Development Adjustment Scheme of a Low-Permeability Reservoir in the SN Oilfield

Abstract

Due to the complexity of low-permeability reservoirs, there is no set of established plans to adjust the development of specific low-permeability reservoirs, and the final development adjustment plan should be determined through comprehensive consideration of many aspects. At present, the development of low-permeability reservoirs in the SN oilfield faces problems. It is urgent to formulate corresponding development adjustment plans to improve the current development situation. In view of the problems of the current development surface of low-permeability reservoirs in the SN oilfield, this paper used the previous research results of a low-permeability reservoir development adjustment for reference, evaluated the reservoir development effect, analyzed the remaining oil distribution via numerical reservoir simulation, and finally designed and optimized a development adjustment plan. The research results show that the injection–production ratio and pressure of low-permeability reservoirs in the SN oilfield were generally maintained, the oil production decreased, the water cut increased, and the remaining recoverable reserves were considerable; the historical matching quality of a reservoir numerical simulation was good. There was more remaining oil in the northeast of the J007 well block and the north of the J008 well block, and the potential of the L2 and L3 layers was great. The remaining oil was mainly concentrated in the areas with high positions, poor physical properties, and imperfect well patterns; the predicted cumulative oil production of Scheme IV in 15 years and recovery were the highest, with the best development effect and the highest economic benefit. This was determined as the development adjustment plan for low-permeability reservoirs in the SN oilfield. The research results of this paper aim to improve oil production, the ultimate recovery factor, and economic benefits of low-permeability reservoirs in the SN oilfield, and to provide a reference for the development of similar oilfields.

Experimental Study on Factors Affecting Oil Recovery in Sandstone-Buried Hill Superimposed Reservoirs

“…Additionally, a weathered crust layer has developed between the sandstone and the buried hills, where the fracture structure of the weathered crust is weaker than that of the buried hills. Due to their unique geological characteristics and relatively high oil reserves, these types of reservoirs have increasingly attracted attention. − The connectivity between reservoirs, the heterogeneity, and the strategy of development are the critical factors affecting the efficacy of reservoir exploitation. − Reservoir connectivity can be determined by comparing the differences in well logging curves across various strata between adjacent oil and water wells . It can also be assessed by introducing tracers and detecting their production within the same well group unit to understand the connectivity between injection and production wells. − Additionally, it can be conducted using data inversion methods. − Studies on the impact of interlayer heterogeneity and development methods on development effectiveness can utilize numerical simulations, physical simulations, and mechanistic research, among other strategies. − …”

“… 7 − 9 The connectivity between reservoirs, the heterogeneity, and the strategy of development are the critical factors affecting the efficacy of reservoir exploitation. 10 − 12 Reservoir connectivity can be determined by comparing the differences in well logging curves across various strata between adjacent oil and water wells. 13 It can also be assessed by introducing tracers and detecting their production within the same well group unit to understand the connectivity between injection and production wells.…”