针对致密砂岩气藏在开发过程中,存在采收率低,气井产水现象严重的问题。本文从致密砂岩气藏气水两相渗流规律着手,采用CT扫描技术识别二维裂缝,并利用FLUENT数值模拟软件,模拟不同压差下致密砂岩气藏的气水两相渗流规律。结果表明:残余...针对致密砂岩气藏在开发过程中,存在采收率低,气井产水现象严重的问题。本文从致密砂岩气藏气水两相渗流规律着手,采用CT扫描技术识别二维裂缝,并利用FLUENT数值模拟软件,模拟不同压差下致密砂岩气藏的气水两相渗流规律。结果表明:残余气分布主要分布在不连通的裂隙之中,少部分气体分布在连通裂缝之中;增大压差,气水分布变化,采收率略微提高;缝网越发育,采出程度越小,最终采收率提高程度越小。建议在致密砂岩气藏开采的过程中,可以采取前期增大压差,后期降低废弃压力的方式,使得致密砂岩气藏可以获得较大的产能。研究结果对于致密砂岩气藏开发具有一定的指导意义。Aiming at the tight sandstone gas reservoirs in the development process, there are problems of low recovery rate and serious water production phenomena in gas wells. In this paper, we start from the gas-water two-phase seepage law of tight sandstone gas reservoirs, use CT scanning technology to identify two-dimensional fractures and use FLUENT numerical simulation software to simulate the gas-water two-phase seepage law of tight sandstone gas reservoirs under different pressure differences. The results show that: the residual gas distribution is mainly distributed in the disconnected fractures, and a small portion of the gas is distributed in the connected fractures;increasing the pressure difference, the gas-water distribution changes, and the recovery rate is slightly increased;the more the fracture network is developed, the smaller the degree of extraction is, and the smaller the degree of increase in the final recovery rate is. It is suggested that when mining tight sandstone gas reservoirs, the method of increasing the differential pressure in the early stage and decreasing the waste pressure in the later stage can be adopted so that the tight sandstone gas reservoirs can obtain a larger production capacity. The results of the study have a certain guiding significance for the development of tight sandstone gas reservoirs.展开更多
随着21世纪以来我国天然气消费量的急剧增加以及对外依存度的持续提升,国内能源安全面临着严峻挑战。在此背景下,碳酸盐岩边水气藏的高效开发对于国家能源安全尤为重要。本文系统分析了碳酸盐岩边水气藏中的水侵问题,涵盖了储层结构特...随着21世纪以来我国天然气消费量的急剧增加以及对外依存度的持续提升,国内能源安全面临着严峻挑战。在此背景下,碳酸盐岩边水气藏的高效开发对于国家能源安全尤为重要。本文系统分析了碳酸盐岩边水气藏中的水侵问题,涵盖了储层结构特征、气水两相渗流特征、水侵规律实验研究以及水侵动态数值模拟与计算。研究显示:(1) 目前,储层孔隙结构表征技术多样化,但研究多集中在微小孔喉和裂缝,针对孔洞的描述以及它们之间的搭配关系、沟通情况及对渗透率的贡献率的研究仍显不足;(2) 现有实验模型难以开展缝洞型气藏的气水两相渗流特征研究;(3) 目前针对水侵规律实验研究较少,认识缺乏统一;(4) 通过分析生产动态资料、试井和物质平衡原理可以进行水侵识别与预测,但这些方法在早期阶段的识别效果受限或是要求多次试井。因此,未来的研究需要开发能承受更高压力和更大尺寸的实验模型、进行多参数大尺度的水侵规律模拟研究和基于实验研究并结合渗流力学与气藏工程等方法针对不同类型气藏建立水侵数学模型,以深化复杂气藏水侵动态的理解,为碳酸盐岩边水气藏的高效开发提供坚实的科学基础和技术支持。With the rapid increase in natural gas consumption and the continuous rise in external dependence since the 21st century, China’s energy security is facing severe challenges. In this context, the efficient development of carbonate gas reservoirs with edge water is particularly important for national energy security. This paper systematically analyzes the water invasion problems in carbonate gas reservoirs with edge water, covering reservoir structure characteristics, gas-water two-phase flow characteristics, experimental research on water invasion laws, and dynamic numerical simulation and calculation of water invasion. The study shows that: (1) At present, reservoir pore structure characterization technology is diversified, but research is mainly focused on micro pores and fractures. The description of cavities, the matching relationships between them, communication situations, and their contribution rates to permeability are still insufficiently studied;(2) Existing experimental models are challenging for studying gas-water two-phase flow characteristics in fracture-cavity type gas reservoirs;(3) There is currently limited experimental research on water invasion laws, and the understanding is not unified;(4) Water invasion identification and prediction can be conducted through analysis of production dynamics data, well testing, and material balance principles, but these methods are limited in early-stage identification or require multiple well tests. Therefore, future research needs to develop experimental models that can withstand higher pressure and larger sizes, conduct multi-parameter large-scale simulations of water invasion laws, and establish mathematical models of water invasion for different types of gas reservoirs based on experimental research combined with seepage mechanics and gas reservoir engineering methods. This will deepen the understanding of water invasion dynamics in complex gas reservoirs and provide a solid scientific foundation and technical support for the efficient development of carbonate gas reservoirs with edge water.展开更多
