Determining the Contributing Reservoir Volume of Horizontal Wells in the Wolfcamp in the Midland Basin
Mickey Friedrich¹ and Mike Milliken²
²AAPG, Pioneer Natural Resources
The purpose of this presentation is to use multiple methods of analysis to estimate the effectively stimulated volume of reservoir for horizontal wells in the Wolfcamp formation in the Midland Basin of West Texas. Estimating this volume is critical in determining optimum spacing and stacking of horizontal wellbores in unconventional reservoirs.
Stimulated Reservoir Volume (SRV), as determined from microseismic, locates seismic events due to rock failure but does not necessarily represent the reservoir volume contributing to production. The reduced volume contributing to production is defined as the Contributing Reservoir Volume (CRV). This paper presents a workflow of using multiple methods - interpreted microseismic, proppant material balance, and calibrated hydraulic fracture modeling - to collectively estimate the CRV in hydraulically fractured horizontal Wolfcamp wells.
Microseismic data is interpreted both by applying a discount factor based on industry studies and by analyzing locations and concentrations of events. Next, a method of proppant material balance is used to estimate the maximum propped dimensions based on the mass of sand that is placed in each cluster of perforations. Finally, a calibrated geomechanical hydraulic fracturing model is used to model the CRV of 25 wells drilled in the Wolfcamp wells throughout the study area.
The approach is demonstrated in the Midland Basin but can be applied in any unconventional reservoir. This methodology can be used for horizontal well spacing and stacking discussions and can provide technical support when designing pilot tests to determine optimal well spacing.
AAPG Search and Discovery Article #90164©2013 AAPG Southwest Section Meeting, Fredericksburg, Texas, April 6-10, 2013