Print this pageAbstract: Integration of 3D Seismic Technologies to Predict Pliocene Gas Sands: Post Appraisal of the El Diablo-1 Discovery, Trinidad
Sharp, J. and Pish, T. - Amoco Trinidad Oil Company;Bailey, J. - Amoco Egypt Oil Company
The combined use of several 3D technologies
such as 3D 
coherency
, 3D AVO, and 3D depth migration led to the El Diablo
discovery. These technologies provided the exploration team with a set
of powerful tools to better understand predrill risk and to accurately
predict prospect resources.
El Diablo-1 is located in the Columbus Basin of Trinidad, approximately 40 miles northeast of Galeota Point in 206 feet of water. The well was drilled to a total depth of 12,400 feet MD, discovering over 300 BCF of gas from five separate Pliocene age sand reservoirs. El Diablo-1 encountered 320 feet of gas pay sand in the primary T-sand objective with an average porosity of 25%, an average water saturation of 18% and a 500 foot gas column. Additional gas pays were identified in the F sand "series" and T-1 sand.
El Diablo-1 has the distinction of being the first
prospect in Trinidad where 3D coherency and 3D AVO were used in conjunction
to successfully predict a gas accumulation. Associated with this successful
exploration process are a number of exploration technology calibrations
useful for future prospect RISK evaluations:
- Gas sands in parts of the Columbus Basin are identifiable as bright spots along the recognizable contact events interpreted as gas/water contacts.
- Gas sands show Positive AVO (increased amplitude
with offset) and strong coherency signatures.
- Both AVO and Coherency
signatures mimic structure.
- Downthrown fault traps are a viable play concept in the Columbus Basin of Trinidad.
- Gas Column heights can be predicted from fault seal analysis and seismic amplitudes.
AAPG Search and Discovery Article #90933©1998 ABGP/AAPG International Conference and Exhibition, Rio de Janeiro, Brazil