bluuebunny/crossref_metadata_2025 huggingface dataset:
Simultaneous estimation as an alternative to young eucalyptus aboveground biomass modeling in ecophysiological experiments
Authors: Oliveira Thiago Wendling Gonçalves de , Rubilar Rafael , Sanquetta Carlos Roberto , Dalla Corte Ana Paula , Behling Alexandre
Published: August 2021

Accurate forest biomass estimates require the selection of appropriate models of individual trees. Thus, two properties are required in tree biomass modeling: (1) additivity of biomass components and (2) estimator efficiency. This study aimed to develop a system of equations to estimate young eucalyptus aboveground biomass and guarantee additivity and estimator efficiency. Aboveground eucalyptus biomass models were calibrated using four methods:  generalized least squares (GLS), weighted least squares (WLS), seemingly unrelated regression (SUR), and weighted seemingly unrelated regression (WSUR). The approaches were compared with regard to performance, additivity, and estimator efficiency. The methods did not differ with regard to the mean biomass estimation; therefore, their performance was similar. The GLS and WLS approaches did not satisfy the additivity principle, as the sum of the biomass components was not equal to total biomass. However, this was not observed with the SUR and WSUR approaches. With regard to estimator efficiency, the WSUR approach resulted in narrow confidence intervals and an efficiency gain of over 20%. The WSUR approach should be used in forest biomass modeling as it resulted in effective estimators while ensuring equation additivity, thus providing an easy and accurate alternative to estimate the initial biomass of eucalyptus stands in ecophysiological models.
Using plants to remediate or manage metal-polluted soils: an overview on the current state of phytotechnologies
Authors: Nascimento Clístenes Williams Araújo do , Biondi Caroline Miranda , Silva Fernando Bruno Vieira da , Lima Luiz Henrique Vieira
Published: August 2021

Soil contamination by metals threatens both the environment and human health and hence requires remedial actions. The conventional approach of removing polluted soils and replacing them with clean soils (excavation) is very costly for low-value sites and not feasible on a large scale. In this scenario, phytoremediation emerged as a promising cost-effective and environmentally-friendly technology to render metals less bioavailable (phytostabilization) or clean up metal-polluted soils (phytoextraction). Phytostabilization has demonstrable successes in mining sites and brownfields. On the other hand, phytoextraction still has few examples of successful applications. Either by using hyperaccumulating plants or high biomass plants induced to accumulate metals through chelator addition to the soil, major phytoextraction bottlenecks remain, mainly the extended time frame to remediation and lack of revenue from the land during the process. Due to these drawbacks, phytomanagement has been proposed to provide economic, environmental, and social benefits until the contaminated site returns to productive usage. Here, we review the evolution, promises, and limitations of these phytotechnologies. Despite the lack of commercial phytoextraction operations, there have been significant advances in understanding phytotechnologies' main constraints. Further investigation on new plant species, especially in the tropics, and soil amendments can potentially provide the basis to transform phytoextraction into an operational metal clean-up technology in the future. However, at the current state of the art, phytotechnology is moving the focus from remediation technologies to pollution attenuation and palliative cares.
Nano-silica added to Portland cement
Authors: Mendes Thiago Melanda , Repette Wellington Longuini
Published: August 2021

For a controlled particle size distribution, nano-silica was added to three different cements. The chemical and mineralogical compositions of the cements were characterized by fluorescence and X-ray diffraction. The granulometric distributions of cements and nano-silicas were obtained by laser granulometry and dynamic lightning scattering. The specific surface area of the raw materials was determined by gas adsorption. The effect of nano-silica and type of cement on rheological behavior was evaluated by rotational rheometry. The mechanical performance was investigated through the compression strength. The microstructural analysis was performed by scanning electron microscopy. The water demand and the consumption of dispersant increases according to the nano-silica content. The reduction in the inter-particle separation, and the agglomeration of nano-silica led to an increase in the viscosity of the suspension. The mechanical performance was directly affected by the specific surface area of the cements. Microstructural analysis showed that nano-silica changed from a layered adsorbed structure, to a porous or agglomerated structure.
Fatigue Behaviour of GFRP Reinforced Beams
Authors: Januš Ondřej , Girgle Frantisek , Kostiha Vojtěch , Prokeš Jan , Stepanek Petr
Published: August 2021

This article deals with the influence of fatigue loading on the behaviour of GFRP (Glass Fibre Reinforced Polymers) reinforced concrete elements. The aim of the experimental programme is to quantify the effect of fatigue loading on the mechanical properties of GFRP reinforced beams subjected to flexure. The proposed element was a beam simulating the cut-out part of a reinforced concrete slab directly subjected to traffic loading. The dimensions and the amount of reinforcement were adjusted regarding the possibilities of the testing laboratory and to ensure the repeatability of the test. Two different fatigue loading schemes were experimentally verified: a) a constant load amplitude, b) a gradually increasing amplitude. The applied fatigue load with a constant amplitude was designed to achieve a fatigue life of the element ≥ 2×106 cycles. In the case of fatigue loading with an increasing amplitude, the load was increased every 50,000 cycles by 5% of the maximum load in the cycle. The resulting fatigue life was compared to the expected fatigue life determined according to Miner's rule on linear fatigue summation.
Well Integrity Diagnostics Using Acoustic Event Classification on Distributed Acoustic Sensing Data
Authors: Noble Lilia , Rees Hugh , Thiruvenkatanathan Pradyumn , Langnes Tommy
Published: August 2021

