bluuebunny/crossref_metadata_2025 huggingface dataset:
Use of Nanomaterials for Early Detection of Flow Restricting Substances
Authors: Louis Stephen George , Wang Luke Qiliang
Published: April 2022

Objectives/Scope

Deposition of inorganic and organic flow-restricting substances are critical flow assurance issues that results in oil and gas production loss of over $10 billion annually (Frenier, W.W. 2008). These depositions can cause a serious degradation of or cessation of production flow and require additional maintenance of facilities. In the context of a subsea environment, the loss in revenue and intervention costs are even more substantial.

A novel solution has been developed in the form of an inline physical sensor, containing a nanoscale particle coating, that can prognostically detect the deposition of flow restricting substances, and dynamically adjust chemical dosage in the production system. The process patent was granted in March 2021 (#10,947,818).

This paper describes the preliminary flow test demonstrating the scale inducing properties of the nanomaterial referred to as FloSav. Next the paper discusses the 24-month, onshore field trial which was successfully used to reduce chemical inhibitor dosage by 20% without any production loss or downtime. Thirdly the paper examines what additional testing will be employed in order to be fully qualified for deployment.

Finally this paper provides an overall plan on how to deploy this technology for an offshore application and the benefits that can be achieved including the reduction of production chemical usage while enhancing flow from the subsea well to the topside facility.
Cost Effective Fixed Offshore Platform in Shallow Water without Jacket
Authors: Chatterjee Prabir Kumar , Shah Jinesh
Published: April 2022

This paper proposes an alternative design of small wellhead platforms in shallow water that require permanent manning due to operational requirements. The proposed structure is a combination of two monopods of moderate diameter (54″) connected rigidly by structural members. Multiple wells can be drilled through one of the two piles by using conductor sharing wellhead technology. The inadequate structural stability of the twin-pile platform without a jacket against environmental loads will be ensured by a few tie members connected to seabed with help of specially-designed small concrete foundations. Tie members will be bolted to the pile and the foundation. Each tie member will be lifted offshore together with the concrete foundation for quick installation and correct positioning of the foundation on the seabed. The pre-fabricated deck will be welded to the top of the pile. Numerical studies include structural design of a platform at 20m water depth for omnidirectional waves of 10.5m height as per API RP 2A working stress design method. Analytical method is provided to simulate interaction of concrete foundations with soil that can be easily implemented in structural analysis. The results indicate that the proposed structure has considerable reserve strength against failure due to extreme environmental loads and impact from medium sized boats.
The Importance of CO2 Composition Specification in the CCUS Chain
Authors: Erickson Dale D , Haghighi Hooman , Phillips Chris
Published: April 2022

Carbon Capture and Storage (CCS) has seen growing momentum as a crucial strategy for meeting CO2 emission reduction targets. However, it comes with different technical and strategical challenges. One of the major challenges associated with CCS is the multi-actor value chain, which based on individual actor requirements, may not be necessarily aligned with each other and therefore requires coordination and agreement.

An important design consideration is the quality of the CO2 stream as it moves through the CCS process. Various industries still consider CO2 as a waste stream and as such it only has limited quality control based on local regulations. This paper will discuss the various issues associated with CO2 quality in the various elements of the CCS chain, from collection, through transportation to storage.

There are various technologies providing discrete solutions for different elements of the CCS chain. However, for a cost-effective CCS design, a holistic approach should be applied.

At custody transfer points within a CCS chain, CO2 will need to meet specification criteria for type and quantity of allowable impurities. Impurities may be inherent in the captured CO2 or carried over from processes or reaction by-products. Some impurities may have significant impact on the behaviour of CO2 rich fluid even in small ppm quantities and adversely affect the CCS chain integrity or operation. CO2 not meeting specification criteria risks non-acceptance at custody transfer points. This paper shall address the critical considerations for CO2 quality at each of the CCS chain interface points.

This paper will provide a high-level overview of how impurities can significantly affect the calculation of CO2 rich fluid properties and behaviour, chemical reactions, corrosion risk, etc. Additionally, some of the gaps in the current understanding and standards will be addressed and their possible economic impact on CCS chain design and operation.

The novel part of this work is holistically looking at the whole CCUS chain and addressing how CO2 quality and specification can affect each part of the chain and their impact on the economics and viability of the solution.
Aoka Mizu FPSO Hybrid Twin Pilot - A Spectral Approach for Holistic Hull Structure Monitoring from Strain Gauges Measurements and Structural Analysis
Authors: Sireta François-Xavier , Van der Cammen Jeroen , Storhaug Gaute
Published: April 2022

Bluewater has partnered with DNV to pilot the hybrid twin solution on the Aoka Mizu FPSO, using data from that sensor system to monitor the fatigue damage in the hulland then update the RBI inspection plan accordingly (if needed).

