The Bone Spring Formation in the Delaware Basin has more than 23,000 economic drilling locations remaining in the basin. How do you identify and high-grade those remaining drilling opportunities? While spacing and completion still matter, the best wells will be in the right facies within the desired bench. This study demonstrates a methodology for building a predictive tool to assess remaining drilling locations by employing a multivariate analysis on geological and geophysical data to delineate areas of optimal reservoir properties. This analysis focuses on the Leonardian-age clastics, carbonates and shales of the 2nd and 3rd Bone Spring Sand in a study area in southern Lea County, NM. The goal of this study was to accurately predict the first 12-month BOE and first 12-month water using a multivariate model comprised of data from wireline logs and rock properties derived from 3D seismic data. The most significant subsurface variables for predicting hydrocarbon production are Phi-H, sonic, impedance, temperature, and TOC; for water production the important variables are Phi-H, total water saturation, and clay volume. The sweet spot is not defined by one property, but by understanding the optimal mix of these properties. This approach demonstrates a predictive workflow for quantifying the local impact of facies and property variation on well performance that can be used quantitively for forecasts, lookbacks, and scenario evaluations.
The Delaware basin is known for laterally heterogeneous reservoir targets within the Wolfcamp and Bone Spring intervals. Studies by Saller and others (1989), Montgomery (1997), and others delineate cyclic sedimentation within the basin. Primary drivers behind sedimentation patterns include allocyclic features, such as eustatic sea level fluctuations and autocyclic features, such as carbonate debris flows along steep carbonate margins flanking the basin. Other authors have proposed a simultaneous influence of both autocyclic/allocyclic features to explain observed depositional patterns (Crosby et al., 2018, Walker et al., 2021). Primary lithofacies encountered in the Bone Springs stratigraphic succession include those that represent quiescent bottom water settings (spiculitic limestones, pelagic shales and siltstones, laminated mudstones) and others that represent high energy debrites (dolomitized breccias and bioclastic packstones) and siliciclastic channel, levee, and fan lobe (fine grained sandstones) (Montgomery, 1997).