Injection wells experience extremes of pressure and temperature as well as expansion and contraction during their normal operating cycles. This can cause numerous well integrity issues related to corrosion, leakage, degradation of barrier elements, operational practices that all put the health of the well at risk and require appropriate management.

This paper will describe a case of a North Sea injection well that over time had developed sustained casing pressure (SCP) in the B-annulus. As a critical well in the development it was necessary to understand the origin and nature of the SCP as this would set further operational plans for the well helping to decide whether the well could continue to be operated safely, would require an intervention, or potentially will be abandoned. A leak investigation was needed to try to determine the source of the pressure, the type of fluid causing the pressure, the fluid path, and whether there was an injection out-of-zone as a result.

To address all of the set objectives Distributed Fibre Optic (DFO) system was selected as a technology of choice. DFO provides an advantage over traditional leak detection methods through the ability to simultaneously monitor entire length of the well recording both acoustic and temperature profiles. Distributed Acoustic Sensing (DAS) was used to record acoustic signature of the well helping to determine the leak origin and likely pathway, while Distributed Temperature Sensing (DTS) was used to record well outflow profile and advise on possibility of out-of-zone injection. Use of pattern recognition techniques allowed to extract leak signature from background noise and other acoustic signals helping to pinpoint leak location.

As a result of the application of DFO technology coupled with appropriate processing techniques way ahead for the well was identified providing an operator with a confident answer and saving on further intervention costs.
Innovation and Integration: Exploration History, ExxonMobil, and the Guyana-Suriname Basin
Authors: Varga Audrey L. , Chandler Matthew R. , Cotton Worth B. , Jackson Erik A. , Markwort Ross J. , Perkey Randy A. , Renik Byrdie , Riley Tina , Webb Susanna I.
Published: August 2021

Exploration in the Guyana-Suriname Basin has been a decades-long endeavor, including technical challenges and a lengthy history of drilling with no offshore success prior to the Liza discovery. The 1929 New Nickerie well was the first onshore well in Suriname, and was followed by 30 years of dry holes before the heavy-oil Tambaredjo field was discovered in the 1960s. In the 1990s, nearly 40 years after the Tambaredjo discovery, ExxonMobil utilized the 1970s-vintage, poor-to moderate-quality, 2D seismic and gravity data available to create a series of hand-drawn, level-of-maturity (LOM) source and environments-of-deposition (EOD) maps over the basin to move their exploration efforts forward. This work established the genetic fundamentals necessary for understanding the hydrocarbon system and led to negotiation for and capture of the Stabroek Block in 1999.

The Liza-1 success in 2015 spurred extensive activity in the Basin by ExxonMobil and the Stabroek Block co-venturers, Hess Guyana Exploration Limited and CNOOC Petroleum Guyana Limited (Austin et al. 2021). The collection of extensive state-of-the art seismic data has been leveraged to enable successful exploration of multiple play types across the Guyana-Suriname Basin. Further data collection, including over 2 km of conventional core and additional seismic data acquisition and processing, has enabled ExxonMobil to adopt interpretation techniques that are applied across the entire basin to characterize and understand the subsurface better.

From initial hand-drawn maps to the use of advanced technology today, ExxonMobil's work in the Guyana-Suriname Basin has relied on integration of geologic and geophysical understanding as well as the ability to leverage new technology to continue a successful exploration program with 8 billion barrels discovered to date.
Principles for Selection of the Quality, Health, Safety and Environmental Digital Solution
Authors: Efendi Riad , Cabassa Marc , Cagnart Bruno
Published: August 2021

A digital solution for the Quality, Health, Safety and Environmental (QHSE) management system has lately become almost a must for any progressive company, especially the one that strives to take on, pass and maintain third-party certifications (such as ISO 9001, 14001 and 45001).

However, its selection may be a complicated process balancing interests of field workers, executives, procurement, IT, safety/environmental/risk managers and training personnel.

The process of selection of the QHSE digital solution starts with defining the scope of the project and its sponsors, stakeholders, resources and budget (most likely estimated, at initial stage).

The next step is building of a list of requirements of a desired solution based on feedback from business. It will be followed by research of available solutions on the market and/or in-house capabilities to develop one.

Three to five vendors with solutions best conforming to the defined requirements will be requested to do presentations of their capabilities, followed by proof-of-concept for 2-3 top candidates, leading to a selection of a winner.

