bluuebunny/crossref_metadata_2025 huggingface dataset:
Overcoming the Challenges and Complexities of Maintaining the Integrity of Subsea Infrastructure in Cook Inlet, Alaska
Authors: Kidwell Rachel B. , Bacher Tasha M.
Published: April 2023

Legal Notice: Any use of trade, product, methods, terminology (lingo, etc.) or firm names are for descriptive purposes only and do not imply endorsement by that company, Hilcorp Alaska, LLC, or any of its affiliates or parent company.

Objectives/Scope

The objectives of this paper are to highlight the following:

The complexities of managing and maintaining a fleet of aging offshore infrastructure in Cook Inlet, Alaska, using conventional and unconventional methods. The continued search for innovative solutions and refining current processes to extend the life of these facilities. Once the facilities have reached the end of their producing life, retrofit for other potential useful opportunities such as capitalizing on the renewable resource possibilities Cook Inlet possesses.

Methods, Procedures, Process

Results, Observations, Conclusions

Cook Inlet, Alaska is the state's main industrial water way and home to 15 offshore production platforms owned and operated by Hilcorp Alaska. Operating in the Cook Inlet is extremely complex and difficult because of its unique environment.

Many of those 15 platforms were installed in the 1960's and originally thought to have short life expectancy. Over 60 years later, due to regular inspections and repairs guided by API 2 SIM, most of the facilities are still producing.

Many typical forms of inspections and repairs cannot be conducted in Cook Inlet. Operators, inspectors, contractors, and divers must get creative to overcome many hurdles to achieve the tasks necessary for operation and structural integrity.

When platforms go through the P&A process, the threat of environmental hydrocarbon pollution is removed. Hilcorp is currently looking into renewable resource opportunities for these structures to further achieve its goal of extending the useful opportunities of these facilities, given their robust infrastructure.

Additive Industry Information

This paper details the continuing challenges and constant search for new technologies. The hope is to educate the industry on the specific resources and technology that is needed in Cook Inlet and sharing the unconventional methods that have been developed over the years.

This paper does not discuss downhole operations.
Evolving Methods for Design by Analysis for Glassy Polymers in Marine Applications
Authors: Kemper Bart , Stromer Jarl
Published: April 2023

The use of glassy polymers such as acrylics and polycarbonate for marine hulls, windows, and transparent housings has been in more demand due to increasing use of ROVs, AUVs, and smaller non-military submarines. New "Design By Analysis" (DBA) methods will provide for innovative applications while maintaining safety, reliability, and traceability.

The new approach will account for the type of application while enabling new materials and shapes through a combination of experimental and computational methods based on Verification, Validation, and Uncertainty Quantification (VVUQ). Previous standards for life-critical applications like diving systems and submarines were locked into 1970's empirical methods based on defined shapes without directly using material properties. Other uses of glassy polymers, like camera housings, have been more ad-hoc. The method under development will give equipment designers the option to use modern methods like Finite Element Analysis and Computational Fluid Dynamics to innovate within existing engineering code processes.

American Society of Mechanical Engineers (ASME) Pressure Vessels for Human Occupancy (PVHO) codes and standards was developed in the 1960's and 1970's based on US Navy-funded experiments. It has a proven safety record, so much so it was recently incorporated into the ASME Boiler and Pressure Vessel Code for industrial equipment. Limited by its empirical basis, it does not use material properties directly to allow you to reduce the thickness by increasing the strength, as one example. Another limitation is the tables in the code are limited to a specific range of shapes and geometric parameters, all of which were set over 50 years ago without any provision to add new shapes or parameters. These limitations have constrained later equipment development, particularly where there are requirements for engineering code compliance. The proposed DBA method under development through ASME uses PVHO applications as the benchmark for the most extreme risk, given the issue of having humans in a confined space under pressure. Once established, this method can be used for other applications ranging from spaceflight to autonomous vehicles to architectural use with the design margins adjusted based on risk analysis, all with traceability provisions for design, materials, manufacturing, and testing.

The techniques proposed for this DBA method are proven and can be used immediately by equipment designers regardless of being part of an ANSI-approved engineering standard.
Harnessing Leak Detection System in Offshore Pipeline Operation
Authors: Susanto Tedy , Nurmansyah Muhammad Dedy , Ladd James Thomas
Published: April 2023

Delivery of crude oil from Single Point Mooring (SPM) through subsea pipeline to Onshore Receiving Facility (ORF) play critical role for refinery processing and operation. The pipeline laid in seabed, connecting oil tanker to storage facility on onshore side. Leak Detection System (LDS) is required to monitor any oil leakage from the pipeline. If leak happens and no LDS in place, mitigation action will be late, cause much oil or gas will be released to the environment, dangerous for ocean habitat, harmful for human and asset safety i.e. explosion and fire, then it can impact on company reputation that own or operate the pipeline.