In this paper, the hybrid twin method is presented which combines strain gauges’ data with 3D Finite Elements analysis of the hull structure, allowing the complete reconstruction of the structural response everywhere in the structure, based on the measurements from only a few sensors.

The method is validated using one full year of actual strain gauges’ measurements on the hull. The responses at main deck level are cross validated using some sensors as references and predicting their responses from the other sensors. The FPSO heading is also predicted from the deck strains and compared to direct heading measurements to validate the implicit calculation of the environment from the response. By combining the deck sensor readings with the 3D Finite Element model the fatigue damage at selected hot spots in the hull is calculated.

Those damage values are then used in the RBI calculation to replace the design damage values so that the RBI is updated based on measurements.

The key benefit for such approach to operators is the possibility for operators to keep track of the remaining life of the structure and being able to demonstrate it, which is crucial when it comes to optimizing inspection plans, selling, or redeploying an asset.
Case Study: Predicting Electrical Submersible Pump Failures Using Artificial Intelligence
Authors: Silvia Shejuti , Prior Malcolm , Gilad Yocheved
Published: April 2022

Unplanned Electrical Submersible Pump (ESP) failures can have a profound impact on well production and overall field economics; therefore, it is important to reliably predict the onset of damaging operating conditions and take proactive action to prevent early failure of an ESP. Most operators rely on production engineers to monitor and optimize equipment performance with remote monitoring and surveillance technologies that provide threshold-based diagnostics to detect electrical or mechanical problems. Due to inherent limitations in exception-based monitoring, it is extremely difficult to reliably predict the root cause of equipment failure and remaining useful life (RUL) of an ESP.

A major operator in the Americas was experiencing similar operational challenges in three of its producing assets. Unplanned failures happen frequently since they are hard to predict ahead of time with the data available to production engineers. This case study demonstrates how Advanced ESP Predictive Failure Analytics (PFA) technology has helped this operator to detect such events and extend ESP run life.

Methods, Procedures, Process

PFA is an innovative technique that leverages artificial intelligence (AI), life data analysis, physics, and knowledge-based methods to predict electrical and mechanical events and provides an estimate of RUL of an ESP. The data-driven models are trained using sensor time-series of historical failures and entail advanced data processing, interpolation, quality evaluation and feature engineering. The trained models are deployed to predict short term damage events that may lead to immediate failure, such as broken shaft, short-circuit, grounded downhole sensor failure, as well as long term events which build up over time, such as sand, and scale deposition.

Results, Observations, Conclusions

For one ESP, PFA detected scale deposition and predicted a sharp decline in RUL. After confirming the decrease in production fluid, and other surface and downhole sensor trends indicating scale deposition in the ESP, the production engineer applied chemical injection and avoided the failure. For a second ESP in this case study, PFA detected a grounding condition and predicted sudden decline in RUL. The production engineer noticed motor amps increased beyond the recommended threshold and performed electrical optimization to reduce motor amps. The ESP ran for another year and eventually failed due to grounded downhole sensor failure, which PFA had detected two weeks prior to the failure.
The New ISO/API P-Y Curves in Clays and their Reconciliation with the PISA Framework
Authors: Jeanjean Philippe , Zakeri Arash , Zhang Youhu , Andersen Knut H
Published: April 2022

ISO will soon issue the Draft International Standard (DIS) ISO 19901-4 to its members for comments and ballot. This DIS document includes major updates to the present state of the practice, including new p-y curves that will replace the long-standing API Matlock p-y curves for clays. The new p-y framework for offshore piles and well conductors results from comprehensive and extensive research that has successfully been tested against numerous field load tests and monitoring data. It covers monotonic, cyclic and fatigue loading conditions and uses fundamental soil properties to generate the p-y curves applicable to the loading scenario.

The release of this DIS document coincides with a significant industry momentum to develop offshore wind energy, which often includes the use of large diameter monopiles. Significant research, including the PISA project, has been conducted to provide design guidance for the offshore wind sector.

