Charles Kerans¹

(1) Bureau of Economic Geology, The University of Texas at Austin, Austin, TX

ABSTRACT: 50 Years Hence -- Evolving Technologies and Opportunities in Carbonate Systems

Carbonate reservoirs are famous for their prolific reserves and infamous for their complexity and unpredictable behavior. Yet it is precisely this combination of vast promise and challenging technical frontiers that ensures that carbonate hydrocarbon reservoirs will form the cornerstone of global energy supply for the next half-century. The vast resource still remaining in giant carbonate oil fields in the Middle East, the Caspian region, the Cretaceous of Latin America, the Atlantic and Caribbean provides substantial motivation for a renewed focused R&D effort in carbonate exploration and exploitation similar to the spirit that thrived during the Shell golden years of the late 50's to 1965.

The basis for our modern understanding of carbonates has evolved very rapidly, almost entirely within the last half-century. In the mid-late 50's, spurred by carbonate discoveries in the Permian Basin and Middle East, research on environments of modern carbonate deposition and related petrographic and diagenetic studies took place. Central to this effort was Shell's Bellaire/Coral Gables group during the "golden years" between 1955 and 1965. Their integrated research on all aspects of modern and ancient carbonate depositional environments, diagenetic systems, and construction of reservoir-scale carbonate models revolutionized our understanding. The late 60's and 70's saw studies focus ever inward, with reservoir-scale facies models, microfacies, sequencing of diagenetic events, and petrography gaining importance. The 80's saw an explosion in the application of trace element and isotope geochemical techniques for documenting the processes and hydrologies of carbonate diagenetic systems with the goal of developing predictive models for carbonate diagenesis and porosity development similar to that achieved in the 60's for carbonate depositional facies. Before this diagenetic research reached fruition, Exxon's concepts of sequence stratigraphy exploded onto the carbonate scene, and the last 15 years has seen rapid development and application of these concepts at exploration and development scales.

AAPG Search and Discovery Article #90906©2001 AAPG Annual Convention, Denver, Colorado