Tankers transport crude oil via subsea pipeline to oil refinery storage tank including activities such as loading, unloading, and flushing line. Pipeline LDS project scope of works comprise hardware, software, and service. The integration amongst these parts will determine project completion success criteria. Supervisory Control and Data Acquistion (SCADA) system located in Central Control Room (CCR) is used to monitoring all pipeline operation over long distance. The connected data start from smart field devices, collected by Remote Telemetry Unit (RTU), transmit by telecommunication media, and finally reach the CCR. All operation setting can be adjustable according to different kind of oil product LDS software is an advanced high fidelity software application for the pipeline industry which meets the American Petroleum Institute Recommended Practice (API RP) 1130 Computational Pipeline Monitoring (CPM) system.

When the SCADA and LDS system were installed, the project will continue into commissioning and critical tuning phase where actual values and Standard Operation Procedure (SOP) is established or revised. SPM's power availability from solar panel and telecommunication bandwidth should be monitoring all the time. Parallel with that, there is the possible threshold setting should be estimated as per API 1149 that impact on leak detection performance from several factors i.e. accuracy of pressure, flow, and temperature transmitter, slack line condition, and properties of products. The crude oil coming with different API from different oil producer. The system will continuously calculate imbalances using data gathered from field devices. Dynamic threshold adjustment to mitigate transient alarm and avoid false alarms, which these are temporary changes and are removed after time averaging period end. By have all these information via SCADA and Closed Circuit Television (CCTV) system, it will reduce boat trip to the SPM, which means reduce CO2 emission and operating cost. LDS system will monitor the pipeline leakage and provide good mitigation plan by located the leak with Global Positioning System (GPS), delivering crude oil using offshore pipeline will be safer to human safety and environment.
A Comprehensive Evaluation of Properties of Common and Regional Cement Formulations from a Well Integrity Standpoint
Authors: James Abraham Jocin , Devers Cameron , Teodoriu Catalin , Amani Mahmood
Published: April 2023

Oilfield cements have been an integral part of any drilling operation and forms the primary barrier when it comes to ensuring wellbore integrity. The strength of the cement layer is one of the primary factors that confirms the success of the drilling job and ensures the well remains productive and without issues throughout its productive years.

The type of cements used in any oilfield operation depends on several factors including, but not limited to lithology, type of formation, pressures and temperatures, type of formation fluids and the overall purpose of the cement job. This requires customized cement jobs and recipes specific to the well and the section being drilled, and this is ensured by the use of specialized additives to the base cement mixtures to control its properties. Due to major differences in lithology, standardization, and properties of hydrocarbon reservoirs in the Middle East and the rest of the world, several customized recipes and formulations are used which are specific to the region. This paper is aimed at aggregating available information from common cement recipes in the Middle East and North America, and evaluating properties based on laboratory results available from representative experiments done as part of developing a cement database.

The differences in geology have resulted in fundamental variations in cement formulations used in Middle East and North America. Literature from the Middle East region overwhelmingly indicated that API Class G is more commonly used, while Class H cement is more commonly favored in North America and the rest of the world. The differences further extend to the type of additives used as well. Formations in the Middle East have a higher occurrence of vugs and fractures, as well as gaseous hydrocarbons and/or H2S needing the use of LCM and other additives. Cement recipes vary from well to well, as does the use of sea water versus fresh water. Additives such as accelerators, retarders, defoamers, as well as fluid-loss control agents, are also commonly used. All these impact the properties of the cement, especially when monitored over time, and when accounting for ageing effects. Several teams have conducted stand-alone evaluations of various cement formulations, and documented their properties, though the presence of a comprehensive database of literature and laboratory-based results are lacking.

Documenting such variations in the cement formulations and comparing the differences can help in better understanding the functionalities and efficiencies of cements used. Integrating these into a comprehensive database with laboratory-tested results can help in creating a knowledge base which could be utilized by the industry to better understand the performance of these cement mixtures over time and identify potential wellbore integrity issues.
Modelling of Multiphase Flow During Transient Operation of a Carbon Capture and Storage System
Authors: Stokes Stephen , Zhai Suling , Haghighi Hooman , McKay Craig James , Erickson Dale Douglas
Published: April 2023

Carbon Capture, Utilization and Storage (CCUS) holds a critical role in securing our net-zero future and significant growth is required in the industry to meet these demands. Typically, CO2 fluid transportation takes place in the dense or supercritical phase before the compressed CO2 is sequestered in a geologic reservoir. However, the CO2 mixture may move across the phase boundary during transient operating scenarios due to the narrow operating envelope. The presence of impurities significantly increases the risk of multiphase flow with implications on the cost of processing, transport, storage and moreover additional challenges to the design, safe operation, and integrity of the system.

