Maintaining the production at mature fields in Western Siberia and the Volga-Ural region, including rolling-out the new technologies is one of the important work areas of Rosneft Oil Company. The quality of the selection technology and the professional skills of experts who form the well interventions program affect the performance of the measures. The current approach to the selection of well interventions is accompanied by a large scope of routine work and requires the use of a wide range of databases and archives. The lack of a single selection method leads to significant time-consuming efforts, the formation of a sub-optimal well interventions program, unsystematic operations, and lack of transparency and subjectivity of the decisions, the complexity of monitoring and control, and missing the expected technical and economic effect.
This paper proposes a fundamentally different approach, which takes the bulk of the routine work, leaving the user with a direct selection of the proposed candidates. The method of selection of well interventions has been proposed allowing, in the automated mode and using a software module, to rank the wells and make recommendations on conducting the well interventions. The authors developed the original sets of geological and technological criteria for the selection of well- candidates for several types of well interventions (BH treatment, remedial cementing, and recompletions). The membership functions have been built for these criteria and their weights have been determined. The algorithm and software module for ranking candidate wells and automated selection of well interventions has been implemented on the basis of fuzzy logic and fuzzy sets theory. In addition, it is possible to assess the most appropriate type of well interventions for a particular well. A preliminary testing of the algorithm, the criteria and the methodologies have been performed on a few selected wells with the actual well interventions. A satisfactory results convergence has been obtained for the well intervention type with the actual successful operations. After that, about 500 wells of one of the oil fields in Western Siberia underwent the experimental test processing. In the process of testing and expert discussion, a list of criteria has been adjusted; the wording of criteria and the range of parameter values have been updated.The value for the Company is determined by the improved quality of selection and validation of wells-candidates for well intervention, minimized probability of missing data because of the large volume of information, as well as saved time, effort, and resource. The main value for the Company is the increased production, which results from the multiple choice of well interventions ranked by the types and costs. In addition, it gives improved quality of the selection of wells by eliminating the mistakes of inexperienced staff and a reduction in time to prepare management decisions by allowing mass processing of large fields.