Evaluation of Fracture Stimulation Treatments by Integrated Reservoir Description and Fracture Treatment Analysis in the Pecos Slope Abo Tight-Gas Reservoir, Southeastern New Mexico

摘要

The primary goal of this study was to couple reservoircharacterization of the Abo Formation with hydraulic fractureanalysis and subsequently, to infer infill drilling potential.Two detailed case studies were investigated to reevaluateoriginal hydraulic fracture treatment designs, to compare andevaluate fracture parameters, and to determine if the fracturetreatments were providing sufficient reservoir stimulation.Approximately 80 wells were studied in the southern partof the Pecos Slope Abo Field. Decline curve analysis wasperformed on all wells by a modified set of Fetkovich typecurves. Analysis of this work show linear to near-linear flowin most cases with permeability values less than 0.1 md andvariations in reservoir properties as is typically observed inlow permeability reservoirs. These variations resulted indifficulty in evaluating infill drilling potential.Evaluation of fracture stimulation treatments wasaccomplished by matching recorded surface treating pressurewith a fracture propagation model. Unusually high initiationpressures were observed in the case study wells; initial stressstate, vertical fracture growth, fracture toughness, perforationrestrictions, and the development of multiple fractures in asingle, bounded layer were evaluated as possible causes forthe high initiation pressures. Results from this work showedthe multiple fractures model providing the best match for thetwo wells. Fracture length varied from approximately 1150 ftto 750 ft with a single fracture model and was reduced byapproximately 10 to 30% for each additional fracture added.The fracture data was input into a fractured well performancemodel, which was used to match the production rate andtherefore verify the process.The integration of decline curve analysis and fractureanalysis provided better descriptions of reservoir properties and more accurate designs of fracture propagation models.This combined approach also improved evaluation of infilldrilling potential by evaluating reservoir properties andstimulation.