Determining the optimum number of well tests to improve the success of the applied methods of reservoir and bottomhole treatment
Not infrequently, top management of oil companies challenge the wisdom of well tests. The reason is the production losses caused by the required well shutdowns and the costs of conducting and interpreting. A method for determining the optimum number of well tests is proposed and economically validated by setting probabilistic estimates of success (or failure) of improved oil recovery and enhanced oil recovery treatments and calculation of the costs of the pressure transient analysis considering production losses during well shutdowns. Another method to solve the same problem is also discussed in this paper. It is based on setting of tolerable error or standard deviation. It is found that for the samples of various parameters (pressure, production rates, injectivity, watercut) dimensionless standard deviation vs. the number of wells involved in surveys is practically similar, so, the obtained dependence is close to the Pareto distribution. The calculations by both methods show quite similar results; still, it is recommended to perform calculations for each particular field.