Carbon Capture and Storage (Ccs) Practices in the Enping Field, South China Sea

Abstract

The Enping CCS project is a pioneering effort in China to establish an offshore industrial-scale carbon capture and storage initiative. The project began operations in June 2023, and has an annual capacity to store 300,000t CO2. Its design is tailored to address specific challenges presented by the Enping Field, which include high CO2 concentrations, limited platform space, and shallow high-angle directional drilling. Notably, the Enping Project distinguishes itself from other offshore CCS projects worldwide, including those like Sleipner, Snøhvit, and Gorgon projects. This paper provides an overview of the CCS practices implemented in the Enping Field. The associated gas produced from the Enping Field, containing 84% to 94% CO2, is considered suitable for direct sequestration in saline aquifers. The CO2-rich gas undergoes dehydration via the molecular sieve method, followed by a three-stage compression process, reaching 11 MPa before injection. The injection process utilizes a shallow, low-angle, directional well, securely storing CO2 in a saline aquifer at depths of 830-920m. The knowledge and experience from the Enping project have reference significance for regions confronting similar challenges in managing high-CO2 natural gases in offshore environments.

Keywords: CCS, offshore carbon storage, South China Sea, Pearl River Mouth Basin