Three Dimensional Geological Modeling using Seismic Inversion in a Reservoir Integrated Study for a Giant Heavy Oil Field: Rubiales Field, Eastern Llanos Basin, Colombia, South America

Gomez, Yohaney¹; Morales, Diego; De Souza, Thais; Yoris, Franklin; Alvarez, Gabriel; Reina, Claudia; Landaeta, Libia; and Castellanos, Diego
¹[email protected]

Rubiales Field is located at the southeast of the eastern Llanos Basin, the area with the largest heavy oil reserves in Colombia (12 degree API). The reservoir is Tertiary sandstones of the lower Carbonera Formation, deposited in a predominantly fluvial environment, informally known in the area as "Arenas Basales". As of January 2013, more than 700 wells have been drilled and completed in this reservoir with cumulative oil production of 205,6 million barrels of oil.

The available information for this study was 349 kilometers of 2D seismic lines, 325 km² of 3D seismic, hydrocarbon indicator volumes, shale volume and porosity volume (from Elastic Seismic Inversion) and laboratory data from 14 cores. The integration of different disciplines and the use of 3D seismic elastic inversion, with a detailed study of the sedimentary framework, has helped to improve the field development strategies.

The goal of this study was to quantify original oil in place, reserves and to improve strategies for the field development plan. Specifically, non- drained areas were identified with analytical and numerical simulation models. A particular challenge of this study was to identify the economic development strategies under the very tight time constraint for the development of the field.

Previous stochastic models were generated using a Gaussian simulation process for facies population. However, the prediction of the geometry of the sand bodies was not satisfactory due to reservoir complexity. This new model, based on seismic elastic inversion, gave a better understanding of the continuity of the sand bodies and provided better prediction of reservoir properties. It became the static model input to numerical simulation of the reservoir.

The main product of this study was a model that captured the complex stratigraphic variations of the reservoir unit. This in turn has allowed for optimizing locations of both vertical and horizontal wells.

AAPG Search and Discovery Article #90166©2013 AAPG International Conference & Exhibition, Cartagena, Colombia, 8-11 September 2013