Despite the process described here being very straightforward, there may be pitfalls caused by complex interplay of interests of different disciplines and divisions within the company.

The most important conclusions addressing these pitfalls are:

It is unlikely that you will find one vendor, whose solution will become the best fit for all disciplines comprised by your management system (quality, occupational health, safety and environmental). An early decision needs to be made (most likely at the executive level) if you would go with a One Solution (Best-of-Suite) or different specialized software (Best-of-Breed) approaches. You need to get a very good idea of various QHSE-related software currently being used in your company at local or division levels. If the decision is made to switch to a new comprehensive digital solution on a global level, you will need to get a buy-in from local/division users before making this switch. Finally, you need to ensure that all stakeholders and interested parties are involved in (or at least informed of) the selection process and agree on its scope.
Hull Condition Monitoring and Lifetime Estimation by the Combination of On-Board Sensing and Digital Twin Technology
Authors: Sugimura Tadashi , Matsumoto Shunsaku , Inoue Soichiro , Terada Shin , Miyazaki Satoshi
Published: August 2021

The industries using floating facilities such as FPSO and offshore wind turbine are increasing. Since these vessels have been fixed and operated in the installed area for a long period of time, they cannot be regularly docked, inspected and repaired as opposed to normal ship case, and limited to the inspection of the hull outer plates from under the water and the inspection of inside the tanks are conducted once every five years. These inspections involving visual inspections and thickness measurements at representative points, only examine the current state, and don’t evaluate quantitatively the future potential (remaining life) over the subsequent long operation period. To predict residual life in order to maintain the integrity of these structures, digital twin technology is proposed to realize this demand. This paper shows the method to develop digital twin assessment which solve the insufficiency of conventional monitoring and simulation method in order to utilize for risk-based inspection (RBI) and condition-based maintenance (CBM) to the operators.
Drilling with Glass and Air: Using Hollow Glass Spheres to Address a Wide Ranging Drilling Challenge in a Safe, Efficient and Cost-Effective Manner
Authors: Rylance M. , Tuzov Y. , Sherishorin V.
Published: August 2021

A major development with multiple rigs delivering extensive multi-laterals encountered a pervasive mud-window issue within the reservoir. The resulting severe mud losses, extensive NPT and formation-damage was also deteriorating with time due to depletion. Conventional approaches to stem losses had failed and adoption of an energized mud-system with acceptable Effective Circulating Density (ECD) was not considered cost effective, pragmatic nor safe. Instead a novel application using Hollow-Glass-Spheres (HGS) was trialled, that demonstrated an effective and highly successful outcome.

With 10 rigs drilling 60-70 wells per-year, each with 5,500 to 6,750m in the reservoir, quick resolution of the issue was required. For these reasons the Team at bp Russia looked carefully at alternatives that might fit the mud-window, but that offered a realistic approach for the environment and conditions in Eastern Siberia. The Team identified HGS as an approach to lighten the mud, often used for cementing ECD, application for drilling has been limited. For this approach we required an option with broad capabilities that could be scaled-up and exported to other development areas where such issues existed.

This paper will report on the planning, delivery, and execution of a pilot on the Sb. field at TYNGD, in Eastern Siberia. Initially deployed on three wells, including multi-laterals, the paper will walk through the engineering considerations, during the planning and execution phases. Reporting comprehensively on the data gathered and the many lessons learned during the incremental and stepwise deployment. Data will be provided that demonstrated loss-free drilling was achieved where this had not occurred before, with a dramatic reduction in NPT, FLA needs and costs. The paper will also report on the post drilling productivity and comparison with offset wells drilled with conventional mud systems and suffering severe losses. The results of this pilot have beaten all expectations, there have been many insights and the Team are now looking to set a timetable to scale-up across the NOJV. Much has been learned, waste HGS material has been demonstrated to be an effective FLA pill in other sections of the well and centralisation of mud process may offer additional cost savings and improvements. Further efficiencies are expected to be achieved and potential across the Company portfolio could be a major game changer.

HGS for cementing is well documented, application for drilling fluids has been less reported and almost exclusively applied to one-off sections/wells. The TYNGD application is novel as this is a major new development with 10 drilling rigs. Application is on multi-laterals and prior offset wells are available for direct comparison. The results of the approach demonstrate a new way of performing well construction in an effective manner for major Field Developments where losses are prevalent.
Electrically Heated Trace Flowline on Ærfugl Project - A journey from Product Qualification to Offshore Campaign
Authors: Mencarelli Guy , Bourbon Jean-Philippe , Forbord Kristian Per , Gibson David
Published: August 2021

The Ærfugl field is close to the existing Skarv development located in Norwegian Sea, making it a tie-back opportunity. The hydrate management and operational savings were major drivers for the subsea system design requiring the use of an electrically heated trace flowline (EHTF).