Wellbore integrity and risks associated with phase split and multiphase flow is one of the major concerns for CCUS system operation. This paper discusses the setup of a real time Integrated Asset Model (IAM) using a specialized thermodynamic model for Carbon Dioxide (CO2) rich fluid coupled with a sophisticated thermo-hydraulic model for accurate automated forecasts of the CO2 fluid phase behavior and no touch time for liquid dropout (water and liquid CO2) in the transport system including the wellbores and a simplified multi-tank reservoir model for the injection wells. The IAM simulation results have been benchmarked against field operation data. Two specific use cases are demonstrated in this paper.

Firstly, simulation of a well depressurisation was carried out using the IAM in an offline mode to assess the impacts of phase split during a procedural transient operation (leak-off valve testing). Secondly, a sensitivity on the reservoir pressure was assessed to determine if there will be a consequent "stiff response" / significant system pressure change and a risk of multiphase flow due to the subsurface uncertainty.

The field proven real-time IAM model is shown to provide robust and reliable simulation with speed and is demonstrated to be a novel and valuable tool for CCUS operation planning and optimization.
Mero Giant Field: A Successful Case of Recovery Optimization During Development
Authors: Rosa Marcelo Becher , Orrico Israel Bruno da Silva , Neto Luiz De Abreu Henriques , Rocha Lis Franco , Moura Daniel Henrique Liberal de
Published: April 2023

Five years after Mero Field commercial declaration, around 200.000 bbl/d are being produced, with an expected production peak over 600.000 bbl/d to be reached in the next years. Successful results are being achieved with a reservoir-oriented strategy to minimize risks and maximize value. The main aspects of this strategy, which aims at attaining a recoverable oil volume of more than 3 billion barrels, is described in this work.

Mero's development strategy combines two main phases: the first focused on data acquisition for definition of the global development plan and flexibilities necessary for further optimizations and the second focused on the plan implementation using the flexibilities to optimize results during deployment. On the first step, a development plan with four 180.000 bbl/d production systems and a FPSO of 50.000 bbl/d was conceived, with produced high CO2 content gas full reinjection (WAG) as the recovery method. However, relevant reservoir uncertainties remained, which required actions for guaranteeing that risks could be mitigated and opportunities could be seized during the projects’ execution.

Some of the applied strategies were: an itinerant EWT unit allocated on main dynamic uncertainty areas, the anticipation of a few development wells in strategical reservoir positions, the use of flexible EPCI contracts allowing a range of possible flowlines extension acquisition, and an integrated multidisciplinary rigs schedule using preceding wells data to define next locations final position. Anticipated wells along with EWTs were important to appraise critical reservoir regions and to verify communication between different reservoir zones. Seismic data improvements enabled a better reservoir characterization. However, only during the second phase of the above-mentioned development strategy, using all the gathered information together was it possible to identify in a more precise manner relevant aspects, such as the presence and location of igneous bodies in the reservoir zone, a new area of the reservoir to be drained, and the aquifer characteristics. With knowledge evolution, reducing uncertainties and confirming opportunities, changes in drainage plan were then accomplished after FID, using the EPCI flexibilities milestones, defining the final wellhead locations and well trajectories closer to each project's first oil. The first three Mero projects have already gone through this optimization process with expected gains up to two hundred million barrels of additional oil recovery.

A balance between audacious strategies for project and profit acceleration and flexibility strategies for path correction and optimization has been fundamental for the development of complex fields, such as the pre-salt ones. The strategy herein presented is leading to a successful development of Mero Field and may be used for the development of other offshore projects to maximize recovery and economics.
A Novel Technology to Efficiently Detect Hydrate Formation in Subsea Flowlines
Authors: Chittenden Paul , Sporkel Rolf
Published: April 2023

The objective of the R&D project and subsequent field testing was to develop, test and commercialize a new technology with an emphasis on scanning speed for use in subsea flowlines to detect hydrate plugs through thick subsea coatings without the need for 360-degree access of the pipe.

Acoustic Resonance Technology has proven to be an extremely reliable and accurate way to measure wall thickness of coated flowlines and risers with insulations thicknesses of 90+ mm. While advancing the use of Acoustic Resonance Technology for pipe-in-pipe applications, it was theorized that the resonant frequencies would be able to detect the unique acoustic signature of hydrate formation within a pipe. The client initiated an R&D project to test the use of Acoustic Resonance Technology on hydrate formations in a lab setting. The testing showed a clear indication of hydrate acoustic signatures while only needing access to the top half of the pipe. The client moved to a field test on a 12 km flowline off the coast of Angola.

The offshore field test was completed on an 8-inch 3-Layer polypropylene (3LPP) coated water injection line at a water depth of 1,300 m off the west coast of Angola. The tool scanned 12 km of pipe within 33 hours and identified the length of the hydrate plug. A second tool was launched to complete a 360 degree scan to define exact start and end points of the hydrate plug. Client achieved a significant cost savings compared to comparable methods due to inspection speed and a reduction in pre-inspection dredging time.

