Abstract
The 3-D streamline simulation approach is complementary to finite difference simulation techniques. One of the main advantages of streamline simulation is its ability to display paths of fluid flow and to calculate rate allocation factors. These capabilities have been utilized to improve operating and development plans for a water-flood project.
An incremental development plan for a Saudi Arabian carbonate reservoir that included the drilling of several horizontal injection/production wells is discussed in this paper. A few wells had already been drilled at the start of this study. The main objectives of this study were to improve well placement and injection rates using streamline simulation.
During the course of the study a few limitations of the streamline simulator have been encountered, highlighted, and discussed. The results showed that streamline simulation is still in the development stage in highly compressible systems. It is tricky to follow field/group rate targets and limits along with the individual well rate targets in prediction mode.
Prior to the optimization phase of the study, the streamline simulator was successfully applied to reproduce the historical performance of the reservoir during primary depletion in the absence of any water injection.
Valuable information was obtained from streamline simulation; a) distribution of injected water to associated producers, b) water loss to the aquifer, c) percentage of oil produced due to each supporting injector, and d) amount of water cut attributable to each supporting injector.
Quality indicators were generated to gauge injection efficiency for each well using plots of injection rate vs. offset oil/liquid production rate. Relatively poor performance injectors were identified from this plot. Injection allocation rates and injector drilling locations were then modified through a series of simulations to improve their efficiency. This led to an improved injection pattern in the studied reservoir.