The scope of this paper is to present how the EHTF technology has been further developed, qualified and industrialized during the execution of the Ærfugl project. It will also illustrate how a unique collaborative model between an Operator, an SPS Contractor and an EPCI Contractor contributed to the delivery of the first heated Pipe in Pipe system on a sizable project.

Starting from a conceptual technology selection to the project delivery, numerous qualifications were performed to validate the EHTFsystem design and ease its industrialization. The development of a new technology starts from the component design through system qualification up to the installation phase. It is of prime importance that all the different phases of the system life cycle are equally considered, as being interdependent. By using this holistic design approach right from the start of the qualification phase, the final product eventually meets all the requirements, from the component specification to the system performance.

The collaborative model in place on the Ærfugl project allowed the efficient integration of the Operator at each different step of the design, qualification and industrialization process resulting in delivery schedule savings when compared to a conventional project delivery approach. Several important development activities took place during the Ærfugl project and the holistic design approach backed by robust system engineering processes enabled a smooth and efficient workflow supporting the onshore fabrication and offshore installation readiness activities.

Several fabrication challenges were overcome during the project to safely deliver the EHTF solution with a continuous focus on quality and this paper will also cover the most relevant ones.

Following the Ærfugl project execution, the EHTF technology, supported by a unique collaborative model with the operator, is now fully qualified, and deployed offshore based on robust and reliable manufacturing and installation methods.
Strategic Alliance Enables Fast-Track Engineering and Expeditious Deployment of Novel Flowable Sensors & Water Reactive Nano-Composite Plugs in MENA
Authors: Roy Ting Chen , Bolze Victor , Markel Daniel , Merlau Dave , Muhammad Moin , Dudeja Dhiraj , Yamate Tsutomu , Grullon Gustavo , Wilkinson Christian , Harp Leonard , Shenoy Ramachandra , Roy Indranil
Published: August 2021

Fast-track engineering to expeditiously deploy new technologies in upstream oil and gas heavily relies on timely agreement and synergy between the engineering team and stakeholders on (1) tool architecture (2) operational envelope and wellbore environment (3) qualification criteria(s) and overall verification & validation (V&V) strategy, among others which lead to the product specifications. Here we present a "Case Study" where two new technologies, were engineered to order for the Middle East and North Africa (MENA) regions: a first-generation Pressure-Temperature (P-T) flowable sensor from our "Teleo" product line, and a multilayered water reactive plug for multi-stage stimulation (MSS) and acid frac, designed from bulk ultrafine-grained light alloys and water reactive, nanocomposites.
Enhanced Use of Digital Solutions to Enable New Health Care Services on Calm Buoys
Authors: Jeannin Antoine , Camara de Castro Rodrigo Vieira , Peter Jonathan , de Tessieres Sebastien
Published: August 2021

Offshore fields present a growing need to guarantee safety and productivity while minimizing operational costs and increasing remote assistance. Brownfields are more exposed to risks due to the presence of aged assets requiring in depth inspections to assess potential life extensions. This challenge was tackled with a comprehensive approach to asset integrity management based on the enhanced use of digital solutions to enable new health care services on offshore assets, like CALM Buoys.

In line with the recent Oil & Gas industry trends, new digital technologies have been recently developed and deployed on board our fleet of CALM (Catenary Anchor Leg Mooring) Buoys, such as the 3C Telemetry system, Inspection Tablets, the IDEA Web Portal and the Marine Drone. All these new digital solutions will be presented in the proposed paper concerning their technical capabilities and the overall integrity performance improvements achieved with their enhanced use on offshore assets.

The 3C Telemetry system converts and upgrades CALM Buoys into smart, internet-friendly offloading terminals, connecting the system to Cloud services and ensuring secured data transmission, treatment, storage, and privacy, while delivering reliable accurate information to operators anywhere in the world. Inspection tablets are used to optimize health check campaigns on Buoys with a real-time and remote back office engineering support. These systems can also be connected to the IDEA (Imodco Digital Experience Access) Web Portal to allow online data visualization and analysis of the mooring systems performance.

"The Marine Drone is an unmanned survey vehicle to perform diverless UWILD (Underwater Inspection in Lieu of Dry-docking). The system can perform in depth visual inspections with its ROV (Remotely Operated Vehicle) and high-resolution subsea layout mapping of CALM buoys’ structures with its 3D bathymetry system, all providing high quality digital data post processed by advanced analytical tools for integrity analysis and preventive maintenance planning" (Castro, R., et al. 2020).

Data management has become the most valuable asset for companies seeking to have a better understanding and to continuously improve operations. This paper will demonstrate how Buoys and passive (process wise) equipment, like Turrets, can be operated in new ways: 1. Connected Asset (IoT): 3C Telemetry, Tablets, and the Marine Drone. 2. Platform to share/connect data to algorithms/users: IDEA System. 3. New operating business models enabled by health care approach.
Characterization of Productive Zones with Data from Advanced Mass Spectrometry of HPHT Well
Authors: Barrera Veronica , Mathison Jeimy , Flores Francisco
Published: August 2021

The construction of the A-2 well is considered challenging because it is a horizontal offshore HPHT well in shallow water. In fact, the well had a programmed target to reach the carbonatic rocks of the Upper Jurassic Kimmerdgian age, a light oil producing reservoir of complex type and low porosity, consequently, to select the best intervals with oil presence and define the location of water–oil contact was vital to avoid unnecessary deepening saving additional costs.