This paper will show how field proven technologies, in particular Acoustic Resonance Technology, can be adapted for new uses within the subsea industry. The testing and field work shown in this paper will provide evidence of a faster and more efficient way to detect and measure hydrate formations compared to existing technologies on the market.
Global Performance of an Asymmetric-Monohull FPSO
Authors: Xia Jinzhu , Yusof Fazli , Sukri Hilmi
Published: April 2023

Due to significant levels of transversely imbalanced riser, topsides and structural loads, a conventional monohull FPSO with a large number of deep-water risers hung on one side is not optimal in terms of load carrying capacity, ballasting operation and cargo loading/offloading operation, among other deficiencies. An asymmetric hull form, as applied to the Mero 3 project for the Santos Basin offshore Rio de Janeiro, has proven to be advantageous. In this paper, the asymmetric hull form of the Mero 3 FPSO is presented. The stability, global strength, vessel motion, wave loads, ballast and cargo operations as well as wet tow performance of the FPSO are discussed.

The global performance of the Mero3 FPSO has been examined both numerically and through model tests. Extensive stability verification and loading analysis have been performed using the NAPA software. Comprehensive diffraction analysis and wave basin model tests have been conducted to quantify vessel motion, slamming and green water characteristics. A modified dam-break solution is proposed to determine green water height and speed profiles on the FPSO deck for structural and equipment protection design (Xia et al., 2022). A novel frequency-domain approach is developed to provide both extreme and fatigue design loads for the bilge keel (Xia et al., 2023). The wet tow performance is studied through towing tank model tests and SafeTrans simulations.

Compared to an initially proposed symmetric hull form design, the asymmetric hull form results in more even transverse cargo distribution. It is shown to reduce ballast operation, reduce structural strengthening requirement and improve cargo loading/offloading operability, in addition to improving storage and ballasting capacities. The hull form exhibits excellent motion performance in the Mero3 field that is susceptible to swells. In the 100-year return design conditions, the maximum roll angle is below 6.5 degrees. This makes normal process operation in the 100-year return storms possible. The favorable motion performance also brings benefits to the fatigue lives of the steel catenary risers (SCRs) and the mooring system. Wave slamming on the hull becomes a minor issue with the ballast draft of more than 14m. Design for green water impact is also manageable with improved green water profile quantification developed during the project. Based on the results of the towing tank model tests, no fish-tailing stability problem is expected during the wet tow. Conventional two or three tug tow from yard to field is feasible.

For the first time, the offshore industry is seeing the successful application of an asymmetric monohull for a large FPSO, to be installed in the deep-water Santos Basin offshore Rio de Janeiro. The asymmetric hull form offers optimal global performance in many respects for applications similar to the Mero3 FPSO.
Building a CCS Hub at Scale in North America
Authors: Sandhya Sundar Ram , Preston Broom , Mohammed Saratu , Uvwo Ayse
Published: April 2023

Carbon Capture, storage (CCS) and utilization is an integrated solution that can help to abate against carbon dioxide emissions aiding to meet local and global net zero goals. A suite of technical solutions works to capture CO2 that is emitted, followed by compression into pipeline or barging systems that transport into storage sites. At these storage sites, CO2 is injected into rock formations that permanently sequester the CO2 for a long time.

This paper discusses Shell's (refered as "company") ADIP-ULTRA solvent technology, which provides pre-combustion CO2 removal and has been applied to more than 500 units around the world, including the company's operated Quest project in Canada. Quest in Canada is one of the most mature CCS operations in the world having sequestered nearly 8MT so far safely. As part of this technology our company also currently licenses a post combustion capture technology across multiple industries including power, steel, cement, and refining.

In this paper, we will share some of the successful ways of working to overcome barriers of development to create a CCS hub including aspects of successful capture, transport and storage (in underground reservoirs) at scale in North America.
Quantitative Comparison of Four-Point and Multi-Point Support Configurations for FPSO Topsides Module Structures Design
Authors: Lim SawHoon , Luquiau Eric , Van-Meenen Cecile , Tan Jaime HuiChoo , Sablok Anil
Published: April 2023

This paper presents a comparison of four-point and multi-point support configurations for the structural design of typical ship shaped FPSO topsides modules. Quantitative structural assessment is performed for modules with operating weights of between 1,100 MT and 4,800 MT to determine the optimum numbers of module supports for reduced steel weights and costs. Structural analyses of three ship shaped FPSO topsides module structures of different sizes, weights and stiffness values, supported on four-point supports and multi-point supports are performed for in-place and pre-service conditions. Between 9 to 19 supports are provided for the multi-point support configuration cases. Hull deflections based on several reference hulls with single-bottom or double-bottom construction, and suitable fabrication tolerances are considered in the module structural design. Steel weights considered include the weights of the support/interface structures and the hull deck local reinforcements besides the main module structural weight, for strength requirements. For the cases assessed, it is found that by using multi-point support configurations the module structural weights could be lowered, and the weight savings reduce almost linearly as the module overall weight and/or module vertical structural stiffness increase. Based on the module structural configurations considered, a maximum module overall weight has been determined for effective use of multi-point supports instead of four-point supports to produce significant steel weight savings of more than 10% for the main module structures and more than 50% for the interface structures. For modules with greater overall weights, four-point support configuration is found to perform better than multi-point support configurations.

