Modern societies are still very much dependent on oil and gas resources for their smooth functioning. However, natural oil and gas resources are limited and non-renewable. In order to keep up with the growing demand for hydrocarbons, we need to find and secure alternate sources of natural oil and gas. Fortunately, a massive and mostly untapped reserve of oil and gas waits beneath us.
Oil shale is a flaky sedimentary rock with high organic content. When low-maturity oil shale is heated for extended periods of time, its organic molecules break down via pyrolysis and transform into lighter and more useful oil and gas. This forms the basis of a promising strategy known as in situ upgrading (ISU), whereby heating wells are drilled and laid out directly into the shale layer to provide the necessary heat for pyrolysis. The hydrocarbons produced on site are then extracted through a separate production well. While the process is technically feasible, there is, however, no agreement on whether it is economically feasible as well.
To address this knowledge gap, a research team from Northeast Petroleum University, China and China University of Petroleum in East China recently conducted a study on ISU technology. Led by Dr. Li Wenbiao from Northeast Petroleum University, the team analyzed the economic feasibility of ISU from the perspective of the energy consumption ratio (ECR). Put simply, ECR is a measure of how much of the energy provided to the heating wells is used for pyrolysis in relation to the energy lost to heat diffusion and absorption into minerals, water, and surrounding rock.
As described in their paper published in Earth Science Frontiers, the team employed a geological model to look into the factors that affect ECR the most. In their model, they accounted for the heating well design and layout, heating technology, and shale composition, among other parameters and variables. Also visit the website for the press release based on this study: https://www.earthsciencefrontiers.net.cn/EN/news/news31.shtml
The results of their analysis indicate that appropriate spacing between the heating and production wells is crucial to improve the efficiency of ISU. The team also determined the minimum total organic content in the oil shale that leads to acceptable ECR values. Moreover, they also compared and contrasted new heating methods to increase the efficiency of ISU beyond the conventional approach using heating wires. “One important way to increase the efficiency of ISU is to explore alternative heating technologies, such as convection and electromagnetic heating,” highlights Dr. Wenbiao.
Overall, the team hopes that the findings of their study would help pave the way for an economically viable ISU technology. “We want our results to promote the application of ISU technology for optimized oil shale exploitation,” says Dr. Wenbiao.
Let us hope his vision becomes a reality soon and that low-maturity oil shale becomes a reliable source of hydrocarbons to meet our energy demands.
Authors: Lu Shuangfang1, 2, 3, Wang Jun3, Li Wenbiao1, 2, *, Cao Yixin3, Chen Fangwen3, Li Jijun3, Xue Haitao3, and Wang Min3
1Sanya Offshore Oil & Gas Research Institute, Northeast Petroleum University
2Key Laboratory of Continental Shale Hydrocarbon Accumulation and Efficient Development, Ministry of Education, Northeast Petroleum University
3Key Laboratory of Deep Oil and Gas, School of Geosciences, China University of Petroleum (East China)
About Earth Science Frontiers
Earth Science Frontiers is a bimonthly peer reviewed scholarly journal co-sponsored by the China University of Geosciences (Beijing) and Peking University. It was first published in 1994, and academician Wang Chengshan is the current Editor-in-Chief. Each issue of the journal is centered on a specific geoscience topic and managed by experts in that field as Guest Editors. Each issue also contains a number of articles on self-select subjects. Articles published on Earth Science Frontiers cover all disciplines of earth sciences with emphasis on frontier and innovative basic research. At the same time, the journal also publishes research findings that may be considered contentious. Over the years, Earth Science Frontiers has won several publisher awards, including “The Internationally Most Influential Journal in Chinese Language” and “The Top 100 Outstanding Chinese Scholarly Journals.” In 2019, Earth Science Frontiers was selected among top-tier journals to join a national action plan for achieving excellence in science and technology research publishing in China.
About Dr. Li Wenbiao
Li Wenbiao is currently a researcher at the Northeast Petroleum University in China. His research expertise lies in isotope geochemistry, natural gas, isotope fractionation, and shale gas. He works in collaboration with the China University of Petroleum. Dr. Wenbiao has published 19 papers with over 170 citations to his credit.
Earth Science Frontiers
Method of Research
Subject of Research
Economic feasibility and efficiency enhancement approaches for in situ upgrading of low-maturity organic-rich shale from an energy consumption ratio perspective
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