Feasibility Study for Well pattern Encryption in Complex Fractured Block Reservoirs--Taking the Liu 90 South Fault Block in the Jidong Oilfield as an example

Abstract

Jidong oilfield belongs to complex fault block reservoir, and the development has now entered into high water-cut stage. when using Well pattern encryption technology to stabilize production, it is necessary to study the feasibility of Well pattern encryption to ensure a better economic benefit. In this paper, we use theoretical analysis method, consider the influence of oil price on the calculation, improve the economic limit Well pattern density calculation formula, calculate the economic limit Well pattern density under different recovery rates, make recovery rate prediction for different Well pattern density scenarios by combining with Sherkachov's formula, and use the curve intersection method to determine the Well pattern density at the break-even point, so as to determine the economic feasibility of Well pattern encryption. The example calculations show that the use of well network encryption alone does not meet the development requirements of the Liu 90 South block and has no significant economic benefits, so a combination of two-three methods is needed to further improve the recovery rate. Numerical simulation prediction results show that the two-three combination method can improve the recovery rate by 14.54%, accumulate 28.88×104t of oil increase and increase revenue by 678,245,000 yuan.

Numerical Simulation of Fracture Flow Interaction Based on Discrete Fracture Model

“…Through micro-scale flooding experiments, they discovered that large-scale fractures have a strong flow interaction effect on small-scale fractures. Wang et al [12] pointed out that the aperture difference between multi-scale fractures can result in a significant difference in permeability, which creates strong flow barriers from large-scale fractures to small-scale fractures. When water breakthrough occurs in a large-scale fracture, it becomes challenging to displace the remaining oil in the small-scale fracture [13].…”