Pressure Maintenance by Gas Injection in the
Opelika Field of Henderson County, Texas, by T. W. Clay, Pages 40 - 56
from:
East Texas Geological Society Symposium: The Character of Deep Lime Crude Oils of East
Texas
Copyright
1954 by The East Texas Geologic Society. All rights reserved.
Pressure Maintenance by Gas Injection in
the Opelika Field of Henderson County, Texas
T.W. Clay
Lone Star Producing Company
Dallas, Texas
ABSTRACT
The Opelika field, although similar in most respects to other relatively deep Glenrose
lime-stone reservoirs in the East Texas area, is unique in that a gas injection program
has been in operation since shortly after the fields discovery. The field is
composed of four principal reservoirs, of which only one - the Main Rodessa - is oil
productive; here the oil occurs as a deposit on the flanks of a relatively large gas cap.
Cycling and pressure maintenance operations were conducted in the gas cap prior to the
discovery of oil and, consequently, reservoir pressure was maintained at a high level even
though oil was not discovered until several years after gas operations commenced. At the
time oil was discovered the field pressure was approximately 3300 psig. Subsequent to the
discovery of oil cycling and pressure maintenance operations continued and the current
volumetrically weighted average pressure is approximately 3,000 psig.