This paper achieves two objectives:

First, it presents a detailed discussion and context behind the exact formulations of the new p-y framework as it appears in the ISO DIS document, without repeating the underlying development, calibration and verification processes that are already published. Second, it demonstrates that the new ISO p-y curve framework and the PISA distributed lateral load resistance curves in clays are entirely consistent with each other. This is done by de-normalizing the published PISA curves for the Cowden site, re-normalizing them in the ISO format, and comparing the bearing capacity factors and the shape of monotonic p-y curves obtained with the two methods for the Cowden site conditions.

The second objective is an important factor in understanding the overlap and alignment between the techniques used in the offshore oil and gas sector and those used in the offshore wind sector.
From Model to Reality: Practical Insights from Mooring Integrity Monitoring Using Vessel Position Data
Authors: Jayasinghe Kanishka Milinda , Thomas Clare Victoria , Kilner Andrew Allan , Eassom Adrian Conrad , Gumley Jonathan Matthew
Published: April 2022

Safe and reliable access to offshore energy, whether it be through hydrocarbon or renewable sources, requires offshore infrastructure held on station by well designed, well installed and well monitored mooring systems. The bounds of what is possible with mooring integrity monitoring technology has expanded in recent years, providing stakeholders with a more complete view of risk over the life of the floating facility. As regulatory requirements eventually follow from these innovations, there is also increasing pressure on operators to expand their monitoring capabilities to retain compliance.

This paper presents an overview of some of the insights gained from using Global Navigation Satellite System (GNSS) vessel position data and metocean data for real-time mooring integrity monitoring. The means through which a GNSS-based integrity monitoring system can be programmed to detect mooring failures is presented and compared with alternative monitoring techniques. The potential for such a GNSS-based system to complement or replace other methods such as in-line load cell is discussed, particularly in scenarios where the installation or replacement of such direct mooring line monitoring technologies can be prohibitive from an operational or cost perspective.

The practical considerations gathered from seven combined years of operational mooring integrity on various offshore facilities are also discussed, including the use of metocean monitoring and forecasts, data rate, resolution, accuracy, delay and quality considerations, and the challenges involved in rolling out such a system on an operating facility.

This paper provides operators of floating facilities with insights into the kind of data which should be considered for an effective monitoring solution, as well as an approach to combine different data streams (vessel offsets, first order motions and environmental data) to derive a holistic assessment of mooring integrity. This information can be valuable for operators defining the scope of monitoring for new facilities or looking to get the most value out of the data on their existing facilities, where a system such as the one presented can provide a quantitative basis for operational decisions and improve the regulatory and risk compliance of offshore facilities.
Characterization of a New Green Material for Offshore Well Completions and Downhole Treatments
Authors: Monreal Gabriel , Zamora Frank , Ovrebo Hans Henrik , Orizondo Peter , Soidinsalo Otto
Published: April 2022

In oil and gas well construction during the drillouts or wellbore cleaning process, one of the most critical functions of land and offshore completions fluids is the ability to suspend solids effectively under extreme downhole conditions. Conventional agents such as xanthan gum, HEC and numerous other polymers have historically been used to accomplish this function, albeit with limitations. Functionally, these commonly used polymers depend primarily upon viscosity rather than elastic characteristics to suspend solids and require intensive chemical processing that leads to high deployment cost.

Recently microfibrillated cellulose (MFC) has been investigated as a prospective suspending agent in carrier fluids for extreme downhole conditions. MFC is a unique type of superfine cellulose fibrils obtained from fully sustainable sources that have been subjected to proprietary treatment procedures, resulting in fibril bundles consisting of lateral dimensions in the sub-micron scale and lengths up to micron scale with abundant terminal hydroxyl functional groups. When dispersed into aqueous solutions, the resulting fluid has been characterized to have several favorable rheological, chemical and mechanical properties.

Rheological measurements show the viscoelasticity of MFC dispersions is dominated by their storage modulus (G′ > G″) even with fluids formulated with as low as 0.25 wt% (about 20 lbm MFC /1000 gallons). The result is a suspension that exhibits superior particle suspension properties compared on a mass basis to conventional materials such as guar, CMC, HEC and xanthan gum. In addition, MFC solutions exhibit comparatively high viscosities at low shear rates but thin by several orders of magnitude at high shear, a characteristic that implies less work on surface equipment while having the ability to suspend solids at very low pump rates. MFC dispersions also have an excellent brine tolerance, demonstrating stable suspensions over weeks in fluids containing up to 150,000 mg/L TDS. The dispersions are stable at downhole relevant temperatures, applicable at low and high pH levels and resistant to shear degradation. Finally, MFC originates from natural resources and is environmentally benign and biodegradable.

