ZHAO, KAI, and * IAN LERCHE, University of South Carolina, Department of Geological Sciences, Columbia, SC

ABSTRACT: Inversion of Dynamical Indicators (Multiple Well Setting) in a 2-D Fluid Flow/Compaction Model: Synthetic Tests and a Case History

A dynamical tomography method, which inverts dynamical indicators to evaluate the parameters controlling geological events as well as those in intrinsic equations of state, was introduced into a 2-D fluid flow/compaction model with the assumption of invariance to spatial location of parameters in equations of state, but allowing geologic process parameters to vary with well location. Synthetic tests are given to illustrate the operation of the system. Using the observed downhole quantities formation thicknesses, variation of porosity, permeability and fluid pressure with depth from multiple wells of the Navarin Basin, Bering Sea, Alaska, the numerical algorithm was tested and found to be effective in a non-linear inverse sense to determine and/or constrain the parameters entering quan itative models of dynamical sedimentary evolution.

The predictions of present day formation thicknesses, porosity, permeability and fluid pressure with depth are close to the measured data at all well locations. In this way the geohistory and structural development of the basin can be defined better, which helps in the reconstruction of thermal history, and so of hydrocarbon generation, migration and accumulation histories.

AAPG Search and Discovery Article #90987©1993 AAPG Annual Convention, New Orleans, Louisiana, April 25-28, 1993.