Being the data interpretation of the geochemical profile in the JSK zone of main importance for reservoir characterization, allowing to determine prospective intervals in a timely manner as a key task. The information from the lithological description was integrated into the geochemical profiles, where intervals of interest are related to hydrocarbon impregnations, fluorescence and visual porosity of each one of the samples.
Value Creation and Cost Management by Use of the New ISO 15663 Life Cycle Costing Standard
Authors: Willmann Endre , Østebø Runar , Montalvao Eduardo H. R.
Published: August 2021

The new edition of the ISO 15663 standard has been developed during the recent years and will strengthen the industry cost management for business value creation. This paper shows how such standardization can be used to further enhance and promote adoption of a common and consistent approach to life cycle costing in the offshore oil and gas industry.

The new ISO 15663 edition maintains key principles from previous editions, but does also introduce an improved and revised management methodology for application of life cycle costing. The purpose is to provide decision support for selecting between alternative options (e.g., projects, operational and technical subject matters) across life cycle phases, also aligned with overall corporate business objectives such as HSE and sustainability. It also provides the means of identifying cost drivers and a framework for value optimization over the entire life of an asset.

The international standard is providing an essential set of normative requirements on how to implement and apply the life cycle costing methodology and the decision criteria, supported by an exhaustive part of recommended practices. This includes the identification of common and specific contractual considerations for operators, contractors and vendors (e.g., complementary metrics besides expenditure, such as systems availability guarantee and risk-sharing clauses). It also includes the application in the life cycle phases of an asset, the techniques and data input, examples of application, and assessment and lessons learnt. Capital expenditure (CAPEX), operating expenditure (OPEX), revenue and lost revenue (LOSTREV) factors are addressed. The standard includes an unambiguous definition of the economic objectives of a project and application of the same business criteria when making major engineering decisions. The life cycle costing methodology is applicable to all asset decisions in any life cycle phase, but should be applied only when expected to add value for decision-support. The required extent of planning and management of the appropriate life cycle costing is depending on the magnitude of the costs involved, the potential value that can be created and the life cycle phase.

This paper demonstrates how the new ISO 15663 can be utilized by providing new examples of life cycle costing, to give all participants in the process — oil and gas operators, contractors and vendors — an up-to-date and streamlined set of requirements and guidance, encouraging a fit for purpose application. The paper does also present unique key economic evaluation measures such as life cycle cost (LCC) and net present value (NPV).
New Downhole Sand Entry Detection Technology Leads Directly to Successful Remedial Work and Additional Oil Production
Authors: Agrawal Gaurav , Eissa Moustafa , Singh Kamaljeet , Dutta Shaktim , Kumar Apoorva , Okeke Uche
Published: August 2021

The consequences of sand production are often disadvantageous to the short and long-term productivity of the well. Although some wells routinely experience controllable sand production, these are the exception rather than the rule. Sand production and its management over the life of the well is not an attractive situation but is often essential to extract the resource. Knowing the root cause behind sand inflow in a well and the possible results can inform an appropriate strategy to safely extract as much of the resource as possible.

The sands in such reservoir units often have high permeability and are mechanically weak and prone to sand production. The producing wells are often completed with gravel-packed completions for efficient sand control. Most of the wells have multi-zone completions for better productivity but this further complicates reservoir characterization.

This paper describes the first use of downhole sand impact detection technology in such fields. The sand detection technology integrates the fully digitized high-resolution acquisition with signal processing and interpretation algorithm to enhance the sand particle detections as small as 0.1 mm in diameter and up to 1,500 impacts per second. The tool is designed to immune the sensors from any background noise and gas/liquid jetting effect.

A combination of production logging tools (PLT) and the sand impact detection tool, was used to understand four phase zonal contributions (gas, oil, water and sand) and pinpoint sand entry in these cases. Results exceeded expectations and the ability for the sand detection tool to accurately detect the point of sand entry enabled immediate intervention to eliminate sand production in these case studies. One of them also resulted in increased production of 7.4kb/d oil without any sand flow and with greatly reduced gas-oil ratio as compared to pre-intervention production.