This paper describes the comprehensive characterization of the rheological and suspension properties that distinguish MFC from other conventionally used materials and make it fit-for-purpose as a robust, environmentally benign and high-performance suspending agent for downhole applications.
Anticipated Verification: A Simple Method for Representing Confidence and Trust in Metocean Forecast Information to Effectively Enhance Operational Decision-Making
Authors: Steele Edward , Mylne Kenneth , Neal Robert , Standen Jessica , Geertsema Gertie , Krikken Folmer , de Vries Hans , Amies Jessica , Brown Hannah , Upton Jon
Published: April 2022

It is easy to look back at a past forecast and assess how well it performed relative to the observed weather, but it is an obvious fact that such verification is only possible after the event has passed. Despite advances in skill in predicting variables such as wind speed or significant wave height, a perennial problem for offshore industry users interested in the incisive application of metocean forecast information to effectively enhance their operational decision-making is knowing how much ‘trust’ to place in these data at lead times beyond a few days ahead. Here, for the first time, we propose a method for the stratification of (past) verification statistics that applies unused information from the (future) forecast to anticipate how well the numerical weather prediction will perform a priori, providing a ‘weather-aware’ estimate of its skill (confidence) before the event has occurred.

Stratification is a method for being able to identify differences in characteristics of a particular subset of data, rather than just considering the whole population together. Since forecast performance is partly determined by the ‘drivers of predictability’ at that particular forecast horizon (e.g. prevailing atmosphere/ocean regime), we apply stratification on the basis of the classification of the large-scale weather present at the time to ‘filter’ past verification statistics, as considered in terms of the continuous ranked probability skill score. When used in real-time with a future forecast, the technique offers a refined estimate of the skill by taking advantage of the context of the weather being predicted. The translation of this ‘anticipated verification’ information into a qualitative description offers a robust indicator of confidence, suitable for (dynamically) guiding user trust in the forecast.

Using 2.75 years of archived forecast data from the European Centre for Medium-Range Weather Forecasts (ECMWF) extended-range (monthly lead time) ensemble prediction system (EPS) for an example location in the North Sea, the derivation of a dynamic (conditionally sampled) ‘trust index’ is presented; the application of which being evaluated using trials on unseen data from the same site. The benefit of the approach demonstrates significant potential for improving confidence in decision-making from individual short- to medium- range forecasts, as well as building trust in longer-range forecasts. While not a substitute for meteorologist guidance regarding the comprehensiveness of the various drivers of predictability at sub-seasonal timescales, this is none-the-less an important step in making such forecasts usable, useful and used.
Carbon Transportation and Storage, from Shore to Seabed
Authors: Mossop John , McLaughlin Daniel
Published: April 2022

The Energy Transition is redefining how energy is produced, consumed, and viewed. Many consumers today are requiring a more sustainable method of energy generation as a means of combatting climate change, and nations have pledged to take steps to control climate emissions. Newly developed methods of energy generation and solutions to decarbonize industrial zones, are essential to achieving carbon reduction commitments, and maintain the quality of life expected in today's world. The company has committed to continue to develop and improve its Green by Design™ products to further reduce customer CO2 emissions.

Investing the time and resources to develop equipment used in the injection and storage of CO2 in depleted subsea reservoirs, is a natural fit for most companies with subsea expertise. Having a cost-effective, safe and sustainable plan to transport, inject, store, and monitor CO2 has become the latest challenge facing the offshore industry, but as carbon taxes are implemented around the globe, the economic benefits outweigh the costs. Industry needs to find solutions to fulfill the worlds desire to inject and store CO2.

The development of partnerships/collaborations with logistics and storage development companies to create a plan to address the loading, transportation, injection, storage, and remote monitoring of CO2 is fundamental to enhancing the scale needed to address a global problem. This ‘shore to seabed’ solution allows industrial CO2 producers to cost-effectively reduce their carbon footprint. This coupled with field-proven wellhead and compact tree systems along with patented, carbon footprint reducing technology, can allow CO2 storage operators to economically store CO2 offshore long-term. Digital monitoring around the injection site, which is enabled by a move towards a full electric field further enables optimization and proactive maintenance.
Impact of Admixtures on Pumpability and Short-Term Mechanical Properties of Rock-Based Geopolymer Designed for Zonal Isolation and Well Abandonment
Authors: Chamssine Fawzi , Gargari Pedram , Khalifeh Mahmoud
Published: April 2022

