Integrated Characterization Workflow Enables Ecuador NOC to Increase Oil Production from Very Thin Sand Reservoirs

Abstract

AbstractThe objective of this paper is to describe a comprehensive approach integrating static and dynamic well characterization to optimize well completion and subsequent improving oil production in thin sand reservoirs.The following procedure was used to estimate and optimize the production potential of 3 feet sand reservoir located in Limoncocha Field: Accurate well logging program to identify thin sands. (Vertical Resolution, Static Data)Open Hole Mini DST program to estimate permeability, skin effect, and reservoir pressure and productivity index. (Dynamic Data)Anchored guns with 800 psi of static underbalance to avoid control fluid invasion.Well completion done with drilling rig; No well test is required using this methodology.PVT sample taken in cased hole for further characterization and continuous improvement.Traditional workflows created by operators companies in the Ecuadorian Oriente Basin usually work very well in formations over 20 ft. thick. When such workflows are applied to thin reservoirs, frequently leads to bypassed zones with under estimated production potential. In order to offset this typical scenario, the G&G team working at Limoncocha field developed an integrated workflow to properly perform dynamic and static characterization of this type of zones to determine well productivity and the best completion method at an early stage while the well is still open hole. For this particular case study by a proper analysis the G&G team was able to characterize and predict oil production from 3 feet thin sand located at 11200 ft depth.Mini DST technique played a vital role in the process, becoming the optimum link between static and dynamic data that allowed the proper workflow integration. The application of an early integrated well characterization allowed to set an optimum completion system design including state of the art perforating and optimized ESP design with no prior well test resulting in an improving oil rate of 850 stb/day from 3 feet thick sand overcoming the idea that it is a low productive or no pay zone regarding its current cumulative oil production of 126 MMSTB. This methodology truly predicted the production potential opening a new scenario where deep thin sands are now considered economicalConsidering that the "easy" oil almost gone in the Oriente Basin, this paper describes an innovative workflow that allows proper planning to produce successfully thin reservoirs which in the past were considered low or non-productive.