Wells Fargo (United States)

Abstract Openhole (OH) toe isolation in deepwater high‑pressure, high‑temperature (HPHT) wells remain operationally complex when deeper drilling is required to confirm reservoir boundaries, oil–water contact (OWC), or proximity to salt. Conventional balanced cement plugs can be time‑consuming, uncertain, and risk additional remediation at ultra‑deep measured depths. This paper documents the testing, integration, and field deployment of a metal expandable packer (MEP) used as an open hole toe isolation plug in a deepwater well at ~30,000 ft true vertical depth (TVD) under HPHT conditions (to ~21,000 psi and ~350°F). The MEP concept leveraged existing inventory, a modified liner‑hanger running tool (RT), and a structured engineering and risk‑management process to enable rapid mobilization and execution. The design review covered metallurgy (Inconel 718 base pipe with Sanicro 28 sleeve and SAF 2507 components), elastomer selection [FFKM (Perfluoroelastomer) / TFE-P (Tetrafluoroethylene-Propylene)], and anchoring/sealing requirements (ISO 14310 V3 seal qualification; axial load capacity up to ~1,000,000 lbf). Laboratory and surface integration tests confirmed the RT could actuate and release at required pressures (MEP expansion ~5,000 psi, hydraulic release ~6,000 psi). Field development for the operator involved drilling and completing three wells. A planned contingency was executed on the second well when an undesired zone was intersected at the base of the well. The MEP OH plug was deployed and set per procedure, enabling immediate progression to the OH gravel‑pack completion. Compared with a balanced cement plug (BCP), the MEP approach reduced operational time from ~80 h to ~52.5 h for toe isolation, translating to a total cost reduction from ~$3.7 MM to ~$2.7 MM for an assumed $1 MM/day rig spread, while avoiding cement contamination risks. Results, best practices, and an economic comparison are presented to support broader adoption of MEPs for open hole toe isolation in deepwater HPHT applications.

Abstract Background Hypoxia is a critical mechanism by which cancer cells evade the immune response, promoting tumour survival and progression. Many cancer types exhibit upregulated lipid and cholesterol metabolism as a fundamental adaptation strategy to the hypoxic tumour microenvironment. This metabolic shift supports cancer cell survival under oxygen-deprived conditions, enhancing their ability to resist treatment and metastasize. We will explore whether exercise reduces tumour hypoxia via increased systemic and local circulation across four cancer types. We will also test whether atorvastatin, a cholesterol-lowering drug, would further enhance the effects of exercise. We hypothesize that a combined intervention of increased physical activity and atorvastatin may reduce tumour hypoxia. We will also explore associations between changes in tumour hypoxia and clinical outcomes during oncological treatment. Methods The MOVES study is an open-label, randomized, controlled trial. It enrolls 400 adult patients with advanced cancer (prostate, breast, renal, or ovarian) who initiate first-line standard-of-care oncological treatment. Statin-naïve participants are randomized between three arms: (1) supervised exercise with atorvastatin (40 mg once daily) for three months, (2) supervised exercise without atorvastatin, or (3) unsupervised voluntary exercise. Participants who already use statins at the time of recruitment are randomized into two arms: supervised exercise or unsupervised voluntary exercise. The follow-up period extends for 24 months. Outcomes The study will assess tumour hypoxia in primary tumours and metastases using EF5-PET imaging, as well as tumour metabolic activity measured by FDG-PET. Additional assessments include circulating biomarkers of hypoxia and metabolism, tolerability of oncological treatments, body composition, physical performance, quality of life, depressive symptoms, nutritional status, cancer-related pain, personal relationships, progression-free survival, and overall survival. This randomized exploratory study will characterize the tumour-agnostic effects of exercise and metabolic modulation with atorvastatin on tumour hypoxia. Results from the trial will be published in international peer-reviewed journals following study completion, contributing valuable insights into the potential integration of exercise and statin therapy in cancer care.

Abstract Operational efficiency is critical to the economic viability of deepwater wells. To accelerate completion timelines, the Multistage Single Trip (MSST) system was introduced in the early 2000s, enabling frac-and-pack stimulation across multiple intervals in a single deployment. While this innovation significantly reduced rig time and operational complexity, it necessitated a dedicated deburring run to mitigate the risk of damage to isolation packers caused by perforation burrs. To further optimize the MSST system, metal expandable technology was integrated, eliminating the need for the deburring trip. This paper presents the planning, testing, qualification, deployment, and field results of incorporating the Well Expandable Inner String Packer (WEA-ISP)—comprising the Metal Expandable Packer (MEP) and Well Expandable Anchor (WEA)—into the MSST system. This integration replaced legacy isolation packers and enabled safe passage through perforated intervals without compromising zonal isolation or system integrity. A multidisciplinary collaboration ensured the successful deployment of WEA-ISP without altering well objectives. Key design parameters—including burr height, perforation length, and clearance—were identified to perform rigorous test on the WEA-ISP. The system underwent comprehensive ISO 14310 qualification, demonstrating its ability to withstand up to 15,000 psi differential pressure and anchoring forces exceeding 480,000 lbf. Field deployments in four deepwater wells, including both water injectors and oil producers in the Gulf of America, validated the system's performance. The integration of WEA-ISP into the MSST system eliminated the deburring run, saving an average of 2.7 days of rig time per ~30,000 ft well—equating to over $3 million in cost savings per well. The system supports both 10,000 psi and 15,000 psi treatment pressures without requiring additional inventory. This paper provides detailed insights into qualification protocols, engineering documentation, operational procedures, and contingency planning. The successful implementation of WEA-ISP within MSST completions demonstrates a robust, cost-effective solution that maintains reliable zonal isolation while significantly enhancing operational efficiency.

