Wellbore instabilities represent a major cost in drilling operations worldwide. Information on rock properties, stresses and pore pressure along the planned well trajectory are necessary for obtaining a safe mud weight window and avoiding events such as stuck pipe, mud loss, and well control problems. Currently, drilling teams experience large uncertainties in prediction of pore pressure and wellbore stability, leading to extensive non-productive time. There is today no solution available in the market for automated real-time updates of pore pressure and well stability during drilling ahead of bit. The well logs collected during drilling are used neither efficiently nor systematically to update the drilling operation during operation as efficient as one could do.
The idea is to test a digital workflow from pre-drill basin scale pore pressure modelling using a Monte-Carlo approach, till an automated update of pressure prognosis while drilling from e.g. sonic if available or resistivity logs, and thereby narrow the uncertainty in pore pressure ahead of bit. The innovative approach will reduce the uncertainty also in the predicted mud-weight window ahead of the bit. The project will demonstrate a unique automated approach enabling for real-time prediction of pore pressure and wellbore stability, ahead of bit during drilling and well operations. This will enable smoother decision making while drilling by continually updating the drilling plan. In addition, the uncertainty in the prediction will be quantified and dynamically updated while drilling. The modelled pore pressures in the well, will be compared with along-string measurements. A wire-pipe enables the real time transfer of information from downhole up to the surface at a faster rate than traditional methods. A real-time demonstration as a digital twin will be carried out for AkerBP on a North Sea well in September 2021. The project is owned by Kongsberg Digital, and SINTEF will contribute with research.
There is today no solution available in the market for automated real-time updates of pore pressure and well stabilities during drilling ahead of bit. In this project we will demonstrate such a digital workflow from pre-drill basin scale pore pressure modelling using a Monte-Carlo approach, till update of pressure and mud weight prognosis while drilling from e.g. sonic or resistivity data, and thereby narrow the uncertainties ahead of bit. The uncertainties in the predictions will be quantified and dynamically updated while drilling. This will considerably change the confidence of the drilling team in its choice of strategy during operations and enable more cost-effective drilling.
Major contributors are the pore pressure prediction methods in the Pressim2.0 and PPM modules. Pressim2.0 relies on a rigorous simulation of sedimentation and compaction of identified rock layers through geologic times. Fault compartmentalization and fracture criteria are implemented in the simulation, with the end result of producing a 3D underground map of over-pressured volumes, with end-of-simulation values representing today's situation.
The wellbore stability model PSI is based on improved correlations, giving the user many options to determine necessary input parameters for a comprehensive rock mechanics based failure analysis to determine the mud weight window.
Each of the software modules above is the result of extensive R&D work over several years. In this project these modules will be used dynamically and integrated with real-time logging data and High-fidelity flow model, while drilling.
The new PressureAhead HubApp combines four advanced software tools: Pore pressure prediction output from Pressim2.0, PPM for real-time update of pressure prognosis, wellbore stability prediction from PSI and real-time High-fidelity flow model calculations into a novel Module. The results should be made available in real time to the driller, as visualized in the SiteCom Console.