BUST, VIVIAN, and ERIC J. RAPPORT, Converse Environmental West, Irvine, CA

ABSTRACT: Petroleum Industry Subsurface Techniques Applied to Environmental Remedial Investigations and Strategies: Case Studies

Geological, petrophysical, and petroleum reservoir engineering techniques were applied to remedial investigations to identify (1) geometry and heterogeneity of subsurface sedimentary deposits, (2) distribution of permeable strata, (3) lateral and vertical extent of contamination, and (4) strategic remedial alternatives.

The first step in this methodology is to continuously core and stratigraphically describe the sedimentary sequences in terms of grain size, texture, composition, and sedimentary structures. A lithology log profile representing the median grain size of the cored sedimentary sequences is generated (e.g., an electric log).

Second, the lithology log profile and stratigraphic description became the basis for correlation with models of sedimentary environments of deposition. The sedimentary environment of deposition is the framework on which the geometry, heterogeneity, and correlation of the subsurface geologic units are predicted. An iterative process is required to develop predictive models which accurately represent subsurface geologic conditions.

Third is the correlation of chemical analyses with lithology, depth, and predicted geologic conditions to delineate contaminant plumes. Case studies demonstrate the application and value of this integrated methodology. Highlights of the case studies include (1) technology transfer of American Petroleum Institute core-analysis procedures to measure product saturations and fluid-flow properties on soils, (2) identification of the product saturation profile in the capillary fringe zone, (3) delineation of a plume controlled laterally by the geometry of point bars within an entrenched channel and vertically by lithology heterogeneity, (4) calculation of volume of product in place, (5) Interceptor trench design based on clay strata barriers to water flow, and (6)

development of hydrological properties maps for use in design of remediation systems.

AAPG Search and Discovery Article #90992©1993 AAPG Pacific Section Meeting, Long Beach, California, May 5-7, 1993.