The work clearly demonstrates the practical and effective use of downhole sand impact detection with new sand detection technology to identify and isolate sand production in wells. The innovative tool design makes it feasible to detect even small sand particles in adverse wellbore conditions and varied production rates, thus adding a detection of the fourth phase in an otherwise three phase production log.
Propulsion Solution for Icebreaking LNG Carriers
Authors: Hanninen Samuli , Barisic Matko , Heideman Torsten , Goldon Krzysztof , Viherialehto Sampo , Maattanen Pirjo
Published: August 2021

Since 2007 the traffic volumes in the arctic seas have substantially increased, especially in the North-East Passage following the development of major oil and gas projects. In development of icebreaking LNG tankers the selection of propulsion system is playing a major role determining the vessel performance, safety and icebreaking capability. Recent success of YAMAL LNG project has led to accelerated development of new arctic LNG projects, such as Arctic LNG2. This paper will introduce some outstanding operational results from the revolutionary icebreaking LNG Carriers with modern azimuth propulsion system.

This paper describes the methodology to use remote diagnostics systems (RDS) onboard ice-going LNG carriers to continually record, consolidate, upload, and analyze ice-breaking propulsion performance. We will further describe how vessel operational experience and RDS data can be used in development of icebreaking LNGC propulsion design and product development.

The special focus in this paper will be given on propulsion system of large Arctic LNGC equipped with 3 × 15 000 kW azimuth thruster units. These propulsion devices help ship owners to access opportunities in the Arctic areas by providing safe and reliable operation in the region. Paper will highlight some of the key findings from the ship machinery data collected with RDS (Remote Diagnostic system) and further analyzed by engineer specialist in view of ice loading on machinery system and components.

Podded propulsion solution has played major role on Arctic ship projects, making these challenging projects technically and economically feasible. We will present latest findings and unique results from Arctic LNG carriers, which is valuable information in development of future Arctic oil and gas transportation in the Northern hemisphere.
Significant Performance Improvement with MPD in HPHT Narrow Drilling Window Campaign in the North Sea
Authors: Kamal Babar , Saboor Abdul , MacFarlane Graeme , Kernche Frank
Published: August 2021

Significant depletion in reservoir pressure, huge uncertainties in pore and fracture pressure, high overburden pressure on top of reservoir, Narrow Mud Weight Window (NMWW) and Partial/Total losses whilst entering the reservoir made these HPHT (High Pressure High Temperature) wells conventionally un-drillable. Due to these substantial challenges these wells were considered not only costly but also carry a high probability of failure to reach well TD (Total Depth). MPD (Managed Pressure Drilling) is a safer and more effective drilling technique as compared to conventional drilling, especially in wells with NMWW and downhole hazards. The precise determination and dynamic downhole pressure management was imperative to complete these wells without well control incidents. The Constant Bottom Hole Pressure (CBHP) variant in combination of automated MPD system was deployed with a mud weight statically underbalanced while dynamically managed above formation pore pressure to minimize the overbalance across the open hole. MPD enabled the operator to efficiently navigate Equivalent Circulation Density (ECD) through the pore and fracture pressure window, allowed significant improvements throughout the entire campaign.

This paper discusses the challenges faced during the last three wells drilled in the campaign which includes equipment issues, commissioning delays, losses whilst drilling, Managed Pressure Cementing (MPC), 7" drill-in-liner and plugged/blocked lines due to weather and mud conditions. The paper describes HPHT infill drilling experience, specific techniques, practices as well as lessons learned from each well during the campaign were implemented to address challenges and to improve performance. The MPD system commissioning was optimized by repositioning the lines which saved significant critical rig time. The blowdown points were added on the lines that were not operational continuously therefore a procedure was developed for flushing to avoid plugging. Optimized drilling strategy was also developed where MW was further reduced to avoid losses as observed in previous wells and CBHP was maintained by manipulating Surface Back Pressure (SBP) from surface.

This paper also discusses continuous improvements /upgrades in MPD operating software which assisted the operator in accurate monitoring of flow, SBP and BH-ECD to save significant rig cost in terms of invisible Non-Productive Time (NPT). MPD is a drilling enabler and performance enhancer which saved 80 days of Authorization for Expenditure (AFE) on this challenging HPHT campaign.
Innovative Energy Storage Concept for Saipem Offshore Wind2Sub™ Application
Authors: La Sorda Enrico , Pucci Francesco , Mauries Benjamin , Storheim Birgitte , Arcangeletti Giorgio
Published: August 2021

Reducing CO2 emissions is becoming one of the core targets for countries after the Paris agreement, which sets out a global framework to avoid dangerous climate change by limiting global warming to below 2°C and pursuing efforts to limit it to 1.5°C. To meet this objective also oil and gas operators have started to engage in an important effort to reduce the CO2 emissions in their plants and facilities.

From this perspective Saipem developed its Wind2Sub, a Wind Power for Long Subsea Tie-Back (LSSTB) concept, where its own pendular floating foundation solution, namely Hexafloat, can host a wind turbine generator (WTG), all the utilities needed for subsea field development and operation (power distribution, chemical storage and injection, control system) and a back-up energy system to compensate the intermittent production due to wind persistence, currently a diesel generator (DG).

