Algorithms and Models for Smart Well Planning With Emphasis on Trajectory Optimization

Well planning is a time-demanding procedure, which integrates knowledge and experience of various field professionals, as drilling engineers, pipe manufacturers, drilling mud specialists, geologists, etc. According to OG21 report (1), time spent for planning a well is on average 2–3 months. Drilling engineers have to design a well at minimum costs maintaining wellbore integrity at any time. The wellbore should also allow for maximum production from the reservoir and minimum tortuosity for successful casing running and completion. Fortunately, in the well-explored geological areas, where stratigraphic sequences and corresponding geopressures are known, the main objective can be narrowed down to optimal trajectory design. Optimal wellbore trajectory considers at least three criteria: shortest possible path, collision avoidance and longest possible contact with reservoir. Due to large number of modules involved, well planning requires a holistic approach. At the same time, due to complex interaction between the modules and respective physical models, this task implicates a high level of precision. This paper presents a development of an in-house well planning simulator, which integrates all essential well planning modules in a smart way. Central part of the simulator is represented by a trajectory planning and optimization module, which is based on minimization of wellbore length and dogleg severity. Constraints related to anticollision are also included. Introduction of smart optimization techniques for wellbore trajectory has a real potential of saving time and efforts by providing engineers with multiple options, which satisfy the aforementioned constraints. Our ultimate goal is to automate wellbore planning to the largest possible extent by developing smart optimizers for other vital modules within the well planning simulator.