Property Estimation onto Horizontal Wellbores with Well-Spacing Dependent Error Validation

William M Bashore

Senior Research Fellow

Drillinginfo, Inc

Abstract

A methodology is presented that achieves the direct estimation of property values onto horizontal wellbores.   This process is illustrated using well logs from vertical wells where the interpolation is performed within a geologic framework of structural surfaces and corresponding stratigraphic layering in the intervening zones.  No geo-cellular gridding is required.  Further conditioning of these property estimates using soft data derived from pre-stack seismic inversion is highlighted.  It is always desirable to have a model of associated errors when performing spatial estimation, and it is shown that the magnitude of these errors is related to the magnitude of the distances to the constraining well control.  This error model is constructed using a boot-strap procedure by varying spacings to the nearest vertical well.   Finally, the quantitative impact of the seismic-derived soft information on production forecasting (versus not using it) is computed.

Keywords: 3D property modeling, collated cokriging, superblock search, boot-strapping, decline curve analysis

Bio

Bill is a Senior Research Fellow at Drillinginfo addressing technical challenges such as probabilistic decline curve analysis, production allocation, and multivariate statistical / machine learning analyses.   Prior to his current position, Bill was the SVP of Global Analytics, where he built up the analytics business unit and initiated the play assessment product offerings.  He continues to provide a technical role on the corporate Executive Leadership Team.

Bill came to Drillinginfo with the Transform acquisition.  At Transform, he was the principal author of data analysis and multivariate statistics, waveform classification, many of the seismic processing options, and the original synthetics tools.  Prior to Transform, Bill was VP of Exploration Services at Veritas after the acquisition of Reservoir Characterization Research and Consulting (RC Squared).  Bill was the co-founder and CEO of RC Squared, where he was the principal architect of 3D stochastic property modeling and seismic inversion and integration.  Bill began his career after graduate school at Chevron, spending twelve years in a variety of positions in E&P operations and at the upstream research facility.  Bill holds BS degrees in Geophysics and Geology and an MS in Geophysics from the University of Utah.  Additionally, he has an MBA from California State University – Fullerton.