Experimental Study on the Seepage Characteristics of Multilayer Commingled Production and Influencing Factors of the Development Effect in Low-Permeability Tight Sandstone Gas Reservoirs

Abstract

For low-permeability tight sandstone gas reservoirs, multilayer commingled production technology is usually adopted by a large number of production wells. This production method can significantly increase the productivity of a single well, thereby improving the efficiency of gas field development. To have a better understanding of the seepage characteristics of multilayer commingled production of the SXM (ShaXiMiao) Formation tight sandstone gas reservoirs, an indoor physical simulation experiment of commingled injection and separate production using double-pipe parallel long cores was designed under influencing factors such as formation pressures, permeability contrast, and water saturations. Finally, the contribution of high- and low-permeability reservoirs to the total production capacity under different conditions is clarified, which provides a reference for formulating reasonable development strategies for gas reservoirs. Through the experimental study, we found that the recovery degree of the high-permeability formation is higher than that of the low-permeability formation during the depletion production process. The combination of depletion development and water flooding can greatly increase the recovery degree of gas reservoirs. Under the same production pressure difference condition, the higher the formation pressure and the permeability, the higher the production capacity. If the water saturation increases, the production contribution rate of the high-permeability layer gradually increases, and the production contribution rate of the low-permeability layer gradually decreases.

Experimental Study on Compaction Deformation and Gas Permeability Properties for Crushed Limestone

“…Meanwhile, it is an important direction for the development of clean energy in the future. , CBM is abundant in the mining goaf, and realizing its efficient exploitation and utilization is of great significance to optimize the energy structure . The gas permeability properties of coal and rock media in mining goaf are the basis for studying CBM enrichment and migration and the selection of surface drilling location. , The goaf formed by longwall mining can be divided sequentially into a caved zone, a fractured zone, and a continuous bending zone. , Notably, the crushed coal and rock in the caved zone is a triple pore structure with pores, fractures, and voids, which means that its internal pore space is much larger than the dual pore-fracture structure in the fractured zone and continuous bending zone . Crushed limestone is a common rock in the caved zone; it is of great theoretical and practical significance to master the evolution of its permeability properties during compaction for the efficient extraction of CBM in goaf.…”

“… 6 The gas permeability properties of coal and rock media in mining goaf are the basis for studying CBM enrichment and migration and the selection of surface drilling location. 7 , 8 The goaf formed by longwall mining can be divided sequentially into a caved zone, a fractured zone, and a continuous bending zone. 9 , 10 Notably, the crushed coal and rock in the caved zone is a triple pore structure with pores, fractures, and voids, which means that its internal pore space is much larger than the dual pore-fracture structure in the fractured zone and continuous bending zone.…”

Research on imbibition effect of surfactant fracturing fluid in offshore reservoirs with low permeability and high temperature

“…China's demand for oil and gas resources increases annually and offshore oilfields occupy an important position in the oil and gas supply field. Continuous development in China's offshore oilfields has resulted in a greater proportion of crude oil reserves in lowpermeability reservoirs, as well as increasing development difficulties (Cao et al, 2022;Han et al, 2022;Lin et al, 2022). Block Z of the Bohai Oilfield is characterized by hightemperature and low-permeability.…”