While both four-point and multi-point support configurations for ship shaped FPSO topsides module structural design have their respective pros and cons and have been successfully applied in different FPSO platform designs in the past, the optimum utilization of the two types of module support configurations from the aspect of steel weight and cost, are not well established. This paper presents a direct comparison of both types of support configurations and suggests the optimum support configurations for ship shaped FPSO topsides modules based on the expected module operating weights. This information could serve as a reference in determining the potentially lighter and lower cost module support configurations for topsides module structural design at the start of a ship shaped FPSO platform design project.
Magnetic Coupling for Electric Submersible Pumps (ESPs) and Downhole Gas Compressors
Authors: Patrick McMullen
Published: April 2023

Isolation of critical electrical systems, e.g. motors, from downhole liquids and gasses is critical to downhole tool operation and reliability. A magnetic coupling can allow for hermetic isolation between two rotating systems, such as a motor and a pump. The coupling provides non-contact torque transmittal from one shaft to another using magnetic fields, thus eliminating sealing along rotating shafts, instead relying solely on static seals in housings. The design and performance data is the result of the development of a downhole gas compressor using a magnetic coupling to torsionally link the drive motor shaft and the compressor shaft. While developed and in use for a high-speed downhole compressor, this technology is applicable to conventional ESPs, as the design and integration approach can also be adapted for liquid environments at lower speeds and higher torques.

The requirements for the magnetic coupling were first defined based on the compressor operating requirements. In addition to the torque requirement, critical to magnetic coupling design are the operating speed, fluid, temperature and any other constraints, such as size. These requirements guided the analysis, design and testing of the full-scale components. Empirical analysis tools were used for initial iterations in size and performance of the magnetic coupling, followed by detailed magnetic finite element analysis (FEA) using commercially validated tools for the final performance prediction. With analytical validation of performance, detailed designs were developed and hardware was fabricated. Hardware testing was done to validate performance predictions and alignment with system requirements, including static torque measurements and high speed operation.

The design and analysis of the magnetic coupling was conducted and will be presented along with the build and test results. Pole count in the coupling as well as pole width were optimized to provide the highest torque density for the magnetic coupling. Clearance between the male and female magnetic coupling was minimized to provide maximum torque while still allowing for adequate clearance between the male and female to have a sealing cup in place. Magnetic coupling performance results include static torque measurements and high speed operational testing. Test data was used to validate the analysis approach, thus allowing for development of further magnetic coupling sizes and configurations suited for other downhole gas compressors as well as ESP applications. To highlight the applicability, a magnetic coupling sizing for an ESP application was performed and will be summarized.

This technology offers a coupling that can greatly enhance downhole compressor and ESP performance and reliability. The magnetic coupling is a contact-less coupling system that does not require rotating seals, is easily fully sealed from the environment, and has no operating life limits. The coupling can also be built using state-of-the-art permanent magnets, allowing operation to temperatures of 300°C.
Developing the Next Generation of Pipeline Inspection AUV
Authors: Cheramie Jami , Anderson Alan
Published: April 2023

The offshore industry needs reliable remotely controlled assets to carry out a range of critical services subsea. ROVs and AUVs have performed these tasks for some time, but as operations venture into deeper and more demanding environments, operators are looking for tools with more capabilities that can function with less human intervention.

AUVs have been used for years in place of ROVs to acquire inspection data because they are not tethered to a vessel and can complete preplanned missions without direct control from a pilot. In many cases, an AUV is less costly to deploy and recover than a typical ROV, requires less vessel time on site and can be supported by fewer personnel. Normally, engineers program the AUV's trajectory and mission before a dive, deploy the unit, and download the data for processing and analysis when the dive has been completed. Although AUVs have proven valuable, their usefulness is restricted because of the performance limitations of traditional designs. Torpedo-shaped AUVs can follow a pipeline but because they cannot stop and hover or orbit when anomalies are spotted or when instrument measurements are unclear, they cannot gather all the precise data needed for a pipeline engineer to assess the condition of a pipeline.

Oceaneering established an AUV development program to address the limitations of existing designs and to introduce the ability to hover and improve maneuverability. The goal was to produce an AUV capable of delivering high-speed acquisition of the high-quality data normally only obtained by using an ROV.

The team understood that, as with all technology development programs, transforming its ambitious development plans into a viable commercial product would be challenging and reached out to engage industry partners. The Freedom program, which has spanned a period of eight years, was supported from the outset by TotalEnergies and ChevronETC and at a later stage of development they were joined by Equinor.

