多层普通稠油藏火驱中的能量分析

Energy Analysis of Fire Flooding for Multi-Layer Conventional Heavy Oil Reservoirs

摘要: 通过物理模拟实验和数值模拟计算，系统研究了互层状普通稠油藏蒸汽吞吐后期转火驱开发的能量状态和相关油藏工程问题。研究表明：转火驱后，渗透率高的主力层吸气比例高，易形成火线，造成局部温度升高、压力升高，燃烧状态符合高温氧化生产特征；渗透率较低的非主力层吸气量较小，燃烧状态符合低温氧化特征。低温氧化也产生较多热量，能使油层温度升高，稠油粘度降低。油层压力和油层温度是影响火驱产量的最重要的两个因素，本次研究获得了普通稠油藏火驱中压力对产量的贡献值，研究结果与现场火驱动态相符，为火驱扩大实施提供了理论指导。

Abstract: This paper systematically addresses the energy state and related reservoir engineering problems of converting to fire flooding in the late stage of CSS for interbedded conventional heavy reservoirs through physical modeling and numerical simulation. The research shows that after converting to fire flooding, the principal layer with high permeability takes in more air and is likely to form a combustion front, causing the increasing of local temperature and pressure, complying with the production characteristics of high temperature oxidation; while the non-principal layer with low permeability takes in less air and its combustion state complies with the characteristics of low temperature oxidation. Low temperature oxidation also produces much heat, thereby raised reservoir temperature and reduced oil viscosity. Reservoir pressure and temperature are two most important factors affecting the oil production of fire flooding. This study understands the contribution of pressure to production in fire flooding for conventional heavy oil reservoirs. The results are consistent with the in-situ combustion performance, and provide theoretical guidance for the expansion of fire flooding.