Electromagnetic Stimulation of Lloydminster Heavy Oil Reservoirs: Field Test Results (1995)

Abstract The paper will present the field test results of two electromagnetic (EM) stimulation projects conducted in the Lloydminster heavy oil area. The two wells (AI-11-4B-25 W3M Lashburn and AB-6-51-27 W3M Northminster) produce heavy crude from the Sparky formation. Detailed production, electrical and operational data was gathered and analysed to quantify the effect EM stimulation had On each well's producing characteristics. The main areas covered by the paper include production characteristics (primary and enhanced), in-flow performance relationships (primary and enhanced), operational considerations and some of the related economics. The data discussed to this point has been restricted to reservoir heating. An additional review of a tubing heating electrical configuration test (ran on the Lashburn well) has been -included. The viscous nature of the crude oil being produced caused severe rod fall problems. Tubing heating was initiated to reduce the wellbore fluid viscosity and eliminate the rod fall problem. The paper will conclude with a general overview of the EM stimulation process as applied to the Canada Northwest Energy Limited-locations and the potential for future applications. Introduction The possibility of using electrical energy to heat oil-bearing formations has been attempted on several occasions over the past four decades, In general terms, the electrical (and electromagnetic) energy is converted to heat. Three basic types of heating are possible (dielectric, inductive and resistive). This discussion will deal with the resistive heating process. Canada Northwest Energy Limited et al. (CNW) contracted with EOR International (EOR) to field test the process in the Lloydminster area heavy oil formations. A majority of the heavy oil sands around Lloydminster are well suited to the application of electromagnetic (EM) heating. Many of the formations are relatively thin and not well suited for other secondary, tertiary and thermal recovery methods. The EM heating process as applied in the CNW pilot areas creates a heated zone in the near wellbore region, The application of heat significantly reduces the viscosity of the oil, improves the oil/water flow characteristics, and overcomes some forms of formation damage. The end result is an improved pressure profile in the near wellbore region and a corresponding increase in the oil production rate. Field Evaluations Introduction The electromagnetic (EM) heating process was tested in three Canada Northwest Energy Limited project areas (Wildmere, Northminster and Lashburn). The pilot projects (as listed above) were not economically successful (due to premature equipment failure). They did however provide very encouraging technical information from a reservoir engineering point of view. The electrical delivery system used in these projects consisted of externally insulated casing. The casing was electrically isolated from the wellhead and tubulars. The casing insulation was scraped off across from the reservoir to allow EM energy to enter the formation. The energy flow was into the reservoir and up through the overburden to surface ground wells to complete the circuit.