CO2 Flooding: Its Time Has Come
Authors: Holm L.W. 
Published: December 2007

Distinguished Author Series articles are general, descriptiverepresentations that summarize the state of the art in an area of technology bydescribing recent developments for readers who are not specialists in thetopics discussed. Written by individuals recognized as experts in the area, these articles provide key references to more definitive work and presentspecific details only to illustrate the technology. Purpose: to informthe general readership of recent advances in various areas of petroleumengineering.

Introduction

Carbon dioxide is one of the most plentiful and useful compounds found onand around this planet. It is not surprising that the idea of using CO2 toremove oil from underground reservoirs originated early in the history of oilproduction. In the period just following World War II, significant progress wasmade in the development of CO2 oil-recovery processes. In the 1950's, Whortonet al., Saxon et processes. In the 1950's, Whorton et al., Saxon et al., Beesonand Ortloff, Holm, and Martin published patents and papers on the subject thathave published patents and papers on the subject that have laid the foundationfor the oil-recovery processes as they exist today. Most aspects of CO2flooding, including oil swelling, viscosity reduction, miscibility effects, solution gas drive, and reaction with reservoir rock, were identified duringthis laboratory investigative period. Advances in CO2 flooding technologyduring the 1960's included:definition of the amount of CO2 required foroil recovery and information on the effect of reservoir oil viscosity, reservoir rock type and rock heterogeneity, and phase relationships;development of the use of CO2 as a well stimulant additive in fracturing andacidizing; andfield tests of CO2 flooding.

The first successful field testof CO2 with waterflooding in the Mead Strawn field confirmed that more oil wasproduced by a CO2 slug followed by waterflooding than by waterflooding alone, and that severe CO2 gravity override and channeling do not necessarily occur inthe reservoir. Continued research and field applications in the 1970's addedconsiderably to our knowledge of CO2 displacement mechanisms, phase behavior, mobility control, CO2 availability, and practical transporting, handling, andoperating problems associated with the process. Five field applications andtests-SACROC, North Crossett, Two Freds, Little Creek, and Lick Creek Meakin -provided more information on the design, operation, and economics of CO2flooding projects. Several U.S. DOE, Natl. Petroleum Council, Federal EnergyAdmin., and private investigations identified CO2 sources and supplies, separation processes, and transportation facilities. These 25 years of effortare now beginning to show results. Current field applications are continuingand expanding. A 1982 survey revealed a 65% increase in the number of CO2projects over 1980. Four large pipelines have been started to bring CO2 fromdistant pipelines have been started to bring CO2 from distant (200 to 400miles) sources. Colorado and New Mexico gas fields will supply CO2 for miscibleflooding in the Wasson and other fields in west Texas. Two other pipelines willserve the Purdy Springer and East pipelines will serve the Purdy Springer andEast Velma fields in Oklahoma, and the Little Creek and West Mallaleiv fieldsin Mississippi. CO2 available from refineries and fertilizer plants in the LosAngeles basin has been targeted for immiscible flooding of local heavy-oilreservoirs. Studies have been made of CO2 pipelines to bring additional CO2from Utah and New Mexico to the basin. Although the economic recession andworldwide oil glut have slowed its progress, CO2 flooding's time has come.progress, CO2 flooding's time has come. JPT

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