Practice and understanding of pressure drive development technology for low-permeability reservoirs in Shengli Oilfield

Abstract

The low-permeability reservoirs in Shengli Oilfield are rich in resources， with produced geological reserves of 9.4×108 t， recovery of 13.3%， and unproduced reserves of 2.1×108 t. Enhanced oil recovery and benefit development face many challenges， such as injection failure， displacement failure， and poor swept volume. In order to improve the development effect of low-permeability reservoirs， Shengli Oilfield has innovated the pressure drive technology to tackle these problems. A series of technologies have been developed， including the evaluation criteria for the adaptability of pressure drive technology， the laboratory experimental technology system， and the optimization design method for reservoir engineering schemes by comprehensively applying theories and methods of geology， fluid flow mechanics in porous medium， and reservoir engineering as well as combining physical and numerical simulation. These technologies are supported by zonal pressure drive， combined network volume fracturing， and profile control and drive processes. Field tests showed that pressure drive can quickly replenish formation energy and dramatically improve oil well productivity and recovery. Since March 2020， 450 well groups have been implemented in low-permeability reservoirs， with a cumulative injection of 1 384×104 m3 and a cumulative oil increase of 55.7×104 t. Pressure drive development technology is gradually becoming a new leading development technology for low-permeability reservoirs.

Keywords

• low-permeability reservoir
• water injection improvement
• pressure drive development technology
• energy replenishment
• high-pressure water injection
• hydraulic fracture