Shell (Netherlands)

Zechstein platforms in the Southern North Sea were thought to be fringed by kilometre-scale high-energy progradational carbonates with lowstand wedge geometries. Instead, a new well encountered a halite-rich evaporitic wedge that replicates the coveted progradational carbonates. This study integrates sedimentological observations with geochemistry, petrophysics and 3D seismic data to characterise the evaporitic replicas and then distinguish them from the genuine carbonate platform geometries. The evaporitic wedges generate laterally symmetrical rims around the platforms which are approximately 150m thick and 2000m wide. Wedge precipitation predated the well-characterised basin-wide Z2 drawdown event, and therefore the localised evaporitic progradational system was onlapped by basin-fill halite. The evaporitic wedges often feature domino slumping along weak progradational bedding planes, resulting in blocks that collapsed into the basin. The earliest progradational beds contained the highest concentration of microbialites which assisted stabilisation of the evaporitic wedges on the rims of carbonate platforms, whilst also indicating that the wedges were part of an environmental transition from marine highstand into basin desiccation. Microbial fragments were reworked downslope into brecciated debris flow deposits, demonstrating the relationship between wedge construction and syndepositional collapse on the outer slopes. Petrophysical and geochemical data show that the evaporitic wedges were closely associated with the early stages of drawdown, and a lack of post-anhydrite marine recharge resulted in the depletion of Ca2+ from the brine and accordingly limited anhydrite (CaSO4) precipitation within the wedges. This depletion in brine Ca2+ led to dolomitic microbialites (CaMg(CO3)2) in the lower wedge; however, the upper wedge features Kutnohorite (Ca(Mn,Mg)(CO3)2) showing that Mg2+ also eventually became depleted and was replaced by Mn2+. This analysis characterises a rare evaporitic phenomenon which can hide in plain sight in seismic data and act as a depositional intermediary between platform construction and basin-fill halite precipitation.

Abstract Quest Carbon Capture and Storage (CCS) is an operating CO2 capture facility near Edmonton, Alberta. The facility is designed to capture and store CO2 produced during the manufacture of H2 in Shell’s Scotford Upgrader. The facility is operated by Shell Canada on behalf of the Athabasca Oil Sands Project (AOSP) and aims to capture and store 1 million tons per annum (MTPA) of CO2. The operation began CO2 injection in August 2015 and had stored 9.8 MT CO2 as of December 2024. Quest CCS utilizes three wells for injection of CO2. The wells were constructed using API 5CT Grade L80-Type 1 above the injection zone and duplex stainless steels at the injection zone. This design prioritizes corrosion resistance in the areas critical to containing the target reservoir while lessening capital expenditures associated with corrosion-resistant alloy throughout the well. Online monitoring and thorough inspections have demonstrated this well design is robust for Quest conditions with only minor corrosion findings being documented for future learnings. This paper provides a summary of Quest wells materials of construction, exposure environments, and findings related to corrosion from the to-date successful operation. Limitations of the success of the design for other CCS wells are also discussed.

Abstract The hydrogen industry has been progressing towards increasing hydrogen transport in recent years. With the drive toward increasing hydrogen transportation, hydrogen embrittlement and parameters impacting the process have been scrutinized. While in smaller scale hydrogen projects, long-term hydrogen storage has not been a primary concern, the large-scale deployment of hydrogen demands safe and efficient long-term and high-volume storage options. Therefore, geological reservoirs, including depleted oil and gas fields have been considered for large-scale underground hydrogen storage (UHS) as they have been safely used for CH4 storage for decades. However, microbial activities in UHS are more significant compared to that of CH4 considering that molecular hydrogen is one of the main electron donors for microbial respiration in the subsurface. This demands an understanding of the subsurface microbial biosphere as well as those contaminants absorbed from the reservoir and introduced during drilling, pumping and mining. This contamination can have adverse impacts on the material integrity of both the downhole equipment as well as the above ground transport network for transporting back produced hydrogen. Since selecting resistant materials is not always economically viable, mitigation strategies – including appropriate purification processes – are likely essential for hydrogen repurposing projects. This paper discusses different impurities and how they contribute to a corrosive environment endangering material integrity of the network through a potential synergistic effect with hydrogen embrittlement. Additionally, the potential purification process that can be employed to minimize such impacts will be discussed.

