高含硫气藏地层温度场及硫沉积相态预测模型  

Prediction model of reservoir temperature field and sulfur deposition phase in high-sulfur gas reservoirs

作　　者：胡景宏[1] 方博 王晓冬[1] HU Jinghong;FANG Bo;WANG Xiaodong(Beijing Key Laboratory of Unconventional Natural Gas Geology Evaluation and Development Engineering//China University of Geosciences,Beijing 100083,China;PetroChina Research Institute of Petroleum Exploration&Development,Beijing 100083,China)

机构地区：[1]北京市非常规天然气能源地质评价与开发工程重点实验室•中国地质大学(北京) [2]中国石油勘探开发研究院,北京市100083

出　　处：《天然气工业》2024年第11期92-100,共9页Natural Gas Industry

基　　金：国家自然科学基金项目“基于气—液硫—固硫复杂相变的深层高含硫气藏渗流机理研究”(编号:52074248)。

摘　　要：在深层高含硫气藏高温高压环境中,随着高含硫天然气开发过程中地层温度和压力下降,地层中硫沉积会出现相态变化而造成多种流体渗流特性,溶解于酸性气体中的硫单质逐渐沉积在储层孔隙中,进而影响气井的正常生产。为探究高含硫气藏地层硫沉积的相态变化动态,针对多裂缝水平井生产特征,建立了考虑硫沉积和各种热效应影响的硫沉积相态预测模型,并基于有限体积法求解温压场数值模型,研究了地层温压场分布规律及近井地带硫沉积的相态变化特征。研究结果表明:①自储层边界向人工裂缝方向地层温度是不断降低的,在人工裂缝根端达到最低,研究区的整体温度随生产时间延续先下降后上升;②裂缝导流能力越小,地层温度会越低,硫沉积更容易以固态形式存在;③随着生产时间增加地层中硫沉积逐渐从固态变成液态,液硫首先出现在人工裂缝根端附近。当生产压差增加时,固态硫沉积存在的范围会逐渐缩小。结论认为,该预测模型可深化地层硫沉积相态特征的认识,有助于地层硫沉积规律认识,并为深层高含硫气藏的规模效益开发提供理论指导。In the high-temperature and high-pressure environment of deep high-sulfur gas reservoirs,as the reservoir temperature and pressure decline in the process of high-sulfur natural gas development,the phase change of sulfur deposition may cause different fluid flow characteristics and the sulfur elements dissolved in acid gas deposit gradually in reservoir pores,thus impacting the normal production of gas wells.In order to investigate the phase change behaviors of sulfur deposition in high-sulfur gas reservoirs,a sulfur deposition phase prediction model considering sulfur deposition and various thermal effects is established according to the production characteristics of multi-fracture horizontal wells.In addition,the numerical models of temperature and pressure fields are solved based on the finite volume method,and the distribution laws of reservoir temperature and pressure fields and the phase change characteristics of sulfur deposition near the well are studied.And the following research results are obtained.First,the reservoir temperature decreases continuously from the reservoir boundary to the hydraulic fracture,reaching the lowest point at the root of the fracture,and the overall temperature in the study area decreases first and then increases with the production time.Second,the weaker the fracture conductivity,the lower the reservoir temperature,and the easier the existence of sulfur deposition in solid form.Third,as the production goes on,the sulfur deposition in the reservoir gradually change from solid to liquid,and the liquid sulfur first appears near the root end of hydraulic fracture.When the production pressure difference increases,the range of solid sulfur deposition will gradually shrink.In conclusion,this prediction model is conducive to further understanding the phase characteristics and laws of sulfur deposition and can provide a theoretical basis for the large-scale benefit development of deep high-sulfur gas reservoirs.

关 键 词：含硫气藏 多裂缝水平井 温度场 硫沉积 相态变化 

分 类 号：TE332[石油与天然气工程—油气田开发工程]