Ordinary Portland Cement (OPC) is the primary binder material used for primary cementing and plug and abandonment (P&A). This material has many advantages in parallel with many shortcomings. However, OPC consumes a large amount of raw material and energy for the calcination of limestone emit greenhouse gasses. Geopolymers are inorganic polymers and have binding properties with a network structure of aluminum and silicate. Studies have shown that geopolymer is a one alternative for OPC having superior properties. However, the development of different chemical admixtures can contribute to the technology's development and fasten the prospects of application in the oil & gas industry. Impact of chemical admixtures sucrose, zinc (Zn), potassium (K) and alumina oxide (Al2O3) was studied. The properties analyzed include workability, setting time, fluid loss, viscosity, and uniaxial compressive strength. The use of sucrose, Zn species, K species, and Al2O3 was inspired from results presented in previous studies. The slurries were tested under a bottomhole circulating temperature 50° and a static temperature and pressure of 70° and 14 MPa respectively. The results indicate a retarding effect using sucrose and its combination with Zn and K species. On the other hand, Al2O3 acted as an accelerator on both workability and setting time. No significant effect was observed on fluid loss and viscosity profiles in comparison with the neat mix design. Poisoning effects from sucrose and Zn species were observed as well in the early compressive strength of cured samples after 1 day.
Mechanistic Modeling of Foam-Assisted EOR Simulations: Comparing Two Key Foam Generation Mechanisms
Authors: Izadi Mohammad , Cepeda-Salgado Betty , Kam Seung I.
Published: April 2022

Surfactant/foam enhanced-oil-recovery (EOR) processes have long been regarded as a practical means of overcoming subsurface heterogeneity and gravity segregation, leading to higher sweep efficiency and more cumulative oil recovery. In order to understand the outcome of such processes, modeling and simulating how foam propagates and behaves with the help of mechanistic foam models is crucial. There are largely two different versions of mechanistic foam models available in the literature, but no studies have been conducted to compare and contrast the two models within the context of the numerical calculation itself.

To clarify, the two versions of foam models are based on different types of pore-scale lamella-creation events, both taking advantage of bubble population balance simulations. The first is established on the mobilization-and-division mechanism, implementing the mobilization pressure gradient (∇Po) in the model to produce a large population of bubbles in porous media. On the other hand, the second is formed on the Roof-type snap-off mechanism, incorporating convection-dependent bubble creation at the germination sites into the model.

Therefore, this study investigates similarities and differences of the two different foam models and understand the pros and cons of each foam model. In line with that, this study is performed with the following tasks: (i) identify and borrow representative mechanistic foam models from the literature, (ii) make a fit to coreflood experimental data and determine foam model parameters for each model, and (iii) find the characteristics of the two models and their implications. The laboratory data for supercritical CO2 foam from Yin (2007) and Liu et al. (2010) is chosen to match (i) the pressure responses of no-foam/weak-foam state and strong-foam state and (ii) the steady-state pressure gradients (or drops) of strong foam state at various gas and liquid velocities. The models from Kovscek (1994) and Afsharpoor et al. (2010) are applied to perform the tasks. The results show that both models can reproduce experimental data equally nicely, but depending on how field operations are performed (rate-controlled vs. pressure-controlled) some additional sophisticated steps might be needed to make them equivalent in EOR simulations.
Classification of Wireline Formation Testing Responses Using Unsupervised Machine Learning Methods
Authors: Srivastava Priyank , Bandyopadhyay Mainak , Chakraborty Shantanu , Patwardhan Samarth , Tran Huy
Published: April 2022

This paper presents a novel technique for planning and execution of Wireline Formation Testing (WFT) jobs using recent applications of machine learning. WFT measurements provide a link between the static petrophysical measurements and dynamic rock-fluid properties for enhanced formation evaluation. However, despite the availability of newer generation tools for these services, there are still obstacles related to formation test job design and real-time optimization. Skilled geoscientists traditionally use quicklook analysis and theoretical models in designing WFT jobs to acquire quality dataset. In practice, operators have access to a detailed data repository. However, the learnings from historical jobs may be overlooked during dynamic real time operations and engineers may typically regress to simpler or experienced based models. Some of the methods are self-made to reduce time and energy in data acquisition. Digitization and automation of data provide an opportunity for application of data analytics to support these real-time measurements for an objective evaluation of the dynamic data.

