Evaluation of Manson Lease Oil Field for Improved Oil Recovery Process

摘要

Typical oil fields in eastern Kansas area are shallow, low temperature reservoirs. Historically, waterflooding has commonly been applied as a secondary oil recovery method. In some cases, polymer flooding has been used to optimize the recovery of waterflooding. A polymer augmented waterflood was applied at the Manson lease, part of the West Savonburg oil field, starting in 2000. The lease had a very poor oil recovery and a study was initiated to evaluate reservoir performance in an attempt to understand the cause of the poor recovery. The evaluation processes included development of a geological model, core analysis and reservoir simulation. Poor sweep efficiency was found to result from water channeling thought to be caused by fracturing wells unintentionally during the polymer injection. As a result of the study, infill drilling and modification of field injection were implemented to continue the waterflood. In addition, the feasibility of CO2 application in this low temperature, low pressure reservoir was explored. Oil swelling factors and minimum miscibility pressure were measured using a vapor-liquid equilibrium view cell and a slim-tube apparatus, respectively. At the current reservoir conditions, the displacement of CO2 was found to be an immiscible process and, in general, not an economically viable process.