The Nash Draw Pool (NDP) in southeast New Mexico is a cost-shared field demonstration project in the U.S. Department of Energy's Class III Program. A major goal of the Class III Program is to stimulate the use of advanced technologies to increase ultimate recovery from slope-basin clastic reservoirs. Advanced characterization techniques are being used at the NDP to develop reservoir management strategies for optimizing oil recovery from this reservoir.
Production at the Nash Draw Pool (NDP) is from the Brushy Canyon formation, a low-permeability turbidite reservoir in the Delaware Mountain Group. A major challenge in this marginal quality reservoir is to distinguish oil-productive pay intervals from water-saturated non-pay intervals. An advanced log analysis and interpretation program was developed that can be used to identify net pay in a complex reservoir. By properly identifying productive pay intervals, oil recovery from the Brushy Canyon reservoir is calculated to be 16.7%, rather than the 10% as initially estimated.
Interpretation and integration of recently acquired geological, geophysical, and engineering data revealed that the Brushy Canyon reservoir is much more complex than initially indicated by conventional geological analysis. A new reservoir description is being used to identify "sweet spots" for an aggressive development drilling program, and results of 3-D seismic data and other interpretations are being used for targeted drilling in high-grade areas of the Pool. Reservoir characterization has identified 17 additional vertical locations at the NDP. Due to cultural and potash mine constrictions, some of these wells will be accessible only with deviated/horizontal wells.
This paper presents recent results of an integrated reservoir characterization effort that is being used at the NDP to optimize reservoir management strategies. Because the reservoir is understood in detail, completion procedures and fracture stimulation treatments can be designed more efficiently. Marginal or non-economic zones are not completed which saves perforating, acidizing and fracturing a zone that will not produce enough reserves to return the cost of completion which results in more emphasis being applied to the zones that represent the most potential.