National Oilwell Varco (Norway)

Abstract Drilling automation has emerged as a transformative force in the oil and gas industry, revolutionizing traditional drilling operations to enhance efficiency, safety, and cost-effectiveness. Central to its successful implementation are robust verification and validation (V&V) processes, which ensure the reliability, accuracy, and safety of automated systems. This paper explores the V&V of applications deploying wellbore protection and drilling optimization Advisors integrated with automated drilling control systems (ADCS). Drilling automation applications performing wellbore protection (e.g., pack-off, hookload, over-torque, among others) and drilling optimization functions (e.g., rate-of-penetration (ROP) optimization) are deployed on an edge device connected to an automated rig control system (ADCS). The Advisors parameterize existing capabilities of the ADCS to carry out protection and optimization tasks. The interplay between Advisors and the ADCS is evaluated using a simulated rig environment at different levels: system integration test (SIT) and hardware-in-the-loop (HIL). A variety of test cases are executed to assess how each Advisor performs in conjunction with the ADCS and how stable the integration is under both normal and contingency conditions. Each Advisor performs a self-assessment of its readiness to execute its function safely. The ADCS determines how to assign control of rig activities based on the availability of Advisors. The first layer of V&V, using SIT, simulates surface and downhole sensor signals that are ingested by the Advisors to test the interoperable system. The second layer, using HIL, generates sensor signals via actual programmable logic controllers (PLCs) to achieve a more realistic representation of the rig site. A series of tests enables a thorough assessment of whether each interoperable function between Advisor and ADCS meets design requirements (verification). Furthermore, the execution of these tests in the presence of multiple stakeholders (i.e., operators, drilling contractors, service companies) ensures that the systems perform as intended under real-world conditions (validation). Given the high stakes in drilling operations—including financial risks and environmental concerns—a comprehensive V&V framework is essential. With this approach, potential flaws are detected early in the process and can be resolved during the development phase. This paper presents a summary of the test cases executed for each Advisor across all rounds of testing, along with the corresponding learnings toward achieving seamless interoperability at the rig site. All tests were witnessed by multiple stakeholders representing operators, drilling contractors, service companies, and even assurance and risk management auditors.

Abstract The increasing need for effective carbon capture and storage (CCS) solutions has driven the development of advanced technologies capable of facilitating large-scale CO? management. This paper explores the use of unbonded dynamic flexible pipes in combination with offshore direct CO? offloading systems, emphasizing their scalability and adaptability to transferring CO? from floating injection units. The focus is on presenting the development, qualification, and certification of these fully CO?-resistant flexible pipes, essential for cost-effective vessel-to-well CO? injection systems aimed at permanent geological storage. To address the challenges of CO? stress corrosion cracking (CO?-SCC) and other material failure modes, a new innovative corrosion- resistant material for high-pressure flexible pipes was developed. An extensive testing program was conducted to evaluate the material's performance under CO?-rich conditions. The successful results formed the basis for the certification of a CO?-resistant flexible pipe with a Technology Readiness Level of 5, which is now ready for commercial-scale deployment. Additionally, the paper explores the benefits of integrating flexible pipes with two CO2 offloading systems—Single Anchor Loading (SAL) and Submerged Turret Loading (STL)—known for their endurance, flexibility, and uptime, enabling continuous CO2 injection in all weather conditions. The corrosion-resistant flexible pipe, in combination with the CO2 offloading systems, is an example of two technologies leveraging the desired robustness and efficiency for CCS without the need for complex technology changes affecting the already established subsea infrastructure. Finally, the paper underscores the potential to reduce the time to first CO2 injection by utilizing proven technologies.

This paper presents a method for estimating friction in hydraulic active heave compensated (AHC) offshore winches. The method is a two-step approach where the first step is to model the friction loss in the hydraulic motors based on data from the sub-supplier. The second step requires real-life testing, where the remaining friction losses in the winch system is identified and modeled. In this context, a practice is characterized by obtaining a friction loss estimation with the highest possible accuracy over the widest possible range of operating conditions with a limited amount of experimental work. The method benefits from the use of parametric models, sub-supplier data, and real-life measurements on a 150 t AHC crane from National Oilwell Varco Norway (NOVN). The work is an important part of developing a simulation model that can be used actively in virtual testing and verification of crane operations at NOVN. A friction loss model developed from the proposed method was implemented in a NOVN simulation model. Computed and measured hydraulic pressures showed deviations of less than 10 % from measured results for a 150 t crane operating in AHC.

Summary The problem of heave-induced-pressure fluctuation during drilling is considered. The surge/swab pressures created by the vertical motion of the pipe can excite resonances that may amplify the magnitude of pressure oscillations by a factor of 10. The locations of the resonant frequencies depend on the topside-choke opening and can hence be avoided. By use of a model of the full coupled dynamics, it is shown that the elastic pipe and the mud-in-pipe can also exhibit resonant behavior significantly affecting the downhole pressure. Techniques to avoid resonances are discussed.

Abstract The implementation of extended reach horizontal wells in Saudi Aramco, and in the southern area of Ghawar field in particular, is being increased for production and cost optimization. Logging these wells is a challenge, as production profile of a horizontal section cannot be entirely recorded with conventional coiled tubing (CT). This is mainly because of friction forces between the CT and the wellbore, which cause CT to lock-up significantly shallower than total depth (TD). Although with availability of this limited technique, such as metal to metal friction reducer, still CT reach cannot be maximized effectively. This paper will describe a successful utilization of agitator tool with custom designed e-line bypass that helps CT maximize the coverage of the horizontal section for logging purposes. The agitator tool was incorporated into the Production Logging Tool (PLT) and bottom-hole assembly (BHA). It was activated by pumping to cause the CT string to vibrate, and subsequently reduce the friction contact between the CT and the wellbore to allow CT running beyond the normal lock-up depth. The tool was trial tested in an extended reach horizontal well which has a TD of 12,118 ft. The simulator was showing a predicted lock at 10,400 ft while a dummy run proved a lock-up point occurs at 10,800 ft without activating the agitator. The e-line agitator was activated while the well was flowing at a restricted rate which maximized the reach to the TD and reducing the friction coefficient by around 26%. Different conditions and parameters were conducted in order to understand the best performance of the e-line agitator tool. The implementation of the e-line agitator resulted in extending the reach of CT by an additional 1,300 ft and reaching TD. This additional reach was significant as the last part of horizontal section was contributing water. The production log has been reviewed and showed acceptable measurements. This paper will cover the whole cycle of candidate selection, job design, execution, post job evaluation, lessons learned and conclusion.

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