Outlook and Technologies for Offshore CO2 EOR/CCS Projects
Authors: Sweatman Ronald Earl , Crookshank Steve , Edman Sarah 
Published: May 2011

The challenges facing offshore CO2 enhanced oil recovery (EOR) and carbon capture and storage (CCS) projects are presented in this paper along with potential solutions based on the oil and gas (O&G) industry's CO2 EOR and CCS experience and technology as applied in a few offshore locations. Prospects for future offshore projects are also discussed based on the O&G industry's experience, technology, and best practices. These achievements are the result of a safe and successful 58-year history of well construction and operations in land-based, commercial CO2 EOR projects.

Achieving CCS by injecting CO2 into saline formations or for EOR in mature oil reservoirs is a safe and effective method to reduce GHG (greenhouse gas) emissions. The IPCC has defined enhanced oil and gas recovery via CO2 injection as a recognized form of CCS. Using existing industry experience and technology developed over the past 58 years, CO2 injection into oil reservoirs for EOR has been safely and effectively applied in 18,077 active wells worldwide (17,112 in USA) according to the latest EOR survey (O&GJ, 2010). Production from natural gas reservoirs has also benefitted from CO2 injection in enhanced gas recovery (EGR) applications.

Key results are summarized and major conclusions presented from studies by the American Petroleum Institute; Advanced Resources International; European Commission, DG-Joint Research Centre, Institute for Energy; Kinder Morgan; Norwegian Petroleum Directorate; Bellona Foundation; Norwegian University of Science and Technology; SINTEF Petroleum Research; and others. Conclusions from these studies point to the substantial value of current industry experience as a sound basis for offshore CCS applications.

Offshore CCS/EOR may be more viable than onshore options for areas with high population densities, where offshore reservoirs are within reasonable distances from land, or where there are existing offshore O&G facilities and wells. The technical knowledge base of the petroleum industry can be leveraged for the development of CCS with a strong understanding of the pros and cons of offshore projects, operating experience with safe and economic CO2 capture, transportation, injection, and understanding of subsurface formations for future CO2 EOR/CCS applications.

Introduction

Oil and Gas Industry Experience

The first patent for CO2 EOR was granted in 1952 (Whorton). The Texas Railroad Commission (TRRC report) proposed CCS rule states that " the first three projects (immiscible) were in Osage County, Oklahoma from 1958 to 1962.?? Another early CO2 EOR project was in Jones County, near Abilene, Texas in the Mead Strawn field in 1964 (Holm). The first large-scale, commercial CO2 EOR project (Langston) began operations in 1972 at the SACROC field in West Texas, which continues in operation today. Many more CO2 " flood?? EOR projects have started since then. By 2010, CO2 EOR projects had reached a global total of 127 (112 in USA) with 12 more planned for the USA, as reported in the EOR survey by the Oil and Gas Journal (O&GJ, 2010). Rising oil prices, low cost sources of high purity CO2, and access to miscible fields with large amounts of unrecovered oil have supported growth in CO2 based EOR in the U.S., which now accounts for 272 mbd (O&GJ, 2010) or over 8% of total Lower 48 crude production of 3.22 mmbd in the 2nd quarter 2010, as reported by the U.S. Energy Information Administration.