Roberto Linares1, Claudia Posada2, Myriam Caro2
(1) Ecopetrol - ICP, Bucaramanga, Colombia
(2) Instituto Colombiano del Petroleo, Bucaramanga, Colombia
ABSTRACT: Characterization of fractured reservoir using 3D structural models and outcrop data in calcareous rocks of the Middle Magdalena basin, Colombia
The Middle Magdalena Basin has been explored since the beginning of this century. The most important reservoirs are Eocene through Oligocene in age. The hydrocarbon potential of the Cretaceous rocks has also been identified by some wells in Upper and Lower Cretaceous rocks.
Almost seventy important hydrocarbon fields have been discovered in the basin. These fields are related to structural traps generated during at least two compressional deformation events. The seismic data show that Tertiary deformation over regional Eocene unconformity generally corresponds with Cretaceous deformation under the unconformity.
This study identifies the structural framework and the total curvature of Cretaceous calcareous rocks using three-dimensional structural models of forty oil fields. This work integrates detailed outcrop data, radar images, aerial photographs, 2.000 kilometers of seismic profiles and information of 150 wells.
The compressional deformation has been controlled by the presence of Jurassic and early Cretaceous normal faults. The reverse faults and their hanging-wall structures are the result of two compressional events. Three fracture sets were identified at surface in the Cretaceous rocks, a longitudinal a traversal and a conjugate set. These sets are interpreted as formed by compression during the uplift of the Eastern Cordillera.
Integration of surface data and values of total curvature from three-dimensional models of Rosablanca Formation provides a predictive model for fracture distribution in the anticlines and present how this analysis could aid in the exploration of analogous calcareous reservoirs reducing the exploratory risk of the hydrocarbon prospects.
AAPG Search and Discovery Article #90906©2001 AAPG Annual Convention, Denver, Colorado