Successful Implementation of Managed Pressure Drilling Technology Under the Conditions of Catastrophic Mud Losses in the Kuyumbinskoe Field

This paper presents a study, illustrating results of effective cooperation between the Operator Company of the Kuyumbinskoye field, Drilling Contractor, and Service Company involved in the construction of the horizontal well using the technology of Managed Pressure Drilling (MPD). This article also describes the challenges encountered and successfully implemented engineering solutions permitting to meet these challenges. The main challenge in the Kuyumbinskoye field is the high risk of mud losses in the productive interval. The complex geological conditions as well as the anisotropy of the productive horizon complicate the prediction of catastrophic mud losses zones location. Approximately 50% of the wells were not drilled to the planned depths. To solve this problem, in 2017 a pilot project using MPD technology was initiated. The main goals to be reached by the implementation of this technology were drilling efficiency improvement, risk management, and well construction cost efficiency improvement. In order to achieve the goals, equipment was selected, a comprehensive well construction program was developed and detailed work plans were prepared. As a result of thorough planning and close cooperation at all work stages; the multidisciplinary team successfully completed the construction of 11 wells with an average extension of a horizontal interval of approximately 1000 m, drastically reducing fluid losses and associated non-productive time (NPT). By eliminating NPT and thus increasing the effective rate of penetration (ROP) during one of the wells, the drilling time of the lateral section was reduced to seven days, comparing to an average drilling time of the horizontal section of approximately 20-25 days (with conventional drilling). In addition, the average losses of drilling fluid per well were decreased by more than 1000 m3. The application of specially developed technological solutions during this pilot project not only ensured the attainment of target depths and geological objectives but also confirmed the potential of producing crude oil while drilling. Thus, allow to replenish encountered losses "on the fly" and to save time otherwise required to spend on the drilling fluid preparation. In addition to a technological breakthrough, it is important to emphasize that a high level of Health, Safety, Quality, and Environmental protection (HSQE) was achieved, and no major incidents or accidents were recorded during the entire project. Based on the lessons learned, several engineering, organizational and strategical resolutions were made to further streamline and optimize the well construction process in the field.