To optimize the production performance and investment of an extra heavy oil field in the Orinoco Belt, the development strategy was changed from the initial horizontal well plan to a "maximum-reservoir- contact" well development. A total of 95 single laterals were drilled initially whose information allowed an evaluation of the production performance from individual sands and helped improve reservoir characterization. The average rates for the single lateral wells, however, were lower than expected due to reservoir heterogeneities and the high viscosities of the oil (8.5° to 9.5°API). A multilateral development program started improving the potential for the individual wells and reducing the cost of completion and surface facilities. "Gull wing", "Stacked", "Pitchfork" multi-laterals with and without fish bones, have been used in different configurations to reach the maximum contact with the reservoir. The wells designs depend on the number of sand objectives and the distributions of the sands in the area around the pad drilling location. The fish bones have been used with different objectives such as: improve the initial rate, produce isolated thin layers where it is difficult to place a lateral and investigate upper and lower layers to provide information for placement of other laterals. A total of 172 maximum reservoir contact wells have been drilled with the field development. Some difficulties with the windows and water production have been solved satisfactorily based on the experience of the first multilateral wells. To evaluate the production performance for individual laterals multi-pressure-sensors and fiber optic/flow- trackers devices have been installed in the horizontal sections for some wells and tests performed.
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