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As fields become mature and more laboratory data is available from specific geographical locations, it is possible to characterize, classify crude oils and develop or modify published correlations to better predict oil PVT properties. This paper shows the results from the attempt to classify and to provide calibrated correlations for the Ecuadorian crude oils. This study is divided in two sections, the first one makes a brief introduction to the main Ecuadorian oil fields, then the Oriente basin´s geology is described, geographical and statistical variation of crude oil properties is shown by reservoir and geological play. At the end of the first section, different criteria are applied to classify PVT samples showing that most data lie in the range of heavy oil. The second part uses the minimum square method to modify published correlations to provide relationships that helps the reader to better estimate oil properties in the absence laboratory data. Modified correlations as well as statistical results from the comparison of measured and predicted properties are listed at the end of this section.

Completion with anchored guns instead of killing techniques have been used extensively in Ecuador since 2008, completing 111 works to date only in Block 15. During this process several continuous improvement practices as well as new completion techniques were implemented including: Job design improvements: Well integrity analysisPenetration and Flow profile analysis on a foot by foot basisOptimization of the current designs by comparing dynamic under/over balance pressure recording with the simulation resultsPost audit of the calculated vs actual productivity Operational improvements: No fluid loss control used in workover operationsUp to two days of early production due to control fluid does not go into formation.Cost reduction since no special control fluid is used when perforating with static/dynamic underbalance and anchored guns.Minimal fluid loss control when perforating with anchored guns (small overbalanced perforating).New dual concentric completion architecture with anchored guns on the lower sands.The use of anchored guns in reentry wells with 5 ½" casing.Rig time saving when running anchored guns in monobore completionNew perforating procedure in monobore completion by activating anchored guns when ESP is running in hole, then pump is placed to the designed depth, this new operational sequence helped to prevent ESP damage due to high pressure is needed to activate firing head during workover operations when a low pressure reservoir is perforated. Productivity improvements: Significant reduction in both perforating and completion skins using static and dynamic underbalance. This paper shows different case studies of completion and perforating designs that enabled to reduce skin as well as completion time in Block 15. A new completion procedure using anchored guns with dual concentric completion is also described.

The 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 economical Considering 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.

This paper shows the results of the Lower U Sandstone prediction of Limoncocha Oilfield using the pre-stack elastic seismic inversion method, based on available well and seismic data. This study was focused to reduce the uncertainty in the location of new wells. The Poisson's Ratio (PR) is the most sensitive elastic parameter for discriminating lithology. Data of 49 wells were used in this study and the cross-plots analysis between mean PR obtained of seismic inversion and sand net thickness gotten of the wells show the best correlation (90%). Based on the results of this study 21 new wells were located and drilled, including horizontal and sidetrack wells. Currently, the cross-plots between these parameters in the Lower U Sandstone, including the new wells, keep a high correlation (83%). These results show the validity of this method for predicting the net sand thickness of the Lower U reservoir in the Limoncocha Oilfield. Production data were also correlated with the mean PR, and the best production matches with thickest sand development. Maybe this method could be applied in other Oilfields with similar results.