文摘针对致密砂岩气藏在开发过程中,存在采收率低,气井产水现象严重的问题。本文从致密砂岩气藏气水两相渗流规律着手,采用CT扫描技术识别二维裂缝,并利用FLUENT数值模拟软件,模拟不同压差下致密砂岩气藏的气水两相渗流规律。结果表明:残余气分布主要分布在不连通的裂隙之中,少部分气体分布在连通裂缝之中;增大压差,气水分布变化,采收率略微提高;缝网越发育,采出程度越小,最终采收率提高程度越小。建议在致密砂岩气藏开采的过程中,可以采取前期增大压差,后期降低废弃压力的方式,使得致密砂岩气藏可以获得较大的产能。研究结果对于致密砂岩气藏开发具有一定的指导意义。Aiming at the tight sandstone gas reservoirs in the development process, there are problems of low recovery rate and serious water production phenomena in gas wells. In this paper, we start from the gas-water two-phase seepage law of tight sandstone gas reservoirs, use CT scanning technology to identify two-dimensional fractures and use FLUENT numerical simulation software to simulate the gas-water two-phase seepage law of tight sandstone gas reservoirs under different pressure differences. The results show that: the residual gas distribution is mainly distributed in the disconnected fractures, and a small portion of the gas is distributed in the connected fractures;increasing the pressure difference, the gas-water distribution changes, and the recovery rate is slightly increased;the more the fracture network is developed, the smaller the degree of extraction is, and the smaller the degree of increase in the final recovery rate is. It is suggested that when mining tight sandstone gas reservoirs, the method of increasing the differential pressure in the early stage and decreasing the waste pressure in the later stage can be adopted so that the tight sandstone gas reservoirs can obtain a larger production capacity. The results of the study have a certain guiding significance for the development of tight sandstone gas reservoirs.
文摘随着21世纪以来我国天然气消费量的急剧增加以及对外依存度的持续提升,国内能源安全面临着严峻挑战。在此背景下,碳酸盐岩边水气藏的高效开发对于国家能源安全尤为重要。本文系统分析了碳酸盐岩边水气藏中的水侵问题,涵盖了储层结构特征、气水两相渗流特征、水侵规律实验研究以及水侵动态数值模拟与计算。研究显示:(1) 目前,储层孔隙结构表征技术多样化,但研究多集中在微小孔喉和裂缝,针对孔洞的描述以及它们之间的搭配关系、沟通情况及对渗透率的贡献率的研究仍显不足;(2) 现有实验模型难以开展缝洞型气藏的气水两相渗流特征研究;(3) 目前针对水侵规律实验研究较少,认识缺乏统一;(4) 通过分析生产动态资料、试井和物质平衡原理可以进行水侵识别与预测,但这些方法在早期阶段的识别效果受限或是要求多次试井。因此,未来的研究需要开发能承受更高压力和更大尺寸的实验模型、进行多参数大尺度的水侵规律模拟研究和基于实验研究并结合渗流力学与气藏工程等方法针对不同类型气藏建立水侵数学模型,以深化复杂气藏水侵动态的理解,为碳酸盐岩边水气藏的高效开发提供坚实的科学基础和技术支持。With the rapid increase in natural gas consumption and the continuous rise in external dependence since the 21st century, China’s energy security is facing severe challenges. In this context, the efficient development of carbonate gas reservoirs with edge water is particularly important for national energy security. This paper systematically analyzes the water invasion problems in carbonate gas reservoirs with edge water, covering reservoir structure characteristics, gas-water two-phase flow characteristics, experimental research on water invasion laws, and dynamic numerical simulation and calculation of water invasion. The study shows that: (1) At present, reservoir pore structure characterization technology is diversified, but research is mainly focused on micro pores and fractures. The description of cavities, the matching relationships between them, communication situations, and their contribution rates to permeability are still insufficiently studied;(2) Existing experimental models are challenging for studying gas-water two-phase flow characteristics in fracture-cavity type gas reservoirs;(3) There is currently limited experimental research on water invasion laws, and the understanding is not unified;(4) Water invasion identification and prediction can be conducted through analysis of production dynamics data, well testing, and material balance principles, but these methods are limited in early-stage identification or require multiple well tests. Therefore, future research needs to develop experimental models that can withstand higher pressure and larger sizes, conduct multi-parameter large-scale simulations of water invasion laws, and establish mathematical models of water invasion for different types of gas reservoirs based on experimental research combined with seepage mechanics and gas reservoir engineering methods. This will deepen the understanding of water invasion dynamics in complex gas reservoirs and provide a solid scientific foundation and technical support for the efficient development of carbonate gas reservoirs with edge water.
