油砂SAGD开发后期转火驱数值模拟

Numerical simulation of fire flooding for later SAGD development of oil sand

 王泰超 2 朱国金 2 田冀 2 王凯 2 吴昊 2

中海油研究总院，北京100028 海洋石油高效开发国家重点实验室，北京100028）

CNOOC Research Institute, Beijing 100028, China State Key Laboratory of Offshore Oil Exploitation, Beijing 100028, China)

 当蒸汽辅助重力泄油（SAGD）开发进入平台期末时，日产油量降低，汽油比急剧升高，在蒸汽腔发育的楔形区域存在大量剩余油，造成热量的损失，并降低了开发的经济性。文中提出了SAGD开发后期转火驱的接替方式，基于加拿大某油砂区块储层、流体特征建立数值模拟机理模型，将蒸汽腔波及至油层顶部边缘位置时作为转火驱的开发时机，利用在SAGD井两侧添加的垂直注气井排与原水平生产井分别作为火驱开发的注、采井，对转驱开发进行油藏数值模拟研究。结果表明：转驱开发分为4个阶段，即气驱次生水期、火驱见效期、火驱稳产期以及产量递减期；转驱采出程度达到20.9%，平均空气油比仅为788 m3/m3，最终采收率达到82.1%。该研究对于油砂高效开发具有积极的推动作用。

 The daily oil production decreases and the steam oil ratio increases sharply when the steam assisted gravity drainage (SAGD) comes into its later stage with great residual oil existing in the wedge zone, resulting in the loss of heat and the reduction of the economic gain. This paper proposes a new method, turning to in-situ combustion(ISC) in the later SAGD. Firstly, a numerical model was established on the basis of reservoir and fluid parameters from a block in Canada, and the time when the steam chamber spreads to the edge of the SAGD well pair pattern is determined to be the optimum time to turn to ISC for the typical reservoir. Taking the adding vertical wells as air injection on both sides of the SAGD well and horizontal well as production well, the numerical simulation was studied. The results show that the development of in-situ combustion is divided into 4 stages: the period of gas driving, the response period of battle line, the period of stabilized production and the production decline period. Another 20.9% of the OOIP can be obtained in the ISC stage, with the air oil ratio of 788 m3/m3, and the ultimate oil recovery of the reservoir is 82.1%. The study of in-situ combustion has a positive effect on the development of oil sand.

10.6056/dkyqt201706022