低渗透稠油微波原位加热开采数值模拟研究

针对低渗透稠油油藏开采过程中储层注入能力低、热损失高、水资源消耗大等问题,采用数值模拟对微波加热稠油开采技术进行研究,通过建立电磁-传热-流动多物理场模型,明确了微波加热稠油的降黏作用和传热机理。研究结果表明:稠油油藏微波加热后可分为电磁穿透区、多孔介质传导区和未加热区3个区域;最佳辐射频率为2 450 MHz,增加功率可快速提高地层温度;为了避免井筒附近出现过热现象,应采用降功率的阶梯式加热模式;水力压裂裂缝可有效改善低渗透油藏的渗流通道,可与微波加热协同开采稠油油藏。该研究可为低渗透及高黏度稠油的开发提供借鉴。

Numerical Simulation Research on Microwave In-situ Heating Technology for Developing Heavy Oil in Low-permeability Reservoirs

In the exploitation of low-permeability heavy oil reservoirs, aiming at the problems such as low reservoir injection capacity, high heat loss, and large water consumption, etc., numerical simulation technique was used to study the microwave heating technology for developing heavy oil. Through establishing multiple physical field models such as electromagnetic field model, heat transfer field model, and flow field model, the heavy oil viscosity reduction effect and heat transfer mechanism of microwave radiation was clarified. The research results show that after microwave heating, heavy oil reservoirs can be divided into three zones, namely electromagnetic penetration zone, conduction zone in porous media and unheated zone; the best radiation frequency is 2 450 MHz, and increasing power can quickly increase the formation temperature; in order to avoid overheating around the wellbore, a stepped heating mode with gradual power reduction should be adopted; hydraulic fractures can effectively improve the seepage channels of low-permeability reservoirs, and it can be used in conjunction with microwave heating to develop heavy oil reservoirs. This research can provide a reference for developing low-permeability and high-viscosity heavy oil.