Case Studies of Current Trends in Development Geology

Neal D. Livingston

Traditionally, development geologists have been responsible for studying leases, logs, and cores in detail in support of engineering functions. These responsibilities have grown from defining gross reservoir geometries to understanding subtle differences in reservoirs attributed to stratigraphic and structural complexities, depositional environments, and hydrodynamic processes. To handle these increased responsibilities, expertise has become essential in the areas of computer applications, log analysis, modeling, and management of produced water.

Examples of the use and application of each area to projects from fields on the west side of the San Joaquin Valley demonstrate current techniques employed by development geologists and the evolution of a development department within Texaco. A study of a property in the South Belridge field on which 330 wells were drilled over a two-year period illustrates how computer resources have become vital in handling the vast amount of data needed to perform detailed geologic studies. Intricate geologic characterization has become essential to optimizing and defining reservoir performance in several fields: (1) Southeast Lost Hills, a complex diagenetic trap; (2) Buena Vista Hills, where log analysis is needed to make reserve estimates and step-out potential meaningful; (3) Midway-Sunset fiel , for which detailed geology leads to new field-wide models and future prospects. Increasing environmental concern over waste disposal has required an important involvement of development geologists in the geologic and hydrologic aspects of subsurface injection of produced water and other brines in the Santiago Creek field. Instead of providing a training ground for future explorationists, development geology should be viewed as an alternative career with potential for a much greater demand in the future.

AAPG Search and Discovery Article #91038©1987 AAPG Annual Convention, Los Angeles, California, June 7-10, 1987.