Experimental Study on Physical Simulation of Different Development Methods for Horizontal Wells in Heterogeneous Conglomerate Reservoirs.

Abstract

Heterogeneous conglomerate reservoirs are highly complex in petroleum engineering, with varying rock properties and distributions that significantly affect oil and gas extraction. This study investigates the conglomerate oil reservoir of the Lower Wuerhe Formation in Block 8 of the Karamay Oilfield. Physical simulation experiments were conducted to evaluate various development methods, including planar depletion, vertical depletion, water injection, and gas injection. The fluid migration patterns and recovery efficiencies in horizontal wells within these heterogeneous conglomerate reservoirs were analyzed. The results show that the gas injection rate plays a crucial role in stabilizing the gravity-driven front in fractured reservoirs. Lower injection rates slow the front's migration and delay gas breakthrough, thereby reducing the oil-carrying capacity. High-angle fractures were found to enhance the effectiveness of gas injection. Continuous gas injection with intermittent pauses helps stabilize the gas-liquid interface, promotes pressure diffusion, and expands the affected volume. Gas flooding offers a wider sweep area and higher mobilization compared to water flooding and depletion, improving the recovery efficiency by 36.2% and 50%, respectively. Furthermore, gravity drive significantly enhances sweep efficiency and recovery rates, achieving improvements of 60.9% and 32.8% compared to depletion and water flooding. These findings provide valuable experimental data that can be used to optimize recovery efficiency in heterogeneous conglomerate reservoirs.