The objective was to be prepared for a total and sudden loss scenario while drilling and coring a challenging well in the Barents sea. A dual-gradient Controlled Mud Level (CML) system with Controlled Mud Cap Drilling (CMCD) mode was installed on the rig to manage minor and/or total losses. Prior to spud of the section, an advanced dynamic simulator with the actual well configuration loaded was used to conduct offline training, and prepare the drilling team and involved service personnel for the operation. Experience from previous wells in the area identified the risk of drilling into karstified carbonate zones with the potential of leading to total and sudden losses. An advanced dynamic simulator was used to reflect the details of the CML system to be used. The rig crew together with the CML operator and other involved service personnel were trained on how to manage a total loss scenario by switching from CML to CMCD mode. All relevant operational procedures were used as a basis for creating training scenarios and operational preparations for the exercises. This paper will briefly present the simulator set-up, the operation/training procedures and results from the training. Feedback from the operation itself will also be described including lesson-learned from utilizing a full-scale dynamic simulator with the actual well loaded during preparation for operation.

As part of the digitalization and utilization of Automated Monitoring during drilling operations, real-time dynamic modelling of downhole combined with 3D dynamic visualization have been implemented on the drillfloor in offshore rigs. The objectives have been to give the driller instant feedback on the ECD and other effects of the operations and allow for a safer and smoother operation within the limits of the well. The basic elements of this technology are A digital twin of the well with all relevant data and properties included. A set of integrated transient models (hydraulics, surge & swab, displacement, mechanical friction). These models are driven by the RT data from operation and compute critical safety parameters which are presented for the driller. A diagnostic module analyzing differences between measured and modelled parameters and trends. A 3D Virtual Well which visualize the downhole well, the risk matrix, the diagnostics and messages as well as the ECDs at critical positions in the well. The 3D System has been utilized during drilling of several very challenging ERD and Multi-Lateral wells on two platforms in the North Sea. The system was also used during tripping in and out of the well, and during running of casing and liners. During these operations there is no PWD data available, and the modelled ECD values proved especially useful. The Trip-risk log from the Geologist was included in the 3D View during these operations, and the Driller could then see on the 3D when a risk was coming up. This paper will present the experiences from using the dynamic 3D & modelling system on several wells. The feedback from the Drillers and Drilling manager have been positive, and the results are very promising.

A Life Cycle Drilling Simulation System (LCDSS) was utilized during planning, training, and operation in support of a very challenging drilling operation in the Norwegian Sea. The LCDSS constitute a total modeling system tailor-made for planning, advanced training real-time simulation and decision support. In order to utilize the LCDSS, the work processes were modified and fit-for-purpose communication lines were established. In preparation, an advanced training session was performed using a dynamic downhole training simulator linked to a topside rig simulator, for training of the drilling teams. Prior to operation data transfer was established so that during the operation simulations was performed in real time using the ongoing operational parameters as input. Automatic look-ahead simulations of ECD and temperatures were performed with the calibrated models on the fly as support for decisions. Every day drilling forecasts were made 12 to 24 hours ahead. This was done by means of a transient planning model populated with all relevant data from the operation. These forecasts were communicated to the drilling team as a basis for the upcoming operation. This paper will first present the Life Cycle Drilling Simulation System, then elaborate on the use of this in the preparation/training phase and operational phase including forecasting. Special focus will be given to how the work process and communications were modified and the results thereof. The operation was successful, and the LCDSS was a contributor to this.

Dynamic Real Time Simulation, Forecasting and 3D Visualization was utilized extensively in support of a very challenging HPHT drilling operation in the Norwegian Sea. The well was a vertical exploration well in the Haltenbanken area. In preparation to the operation, an advanced training session was performed using a dynamic downhole training simulator linked to a topside rig simulator, for training of the drilling teams. A real-time link was established with the operation, and WITSML data in addition to all well, fluid and string data was streamed into a dynamic, real-time simulation system. This simulation system provided the following; RT dynamic modelling of the pressure (ECD) and temperature profile in the wellbore; the cuttings distribution and its effects on the ECD;Automatic look-ahead simulations of ECD and temperatures on the fly was performed with the calibrated models as support for decisions.RT profiles of simulated versus measured pressure at the PWD, and simulated versus measured standpipe pressureRT dynamically updated 3D Visualization of the downhole wellbore with a continuously updated risk picture made available for the drilling teams. Seamlessly linked to the RT system was a sophisticated what-if and planning model. 24 hour forecasting of operation was provided every day, and this gave a very good indication of future possible operational impacts. In addition to 24 hours forecasting, pre-planning simulations of upcoming sub-operations as well as what-if simulations on the fly were performed. The results from these simulations were used to update the risk register and made available in the 3D Visualization window. Three specific cases will be discussed in the paper; Pre-simulation of running the 9 7/8″ casingPre-simulation of cementing the 9 7/8″ casingRT modeling of ESD in case of mismatch between rig calculated and measured values In these cases the simulations provided valuable results which increased the risk awareness and prevented problems. The paper will also discuss the RT 3D Visualization and its impact on reducing risks and communicating the dynamic risk picture. The total simulation system with infrastructure, models and challenges will also be presented. The operation was successful, and the results from the simulation system was a contributor to this.

As part of the digital transformation in oil and gas industry, well construction move toward new efficient methods using digital twins of the wells. This paper will highlight how the drilling operations are monitored, how a digital twin of the well is utilized and how learnings are implemented for future wells. A Digital Twin is a digital copy of assets, systems and processes. A Digital Twin in drilling is an exact digital replica of the physical well during the whole drilling life cycle. Its functionality is based on advanced hydraulic and dynamic models processing in real time. By utilizing real-time data from the well, it enables automatic analysis of data and monitoring of the drilling operation and offer early diagnostic messages to detect early signs of problems or incidents. In the current study various actual operational cases will be presented related to different wells. This includes using digital twin during drilling under challenging circumstances such as conditions when using MPD techniques. Also, various diagnostic messages which gave early signs of problems during running in the hole, pulling out of the hole and drilling will be presented. High restrictions were detected using comparisons of real-time values and transient modelling results. These will be discussed. Different real cases have been studied. Combining digital RT modelled and real-time measured data in combination with predictive diagnostic messages will improve the decision making and result in less non-productive time and more optimal drilling operations.