Miscible CO2 Flooding Using Horizontal Multi-Fractured Wells in San Andres Formation, TX – a Feasibility Study
The San Andres is a well-known dolomitic enhanced oil recovery target with low matrix permeabilityin the area of interest. A reservoir simulation study was undertaken to investigate the feasibility of using horizontal multifractured wells in low permeability miscible floods. A reservoir model was developed for the area of interest and was history matched with the primary production data from the field. The model was then used to illustrate the CO2 miscible flood potential by quantifying the incremental recovery over the primary production scenario.
Compositional modeling was used in the study to evaluate CO2 flooding feasibility and efficiency. A holistic workflow including PVT modeling, petrophysical analysis, geomodeling, and hydraulic fracture modeling, provided integrated input into the reservoir model. Continuous CO2 flooding was explored as an operating strategy. Furthermore, water alternating gas (WAG) cases were designed and run as a more realistic and cost-effective method of implementing miscible flooding. Based on the history-matched model, sensitivity analyses were conducted on hydraulic fracture geometry, well spacing, injection patterns and operating conditions for the primary production scenario, continuous CO2 flooding and WAG scenarios.
