Recovery of Bitumen From Tar Sand Deposits With the Radio Frequency Process

Summary The IIT Research Institute (IITRI) radio frequency (RF) process for tar sands consists of two steps: (1) the deposit is volumetrically heated with RF energy to lower the viscosity of the bitumen, and (2) the bitumen is produced by one of several petroleum recovery methods. The RF heating step is accomplished by inserting tubular electrodes into boreholes and by energizing them with an RF power source. The electrode pattern is designed so that the deposit between the electrodes is uniformly heated with a minimum energy loss. The operating frequency is selected on the basis of the electromagnetic characteristics of the deposit. The recovery techniques that we investigated include replacing the heated bitumen with sodium silicate solutions, by gravity drainage, and by autogenously developed steam and hydrocarbon gases. Two small-scale field experiments were conducted in the Asphalt Ridge tar sand deposit near Vernal, UT. About 25 m3 [33 cu yd] of the deposit was heated with RF energy, and about 35% of the total in-place bitumen was recovered during the 3-week test period.