Abstract
Abstract
Automated rig pump startup sequences are a common component of rig control systems (RCS) where the operator programs a sequence to the controller for its execution. This sequence is entered manually and it does not change unless the operator modifies it. The current paper presents a new approach towards pumps management, where the startup sequence is updated automatically for every new startup event, considering the current state of the equipment and the formation downhole.
A digital twin of the wellbore equipped with physics-based transient models calculates the hydraulic parameters to build the startup sequence for every pump startup event. The startup sequence is updated continuously and automatically while drilling using the current state of the formation and rig equipment as inputs. The sequence calculated by the digital twin in real-time is then transmitted to a hydraulics automation application to monitor the execution of the startup events. In addition, the hydraulics application can write the startup sequence to automated drilling control systems (ADCS) to execute the pump startup process using tailored sequences for every event.
The transient hydraulic model that enables the estimation of a safe and optimum pump startup sequence has been integrated into digital twins used during pre-job planning as well as in real-time deployments. The model successfully updates the startup sequence in response to changes in pressure limitations at surface and downhole. In addition, the model responds to changes in the gel formation process to adjust the startup sequence accordingly. Furthermore, the digital twin calculates the hydraulic limits to consider for an effective monitoring, such as the flow rate, surface pressure, flow rate gradient and pressure gradient at surface.
The calculated sequence and limits are transmitted to the hydraulics automation application, which monitors the execution of the startup sequence and calculates key performance indicators related to the process. This makes it possible to identify invisible lost time during startup operations. Furthermore, the startup sequence is exposed by the hydraulics automation application to ADCS to automate the execution of the startup and shutdown processes.
A case study from the North Sea confirms the effectiveness of the approach and illustrates its benefits. It illustrates the collaboration between multiple advisors and a single ADCS, when all features are deployed simultaneously in real-time, and then executed automatically by the ADCS. Four different applications were deployed in connection to the ADCS, namely the pump management application, tripping advisor, rate of penetration (ROP) optimization and stringer drilling (SD) advisor.
In contrast to mechanical automation practices, the proposed method automatically calculates a new sequence for the pumps for every new startup event, considering the pressure environment at surface and downhole. In addition, the sequence is transmitted to the ADCS for execution and real-time monitoring, closing the control loop to the equipment.