A total of 57 commercially viable gas-displacement projects in Texas are classified into seven depositional environments. We collected reservoir and petrophysical data and depth and oil gravity for each reservoir, which gave us a generalized case model for each depositional environment. We also collected and analyzed information about the design of these projects, concentrating on pattern, spacing, and production processes previously applied.

Cost calculations that are presented are in accordance with a previous cost study by Beike and Holtz.1  Finances were analyzed for the case model of each depositional system according to net present value and internal rate of return. We also used an economic sensitivity analysis to investigate the effect of oil price, well spacing, and incremental recovery.

The potential for reserve additions from CO2 flooding in Texas is substantial. An additional 1,730 reservoirs are candidates for gas-displacement recovery. This set of reservoirs contains 70 BSTB of original oil in place, 23 BSTB of mobile oil, and 37 BSTB of residual oil. Factoring in a conservative reserve growth recovery of an additional 10 percent of original oil in place, we estimate that future GDR projects could produce 7 BSTB in Texas. Most of this reserve growth will continue to come from restricted to open-platform carbonate reservoirs in West Texas.

You can access this article if you purchase or spend a download.