The present paper will explore new solutions to ensure the continuity of the energy supply from Saipem Wins2Sub, based on green technologies. This may be done by collecting the generated surplus energy from a renewable energy system, in this case from WTG to a topside or subsea power storage. By adopting an Energy Storage System (ESS), it will be possible to use this energy when production from wind is low or null. This concept will replace the diesel generators, or any carbon fuel, so that the whole system will become green self-sustaining, as an energy island, without CO2 emissions.

The activities performed during the concept development are articulated through the following steps: a selection of two typical oil field scenarios where Wind2Sub solution can be applicable; screening of the current technologies to store energy and a selection of those viable to the two selected scenarios; wind conditions and WTG power analysis with estimation of the amount of the energy to be stored; preliminary design of the ESS; preliminary cost estimation.

The study was carried out by using a digital tool developed by Moss Maritime in the context of a Proof of Concept based on Floating energy storage. The tool allows to evaluate the feasibility of a solution through modellization of different renewable energy scenarios, demand profiles, simulation of operation, pre-sizing of the systems and cost estimation (LCOE, LCOS, LCOH).

The ESS combined with Saipem Wind2Sub will be described more thoroughly in the present paper through the explanation of the results achieved within the case studies.
Autonomous Inflow Control Valve Multiphase Flow Performance for Light Oil
Authors: Taghavi Soheila , Gisholt Einar , Aakre Haavard , Håland Stian , Langaas Kåre
Published: August 2021

Early water and/or gas breakthrough is one of the main challenges in oil production which results in inefficient oil recovery. Existing mature wells must stop the production and shut down due to high gas oil ratio (GOR) and/or water cut (WC) although considerable amounts of oil still present along the reservoir. It is important to develop technologies that can increase oil production and recovery for marginal, mature, and challenging oil reservoirs. In most fields the drainage mechanism is pressure support from gas and/or water and the multiphase flow performance is particularly important. Autonomous Inflow Control Valve (AICV) can delay the onset of breakthrough by balancing the inflow along the horizontal section and control or shut off completely the unwanted fluid production when the breakthrough occurs. The AICV was tested in a world-leading full-scale multiphase flow loop located in Porsgrunn, Norway. Tests were performed with realistic reservoir conditions, i.e. reservoir pressure and temperature, crude oil, formation water and hydrocarbon gas at various gas oil ratio and water cut in addition to single phase performances. A summary of the flow loop, test conditions, the operating procedures, and test results are presented. In addition, how to represent the well with AICVs in a standard reservoir simulation model are discussed. The AICV flow performance curves for both single phase and multiphase flow are presented, discussed, and compared to conventional Inflow Control Device (ICD) performance. The test results demonstrate that the AICV flow performance is significantly better than conventional ICD. The AICV impact on a simplified model of a thin oil rim reservoir is shown and modelling limitations are discussed.

The simulation results along with the experimental results demonstrated considerable benefit of deploying AICV in this thin oil rim reservoir. Furthermore, this paper describes a novel approach towards the application of testing the AICV for use within light oil completion designs and how the AICV flow performance results can be utilized in marginal, mature, and other challenging oil reservoirs.
Low-Temperature Diverter Improves Operational Efficiency and Well Performance in Offshore Application
Authors: Vidma Konstantin , Bremner Samuel Edward , Ziyat Sophia , Choo Daryl , Abivin Patrice , Yusuf Temiloluwa Iyenoma
Published: August 2021

Near-wellbore diversion during acid fracturing or matrix acidizing is widely used to improve reservoir coverage and to save time spent on zonal isolation. It is particularly useful in offshore operations where efficiency is crucial. Diversion is typically achieved by dynamic placement of degradable solid particulates into perforations, wormholes, and/or fractures to divert the treatment fluid to understimulated zones. The diverting material must maintain integrity and mechanical strength during the operation before degrading at the downhole temperature in the presence of stimulation fluids. Whereas currently used materials work very well in a wide temperature range, at temperatures below 140°F (60°C), finding an appropriate diverting material that balances the trade-offs between surface shelf-life, stability during treatment, and fast downhole degradation is a challenge. This paper presents a novel low-temperature diverter that pushes the degradable diverter temperature limit down to 70°F (21°C). The new material was deployed in a matrix acidizing job performed on an injector well in the North Sea. Field deployment was preceded by an extensive laboratory testing program to verify diversion efficiency and acceptable degradation.

