DOS SANTOS, SERGIO, Corpoven S. A., Venezuela

ABSTRACT: Influence of the Allochthonous Pirital Block on the Well and Surface Seismic in the Northern Monagas Area, Eastern Venezuela Basin

The Casupal-Bosque area in Northern Monagas is a province characterized by thrust faults due to the post-middle Miocene compressive regime. The most important tectonic element of the area is the Pirital thrust. The presence of this block at the surface, the high velocities (Cretaceous) rocks, the strong fracturing and the high dips cause the poor resolution of the seismic data. This effect occurs across in a north-south zone of approximately four (4) kilometers in the East-West strike direction of the block. In this paper results are presented of experimental seismic lines recorded to improve the seismic image beneath the block. Well seismic data of the area has also been studied.

The results obtained from the experimental seismic lines show that, the quality of the data in the prospective level (Naricual Formation) beneath the allochthonous block did not improve substantially, even though a pre-stack time migration technique has been applied. The results on the well seismic data have been more successful after some modeling of the real and synthetic data was done. These results indicate that in complexed structures the well seismic data can not be used as a predictive tool, rather than a complement and definition of the structural interpretation.

AAPG Search and Discovery Article #90988©1993 AAPG/SVG International Congress and Exhibition, Caracas, Venezuela, March 14-17, 1993.