Optimized reservoir development with high-angle wells, El Furrial field, Venezuela

The El Furrial field is one of Venezuela's major field assets and is operat ed by PDVSA (Petroleos de Venezuela, S.A.), the national oil, company. Its current production of more than 450,000 BOPD makes it a giant oil field. De velopment of the field, which has an average reservoir depth of approximate ly 15,000 ft, is in its mature stages owing to implementation of high-press ure gas injection. PDVSA has consistently followed a forward planning appro ach related to reservoir management. Using high-angle deviation drilling te chniques allows development wells to be strategically located by penetratin g the reservoir at high angles to optimize production rate, extend well lif e: increase reserves per well, reduce operating expenses, and reduce total field development costs. A reservoir model was constructed and simulated with detailed reservoir str atigraphy to determine realistic potential of high-angle wells (HAW's). Fiv e wells had been drilled as of June 2000, and the first four wells have pro ved the effectiveness of the design. The philosophy, modeling technique, we ll design considerations, problems encountered well results, and economic c riteria provide a clear understanding of the risk of this technology not pr eviously used at this depth in Venezuela. The result was the first HAW in t he deep, challenging environment of eastern Venezuela. Results show that optimization objectives can be attained with HAW's, mainl y increasing per-well production rate, maximizing per-well recovery, and ex tending the breakthrough time of gas or water from pressure maintenance and enhanced oil recovery projects. Well results indicate that the geological and simulation modeling technique is reliable and accurate. A pilot program shows chat HAW technology provides major advantages to increase production rate and reduce the overall number of wells needed to reach production obj ectives. However, the project also has experienced a number of unexpected d rilling problems.(1) The costs associated with the total project are significant, but more impor tantly. this program becomes very attractive because of the long-term benef its of decreased water-cut related to current water injection: decreased ga s breakthrough owing to high-pressure eat; injection, and fewer wells requi red to meet production goals. Technical contributions include the following: The modeling technique of applying detailed stratigraphy to a full-scale re servoir model is accurate if performed with the appropriate objectives in m ind. The application of state-of-the-art drilling techniques to attain high angl es at deep drilling depth is possible; however, drilling problems caused by formation instability require more study and experience. This method can be applied to other fields in the eastern Venezuelan basin currently under, or planned to be under, enhanced recovery programs and dev elopment programs.