Design and Implementation of a CO2 Flood Utilizing Advanced Reservoir Characterization and Horizontal Injection Wells In a Shallow Shelf Carbonate Approaching Waterflood Depletion, Class II

Abstract

Work reported in this document covers tasks in Budget Phase II. The principle task in Budget Phase I1 is Field Demonstration. Since starting carbon dioxide (C02) injection in July 1996, several operationally related issues emerged within this reporting period. These include out of zone C02 injection, conformance methods, high reservoir pressure, and lack of injectivity and productivity. The under-performance is related to: 1) 2) 3) "Out of zone" COZ injection. Through-wellbore communication of abandoned wells. Productivity and injectivity of wells. To resolve these issues a redevelopment scheme was initiated in early 2000 after several discussions with the Department Of Energy. The redevelopment centered around short radius lateral drilling and selective stimulation in the upper San Andres and was determined to be the optimum redevelopment scheme to improve the C 0 2 flood. The optimum development with regard to recovery and economics follows a two phased approach. Redevelopment PHASE I-Test lateral technology, improve offtake in center of CO2 flood. Redevelopment PHASE I1-Improve in zone injection and reduce reservoir pressure ix