Abstract

This report summarizes a two-well drilling program, in 1987 and 1988 by Pogo Producing Company in Salt Flat Graben. The main objective was the Leonardian shelf-margin (Victorio Peak-Abo) sequence of carbonates, which can be observed to the south of the prospect at the outcrop in the Sierra Diablo; and to the north in the southern Guadalupe Mountains. Numerous live oil shows have been seen in wells drilled in the graben; and this was particularly true in the Leonardian through Pennsylvanian sections of the Pogo, Victorio Unit No. 1, but no oil was recovered during formation testing. Water recovered from the bolson fill had chlorides of approximately 30,000 ppm, but sub-fill formation fluids were extremely fresh. Numerous high risk exploration plays remain in the Salt Flat Graben area; however, late faulting diminishes the potential for the preservation of unflushed structures. Seismic exploration records (CDP), ranging from 1970 brokered data to 1983 Pogo proprietary shooting presented a combination of bolson-fill problems and occasional low multiplicity due to surface effects. These resulted in poor to fair data quality, which, nevertheless, allowed mapping of major boundary faults and gross structural character, defining a good reflector at the base of the fill. Portions of a reprocessed Hunt Petroleum seismic line (CDP, migrated), has been chosen for this study because of its proximity to a cross section, which it parallels. Although numerous problems present themselves in interpreting the line, nevertheless; a reasonable picture emerges that allows some comparisons to the outcrops.