The result of this collaborative effort is Freedom™, a hybrid AUV/ROV system that performs accurate, high-speed, single-pass, close-proximity inspections. This project has helped establish a new methodology that expedites development, testing, validation, and approval of technology, involving operators from inception through deployment to provide a high level of comfort to them for adopting serial-number-one technology. This paper explains how that methodology was developed and how it provides a way to expedite product development that aligns with industry needs and simplifies commercialization.
A Predictive Numerical Model to Optimize Wellbore Expandable Seal Design for Swab Resistance in Annular Flow
Authors: Seymour Nathan , Gupta Susheel Kumar , Jin Henghua , Kamath Raghu , Shukla Shrish
Published: April 2023

Seal swabbing is a physical phenomenon in which the expandable sealing element of a completion tool, such as a packer or a plug, deploys prematurely when fluid flows over the sealing element. Seal swabbing occurs when a tool is run in hole or when fluid is circulated over the seal and the seal deforms and plugs the annulus. This is an undesirable phenomenon that can lead to a considerable loss of time and money in removing the packer from the well. Packer ratings for annular fluid bypass are typically validated using a physical test and recorded as run-in-hole (RIH) speed and reverse circulation (RC) flow rate. The use of physical testing to evaluate the fluid bypass performance of a packer is expensive and becomes cost prohibitive if the seal design is sensitive to swabbing and the design has to be iterated to achieve the required flow target.

This paper presents the physics behind seal swabbing and proposes a predictive numerical model to improve the tool design for swab resistance using digital simulation. The proposed seal swab model was validated using physical tests. The model was able to predict the flow rate with a deviation of 8% at room temperature and 18% at a high temperature. The numerical model likely underpredicted the flow rate at the high temperature because of differences in elastomer mechanical properties between the model and the physical test, such as the coefficient of thermal expansion, and the stiffness. Nevertheless, the current model was conservative, and the methodology was able to accurately predict the failure mode and flow rate for seal swabbing. This provided the engineering teams with a method to detect the swabbing risk and redesign the seals.
Overcoming Challenges in the Development of Standardized Steel Riser Designs
Authors: Capinam Alves Junior Jaques , Stail Bordin Franciele , Ferreira Senra Stael , Familiar Solano Rafael
Published: April 2023

The demand for subsea projects adopting steel risers in Petrobras have increased in the last years. In parallel, new frontiers in ultra-deep waters offshore Brazil are emerging, beyond the pre-salt of Santos Basin, bringing new challenges to the conception of subsea systems and riser designs. This paper aims to present relevant solutions and new strategies that have been used by Petrobras in the development of standardized SLWR (Steel Lazy Wave Riser) designs that endure the entire production life of typical subsea projects.
Advances in Satellite Technology for Ice Management
Authors: Bobby Pradeep , Power Desmond
Published: April 2023

The need to monitor ice conditions has motivated the launch of several earth observation (EO) satellites and ice mapping applications are among the highest consumers of satellite data. However, oil and gas operations (O&G) in ice-prone (both sea ice and iceberg) environments have largely been using EO data for upstream, strategic reports on ice conditions. There are many recent and upcoming advances in EO technology that are already enabling satellites to be used for other critical operations and there is value in using satellites extensively for ice management. The remainder of this paper briefly describes these advances and their impact on detecting ice conditions to support oil and gas operations.
Improving FPSO Integrity by the Development and Certification of Composite Materials Into New Applications and Locations on Topside and Hull
Authors: Filho Gonçalves David , Neto Jarreta Claudio , Gamaliel Gustavo Souza , Eves Simon
Published: April 2023

Objectives/Scope

Over the years, FRP Grating has provided significant weight reduction and cost savings on many projects contributing to the success of offshore oil and gas projects. However, the use of other structural FRP products such as FRP handrails, ladders, tertiary structures offshore has been held back by the lack of similar rules and guidance. The objective of this project was to devise proposed guidance for a Type Approval of FRP handrails in fire integrity applications.

Methods, Procedures, Process

The FRP Industry Group (IG) promoted the extended use of existing FRP Products into new applications and locations offshore. Taking into account the life cost cycle concept connected safely operation, in January 2019, the Industry Group began the development of a Fire Integrity Matrix for FRP handrails offshore. The IG recognized that the Structural Fire Integrity Matrix format of the FRP Grating had over the years been widely adopted and therefore decided to adopt a similar structural Fire Integrity Matrix for FRP handrails. Heat flux and duration requirements for the R0, R3, R2 and R1 performance levels were then proposed, based on industry practice. The FRP handrail Fire Integrity Matrix sets out a series of fire integrity tests which give performance data for owners/engineers to use in risk assessments.

