究的重要手段,即开展不同温压条件下高含硫气体的相态及微观流动室内实验,并与分子模拟、数值模拟方法相结合,分析地层硫沉积机理及规律。未来应着重加强三方面的基础研究:结合硫溶解度实验,采用分子模拟方法开展分子尺度下的硫溶解行为研究,揭示硫溶解机理;进一步开展高温高压条件下多硫化氢和硫组分变化实验,建立考虑化学反应和热力学平衡的气-水-液态硫三相相平衡模型;加强固态硫伤害及气-水-液态硫三相渗流实验研究,采用分子模拟方法获取各流体组分间多相流动力学行为参数,联合介观尺度多相流模拟方法,模拟多孔介质中气-水-液态硫三相渗流规律。在此基础上,进一步开展储层硫沉积预测数值模拟和硫防治技术研究,为我国以普光、元坝为代表的高含硫气田防硫、控硫、治硫对策制订提供依据。

The formation sulfur deposition in high sulfur gas reservoir has an important influences on enhancing oil recovery and stabilizing production in middle and late stage of gas reservoir development.Based on the research progress of sulfur solubility,fluid phase equilibrium and formation sulfur deposition damage in high sulfur gas reservoirs,it is suggested that laboratory experiments on the phase and microscopic flow of high sulfur gas under different temperature and pressure conditions,combined with molecular simulation and numerical simulation,are important means to reveal the mechanism and law of formation sulfur deposition.In the future,the following three studies should be emphasized:combining with the sulfur solubility experiment,molecular simulation method should be used to study the sulfur dissolution behavior at molecular scale and reveal the mechanism of sulfur dissolution;experiments on the changes of hydrogen polysulfide and elemental sulfur composition under high temperature and high pressure need to be further carried out to establish a gas-liquid-sulfur three-phase equilibrium model considering chemical reaction and thermodynamic equilibrium;strengthening experiments study on sulfur fixation damage and gas-liquid-sulfur three-phase seepage,molecular simulation method should be used to obtain mechanical parameters of multiphase flow between fluid components,combined with mesoscale multiphase flow simulation method to simulate gas-liquid-sulfur three-phase seepage in porous media.On this basis,the numerical simulation of reservoir sulfur deposition prediction and sulfur control technology research are further carried out,which provides a basis for the formulation of sulfur control strategies for Puguang and Yuanba gas fields with high sulfur content in China.