多层油藏火驱开发模式探讨

针对多层油藏火驱开发过程面临的点火初期井筒内发生燃烧和储层纵向有效动用程度低、油藏动态跟踪和调控难度大等问题,结合室内实验数据、矿场试验数据,运用油藏工程分析方法,明确了火驱的本质特征是高温氧化反应,保证高温氧化的最关键参数是不同阶段注气强度,火驱开发是一种末次采油方式。将上述研究成果应用于多层油藏火驱开发方案设计中,结果表明:多层油藏火驱开发方案应细分开发层系,开发目的层的总厚度应小于30 m,含油层段厚度应小于20 m;开发程序可采用自下而上、逐层上返,通过层间接替实现长期稳产。研究内容对多层油藏火驱开发提高采收率和降低工程风险具有重要意义。

Study on Fire Flooding Development Mode of Multi-layer Reservoirs

In the fire flooding development process of multi-layer reservoirs, in the early stage of ignition and combustion in the wellbore, there exists some problems such as low longitudinal effective producing degree of the reservoirs, and difficulty in tracking and controlling reservoir dynamics. In response to these problems, combined with indoor experimental data and field test data, by using reservoir engineering analysis methods, it was clarified that the essential feature of fire flooding is high temperature oxidation reaction, that the most critical parameter ensuring high temperature oxidation was the gas injection intensity at different stages, and that fire flooding development mode was a last mode for oil recovery. Applying the above research results to the design of a fire flooding development plan for a multi-layer reservoir, and the results show that the fire flooding development plan for multi-layer reservoirs should subdivide the development formation, that the total thickness of the target layer should be less than 30 m and the thickness of the oil-bearing sublayer should be less than 20 m, and that stable production can be achieved by layer-by-layer return and replacement from bottom to up. The research content is of great significance for the fire flooding development of multi-layer reservoirs to maximize the recovery rate and reduce engineering risks.