A Tensor Petrophysical Model Using the Waxman-Smits and Equivalent "Dual Water" Swt Equations
Publication Date: 2008-Jul-25
The IP.com Prior Art Database
Presented herein are fundamental business objectives which can be achieved by securing intellectual property described by such invention disclosure: 1) Make quantitative analysis methods available to petrophysicists that increase the accuracy of water saturation calculations in shaly sand formations. 2) Provide a petrophysical interpretation framework that can be used to show the economic benefits of resistivity data and therefore justify its effective utilization, commercialization and marketing. 3) Integrate data from commonly used wireline logging instruments including, but not limited to nuclear magnetic resonance porosity, resistivity and acoustic image logs , bulk density (density porosity), neutron porosity, etc . 4) Reconcile petrophysical shaly sand analysis models which apparently were contradictory or lacked important pieces in their petrophysical model description of shaly sands that are now possible with the data. 5) Provide a petrophysical framework for market acceptance and entry point with client petrophysicists that demonstrates the value of ' vertical and horizontal resistivity data for use with either a "dual water" or Waxman-Smits (WS) based petrophysical interpretation model. The petrophysical model presented and referred to as the "tensor model" volumetrically describes formations referred to by petrophysicists as "shaly sands" that are composed of detrital grains and any volume or combination of laminar, dispersed, and/or structural shales that form a clastic sedimentary formation. The tensor model demonstrates that traditional, empirical bulk volume "effective porosity - effective water saturation" models are incorrect and inappropriate for quantitative analysis of shal y sand formations.