Well evaluation is the primary method used in the oilfield to determine the true well's production potential and reservoir characteristics. During a well evaluation, downhole parameters are commonly registered using downhole memory gauges, which can only be retrieved and read after the evaluation have finished. The problem with this conventional method is the uncertainty or ambiguity results and the inaccurate data of the downhole parameters; which often lead to inefficient tests times and difficulties for well test interpretation.The use of Fiber Optic for Real-time downhole measurements conveyed on Coiled Tubing (CT) and Nitrogen (N2) Lifting provide a unique live insight that allow us to monitor the well response while production or evaluation is performed, eliminating the uncertainties that surrounds traditional methods. Nitrogen lifting with Coiled Tubing was introduced as an alternative evaluation method for the common Hydraulic Jet Pumping that proved advantages accelerating well response and increasing the accurate of the reservoir data for well evaluation and artificial lift design nevertheless this still faces the delayed on the pressure data and transient interpretation. Implementing the Real Time downhole measures (P, T) is possible to eliminate uncertainties of reservoir parameters that surround well evaluations, adjust job parameters on-site, optimize job resources and time and finally anticipate artificial lifting design. This paper will present the results of the implementation of this new method in the area for well evaluation allowing real-time measurements of down hole pressure/temperature. Combining the fluid lifting with N2 through the CT, reservoir response is continuously monitored; thereby, allowing in advance an adequate design of the lifting system reducing nonproductive time. Real-time measurements and accurately data of the reservoir allow defining if a further stimulation treatment is needed. Actual treatment program can be continuously monitored or modified, to achieve optimal results. The first trial using the system demonstrated that the application can be used with a high degree of accuracy and control for the parameters and treatment designs that are not achievable using conventional techniques as the Hydraulic Jet pumping, gauges conveyed in slick line, joined tubing and/or using surface data to predict downhole behavior.

This paper describe in details the design and successful operation of an acid diversion completion system, which was used for first time in an exploratory project offshore Brazil. The most significant discoveries in a recent exploratory campaign in Campos Basin were in carbonate reservoirs. The first vertical well test showed a high heterogeneous and natural fractured carbonate reservoir. Considering the reservoir characteristics, analytical and numerical modeling was performed to assess the productivity of horizontal wells compared to vertical wells. As part of the Operator strategy of developing this oil field using maximum reservoir contact, a well test evaluation project in the open hole section, mitigating the risk of reducing the production, fractures cementation, etc. was performed. The whole project was developed to address the challenges of carbonate horizontal wells i.e. low permeability sections contributing marginally to the total production. A multistage horizontal open hole completion was designed and installed to perform a separately and selective stimulation in more than 3,000 ft of horizontal section. Previously, the most advanced technologies for open hole completions with mechanical isolation were reviewed to have the ability to perform multiples stimulations (fracture or matrix) in one continuous and more efficient operation. Based on final reservoir data obtained during the horizontal open hole navigation and a calibrated Geomechanical model, the acid diversion completion system was selected to perform an acid stimulation instead of a high pressure acid fracture job. The application was successfully run in this anisotropic carbonate reservoir and eight compartments were stimulated using an acid plant and high pressure pumps mounted on a Supply Boat dynamically positioned. More than 1000 barrels of stimulation fluid; a mixture of hydrochloride acid, and a visco-elastic agent to improve diversion were pumped stage by stage to the reservoir with a real time monitoring at the operator Support Center in Rio de Janeiro. After all the stimulation jobs and to prevent the high fluid losses, the well was shut in downhole using the reservoir formation isolation valve. A DST string was run. CT and Nitrogen were used to kick off the well and after 6 hours the well started to flow naturally, with first oil at surface within the first 8 hours of flow.

Shushufindi field is the largest field in the Oriente Basin in Ecuador and is located 100 miles east of Quito. It contains 3.7 billion barrels original oil in place (OOIP) and represents 10% of country's production. Determining reservoir properties using evaluation with hydraulic pumping for well testing has been a common practice in Shushufindi field since development in the early 1970s by Texaco Gulf Company and continuing in recent history with state company Petroamazonas.Due to the high level of depletion and reservoir characteristics, obtaing good quality data from well testing is a challenge, and if a decision is made based on the wrong information, it could have a severe negative impact on the asset. Ambiguity in the results of well testing with a hydraulic pumping method can stem from failure on downhole shut-in that allows the development of wellbore storage, which in turn would lead to difficulties for well test interpretation, accurate flow capacity/ productivity evaluation, fluid sampling, etc.To clarify all well testing concepts and results, a new procedure was developed for well testing in this field that uses a combination of drillstem testing tools, coiled tubing, and nitrogen lifting. With the developed method, the test is combined and continually conducted to test flow rate and drawdown buildups including downhole shut-in, providing reservoir and fluid parameters for a better evaluation and for artificial lifting design.This paper will present a study of the implementation of this new method, covering the areas of well evaluation and the outstanding results in accelerating well response. The procedures are generally easy to follow and to understand and have an impact in reducing rig time and nonproductive time and result in a faster return of the well to production (workover). The pilot showed excellent results in obtaining reservoir property measurements that were validated by reservoir modeling and production history. The process is robust, repeatable, and applicable to other fields with similar characteristics.

In 2007, a new Independent Brazilian Oil and Gas company acquired 21 exploration offshore blocks, increasing its portfolio up to 29 blocks by March 2009. Ambitious exploration and production goals were set, such as Drilling Commencement by Q3 2009, Minimum Well Drilling Commitments in four Basins by 2010/11, Initial Development in the Campos Basin and First Oil by 2012. The first three initial goals have already been met and the fourth one is well online to be met as expected with the FPSO already in the Brazilian coast. One of the key elements to reach these objectives is recognized to be the implementation of a focused innovative decision workflow, supported by a real time monitoring process from a cross-disciplinary Operations Support Center (OSC). This paper presents this innovative work scheme, based on a collaborative working environment between the operating and service companies during the well testing operations, with the most advanced monitoring and interpretation tools. It includes a concrete field case which resulted not only in improved risk identification, prevention and mitigation, but also in operational performance optimization. This case was a horizontal open hole test of 1080 mts with 90 deg deviation. The real-time collaboration resulted in significant rig time savings, mitigation of unexpected events consequences, and delivery of higher productivity comparing similar wells results in the area. This innovative decision workflow implemented in Brazil is considered as a high-technological reference model for operating companies, locally in Brazil and others around the world, to achieve success during challenging Well Testing operations.