Technical Paper

Predicting Pore Pressure from Onshore Seismic Data in the Delaware Basin

Written by:  Sam Green and Jeremy Meyer of Ikon Science, and Marianne Rauch-Davies, Bob Schmicker and Steven W. Smith of Devon Energy

Based on wireline logs, core data and pressure information obtained directly during drilling, the various shale units within the Wolfcamp Formation in the Delaware Basin are known to be variably pressured with depth, and the pressure can change laterally within the same rock formation. Zones with anomalous high pressure can generally be linked to better producing wells. Unknown overpressured areas are also considered a drilling hazard and being able to predict these cells is of high interest. Pore pressure prediction using onshore seismic data is not trivial as the relationship between porosity and overpressure is complicated by a relatively complex geological history. A prestack facies-based seismic inversion process, capable of producing physical estimates of impedances and density, was used to invert the seismic dataset for facies and elastic properties. This paper discusses this methodology and the results.