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testing the population probability within the sample confidence intervals

Production or injection test with completion string in place Production and injection well tests, performed using production logging tools, are conducted to obtain pressure and optional flow measurements. Figure 3 shows a sketch of a basic version of the PS Platform* new-generation production services platform, equipped with a gas holdup sensor. During a well test, a particular flow rate schedule is applied to the targeted reservoir, using surface or downhole flow control equipment (in the case of conventional testing and production or injection well testing) or a software-selected drawdown routine (in the case of wireline formation testing). The resulting pressure changes and the flow rates (surface and optionally downhole) are recorded versus time, typically either in the same well or probe, or in a nearby well or probe during interference tests. From the measured pressure response, and from predictions of how reservoir properties influence this response, one can infer the values of these properties, which include permeability, skin factor and other parameters. A particular aspect of well testing is formation fluid sampling, which is one of the main reasons wells are tested. Well tests are quite varied in nature. Unlike logging runs, which consist of recordings of static formation properties such as density and resistivity, well tests must be designed before they are executed. Effective well testing must obey the design-execute-evaluate cycle, where the operations are first designed to target the measurement of specific parameters, then executed in the field, then evaluated—the evaluation expectedly yielding the values of the targeted parameters. If the objectives are not met, the evaluation feeds back into the design of future tests—sometimes also into the design of the test being performed—and the process continues through the design-execute-evaluate cycle to optimize the results versus the expectations. Because well tests can be designed to achieve many objectives under highly varied environmental and reservoir conditions, implementation in the field can be performed in a number of ways, using many different hardware configurations and an extensive suite of interpretation methods