Toward Drilling Automation: On the Necessity of Using Sensors That Relate to Physical Models

摘要

Current top-side and downhole instrumentation at the well site has been developed for the purpose of manually conducted drilling operations. The emergence of automatic drilling analysis software shows the limitations of today抯 measurements capabilities. It is therefore time to analyze the requirements for onsite instrumentation in order to implement new, efficient drilling automation technologies. On one hand, drilling is facing more and more difficult conditions with narrow geo-pressure windows, deep water or high- pressure and high-temperature (HPHT) conditions. On the other hand, unconventional hydrocarbon reserves may require a considerable amount of wells to be profitable. Drilling automation, by means of smart safeguards, automatic safety triggers, managed pressure drilling (MPD) and ultimately complete or semi-autonomous drilling rigs can provide the solution to safely construct wells in these challenging settings. The common denominator for the vast majority of drilling automation solutions is the use of physical models of the drilling process in the form of heat transfer, mechanical and hydraulic models. By analyzing the requirements of those models for necessary boundary conditions, it is possible to derive which measurements should be made both at surface and downhole in order to obtain stable and accurate calculations. This analysis also provides a way to estimate the necessary accuracy of the boundary conditions to ensure reaching the target control tolerance. Using the boundary condition analysis, it is possible to derive precisely which measurements should be done and where they should be performed. As a result, a typical organization of sensors that is compatible with the implementation of drilling automation solutions is derived.