ABSTRACT
Field tests of various thermal enhanced oil recovery processes in the thin reservoirs of the Saratoga field in southeast Texas are in progress. The primary objective is to evaluate recovery and economics for each of: dry in-situ air combustion, wet in-situ air combustion, and steamflooding, to determine the optimal process.
The Saratoga field is one of many piercement type saltdomes located along the U.S. Gulf Coast. The field contains numerous Miocene sandstone stringers, averaging 20 feet in thickness and ranging in depth from 150 to 1900 feet, from which approximately 17% of the original oil-in-place has been produced by primary methods. The reservoirs contain low to medium gravity (14-22 °API) crude, with moderate to high viscosity (100-1000 cp), which make secondary recovery by a process such as waterflooding highly unfavorable. Thermal recovery processes were initiated in this field in the early 1970's; eight fireflood projects have been completed, while four wet in-situ air combustion projects and one steamflood project are ongoing.
Evaluation of these projects will provide a basis for the application of the appropriate thermal recovery process in thin, shallow reservoirs, typical of the Gulf Coast.