Results, Observations, Conclusions

An FRP handrail product was subsequently subjected to the Fire Integrity Matrix tests by recognized laboratory certified by a classification society. The tests were followed by IG and found to meet all the test requirements. The data was subsequently assessed by Classification Society and the product was awarded a new Type Approval allowing, for the first time, use in fire integrity applications offshore.

Novel/Additive Information

The work by the Industry Group in devising the Fire Integrity Matrix for FRP handrails is a highly significant step forward for the extended use of FRP offshore, with classification society approval.
An Extended Mini-DST Depth of Investigation Using a New Formation Testing Tool and Innovative Analytical Model
Authors: Berkane Mustapha , Ali Ahmed Moge , Rahman N. M. Anisur , Gisolf Adriaan
Published: April 2023

Drillstem tests (DSTs) and mini-DSTs are established reservoir dynamic evaluation techniques used to gather pressure transient data. A DST is still the preferred option for field-scale evaluation because the depth of investigation (ri) in a mini-DST is generally limited to tens of feet. Based on recent technology advancements being deployed, a review of the parameters affecting ri analytically and numerically is essential as these values have significance on operational efficiency.

The most recent analytical models have shown that the production rate has a major effect on ri estimates, and this paper will focus on the most recent innovations in both hardware and analytical models that can extend the mini-DST data. Specifically, in-depth comparisons of new analytical models with van Poolen and Kuchuk’s equations will be presented. The discussion will extend to key hardware components with focus on pumping rate and gauge resolution. Finally, the new approach will be validated using data from restricted locations, from a thick high-permeability sandstone, and from a thick low-permeability carbonate.

The van Poolen equation shows that for a fixed buildup time, a formation tester rate of 10 bbl/d compared to a DST rate of 1,000 bbl/d would result in the same radius of investigation, given that the equation does not account for flow rate. Kuchuk’s equation and the new analytical models show that flow rate has a direct impact on detectable ri—the higher the flow rate, the higher the detectable ri. Pressure transient analysis (PTA) was used to illustrate the impact of flow rate and gauge resolution on data quality, particularly on the portion of the flow regime relevant for detectable boundaries. In addition, a PTA plot superimposing flow rates from measured downhole data is combined with an idealized gauge to help to determine the magnitude of the apparent gauge resolution and its impact on the detectable ri. Both the new and traditional radius of investigation equations show that data acquired with the new formation tester tool obtains a deeper depth of investigation due to excellent data quality. The results are compared to conventional formation testers with limited flow rate and lower gauge resolution. This paper presents a new approach with a rate-dependent radius of investigation, compared to traditional approaches of van Poolen and Kuchuk. The superior data quality from the new formation tool leads to a substantial improvement in estimated ri.
Comparison of Wellhead Fatigue Methods Using Acoustic and Standalone Monitoring Data for HPHT Developments
Authors: Mercan Bulent , Campbell Mike , Lu Wangming , Chase Thomas
Published: April 2023

In-situ wellhead structural monitoring is used for one of the industry’s first deep water high-pressure high-temperature (HPHT) development projects in the Gulf of Mexico to confirm the integrity of the wellhead system during drilling operations. As part of the monitoring program, the field measurements are collected using acoustic and standalone monitoring systems. In this paper, wellhead fatigue accumulations determined based on different motion sensors, data acquisition systems, and data analysis methods are compared.

For the HPHT well drilling period, the subsea stack motions (i.e., LMRP/BOP accelerations) are measured and transferred to the top side in power spectral density (PSD) format via acoustic data communication system. At the same time, the stack motions (accelerations and angular rates) are also measured using another set of standalone motion sensors. Acoustic data transmission provides near real-time feedback to drilling operations while standalone motion sensors store motion measurements locally for future data processing once the instrumentation is retrieved. Wellhead stress transfer functions, which correlate BOP/LMRP motions with stresses at the fatigue hot spots, are developed for both standalone and acoustic sensors using a finite element model of the as-built riser/wellhead system. Next, field data obtained from these different sources (acoustic and standalone sensors) along with fundamentally different analysis methods are used to calculate wellhead fatigue.

Each monitoring method exhibits benefits and limitations depending on the characteristics of the measured wellhead response and monitoring objectives. It is shown that the fatigue results determined based on these monitoring methods can be different if the most appropriate monitoring configuration is not selected.

