Study on RF Heating Mode of Heavy Oil Reservoir Rocks Based on Two Antenna Elements Distributed Along the Horizontal Well

Abstract

ABSTRACT: To achieve precise heating of reservoir layers with varying thicknesses using the RF (radio frequency) heating method while minimizing thermal energy loss, a novel solution is proposed leveraging a multi-antenna configuration. In this configuration, consisting of two antenna elements, the application of equal and distinct voltages to the antenna elements is categorized based on the diverse characteristics of the reservoir. Additionally, the impact of inter-antenna element distances on temperature profiles was thoroughly examined within these configurations. Research results indicate that these configurations can effectively address varying heat requirements of the reservoir, whether necessitating more, less, or no additional heat, through the adjustment of both distance and voltage. This comprehensive approach offers a viable solution to enhancing the efficiency of heavy oil reservoir heating processes during RF heating in horizontal wells at the operational level. 1. INTRODUCTION As one of non-conventional hydrocarbon resources, heavy oil reservoirs are widely distributed in the world. Nevertheless, high viscosity prevents the rich resources from being large-scale exploited (Hassanzadeh and Harding, 2016). Besides, with the situation of sustained low oil prices, traditional thermal recovery projects have been terminated because of high production costs and low recovery efficiency (Hasanvand and Golparvar, 2014; Wise and Patterson, 2016). To solve the above problems, oil companies are exploring other alternative heating processes, one of the most promising being radio frequency (RF) heating technology. It is effective in deep, shallow, thin and thick reservoirs, besides the extra energy loss in the pipeline, wellbore and overburden can be avoided (Chhetri and Islam, 2008; Wang et al., 2018). In recent years, many scholars have investigated the feasibility of RF heating. Ramcharan et al., 2016 explored the viability of using RF heating to extract heavy oil by applying COMSOL Multiphysics and CMG software. Their research results indicated that when an operating frequency of 10 MHz and a current of 50 Amperes were applied, the oil recovery rate was in the range 30-60%. Saeedfar et al., 2016 developed a synthetic homogenous reservoir model to conduct the simulation of RF heating method, and the results revealed that the method had the ability of highly efficient heating of oil sand reservoir.