Fina Oil & Chemical Co. has started interpretation of the first batch of data from one of the largest three dimensional seismic surveys shot on land in the U.S.
The survey covered 46.8 sq miles of Fina's Mecom Ranch property, west of the town of Cameron in Cameron Parish, La.
Fina operates two fields on the property, East Mud Lake and Second Bayou fields. These fields, discovered in the 1950s, have combined cumulative production of more than 1 tcf of gas.
The 3D survey will assist in future development of both but was also designed to identify, confirm, and define exploration prospects.
The main exploration potential is thought to lie in Miocene sands deeper than those drilled to date and in fault blocks undetected using conventional 2D seismic.
The Miocene section is greatly expanded by a large listric growth fault that becomes nearly horizontal in the survey area. The production is controlled by a complex combination of structure and stratigraphy.
Fina anticipates finding mainly gas in the deeper Miocene horizons.
LARGE LAND SURVEY
Fina, with Grant Norpac lnc.'s Cajun Exploration subsidiary as geophysical contractor, shot the survey last year. Planning for the project started in January 1990, field work began in March, and acquisition was completed Sept. 21.
More than 3,300 shot holes were drilled and detonated. Fina used 960 live recording channels for each shot.
The operation, carried out southwest of sprawling Calcasieu Lake, required marsh buggies to drill shot holes and carry out initial work and air boats and helicopters to transport equipment.
Seismic Group Recorder II telemetry equipment was used to record the data.
Interpretation of the data is expected to take about 12 months.
Fina plans to be very active drilling development and exploration wells at Mecom Ranch for several years.
Among the main reasons 3D surveys have not been used extensively on land are that permitting can be expensive, surface access can be difficult to gain, and the operator usually must deal with a large number of land owners.
Fina owns about 80% of the surface rights at Mecom Ranch, so access was not a problem.
Shooting 3D seismic is more expensive on land than offshore. Nevertheless, large land 3D surveys are becoming more popular.
A 100 sq mile 3D survey is being proposed in South Louisiana for 1991.
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