Abstract Oilfield assets are subject to a daily and perpetual decline, and as existing oil fields mature, recovering the remaining reserves is increasingly difficult. Billon dollar investments have to be made continually to offset the natural depletion and increase the production. The amount invested to overcome the depletion rate and increase the production is challenged by efficiency losses and rising expenses such as those generated by conservative drilling parameters, "train wrecks", hidden flat times and experience of the various service crew's personnel available in today's industry. This paper will focus on the engineering aspect of wellbore construction that enhances the development of the oldest Colombian oilfield. Significant improvements have been achieved in drilling operations by focusing on the effective application of drilling engineering, lessons learned, Company's best practices, and the adoption of state-of-the-art rig technology, thus reducing the drilling cycle by improving flat-spot operations and drilling operations, allowing the continuity of the development of the La Cira-Infantas mature oil fields in Colombia. Before September 2008 four conventional rigs were being used to drill an average of 14 wells per month. In January 2009, due to the early success of the program, and the need to optimize the CAPEX under the then current market situation only two automated rigs remain in operation, drilling an average of 14 wells per month and reducing the well cost-per-foot in more than 18% while oil production has increased in the order of 42%, and the success of the drilling operations have led to switching from an intensive work over/well services campaign to a more efficient drilling campaign.