Simulation of Gelled Polymer Treatments in the Arbuckle Formation, Kansas

Abstract

Abstract Gel polymer treatments have been carried out on a large number of producing wells in the Arbuckle Formation of Central Kansas. These treatments have been aimed both at reducing water coning from an underlying aquifer and increasing oil production. This paper describes computer simulation of two of these gel-treated wells. One is a well for which the treatment was successful and the second is a well which responded far less favorably. For each well, performance before, during and after a treatment was modeled using single porosity and dual permeability models, i.e. reservoir simulators that are based on matrix flow only or on fracture-matrix flow. For the fracture-based model, it was assumed that the producing well was connected to an underlying aquifer through a high vertical permeability fracture system. Well performance during the polymer injection period of the treatments and the post-treatment behavior were such that there were major differences in history matching between the single porosity model (no fractures) and the fracture model. For the well that was treated successfully, behavior during polymer injection as well as post-treatment performance could be matched only with the dual permeability model. No reasonable set of parameters was identified for the single porosity (matrix flow) model that allowed a suitable history match of these same data. For the well that was treated unsuccessfully, the converse was true. An acceptable history match was obtained only with the single porosity model or with the fracture model with a very sparse fracture density. The results indicate that the presence of natural fractures connected to an aquifer is an important feature of the Arbuckle wells that respond favorably to polymer gel treatments.