In this paper we propose use of unsupervised machine learning models, by which routinely recorded real-time measurements can be used to optimize the test design and real-time operations. Basic principles of interpretation of WFT are used to develop quality parameters and classification based unsupervised machine learning models (Self organized maps, K-means and Hierarchical Clustering). These machine based recommendations can aid in designing and optimizing the real-time job while ensuring quality of the results. In this way, highest quality testing results can be acquired to improve the integration of the dynamic data into the petrophysical analysis. This also will enable standards to be established for real-time data acquisition that can save testing time while improving data and quality.

Results show that machine learning models can be a powerful tool to develop a machine based recommendation systems for classification of WFT responses that are dependent on petrophysical parameters.
Integrated System Modelling and Its Applications on Unconventional Wellpad Design Planning
Authors: Nguyen Thao , Anandhan Muthu
Published: April 2022

This paper aims to describe the capabilities of an end to end, fully integrated system model and the potential opportunities for its application. This integrated system modelling approach can be applied not only to unconventionals, but any value stream, including onshore, offshore, and conventional wells. The ultimate goal of this approach is to drive business decisions through systems modelling that are strongly anchored on historic data and knowledge.

When considering procuring oil and gas in any discipline, extensive planning must take place to achieve maximum value. Within unconventionals, the type of planning involved for drilling, completions, and production vary greatly from one another, but are inexplicably interconnected. For example, the effect of a design change made within completions on the other sub-functions are not fully clear. The desire for fully connected and streamlined operations within each sub-function necessitated full transparency of KPI's (Key Performance Indicators) and mutually agreed upon value drivers for the businesses. This incentivized the development of the integrated system model, abbreviated ISM.

The ISM presents a holistic view of the impacts that a well manufacturing design change makes on financial metrics such as FCF (Free Cash Flow) and VIR (Value Investment Ratio). Through the integration of CAPEX, production and economic models, the ISM provides a platform for the front-end working team to quickly assess the end-to-end impact of changing drilling or completions design parameters. The ISM contains detailed drilling, completions, and production models to perform design studies within each of these sub-functions. At any point during the design study an engineer can look at the impact of the design choice they made within one of these sub-functions on to the higher-level business operational/financial metrics (time to first oil, time on online, free cashflow, etc.) It also takes a reference type curve as an input for the selected basin and scales it for different design options. The ISM simulates the cycle time, critical path, capital spend and supply chain for the given design. The ISM also has an economics module where the financial metrics are estimated.

The integrated system model has delivered tangible monetary value to the businesses through identification of optimal design choices with high confidence while maximizing three-year free cash flow. The tool has uncovered additional possibilities of increasing the well's production through design exercises such as unchoking wells, further frac spacing/lateral length optimization, etc. The ISM has delivered these tangible values at a fraction of the time that would take multiple full-time employees to do. Additionally, the ISM has improved team efficiency by integrating across multiple silos and provides a standardized platform for exploring quantifiable future ideas.
Determining Ceramic Sand Screen Operational Envelop and Service Lifetime Prediction Model
Authors: Barth Peter , Zimmermann-Ptacek Johanna , Saeby Jan , Hicking Steven , Xu Hui , La Pointe Michael , Kamsvag Trygve , Brysch Jessica M. , Gutierrez Luis Gerardo , Jackson Richard Steven , Gundemoni Bhargava Ram , Danielsen Trond Helge
Published: April 2022

Downhole sand control selection plays a vital role in sand free production optimization over the well lifecycle. Design and selection criteria to assess the optimum sand control methodology requires consideration of many inputs to assess the sand control service life. A qualified sand control method, offering high erosion resistance is critical to enhance service life, especially in cases where small particles may be entrained in the produced fluids at high velocity. An integrated approach considering advances in filter media material, allow integration of ceramic components, to redefine operating envelope of sand control screen.

In the process of designing and selecting a suitable sand control method for a high-rate gas well application in Norway, ceramic sand screens were considered as a possible solution to manage the high erosion loading expected during production.

To estimate the operational limits for stand-alone ceramic sand screens, a series of erosion tests were conducted by a third party research and testing agency defined by the operator to evaluate the erosion behavior of the ceramic filter element. As indicator for erosion the filtration cut point (FCP) of the ceramic filter element was used. The testing allowed the operating envelope of the ceramic screens to be defined in terms of FCP and erosion load. For a specific increase in FCP value the operational limits for a stand-alone ceramic sand screen can estimated. This methodology was then applied to a specific field application to predict ceramic sand screen lifetime for the expected production profile.