In this paper, we introduce a novel framework for processing SQL queries directly over encrypted financial data using homomorphic encryption (HE). Our solution preserves data confidentiality without sacrificing essential SQL operations, including SELECT, WHERE, SUM, and AVG, all performed on encrypted columns. Unlike traditional approaches that rely on trusted execution environments or secure multiparty computation, our method ensures that data remains encrypted throughout the entire query lifecycle at rest, in transit, and during computation. We present a prototype implementation and evaluate its performance using realistic financial datasets. The results demonstrate a practical balance between computational overhead and data privacy, offering a promising foundation for secure, privacy-preserving analytics in cloud-based financial systems

Abstract This paper provides an account of the design, implementation, and operational insights from a first-of-its-kind Enhanced Geothermal System (EGS) proppant stimulation targeting a dry rock setting with ~330 °C (626 °F) bottomhole temperature. It highlights the unique challenges of creating a high-temperature EGS and the innovative strategies employed to mitigate them, with the goal of advancing the scalability and viability of geothermal energy as a sustainable resource. The demonstration project involved recompletion of an existing wellbore to facilitate advanced stimulation strategies aimed at enhancing rock permeability in extreme thermal and mechanical stress conditions. Tailored high-pressure stimulation techniques, supported by real-time monitoring, were employed to create a system of interconnected pathways between an injector and future producer well pair. Simulation models were used to predict fracture propagation and optimize stimulation parameters. A suite of diagnostic tools, including fiber optics, microseismic arrays, acoustic pulsing, and chemical/nanotracers, provided real-time and post-process insights into the engineered reservoir volume and fluid dynamics. Initial results indicated that the project has created a reservoir with enhanced flow capability through propped fractures. The use of fiber optics yielded real-time data on temperature and microseismics, while microseismic mapping provided insights on subsurface dynamics and fracture orientation validation. Preliminary findings demonstrate the feasibility of high-temperature EGS development, while ongoing interpretations aim to refine understanding of reservoir behavior and optimize operational strategies. Currently, the drilling and stimulation of the twin well has been completed utilizing an optimized stimulation approach including but not limited to the implementation of the world's first sleeve above 300 °C (572F) for stimulation purposes, application of hybrid stimulation fluid for geometry creation and many more innovative approaches. This project represents a pioneering effort in extreme-temperature EGS development, contributing invaluable data and operational insights to the geothermal sector. By addressing the unique challenges of high-temperature reservoirs, the paper offers insight and adaptive strategies that serve as a foundation for future EGS geothermal initiatives and enables the development of superhot rock (SHR) geothermal to support scalable, dense, lower-carbon intensity energy sources.

Abstract Human trafficking and child trafficking are serious violations of human rights. Child trafficking is a despicable form of crime inflicted on the most vulnerable segment of the society. Availability of reliable estimates of the prevalence of child trafficking for various subpopulations is the first priority in tackling this problem. In our study, subpopulations are children of age 5–17 years living in small geographic regions (or chiefdoms) in Sierra Leone. We develop improved estimates of the true rates of prevalence and identify the most adversely affected regions by estimating the unknown true ranks. These estimates shed light on the severity of the problem and bring attention to the critically affected regions (i.e., chiefdoms). Using household survey data from Sierra Leone, we propose a unit-level hierarchical Bayes probit regression model to reliably estimate the prevalence rates of trafficking in the chiefdoms. Using Markov chain Monte Carlo generated samples of the small area characteristics from the posterior distribution of the hierarchical Bayes model, we compute point and interval estimates of the prevalence rates, and a set of probability distributions for the unknown true ranks of the small areas in terms of their prevalence rates.

This commentary discusses the provision of cardiopulmonary resuscitation to casualties in a diving bell. This single resource consolidates recent advances in the field, published in different medical journals, to support dissemination across the wider diving industry. It summarises the evaluation of techniques for the provision of manual cardiopulmonary resuscitation (CPR) to a seated casualty, including head-to-chest, knee-to-chest, and prone knee-to-chest compression delivery, and concludes that the only safe and potentially effective approach in a diving bell setting without room for a supine casualty is knee-to-chest CPR. The evaluation of a mechanical CPR device is discussed; it is found to be as effective as existing devices and manual CPR in terms of compression efficacy and is well-suited to the setting. The development of a bespoke resuscitation algorithm, together with deviations from accepted advanced life support algorithm principles, is presented. A novel 'upright CPR' technique for the provision of CPR to a seated casualty, developed during the algorithm evaluation process, is described. Finally, areas where evidence is still lacking, and research priorities for the future, are discussed; a key area for future work is the development and testing of a defibrillator suited to a diving bell setting, where space constraints, a heliox atmosphere, and the risk of both fire and rescuer injury are ever-present.