Simulation study of development strategies for a gravity-assisted, cyclic-steam project

New developments of a simulation study of a mature cyclic stream injection project in California are presented in this paper. Decline of production rates was observed in the field, and it forced the operator to look into strategies of infill drilling and recompletion of existing wells. Horizontal infill wells, recompleted vertical wells, and mixed strategies were considered as the alternatives for further development of the reservoir. In 1996 Chona et al. presented the results of a simulation study for this field, where productive sands of a 60 degrees dip were modeled as vertical layers. In the presented simulation study, a new model is used. The model includes the actual reservoir dip. Since the reservoir consists of 8 different sand layers with a limited communication, including the actual dip in the model leads to significant changes of the model performance. Using the developed model, a number of development strategies were simulated. Results of the study are compared to results of Chona et al. to illustrate changes caused by including reservoir dip in the model. Details and description of simulated alternative strategies are presented. For horizontal infill wells, results indicate strong dependence of the cumulative production on the well spacing, injection rate, and well location with reference to the oil column. Strategies are compared on the basis of cumulative oil production. All the presented strategies result in an increase of cumulative production.