Economical Mature Field Revitalization in Low Oil Prices Environment: A Ten Thousand Incremental Oil Production Case Story in the Drago Complex Field, Ecuador

Abstract

This paper presents the results of the most extensive hydraulic fracturing campaign on the same field in Ecuador, along with the methodology appliedto establish the real field production potential and an incremental oil production of 10,000 STB/d. The study started with the review of pressure transient analysis (PTA), resulting in updated values of permeability, skin and reservoir pressure, then conventional and special well logs were revisited to get a consistent approach of reservoir pay intervals. The characterization of formation damage mechanism was performed to confirm and complement the results. Strategic execution of the hydraulic fracturing workovers was implemented for fast track execution and to maximize results. The rigorous and fundamentals-based review showed that additional production potential, on most of the wells in the field, could be achieved by hydraulic fracturing due to the high skin values and the deep penetration nature of the damaged zone. The interventions schedule of producing and nonproducing wells resulted in short deferred production times. All planned jobs were designed with the goal of reaching the maximum production defined by hydraulic fracturing and complete nodal analysis. Most fracturing jobs resulted in folds of increase, FOI, from 2 to 13. The learning curve started from one stage tip screen out, TSO, and conventional long fractures, to two stage hydraulic fracturing, pulsed proppant and propped acid fracturing jobs. Economical evaluation showed that the whole stimulation campaign recovered the investment during the third month of execution. The incremental production outcome from these jobs resulted in ten thousandstandardbarrels per day, 10,000 STB/d, the historical peak oil of the field and the most extensive hydraulic fracturing campaign in the country.