Jennifer L. White¹

(1) Colorado School of Mines, Morrison, CO

ABSTRACT: 3-D Geologic Model of Permeability in a Deep-Water Sandstone, East Brae Field, North Sea

The purpose of this thesis is to predict cementation and permeability distribution in 3-D based on the relationship between quartz overgrowths and permeability. Empirical relationships exist to link quartz overgrowth cement volumes, capillary pressure data, and nuclear magnetic resonance (NMR) responses to permeability. In order to test the relationship, NMR analyses will be performed to quantify pore-body size distributions. Capillary pressure tests will quantify pore-throat size distributions on the same samples used in a preceding study that quantified quartz cementation for the East Brae field. A neural network will be used to predict permeabilities in the uncored wells. A 3-D geologic model will then be built using Earth Vision software (Dynamic Graphics Inc.). The model will include log porosity, core analysis permeability, quartz cement volumes, stylolite abundances, paleo oil-water contacts and mapped horizons and fault surfaces from 3-D seismic data. Assuming there is a relationship between permeability and quartz overgrowth cement volumes, the field wide distribution of quartz cement should be predictable in 3-D, which will lead to a field-wide permeability model.

This thesis includes research directly related to formation evaluation and characterization of a structurally complex reservoir. If the relationship between quartz cement overgrowths and permeability exists, there would be justification for running NMR logging tools in similar sandstone reservoirs. The 3-D geologic model would provide possibilities for further development of this field, perhaps using infill or horizontal wells. Also this model could be taken into a reservoir simulation package for further production modeling.

AAPG Search and Discovery Article #90906©2001 AAPG Annual Convention, Denver, Colorado