A New model of gas-water two-phase seepage based on Newton's law of motion
Jianzhong Zhang,
Shusheng Gao,
Wei Xiong,
Liyou Ye,
Huaxun Liu,
Wenqing Zhu,
Weiguo An,
Donghuan Han,
Baicen Lin
Affiliations
Jianzhong Zhang
University of Chinese Academy of Sciences, Beijing, 101408, China; Institute of Porous Flow & Fluid Mechanics, Chinese Academy of Sciences, Langfang, 065007, China; Research Institute of Petroleum Exploration and Development, Beijing, 100083, China; Corresponding author. University of Chinese Academy of Sciences, Beijing, 101408, China
Shusheng Gao
University of Chinese Academy of Sciences, Beijing, 101408, China; Institute of Porous Flow & Fluid Mechanics, Chinese Academy of Sciences, Langfang, 065007, China; Research Institute of Petroleum Exploration and Development, Beijing, 100083, China
Wei Xiong
University of Chinese Academy of Sciences, Beijing, 101408, China; Institute of Porous Flow & Fluid Mechanics, Chinese Academy of Sciences, Langfang, 065007, China; Research Institute of Petroleum Exploration and Development, Beijing, 100083, China
Liyou Ye
University of Chinese Academy of Sciences, Beijing, 101408, China; Institute of Porous Flow & Fluid Mechanics, Chinese Academy of Sciences, Langfang, 065007, China; Research Institute of Petroleum Exploration and Development, Beijing, 100083, China
Huaxun Liu
Institute of Porous Flow & Fluid Mechanics, Chinese Academy of Sciences, Langfang, 065007, China
Wenqing Zhu
Institute of Porous Flow & Fluid Mechanics, Chinese Academy of Sciences, Langfang, 065007, China
Weiguo An
Institute of Porous Flow & Fluid Mechanics, Chinese Academy of Sciences, Langfang, 065007, China
Donghuan Han
University of Chinese Academy of Sciences, Beijing, 101408, China; Institute of Porous Flow & Fluid Mechanics, Chinese Academy of Sciences, Langfang, 065007, China; Research Institute of Petroleum Exploration and Development, Beijing, 100083, China
Baicen Lin
University of Chinese Academy of Sciences, Beijing, 101408, China; Institute of Porous Flow & Fluid Mechanics, Chinese Academy of Sciences, Langfang, 065007, China; Research Institute of Petroleum Exploration and Development, Beijing, 100083, China
The pore throat size, structure distribution, and lithology of porous media in gas reservoirs are varied, and the gas-water two-phase seepage law is complex, making it difficult to describe the seepage model. Newton's law of motion is a basic law of motion in classical mechanics, and its application in gas-water two-phase seepage modeling is an innovative practice of classical mechanics in seepage mechanics systems. Based on Newton's three laws of motion, a gas-water two-phase seepage model was established from the force analysis of fluid, and the relationship between velocity and pressure difference, pipe radius, water film thickness, viscosity, etc. was derived under the condition that the model reached a stable state, i.e., force balance. The relationship is referred to as the steady-state model. Subsequently. the equivalent permeability representation model was derived based on the steady-state model to calculate the permeability of rock samples with different channel distribution characteristics. The results were consistent with the measured values, and there is a good correspondence between channel distribution characteristics and permeability. The relative permeability calculation method was established based on the steady-state model and capillary pressure curve. The obtained relative permeability curve aligned with the two-phase seepage law and coincides with the relative permeability curve obtained by Poiseuille's law. Finally, a new productivity equation was derived based on the steady-state model, and the Inflow Performance Relationship (IPR) curve calculated by the gas well example was consistent with the traditional equation. The research results were based on the force analysis of fluid in porous media and fundamentally explored the law of fluid flow. The derived seepage model can be used to calculate reservoir permeability, the gas-water relative permeability curve, and gas well productivity analysis and to effectively guide gas reservoir development. The study was a successful application of the basic theory of mechanics in gas-water two-phase seepage in gas reservoirs.
