Surveillance of Steam Assisted Gravity Drainage in In-Depth Extra-Heavy Oil Reservoir

Abstract

In 2008, We presented a paper "Application of Temperature Observation Wells during SAGD Operations in a Medium Deep Burial Extra Heavy Oil Reservoir" at the Petroleum Society's 59th Annual Technical Meeting. After 10 years SAGD technology is already widely adopted in exploiting extra heavy oil in China. This paper summarizes the experience on surveillance of SAGD project in the past years. During SAGD process the adjustment of steam chamber in both vertical and horizontal direction and operation parameters should base on synthetic surveillance data. In the past, the surveillance approach is very limited and the results cannot be used as effective indicators. The successful application of reservoir based synthetic surveillance approach produced reliable data for management of SAGD project in Du 84 block Liaohe Oil field. The applied technical series include pressure/temperature observation wells, pressure/temperature monitoring in horizontal wells, time-lapse seismic monitoring, micro-gravity test etc. With the help of these monitoring data, the accurate and long term effective database was established. The application of synthetic monitoring system provides the opportunity of accurate control of steam injection and production. The temperature and pressure observation well can monitor the vertical development of steam chamber, especially in gas-SAGD process. The observation well can detect the vertical sweep area of injected gas which can give effective approach in SAGD management. The temperature and pressure monitoring and tracer test can provide information for connection between injector and producer. 4-Dimensional seismic and 4-Dimensional micro gravity is a new approach of combination for petro-physical technology and petroleum development. 4D seismic not only can remap the geological body but also it can depict the steam chamber distribution in the reservoir. 4D micro gravity monitoring can accurately detect the front of steam chamber. With these data, the distribution of steam zone and residual oil is clear for future reservoir management. This paper gives a verified approach of surveillance and the corresponding operation adjustment. And this can be guidance for design and application of new SAGD surveillance system.