Effect of interwell mudstone interlayers’ physical parameters on steam-assisted gravity drainage

Abstract：The presence of mudstone interlayers has a great impact on the development of steam-assisted gravity drainage (SAGD) in heavy oil reservoirs.In order to reveal the influence of mudstone interlayers' parameters on the effect of SAGD performance, a numerical simulation model was developed to study mudstone interlayers in SAGD wells by reservoir numerical simulation software CMG based on a block in Mackay river heavy oil reservoir, Canada.Orthogonal experiments were conducted according to the different length, thickness, spacing, vertical distance and permeability of mudstone interlayer.Through visual analysis and variance analysis, the simulation results were analyzed and validated, and the influence degree of the physical parameters of mudstone interlayer on recovery effect was discussed when mudstone interlayer was located in the middle of wells (BIP-A) and the middle inclined (BIP-B) , respectively.The results showed that under BIP-A and BIP-B modes, the effects of physical parameters of mudstone interlayer on recovery efficiency were as follows: length>permeability>thickness>spacing>vertical distance, and length>thickness>permeability>vertical distance>spacing, respectively.In addition, mudstone interlayer should be avoided in the middle of injection-production wells during SAGD production process.It was important to optimize well layout according to the influence degree of each parameter and to take necessary measures such as fracturing to achieve SAGD efficient production.

Keyword：heavy oil reservoir;steam-assisted gravity drainage;numerical simulation;mudstone interlayer;orthogonal experiment;