In literature, there are several previous studies presenting wellhead fatigue calculations based on monitoring data. However, these studies discuss either acoustic or standalone sensor data analyses. This paper provides the combined assessment of acoustic and standalone monitoring approaches for the same monitoring period and compares fundamentally different data analyses methods for HPHT applications. The advantages and disadvantages of each approach are evaluated, and recommendations are provided for when each method should be considered.
Bilingual Education for the Deaf in South Africa - Can it Work?
Authors: Storbeck Claudine
Published: April 2023

Deaf Education in South Africa has reached the point at which inquiry and reflection have become paramount. Education levels remain low with the majority of Deaf students leaving school functionally illiterate, yet this unsatisfactory status quo is manifest in passive consent. Researchers are currently favouring a move toward Bilingual Education for the Deaf, even though the field remains saturated with contentious debates and insufficient evidence to marshal adequate support for one solution. Bilingualism, as an educational paradigm in Deaf Education, acknowledges that the Deaf child's primary language is Sign Language. In addition, the Bilingual approach recognises that the majority of Deaf children (90%) grow up in a hearing community without natural access to their primary language or the natural ability to acquire the spoken language of their family. Consequently, the language of the community/family is accepted as the second language, with the primary focus on second language literacy. This paper will highlight some of the problems in Deaf Education and the subsequent benefits of the bilingual· bicultural approach to teaching Deaf learners. It will also raise crucial questions and concerns which need to be reflected upon and worked through before Bilingual Education (or any other approach) is accepted as the panacea of Deaf Education.
Apraxia of Speech in a Bilingual Speaker: Perceptual Characteristics and Generalisation of non-language Specific Treatment
Authors: Van der Merwe Anita , Tesner Herman
Published: April 2023

Speech production in a second (or third) language in the case of late bilingualism (or multilingualism) is probably motorically more complex than in the first language and greater demands are placed on the speech sensorimotor control system. In the case of defective speech motor planning due to brain damage, this will be particularly true, but to date no studies have been done on bilingual apraxia of speech. In this study the perceptual speech characteristics of a first-language Afrikaans-speaking apraxic person were studied in both Afrikaans and English and also generalisation of improvement after the application of non-language specific treatment aimed at improving speech motor planning abilities. The results indicated that similar perceptual characteristics occurred in both languages, but the problem in the second language was more severe. Improvement occurred in both languages indicating generalisation to the second language. The theoretical and clinical implications of the results are discussed.
Renin-Angiotensin-Aldosterone Axis Inhibition Improves Outcome of Diabetic Patients with Chronic Hypertension and COVID-19
Authors: Kheyri Zahedin , Alizadeh Mahboobeh , Akbarpour Samaneh , Hosamirudsari Hadiseh , Niya Mohammad H. K. , Aliasgharpour Fatemeh , Meidan Mohadeseh M. , Hassanzadeh Shahrbanoo , Dowran Razieh , Jafarpour Ali
Published: April 2023

Background:

Safe use of drugs such as angiotensin-converting enzyme 2 (ACE2) inhibitors and angiotensin receptor blockers (ARBs) in COVID diabetic patients needs comprehensive studies. This study addressed this issue from the Iranian perspective.

Materials and Methods:

Admitted COVID-19 patients were divided into four groups in this historical cohort study. Group 1 included 740 non-diabetic, non-hypertensive patients. Group 2 included 132 non-hypertensive diabetic patients. Group 3 included 154 non-diabetic hypertensive patients. Group 4 included 183 diabetic patients who were under ACE inhibitors or ARBs. Death, intensive care unit (ICU) admission, and length of hospitalization were compared between the groups.

Results:

After considering associated factors such as age, gender, dyslipidemia, cardiovascular diseases, rheumatoid arthritis (RA), chronic kidney disease (CKD), history of surgery, and corticosteroid use, diabetic patients (group 2) were associated with increased mortality (CI 95%, OR 1.93 [1.11–3.33]). Presence of diabetes (group 2) and hypertension were associated with an increased need for ICU admission (CI 95%, OR 1.69 [1.04–2.76]; CI 95%, OR 1.71 [1.08–2.71], respectively). Group 4 patients although having a similar rate of ICU admission with group 2 and 3 patients, had significantly better ICU survival.

Conclusions:

The current study suggests that ACE inhibitors and ARBs are associated with decreased mortality, ICU admission, and better ICU survival in the diabetic subgroup of hypertensive patients.
Disseminated fatal mucormycosis in a relapsed acute lymphoblastic leukemic child
Authors: Latha M. Sneha , Rekha Ravikumar , Julius Xavier Scott , Rajendiran Swaminathan
Published: April 2023

Despite the recent advances in the pharmacotherapeutics of pediatric cancer, opportunistic invasive fungal infections still cause a significant mortality and morbidity in these immunocompromised population, being attributed to the continuous marrow suppression and aggressive chemotherapy. Mucormycosis is the third leading invasive fungal infection after candidiasis and aspergillosis. The elusive presentation and the pleiotropic clinical features of this rare, yet rapidly progressive and frequently fatal infection often cause diagnostic delays, thereby resulting in poor outcomes. A physician's early suspicion and preemptive treatment remains the important key element in the early identification, irrespective of the technological advancements. We report a case of disseminated mucormycosis in a child with relapsed acute lymphoblastic leukemia, who eventually succumbed to death despite timely intervention and appropriate treatment due to aggressive nature of the invasive fungal infection.