In the heart of China’s Sichuan Basin, a groundbreaking study is reshaping the future of gas reservoir management and carbon emissions reduction. Mengyu Wang, a researcher at the PetroChina Southwest Oil and Gas Field Exploration and Development Research Institute in Chengdu, has led a pioneering numerical simulation study that could revolutionize enhanced gas recovery (EGR) techniques and carbon capture, utilization, and storage (CCUS) strategies.
The Sichuan Basin, known for its rich gas reservoirs, is now at the forefront of a new energy paradigm. Many of its gas fields are in the middle to late stages of development, presenting an opportunity to implement CCUS-EGR technologies. Wang and her team focused on Wells 47 and 67 in the Maokou Formation of the Wolonghe Gas Field, conducting CO2 injection tests to assess the feasibility and benefits of these innovative methods.
The study, published in the journal Engineering Reports, which translates to ‘Engineering Reports’ in English, utilized numerical simulations to design optimal parameters for CO2 injection, including mode, timing, and injection-production well patterns. “Our goal was to reduce CO2 emissions while enhancing gas recovery,” Wang explained. “By carefully simulating various scenarios, we aimed to find the most effective and efficient way to achieve both objectives.”
The research involved a detailed analysis of Well 47 to understand how reservoir temperature and pressure change under different CO2 injection rates, timings, and temperatures. This analysis provided crucial insights into CO2 migration distribution within the formation. For Well 67, the team conducted a comparative study to evaluate cumulative natural gas production under different injection gases, production rates, and injection-production ratios, involving Wells 67, 83, and 47.
The findings were remarkable. The optimal injection-production parameters and CO2 injection scheme identified in the study can cumulatively recover 530 million cubic meters of natural gas. This amount accounts for 9.64% of dynamic reserves and 8.03% of geological reserves, significantly boosting the economic viability of depleted gas fields. Additionally, the scheme can store 3.686 million tons of CO2, making a substantial contribution to carbon emissions reduction.
The implications of this research are far-reaching. For the energy sector, it offers a blueprint for enhancing gas recovery in depleted reservoirs while simultaneously addressing environmental concerns. “This simulation test is the first of its kind for Southwest Oil & Gas Field Company,” Wang noted. “It provides a scientific development path for low-carbon new energy through the pilot test of CCUS-EGR.”
As the energy industry continues to evolve, the integration of CCUS-EGR technologies could become a standard practice. This study not only demonstrates the technical feasibility of these methods but also highlights their commercial potential. By optimizing injection and production parameters, energy companies can extend the lifespan of their gas fields, increase profitability, and contribute to a more sustainable future.
The success of this pilot project in the Sichuan Basin could inspire similar initiatives worldwide, driving innovation in the energy sector and paving the way for a more sustainable and efficient use of natural resources. As Wang and her team continue to refine their techniques, the future of gas reservoir management looks increasingly bright, with CO2 injection playing a pivotal role in enhancing recovery and reducing emissions.