Abstract: Exploration and Development in the West Tracy Gas Field

NAHAMA, JOE, and ROD NAHAMA,

The West Tracy Gas Field is located in Section 13, Township 2 South, Range 4 East, west of the main Tracy Gas Field which began producing in 1935. Drilling in the West Tracy area began in 1959. Commercial gas production at West Tracy was found by Nahama and Weagant Energy Company in 1993.

Seismic shot in the region showed the geologic complexity as the West Tracy Gas Field is situated near the intersection of three thrust faults; the Stockton Thrust Fault, Vernalis Thrust Fault, and West Tracy Thrust Fault. Although the original wells drilled by Nahama and Weagant were Winters Sand plays based on seismic anomalies, the resulting gas production was discovered in deeper Lathrop Sands. These productive sands are found on the hanging wall of the Stockton Thrust Fault. The reservoir trap at West Tracy is similar to the trap found in the 352 BCF Lathrop Gas Field. Each well drilled at West Tracy, combined with existing 2-D seismic, illustrates the complexities of the area and the need for 3-D seismic to enhance future exploration efforts.

In addition to geologic complexities of the area, development efforts were slowed as the Lathrop Sands have low permeability and 716 BTU per cubic foot natural gas. Fracture stimulation of the Lathrop Sands was necessary to improve well deliverabilities. As a result of the stimulation treatment, gas deliverability was increased from 500 to 1,500 MCFPD.

Search and Discovery Article #90945©1997 AAPG Pacific Section Meeting, Bakersfield, California