document preview

Abstract
CO2 enhanced oil recovery (CO2-EOR) offers the potential for storing significant volumes of carbon dioxide emissions while increasing domestic oil production. This paper, based on a recently updated report for DOE/NETL, examines the effect that “Next Generation” technologies will have on the CO2 storage and oil production potential of CO2-EOR. The paper examines the causes of sub-optimal CO2 storage and oil recovery efficiencies by current CO2-EOR practices and how a group of advanced or “Next-Generation” CO2-EOR technology could increase both CO2 storage volumes and oil recovery. Technologies investigated include: using increased volumes of injected and permanently sequestered CO2, optimizing well placement and pattern alignment, and using reservoir miscibility and viscosity enhancers.

Introduction
CO2 enhanced oil recovery (CO2-EOR) offers the potential for storing significant volumes of carbon dioxide emissions while increasing domestic oil production. This paper is based largely on an updated report for the U.S. DOE/NETL to examine the effect “Next Generation” technologies could have on both oil production and CO2 storage and utilization1.

A six part methodology was used to assess the CO2 storage and EOR potential of domestic oil reservoirs. The six steps were: (1) assembling and updating the Major Oil Reservoirs Database; (2) calculating the minimum miscibility pressure for applying CO2 -EOR; (3) using minimum miscibility pressure and other criteria to screen reservoirs favorable for CO2-EOR; (4) calculating oil recovery from applying “next generation” CO2-EOR technology; (5) applying the updated cost and economic model; and, (6) performing economic and sensitivity analyses to understand how the combined effects of technology and oil prices impact the results of applying “next generation” CO2-EOR and CO2 storage technology.

To calculate the incremental oil produced by CO2-EOR from oil reservoirs, the study utilized the PROPHET2 model. PROPHET2 is a stream tube miscible flood predictive model that was first developed by the Texaco Exploration and Production Technology Department under a DOE cost share program and has been further modified by Advanced Resources International.2

Domestic Oil Resource Base
The U.S. has a large oil resource base, on the order of 597 billion barrels originally in-place. About one-third of this oil resource base, 204 billion barrels, has been recovered or placed into proved reserves with existing primary and secondary oil recovery technologies. This leaves behind a massive target of 393 billion barrels of remaining, “technically stranded” oil.

Much of the “stranded” oil resides in East and Central Texas (74 billion barrels), the Mid-Continent (66 billion barrels), and the Permian Basin of West Texas and New Mexico (62 billion barrels). California, Alaska, the Gulf Coast and the Rockies also have significant volumes of “stranded” oil.