Abstract
We describe a case study to extract meaningful geological information from a modern high-fold seismic dataset in the north-east Delaware basin. The target of the study is the heterogeneous geology of the Bone Spring and Wolfcamp Formations. A database of well data was used to understand the variation in elastic properties in terms of geological changes that include: mineralogy, organic content and the likely onset of over-pressure. The geology was represented by a set of 5 elastic facies: carbonates, calcareous mudstones, siliciclastics, organic-rich and clay-rich shales. The well data were also used to calibrate seismic amplitudes prior to performing a Bayesian pre-stack inversion to solve for estimates of facies and impedances. The results are shown to provide insights into the regional stratigraphic deposition and evolution of the formations, including mapping of discontinuous carbonate and high TOC intervals. The property volumes are the starting point for future predictive geological, formation-pressure and stress models for informing optimal resource exploitation within the study area.
Introduction
The geology of the Delaware Basin is heterogeneous in both lateral and vertical directions. Understanding the geological complexity is critical for optimizing exploitation strategies in both the Bone Spring and Wolfcamp Formations. Seismic data provide valuable spatial information between and away from well locations, however, the process of extracting the geological information from the seismic amplitudes is non-trivial. In this paper, we describe a state-of-the-art pre-stack seismic inversion study in the north-east Delaware Basin, with the objective of obtaining reliable estimates of the geology across the 380 square mile study area, Figure 1.