This paper presents the results of the study, using CFD simulations and, independent industry testing methodology to investigate the suitability and expected service life for stand-alone ceramic sand screen. Understanding the operational erosion risk profiling enables the operator to apply an erosional resistant stand-alone screen approach offering reducing planning, deployment complexity, lower HS&E risk and increased flexibility in optimising the wells production envelope.
Rapid Gas Decompression RGD and Sealing Performance of Elastomer Seals in Oil and Gas Field
Authors: Chen Xuming , Cheng Hoi Ling , von Hacht Marius , Salem Hamid A. , Zonoz Ray H.
Published: April 2022

The objective of this study was to investigate the relationship between rapid gas decompression (RGD) damage and sealing performance of elastomer seals in simulated well conditions; hence, develop useful advice for dealing with the impact of RGD damage on sealing performance. The goal is to obtain an improved seal validation program. Radially energized rounded-face nonextrusion elastomer seals (or S-seals) and metal endcap seals (MEC seals) fabricated from nonRGD-resistant grades of elastomers were used for this study. The RGD damage to elastomer seals made from hydrogenated nitrile-butadiene rubber (HNBR) materials for wellheads, Christmas trees, and frac tree applications were investigated according to ISO 23936-2, NORSOK M-710, and API 6A Annex F PR2 test procedures. The in-situ sealing performance was evaluated after the RGD exposure to determine the relationship between RGD damage and sealing performance. The test results revealed that the S-seals showed significant RGD damage. The RGD ratings were found to be similar to standard RGD test results based on NORSOK M-710 for the same elastomer. It is noteworthy that all of the seals could still hold pressure in sealing pressure validation tests at both room temperature and 100°C, even though the RGD damage to the seals was significant. These results revealed that the conventionally acceptable criteria based on ISO 23936-2 and NORSOKM-710 are not suitable for the pressure validation test of an actual seal. As for the RGD question during API 6A Annex F PR2 test, the MEC seals also showed extensive RGD damage, which only affected the PR2 test performance significantly at lower temperature, further demonstrating that the sealability of seals is heavily influenced by test conditions such as test temperature. In conclusion, the RGD rating acceptance criteria per ISO 23936-2 and NORSOK M-710 is not representative of the application of a seal.
Applied Methodology as a Model Based Digital Solution for Analysis of Brownfield Decommissioning Alternatives
Authors: Basilio Leandro Pereira , Machado Priscilla Badega , de Sousa Débora Calaza , de Castro Rafael Vinicius , Juliano Diego Russo , Andreotti Marcelo
Published: April 2022

As an offshore asset approaches its designed life, and hydrocarbon production tends to decrease to a non-economic level, the operators have two options: extend the field's life or decommissioning.

Decommissioning is the removal or abandonment of the field's assets. The process is complex and can be divided into five main pillars: wells’ plugging and abandonment, subsea structure decommissioning, umbilical/risers/flowlines decommissioning, topside removal, and jacket/hull decommissioning. The processes and alternatives depend on the field's characteristics, such as water depth, distance to coast, the weight of subsea equipment, wells’ history and condition, type of hull, as well as local legislation. All these nuances require comprehension regarding the decommissioning processes to target the most cost- effective alternative.

Decommissioning is a costly process. It is necessary to understand the whole development, calculate time for each step and map the daily rate of the infrastructures (boats and equipment) required to estimate the cost by its availability. Depending on the equipment's integrity assessment, the field's life extension can be feasible and should be considered a viable alternative. Based on that, the development of an integrated model based computational system can help abstract the enormous complexity faced in real life, allowing operators to choose the most economically attractive option for a brownfield.

This study aims to propose a methodology developed as a digital solution for analyzing alternatives of decommissioning based on user's input. The methodology consists of gathering the possibilities for decommissioning or life extension, applied to each of the main pillars. Based on the results, it is expected that the present work will deliver an important contribution to the industry regarding the adoption of integrated design practices for the technical and economic analysis of brownfields.
Numerical Assessment of Mechanical Behavior of Mooring Lines Using Hybrid Synthetic Fiber-Rope Segments
Authors: Da Cruz Daniel Magalhães , Guilherme Carlos Eduardo Marcos , Stumpf Felipe Tempel , Bastos Milton Briguet
Published: April 2022

The continuous evolution of the offshore business has created demands associated with new types of installations and in increasingly deeper waters. Mooring systems made from synthetic fiber ropes, and in particular the materials used in these systems, have evolved to meet these demands. However, a single type of fiber may be insufficient to anticipate the best performance (cost/benefit). In this work, the mechanical behavior of hybrid lines composed of segments of different polymeric fiber is studied. For this, experimental data of multifilaments are used for each of the materials, and for hybrid specimens in different proportions. Numerical simulation of mechanical behavior of hybrid mooring system are carried out based on viscoelastic theory.

