Lockhart Crossing CO2 Flood in Louisiana: From EOR to CCS

Document Type

Conference Proceeding

Publication Date

1-1-2026

Abstract

The Wilcox-1 sandstone at the Lockhart Crossing Field, Louisiana, discovered in 1982, has been under waterflood since 1986 and CO2 flood since 2007. With nearly two decades of CO2 injection, 40 years of production and pressure data, and proven reservoir continuity, the field provides an ideal case study for transitioning a mature CO2 flood into a combined EOR/CCS project. This paper documents primary, waterflood and CO2 performance which establishes the technical basis for Lockhart Crossing to serve as a Gulf Coast test case on how a mature CO2 flood can transition to a CCS storage facility. This can be achieved through a multidisciplinary workflow that integrates petrophysical evaluation, core and log data, production and injection history, simulation modeling, and economic screening. Flow units were defined from porosity–permeability trends and extended across un-cored intervals using log calibrations. A dynamic simulation model was constructed and history matched to 18 years of CO2 flood performance. Volumetric and compositional modeling were used to evaluate storage capacity and retention mechanisms. Early in the CO2 flood, the reservoir pressure increased almost 2,000 psi above the original reservoir pressure with no leakage observed, directly testing seal integrity and safe pressure margins for the overlying shale. This was a powerful demonstration of the ability of regional shale layers to prevent CO2 from migrating to the surface. Adjacent aquifers were also evaluated for their potential to provide dedicated storage capacity. Economic analyses compared project value under both continued EOR operations and conversion to CCS, highlighting cost structures, revenue potential, and 45Q credit implications. Three primary technical and economic scenarios investigated in this paper are: 1. Continued/optimized CO2-EOR in the Wilcox-1 sand. 2. CO2 EOR injection in the underlying Wilcox-3 and Wilcox-4 sands that are relatively underdeveloped and, 3. CO2 CCS into the shallower saline Miocene aquifers Original hydrocarbons in place are estimated at 52 MMBO, including 44 Bcf of gas. The simulation model reproduces historical injection and production behavior, confirming both injectivity and containment. Approximately 400 Bcf of CO2 has been injected, with 75 Bcf retained in the reservoir. Wells have remained on natural flow throughout CO2 operations, supported by continuous recycling of CO2 and produced gas, demonstrating sustained reservoir pressure. Petrophysical analysis confirms high-quality flow units in both producing and aquifer intervals which are favorable for long-term injection and storage. Economic screening shows that combined EOR/CCS strategies can extend oil recovery while improving project economics through credit generation and storage validation. This study provides one of the first comprehensive technical and economic justifications for converting a long-lived Gulf Coast CO2 EOR flood into a dual-purpose EOR/CCS project. The unique combination of sustained natural flow without artificial lift, validated seal integrity under elevated reservoir pressure, robust simulation history match, and demonstrated storage capacity supports Lockhart Crossing as a replicable model. By coupling operational performance with economic analysis, the field illustrates how mature CO2 floods can evolve into commercially viable CCS projects. This is achieved via extending recovery while advancing large-scale carbon management in the Gulf Coast.

Publication Source (Journal or Book title)

Proceedings SPE Symposium on Improved Oil Recovery

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