--> ABSTRACT: Outcrop Description Results in Formulating "Ground-truth" Input Variables for Simulation of Hollin Formation, Oriente Basin, Ecuador, by D. Jordan, G. Perez, L. Blacker, and D. Bell; #91021 (2010)

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Outcrop Description Results in Formulating "Ground-truth" Input Variables for Simulation of Hollin Formation, Oriente Basin, Ecuador

JORDAN, DOUGLAS,  GODOFREDO PEREZ, , LAURA BLACKER, and DAVID BELL

Detailed outcrop description of the Cretaceous Hollin Formation (Oriente Basin, Ecuador) is critical in constructing a cohesive stratigraphic model and deriving input variables for a simulation study of the reservoir in the nearby Villano Field "Ground-truth" variables necessary for the reservoir simulation that can only be gathered from the outcrop sections include the geometry and continuity of sandstones and fine-grained units; facies controls on permeability and porosity, thickness variations, and nature of contacts of braided stain and point-bar deposits (the main productive horizons in the Villano Field); and outcrop gamma-ray profiles that are useful in inferring the petrophysical and stratigraphic characteristics of the non-cored sections in the wellbore.

It is essential to understand the variations in types of impermeable elements in order to predict, model, and curtail the amount and effect of water coning through adjacent high permeability reservoirs. Impermeable elements measured on the outcrops are bar tops or vegetated mud flats within the braided stream environment, and overbank/floodplain/levee silts and clays, abandoned clay-filled channels, and clay drapes within the point-bar system. In the Villano Field, additional line-grained bodies are present, namely restricted bay deposits in the Upper Hollin. Object modeling simulation is used to generate models that honor the stability distributions for the dimensions, volume proportions, and well data. Shales in the Hollin are effective barriers to vertical flow, which will have an important effect on the oil recovery efficiency of the aquifer drive mechanism.

AAPG Search and Discovery Article #91021©1997 AAPG Annual Convention, Dallas, Texas.