Publications

The Duri Field, located in Riau province in central Sumatra, is currently the site of the largest steamflood project in the world. Roughly half of the field is currently being flooded in seven project areas. The older steamflood areas are in their mature stages, with the majority of patterns experiencing steam breakthrough. A reservoir simulation study was performed to optimize the operating strategies for these mature steamflood areas. A history-match of a mature steamflood area was developed using a threedimensional, compositional, thermal reservoir simulator. A simple pattem-element, layer-cake (areally homogeneous and vertically heterogeneous) model was used, and an excellent match of six years of historical steamflood performance was obtained by making minor changes to the input parameters. The history-matched model was used to evaluate the effects on performance of terminating steam injection into the reservoir layers with steam breakthrough, and of using different rate reduction schemes. It was found that a combination of steam rate reductions and termination of injection into the breakthrough layers will yield the maximum value for the mature areas. The optimum timing for the initiation of rate reductions was found to be the time at which about one pore volume of steam has been injected. The results of a rate reduction field trial in a portion of a mature area agree well with the simulation results.