Abstract North Kuwait Jurassic Gas (JG) asset has an ambitious gas production target to support domestic gas consumption needs and enable gas independency. Hence there is extensive drilling plan for JG new wells as the only non-associated gas asset in Kuwait. However, North Kuwait fields become extensively congested with +4500 of existing drilled highly deviated and horizontal wells. Hence, the need for an updated and verified wells’ deviation surveys database becomes crucial for anticollision risk. This paper will demonstrate the challenges, workflow and lessons learned of integrated consolidating the deviation surveys database of thousands of wells across all NK assets. Recognizing this importance, KOC has put in place a dedicated team and processes to ensure that all newly drilled wells are captured accurately and quickly. However, the issue of historical wells remains pending. These wells caused issues when planning because no definitive survey database was in place for these wells. During this project, spearheaded by the field development Gas asset and the Drilling teams collaborated to accomplish the first phase of their objective. This phase focused on a selected group of 750 well drilled before 2015, for which data had been available but missing verification. The project team has developed a structured workflow using artificial intelligence to collect and review the existing reporting data in the Daily Drilling Reporting (DDR), KOC information system, Workover reports and programs to cross check and verify the accuracy of the provided surveys. Every survey and borehole have been checked for header, tools assignments intervals, tool codes, total depth of the trajectory, boreholes sequence, borehole geometry and any relevant data to properly define the wellbore defining path and the related uncertainty. Due to the quality of the legacy data, several iterations of data fetching from the original service providers, Quality-check, corrections, and final loading have been performed. Some of the challenges encountered englobed missing surveys portions (gyro mainly), wrong sequences of boreholes, missing boreholes in the system, planned wellbores marked as definitive surveys, or a combination of these issues. This required a great integrated multidisciplinary team efforts including different project's stake holders. Deviation surveys of total 831 wellbores have been verified and updated into the database with excluding approximately 5% of wellbores due to insufficient data to conclude. This results in much better Anti-collision analysis enabling safer trajectories planning for the new planned wells to be drilled within this subsurface area to support achieving the asset production target. This project will increase the level of accuracy of wells Anti-collision risk analysis in North Kuwait fields area and enabling the aggressive field development plan of new drilling of deep Jurassic wells in a safer drilling from anticollision prospective

The reaction kinetics of reductive pyrite (FeS 2 ) dissolution by H 2 is important to predict the long-term aqueous and gaseous sulfide release in underground hydrogen storage and other engineered subsurface sites. We investigated the rates of pyrite reduction based on sulfide formation as a function of temperature (60-150 °C), H 2 partial pressure (0-150 bar), and pH in situ (∼ 4-10) in deoxygenated 0.03 M NaCl solutions. The experiments used natural pyrite powder (ø = 50-100 µm) and were run in hydrothermal batch reactors made of either titanium or Dursan®-coated 316L stainless steel. After experimental durations of ∼ 700-900 h, dissolved S -II (aq) concentrations measured by methylene blue spectrophotometry ranged from 10 -5 to 10 -3 M. Long-term pyrite dissolution and concomitant elevated S -II (aq) concentrations were controlled by the formation of secondary pyrrhotite (Fe 1-x S) and magnetite (Fe 3 O 4 ), which prevented the ion activity product of FeS 2 from achieving rapid saturation. Conversely, in the absence of pyrrhotite and magnetite precipitation, the solutions rapidly equilibrated with respect to pyrite, resulting in low S -II (aq) concentrations. Rates of reductive pyrite dissolution were determined at 12 h from total S -II (aq+gas) concentration vs. time data and were found to increase with temperature and H 2 -partial pressure. The rate dependency on pH at 90 °C, 7 bar P H2 was regressed either with an asymmetric ‘V’-shaped (two rate-pH domains) or a ‘U’-shaped (three rate-pH domains) relation. For this reason, two separate kinetic rate laws were derived, based on the ‘U’-regression ( E a = 35.2 kJ mol -1 ): r = 10 - 5.42 e - 35208 / R T P H 2 0.37 1 - Q K eq or the ‘V’-regression ( E a = 29.4 kJ mol -1 ): r = 10 - 5.13 e - 29370 / R T a H + 0.13 P H 2 0.37 1 - Q K eq The performance of both rate laws was validated by reproducing the experimental S -II (aq) concentrations in kinetic models. This comparison determined their applicability to be valid from 60 to 120 °C, 0-150 bar P H2 , and pH ∼ 6.7-8.6 (‘U’ rate law) or pH ∼ 4.1-8.6 (‘V’ rate law). The rate laws are compatible with geochemical reactive transport codes and will enhance the understanding of geochemical fluid-rock-gas interactions in H 2 -bearing subsurface environments.

The rapid evolution of dynamic network infrastructures has intensified exposure to sophisticated cyber threats, including zero-day attacks and advanced persistent threats, which traditional signature-based security mechanisms fail to address effectively. This paper proposes an Adaptive AI-Driven Threat Intelligence Framework (AID-TIF) that integrates machine learning, deep learning, reinforcement learning, and real-time threat intelligence to enable proactive cyber defense. The framework continuously monitors network traffic and system behavior, detects both known and unknown threats in real time, and dynamically adapts defense strategies based on evolving attack patterns. AID-TIF was implemented and evaluated in realistic network environments against multiple attack scenarios, including DDoS attacks, malware propagation, and insider threats. Experimental results demonstrate a detection accuracy of 95% for known attacks and 85% for previously unseen threats, with a low false positive rate of 3%. Additionally, the framework achieves rapid threat detection within 1.5 seconds and automated mitigation within 5 seconds, significantly reducing potential damage and downtime. The key contributions of this work include a hybrid AI-based adaptive architecture, seamless integration of external threat intelligence, and automated real-time mitigation. Overall, AID-TIF offers a scalable, resilient, and forward-looking cybersecurity solution for modern network environments.

Dielectric elastomers are soft, lightweight, and highly deformable electroactive polymers that undergo large deformations when subjected to mechanical and electrical loading. This unique property makes them promising candidates for applications in artificial muscles, soft robotics, biomedical actuators, and sensors. In this study, the large deformation behavior of a flat, circular dielectric elastomer membrane, clamped at the boundary, is investigated under the combined influence of lateral pressure and an applied electric potential across its thickness. The resulting model provides a framework for predicting deformation profiles and electromechanical stability limits in dielectric elastomer actuators.