Advances in Electrical Heating Technology for Heavy Oil Production

Abstract

Electrical downhole heating has been used for many years for flow assurance and now is being adapted for reservoir stimulation, viscosity reduction and "in situ" conversion of heavy oil. This paper starts with a short review of flow assurance applications in Alaska and Canada as described in SPE-165323-MS. It then reviews the current and developing technology and some of the heat transfer parameters for use of high voltage high power electrical heaters in a number of types of applications. In the past heater voltages have been limited to below 600 volts for mineral insulated cable heaters. Significant material and processing advances have now permitted operation at 4160 volts. This has a number of operational advantages in providing longer length heater capabilities and less parasitic heating loss in the overburden. MI cable production technology is now available to fabricate MI cable heaters that can produce 1600 meters lengths without external splices. The thermal heat transfer from the well casing to the reservoir is usually the limiting factor on the amount of energy that can be transferred from the electrical heater to the formation. Both constant power and constant temperature heaters are explained with the emphasis on in operation reliability of each type of heater. The paper concludes with an economic analysis of the opportunity provided by a high voltage MI cable heater system in a horizontal well.

Electrical Heating for Heavy Oil: Past, Current, and Future Prospect

“…Electrical heating is a method of EOR called Electrical-enhanced oil recovery (EEOR) which can be an alternative method used than the conventional method of EOR. There are three fundamental heat transfers of the electrical heating method into the formation (heat conduction, heat convection, and radiation heat transfer) [48]. Heat conduction will transfer heat based on vibrations for each molecule contact.…”

The Prospect of Electrical Enhanced Oil Recovery for Heavy Oil: A Review

“…There are three fundamental heat transfers of the electrical heating method into the formation: heat conduction, heat convection, and radiation. Heat conduction transfers heat based on vibrations for each molecule contact, heat convection is heat transferred from the transfer of gas or liquid with the heat contained in the vicinity, and radiation is an energy-heating transferred through electromagnetic waves (Sandberg et al, 2014).…”