Research on the basic theory and application of enhanced recovery in tight sandstone gas reservoirs.

Tight sandstone gas reservoirs are characterized by high water saturation, significant seepage resistance, low single-well productivity, rapid decline, and low gas recovery. Enhancing the recovery rate of tight sandstone gas reservoirs is a complex engineering challenge that necessitates thorough, refined, and systematic research into its fundamental theories. This study employs a comprehensive approach integrating mercury injection, nuclear magnetic resonance, micro-model visualization, and simulation experiments of displacement and inter-layer seepage flow, alongside foundational seepage theories, to systematically explore the characteristics of tight sandstone gas reservoirs, seepage patterns, and methods for improving gas recovery.

A New model of gas-water two-phase seepage based on Newton's law of motion.

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.

Water-gas ratio characteristics and development concepts for water-producing gas reservoirs.

Water production from gas wells is a key factor affecting the effectiveness of gas-reservoir development, and it poses serious challenges in terms of increasing the degree of recovery during the waterless production stage and reducing the impact of water production on gas-reservoir development in the middle and later periods. Thus, gas reservoirs must be efficiently exploited on the basis of identifying gas-water layers accurately, defining gas-water relationships, and understanding gas-water production performance. Accordingly, this study analyzes the production characteristics in gas reservoirs with different gas-water relationships, and it summarizes the rules that determine water-gas ratios.