Pilot Testing of a Radio Frequency Heating System for Enhanced Oil Recovery From Diatomaceous Earth

Abstract

Abstract This paper describes a high power, full scale field demonstration of a radio frequency (RF) downhole applicator system which has the objective of ultimately expanding the scope of Texaco's thermal operations beyond conventional operations. Field testing of KAI Technologies radio frequency heating system was performed in the Texaco Denver Producing Division's Midway area, N. Midway field, CA, in a shallow diatomite reservoir during the summer of 1992. Two tests (a low power test and a high power test), gave every indication that RF technology is a viable way of heating a formation. Summary An in-situ borehole radio frequency (RF) antenna heating system at a depth of 620 feet was implemented at a Texaco oil recovery site in Bakersfield, California. A pilot test was conducted to demonstrate the ability of the RF system to both focus thermal energy at high efficiency into a particular subsurface deposit of diatomaceous earth and thereby raise near borehole temperatures to levels that would increase the rate of oil recovery. Prior to conducting this test a laboratory treatability study was conducted which determined both the design of the RF heating system and the temperature that is required for the diatomaceous earth to release its oil. The results of the treatability study and pilot test are discussed along with an overview of the theory and the utility of RF heating for enhanced oil recovery. Plans for further testing and RF system costs will be presented. Background The development of technology for producing oil from heavy oil and tar sand deposits by thermal means has been on-going in the petroleum industry for many years. Since the early 1970's one of the technologies pursued has been radio frequency heating where heating is produced by the absorption of electromagnetic energy by the polar molecules in the formation. In addition to conventional steam flooding other thermal enhanced oil recovery (EOR) techniques have also been evaluated i.e. conduction heating, hot gas injection using electric or gas fired calrods, and electrothermal techniques. A good summary of the current state of electromagnetic techniques for thermal EOR is given in the paper by F.S. Chute and F.E. Vermuelen. P. 105^