Duong Tan Da creator Pham, Huy Giao Chairperson Noppadol Phien-Wej Examination Committee Jang, Seonghyung Examination committee text series technical report th Pathum Thani, Thailand Asian Institute of Technology 2013 continuing eng 39 leaves : ill. The study area is located in Junin area, Orinoco Oil Belt, Venezuela. It is under appraisal and development phase. 3D static model was built for Junin area, including study area. However facies modeling in this model just take responsibility as a background for porosity distribution.It is not considered as an input for establishing appraisal and field development strategy. To adapt the above requirement, facies model of the study area is rebuilt with the contribution of facies patterns from core analysis and the paleo environment of the study area.For the purpose of building facies model, fifteen boreholes were selected to construct the facies log based on the existing standard core facies patterns. As a result, 3D facies model of field X, Orinoco oil belt was built within the cube of 31 x 19 x 0.54 km by using Petrel software of Schlumberger. This facies model was built basing on three (3) reservoir Units. They are Lower Miocene, Oligocene, and Cretaceous. The existing standard core-facies pattern of the previous studies were collected and used for generated facies log of fifteen boreholes. Combined with structural model and the paleo environment of the study area, these results were used for constructing 3D facies model. It covers the area of 31 x 19 x 0.54 km and built by Petrel with the Objective modeling Method. The sedimentary facies from base to top: braided channels, intercalate channel, meandering channels and distributed channels. These results can be used as a reference for simulation works of field X and as one of initial input for establishment appraisal and development strategy.However this facies model was not supported by seismic data such as seismic attributes so it possibly needs some additional qualified data in future to control in order to improve model quality. These data includes: information from new wells, seismic attributes etc. A research submitted in partial fulfillment of the requirements for the degree of Master of Engineering (Professional) in Geo-Exploration and Petroleum Geo-Engineering Research studies project report (M. Eng.) - Asian Institute of Technology, 2013 Reservoirs Venezuela Asian Institute of Technology. http://203.159.5.9/ait-thesis/detail.php?q=B01522 http://203.159.5.9/ait-thesis/detail.php?q=B01522 151208 20260817161127.0