稠油油藏水平井热采应用研究

A SIMULATION STUDY ON THE APPLICATION OF HORIZONTAL WELLS IN HEAVY OIL RESERVOIRS

本文利用油藏数值模拟技术研究了不同类型稠油油藏水平井注蒸汽开采的可行性、相应的开采方式及油层厚度与原油粘度对水平井注蒸汽开采效果的影响。水平井开采方式包括水平井蒸汽吞吐、水平井蒸汽驱与蒸汽辅助重力泄油。研究结果表明，原油粘度与油层厚度是影响稠油油藏水平井开采效果的主要油藏参数，对于油层厚度大于５ｍ、原油粘度小于２０×１０４ｍＰａ·ｓ的特稠油油藏，水平井蒸汽吞吐与蒸汽驱可以获得较好的开发效果；而油藏厚度大于２０ｍ、原油粘度大于２０×１０４ｍＰａ·ｓ的超稠油油藏（或天然沥青），则必须采用蒸汽辅助重力泄油开采技术。

Horizontal well technology in combination with steam injection is being widely used for the development of heavy oil reservoirs. The recovery processes with horizontal wells mainly include steam stimulation, steam drive and Steam-Assisted Gravity Drainage (SAGD). The feasibility study on thermal recovery with horizontal wells for different types of heavy oil reservoir using numerical simulator is made. It is shown that different recovery processes should be adopted according to reservoir characteristics. Reservoir thickness and oil viscosity are the key parameters affecting the performance of thermal recovery with horizontal wells. For extra-heavy oil reservoirs with oil viscosity less than 100,000 mPa. s and formation thickness greater than 5 meters, steam stimulation and steam flooding processes with horizontal wells can obtain a good recovery performance. But for the super-heavy oil reservoirs with oil viscosity greater than 100, 000mPa. s, the SAGD process must be adopted. However, for a successful SAGD project, the formation thickness must be greater than 20 meters due to drilling problem and gravity effect.