Heavy oil recovery using gas injection methods and its challenges and opportunities

Abstract

The relevance of enhanced oil recovery (EOR) and its development are always important considerations when it comes to the approaches used to improve heavy crude oil recovery. As a direct consequence of this, there is a growing demand for the discovery of unconventional resources such as bitumen, shale, and heavy oil. With the diminishing availability of conventional crude oil stocks, it is necessary to make efficient and fruitful use of heavy oil resources. Heavy oil recovery poses challenges due to the high viscosity and low mobility of the oil, making traditional recovery methods less effective. Gas injection has emerged as a promising technique to enhance heavy oil recovery, where different gas injection methods are evaluated to improve the oil displacement efficiency. Several gas injection methods have been employed in heavy oil recovery, including natural gas injection, carbon dioxide (CO2) injection, and steam-assisted gravity drainage (SAGD). Each method has its benefits and difficulties. Natural gas injection is relatively simple and cost-effective, but it may face limitations in terms of the amount of gas available and the gas-oil miscibility. CO2 injection has shown promising results due to its miscibility with heavy oil, which leads to improved oil recovery through swelling and viscosity reduction. The benefits of gas injection methods include increased oil recovery, reduced environmental impact, and potentially lower operational costs. These methods can also enhance the recovery of stranded heavy oil reserves, thereby contributing to global energy security. However, challenges associated with gas injection methods include high viscosity and low mobility, reservoir heterogeneity, the potential for gas channeling, and high capital and operational costs. Despite the challenges, gas injection methods offer significant opportunities for heavy oil recovery. Overcoming these challenges requires advanced reservoir characterization, optimized well design, efficient gas injection strategies. Technological advancements, such as advanced reservoir characterization techniques, improved well design, and optimized gas injection strategies, can help overcome these challenges and enhance heavy oil recovery using gas injection methods. The gas injection methods that are used to recover heavy crude oil have been evaluated in the research along with their benefits and the difficulties that can arise while employing the gas injection methods. This paper focuses on the challenges and opportunities of gas injection methods for heavy oil recovery.