Well completions and workovers. Part 22. Workover evaluations

The objective of a workover evaluation is to find out if the workover was profitable and if not, why not. Evaluations also should be performed with a view toward improving methods and increasing profits even more on future workovers. Workovers can be evaluated from an engineering-operational viewpoint and from an economic viewpoint. When the gathering of post-workover data permits, these can be analyzed concurrently. To evaluate a workover, a great deal of feedback is required for both the engineering-operational and economic analyses, routine well tests along with concurrent bottomhole producing pressures, can be used for a quick engineering analysis of IPR curves. Workover evaluation economics consists of determination of the discounted profit-to-investment ratio and the discounted cash flow rate of return. Both parameters consider the time value of money and long-term profitability. Advantages and disadvantages of each of these criteria are presented. 12 references.