特超稠油油藏水平井蒸汽驱油物理模拟实验

以胜利油田A区块特超稠油油藏为目标区块，自主研发了高温高压二维比例物理模型，研究了不同开发阶段水平井蒸汽驱油机理，开展了油藏压力、井底干 度、注汽强度对水平井蒸汽驱的效果影响的研究。物模实验结果显示，蒸汽驱整个过程分为三个阶段：存水回采期、汽驱受效期、蒸汽突破期。存水回采期蒸汽腔向水平方向扩展，以水平驱替方式为主 ；汽驱受效期蒸汽腔向垂向和水平方向扩展，以水平驱替方式为主，纵向泄油为辅；后期蒸汽突破，蒸汽腔继续向上方扩展，以纵向泄油为主，实现油层整体动用。5 MPa时转蒸汽驱的采出程度高于7 MPa时转蒸汽驱的采出程度；蒸汽驱的井底蒸汽干度应不低于0.4，蒸汽干度越高，水平井蒸汽驱的开发效果越好；注汽强度为1.9 t/(d·ha·m)时温度场最为发育。同时，在高压下提高干度可实现水 平井蒸汽驱的有效开发。以上的实验结果较好地指导了胜利油田A区块特超稠油油藏水平井蒸汽驱开发，取得了明显的开发效果，该研究对于类似稠油和超稠油油藏水平井蒸汽驱开发具有重要的指导意义 。

Physical Simulation Experiments of Steam Flooding for Horizontal Well in Ultra-heavy Oil Reservoir

A two-dimensional scaled high-temperature-high-pressure (HTHP) physical model of steam flooding for horizontal well was developed. Horizontal well steam flooding mechanisms of different development stages were studied based on the A block in Shengli oil field. The effects of reservoir pressure, bottomhole steam dryness and gas injection strength on horizontal well steam flooding were also carried out. Physical model experiment results show that the whole process of steam flooding is divided into three stages: water extraction stage, steam effectively displacement stage and steam breakthrough stage. Steam chamber expands to the horizontal direction in water extraction stage. Steam chamber expands to both vertical and horizontal directions in steam effectively displacement stage, horizontal displacement is the dominator and vertical drainage is supplemented. Steam chamber continues to expand upward, vertical drainage is the dominator and achieves the overall development in late steam breakthrough stage. The recovery of steam driving at 5 MPa is higher than that at 7 MPa. The bottomhole steam dryness of steam flooding should not be less than 0.4. The higher steam dryness, the better is it for the development of horizontal well steam flooding. Temperature field is the most expansive and expanding when steam injection intensity is 1.9 t/ (d·ha·m). Meanwhile, improving the dryness of steam flooding for horizontal wells could achieve the effective development under high pressure conditions. The above experimental results gave a good direction to the development of A block in Shengli oil field ultra-heavy oil reservoir for horizontal well steam flooding, and achieved obviously development effect. The research has important guiding significance to develop similar heavy oil and ultra-heavy oil reservoir by steam flood with horizontal well.