The novel diverter was deployed in a restimulation treatment of a 10-year-old injection well where BHT was reduced to 70°F (21°C) due to long term injection of cold water. An acidizing treatment was designed to incorporate 4 diversion pills of the novel diversion material. All diversion pills were placed without extra operational time or operational issues. All four pills showed an instant pressure response of more than 250 psi as well as a sustained pressure increase of more than 100 psi, providing an indication of effective fluid diversion. The well was switched to injection mode less than 36 hours after the end of treatment without any flowback, providing a tremendous gain in operational efficiency. The post-treatment injection rate increased by 150% for several days, demonstrating significant and fast diverter degradation, despite the low temperature. The injection rate later stabilized at more than twice the pretreatment injectivity. The results demonstrate the viability of the novel low-temperature diverter in wells with BHT of 70 to 140°F (21 – 60 °C).
Novel Experimental Method to Determine the Performance of Vacuum Insulated Tubing VIT for Deepwater Applications
Authors: Ceyhan I. , Vasantharajan S. , Suryanarayana P. V. , Sathuvalli U. B. , Helou A. , Barde P.
Published: August 2021

Vacuum insulated tubing (VIT) is a specialized tubular designed to minimize heat loss from production or injection fluids to the environment in oil, gas and geothermal wells. VIT strings are used in deepwater wells for flow assurance or to mitigate annular pressure buildup. VIT use requires accurate knowledge of its insulating performance. Although VIT performance can be estimated from analytical tools, such as finite element analysis (FEA), an experimental approach provides a more direct measurement and can be used to validate analytical tools. We have developed a new experimental method to address this need.

In this method, one or two VIT joints are placed in an ice-water bath. A precisely measured flow of heated air flows inside the VIT. The temperature change of the flowing air is measured between the inlet and outlet of the VIT test specimen. The insulating performance of the VIT is then calculated from this temperature difference using heat exchanger theory with effectiveness-number of transfer units (&#ξ03B5;-NTU) approach. A proportional-integral-derivative (PID) controller is used to control the air temperature at the VIT inlet by regulating power to the heater.

This paper illustrates the data reduction method and uncertainty analysis using sample test data. The method allows for rapid measurement of VIT performance at many different temperatures, with the air flow rate being used to optimize the test sensitivity and to reduce experimental uncertainty. As currently designed, the apparatus is able to test single- and double-joint VITs with effective body conductivities between 0.002-0.1 W/m/°C (0.001-0.06 Btu/hr/ft/°F) and temperatures up to 400°C (750°F); however, the design allows the apparatus to be modified easily for higher or lower conductivities.

Although designed for VIT, this method may be applied to other types of tubulars. Currently, there is no widely accepted standard method for experimental testing of VIT performance, and it is hoped that this new method may evolve to an industry standard.
Quality Assurance Framework to Enable Additive Manufacturing Based Digital Warehousing for Oil and Gas Industry
Authors: Kandukuri Sastry Yagnanna , Moe Ole-Bjørn Ellingsen
Published: August 2021

Additive manufacturing (AM) makes it possible to produce parts on demand, close to operations, with significantly reduced lead times compared to conventional manufacturing. However, without standardization or guidelines, additively manufactured parts could raise the risk of unexpected or premature failures due to inherent variation of mechanical and metallurgical properties associated with this new technology. This is especially true when the reduced lead time is the desired advantage, where speed may be prioritized over quality. A standardised framework is proposed to free up value locked in physical warehouse inventory and reduce inventory management cost through digital warehousing in a safe and cost-efficient way. Through a joint industry project, with participating companies throughout the entire AM value chain, we propose an assurance framework that answers questions such as: can the digital drawing be available when needed? Can the parts be made ‘first time’ right when needed? Can it be made with the same quality at another location next time? Which party is responsible for the different stages? What requirements should be in place for the companies who wish to manufacture on demand?

The digital warehouse assurance framework discussed in this work demonstrates that digital warehousing powered by AM could potentially shorten lead times for sourcing parts and reduce the need for costly storage, maintenance and coordination of spare parts that are rarely used. We also discuss the different variants of digital warehousing we may see, and the roles and responsibilities various digital warehouse stakeholders have for facilitating unambiguous communication.

AM is already disrupting supply chains in many other industries, but it is in its infancy in the oil & gas, offshore and maritime sectors as they ponder challenges with intellectual property (IP) and usage rights for original equipment manufacturers (OEM) designs, standardization of technology interfaces and the lack of knowledge and trust of the technology. The digital warehouse quality assurance framework proposed and discussed in this work is unique and has potential to not only accelerate adoption of AM in oil & gas and offshore sectors, but also contribute to a significant reduction of emissions, including greenhouse gases.
Facing the Challenges of Implementing Systems Engineering
Authors: Bullion James Anthony
Published: August 2021

The objective of this paper is to introduce and address the programmatic and technical challenges associated with the implementation of systems engineering (SE) at the enterprise level in the oil and gas environment. However, the lessons applied here could be tailored and applied to the project level. Currently, there is a strong movement towards a digital transformation of the industry, from exploration of new fields to the revitalization of more mature fields. A systems engineering environment is a prerequisite for the conversion and implementation of Digitalization Transformation. This paper will outline and address the risks and rewards of the partial to full implementation of the principles and methodologies of systems engineering across the lifecycle of a project. The ideas and methods presented here are what should follow once a decision to implement SE into an organization has been made. It assumes that the reader has reviewed the costs, benefits, and results of a digital engineering approach. The scope of this paper will address the technical as well as the organizational challenges that the initiator should be prepared to address in order to be successful.