This paper, entitled “Using Seismic Inversion to Predict Geomechanical Well Behavior: A Case Study From the Permian Basin” was presented at the GeoConvention in Calgary in 2017.
The in-situ stress and elastic rock properties are first order controls on fracture stimulation behavior and consequently production. These properties can be well understood post drill. However, knowledge prior to drilling provides the opportunity to optimize well planning, including location and landing depth. Seismic inversion can be used to estimate the rock elastic properties, which can be used to estimate the in-situ stress state based on well calibration. A 1D well based model was built for a well in the Permian Basin, which predicted variations in induced fractures observed in image logs acquired in the well. This model was applied to a 3D elastic property volume derived from a joint facies and impedance inversion using rock physics models. The inversion result was then used to predict the mechanical behavior of a well 20 miles away from the original location. The prediction match the observed variation in induced fractures observed in image logs at the offset well location, validating the use of inversion coupled with 1D geomechanics to predict well behavior pre-drill.
Introduction
Production in unconventional reservoirs is controlled by the in-situ rock properties and the behaviour of the hydraulic fracture stimulation. The induced fracture behaviour is controlled by the in-situ stress state and the elastic rock properties. By understanding the variation in elastic properties and in-situ stresses pre-drill can facilitate optimal well planning including well location and landing zone, as well as potential completion strategies. This paper demonstrates a workflow and example demonstrating how the integration of seismic inversion with 1D geomechanical models can be used to predict well behaviour at offset locations.
