STEWARD, DANIEL C., Chevron North American Exploration & Production, Bakersfield, CA., and L. LEE WILLIAMS, Chevron Petroleum Technology Company, La Habra, CA

Abstract: Resuscitation of an Uneconomic Steamdrive Through Reservoir Modeling: Midway-Sunset Field, Section 26C

Fourteen years after shutting in uneconomic steam injection on an area of section 26C, Midway-Sunset field, new development is possible, driven by the results of reservoir modeling. Section 26C produces primarily from the Monarch sand, a prograding confined channel (synform) complex of turbidite sandstones interbedded with diatomaceous shales.

A 2 million cell, 94 acre, 3D geologic model was constructed to capture reservoir heterogeneities. The model was framed on four stratigraphic markers within the Monarch. Permeability, porosity, and water saturation curves were derived by transforms from wells with modern log suites. The model was populated with geostatistical realizations of the derived properties. Multiple realizations of the model were generated, contrasted and compared by using different variograms to constrain trends. Geologic control was thereby provided for fluid flow prediction in a reservoir simulator.

The geologic model was scaled-up for use in the flow simulator. The goals of the simulations were to 1) determine if a history match of the project could be achieved, and if so 2) determine which, if any of the development (predictive) scenarios would be economic. The initial model included 26 producers and 13 injectors. A history match was obtained using actual steam and hot water injection volumes, along with completion changes, etc. over the period of 1980 to 1998. Predictive runs were from 1999 to 2008. To date, forward modeling has identified favorable areas to economically infill drill at the steam pattern scale.

AAPG Search and Discovery Article #90920©1999 AAPG Pacific Section Meeting, Monterey, California