Optimized Reservoir Development Using High Angle Wells, El Furrial Field, Venezuela

Abstract

Abstract The El Furrial field is one of the major field assets of Venezuela and is operated by PDVSA (Petroleos de Venezuela, S.A.), the national oil company. Its current production of over 450,000 BOPD makes it a giant oil field. Development of the field, which has an average reservoir depth of approximately 15000 feet, is in its mature stages due to implementation of high-pressure gas injection. PDVSA has consistently followed a forward planning approach related to reservoir management. Using high angle deviation drilling techniques allows development wells to be strategically located by penetrating the reservoir at high angles to optimize production rate, extend well life, increase reserves per well, reduce operating expenses, and reduce total field development costs. A reservoir model was constructed and simulated using detailed reservoir stratigraphy to determine realistic potential of high angle wells. Five wells have been drilled as of June 2000 and the first four wells have proven the effectiveness of the design. The philosophy, the modeling technique, the well design considerations, the problems encountered, well results, and economic criteria provide a clear understanding of the risk of this technology not previously used at this depth in Venezuela. The result was the first high angle well in the deep, challenging environment of eastern Venezuela, followed by four others. Results show that optimization objectives can be attained using high angle wells (HAW), mainly increasing per-well production rate, maximizing per-well recovery and extending the break-through time of gas or water from pressure maintenance and enhanced oil recovery projects. Well results indicate the geological and simulation modeling technique is reliable and accurate. A pilot program shows HAW technology provides major advantages to increase production rate and to reduce the overall number of wells needed to reach production objectives. However, the project also has experienced a number of unexpected drilling problems. 1 The costs associated with the total project are significant but more importantly, this program becomes very attractive due to: Long-term benefits of decreased water-cut related to current water injection.Decreased gas breakthrough due to high-pressure gas injection.Fewer wells are required to meet production goals. The technical contributions include: The modeling technique of applying detailed stratigraphy to a full-scale reservoir model is accurate if performed with the appropriate objectives in mind.The application of state-of-the-art drilling techniques to attain high angles 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 development programs.