As a result, the behavior of the experimental test is checked against numerical simulation results, that validates the proposed model. Furthermore, a fundamental part of the result is integrated with the idea of optimizing the mooring systems, where it is possible to work with rope segments proportions for the hybrid mooring system, reducing the lifetime Total Cost of Ownweship, but without compromising the structural integrity or floating structure offset. From a practical point of view, it is extremely promising, as this optimization of the proposed mooring system, using a series of rope segments made of different fibrous materials, can, from a maximum allowable horizontal displacement, determine the sequence and proportion of rope segments employed, decreasing the rope manufacturing and/or installation costs.
Factors Controlling the Flow and Connectivity in Fracture Networks in Naturally Fractured Formations
Authors: Cao Meng , Sharma Mukul M.
Published: April 2022

The productivity and injectivity of hydraulically fractured geothermal wells in naturally fractured formations depends on the connectivity of fracture networks created by the interaction of hydraulic fractures with natural fractures. The primary objectives of this paper are (a) to determine the factors that control the connectivity of fracture networks bounded by wells, (b) propose ways in which the flow capacity and fracture connectivity can be improved by changes to the hydraulic fracture design.

A fully 3-D hydraulic fracturing simulator has been developed that considers the interaction of hydraulic fractures with natural fractures by solving for the stresses, fluid flow, fracture growth and intersection. An efficient and practical algorithm is developed to automatically detect and quantify the connectivity of the propagated fracture networks. These propagated fractures, which include hydraulic fractures and reactivated natural fractures, are divided into backbone, dead-end, and isolated fractures. Different well patterns that aim to maximize the connectivity of the injector to the producer (maximize the area of the backbone fractures) are simulated. A sensitivity analysis is conducted to investigate the effect of various parameters on the connectivity of wells through fractures. An optimal well pattern is suggested to maximize the connected fracture area that provides a conductive path for heat extraction from naturally fractured geothermal reservoirs. Our results show that the connectivity of fracture networks is dramatically impacted by the degree of deflection, crossing, and merging of hydraulic fractures with natural fractures.

The detailed parametric study based on the fracture-type-detection algorithm helps us better understand the factors that influence the geometry of fracture networks and guides us in hydraulic fracture design and well spacing optimization in naturally fractured geothermal reservoirs.
The Digital Twin: Optimizing the System Design from the First Draft to the Cloud
Authors: Kubacki Markus , Pedro Duarte da Silva Joao , Placido Neto Amadeu
Published: April 2022

In order to realize the benefits of the digitalization and automation of production and processing systems, users first need to increase the level of integration, controllability and monitoring capabilities of each component applied. Therefore, digital twins turn out to be a highly important asset not only for designing greenfield applications, but also for improving brownfield machines. Up to now, digital twins were barely implemented to their full potential throughout the design, integration, and operation phases of production and processing equipment.

Based on the experiences gained during the development of a subsea valve actuator, this paper highlights the importance of the digital twin to speed up the engineering and qualification of an innovative mechatronic system, reducing not only the time to market, but also increasing quality and allowing a fast reaction to the experience of the users.

As a perspective, the paper shows how an accurate digital twin is a key to successful integration of a new component into complex machines. This includes the entire product lifecycle, from the conceptual work of a system and its virtual commissioning up to remote cloud-based monitoring systems.

This paper finishes with an overview of some of the challenges which need to be resolved by the cooperation among different players in order to allow a wide and deep application of Digital Twin in the energy sector industry.
1-Click Automatic Well Design Using Integrated Cloud Software
Authors: Hassan Mohamed Ali , Strand Jim
Published: April 2022

Well Construction Automation is gradually becoming more prominent in oil & gas industry. It encompasses the application of digital technology in all aspects of well drilling and completion (i.e., automatic well design, digitalization of downhole tools & surface equipment, remote monitoring, real time data transmission, and robotic rig systems). This paper presents a new workflow of Automatic Well Design, at a mere click of a computer mouse, using integrated cloud software.

A software tool, named WellDesign, is used to demonstrate Automatic Well Design workflow. It utilizes networks and cloud computers for data storage and collaboration and offers a set of Application Programming Interfaces (APIs), enabling full automation, where whole or parts of the software can be operated by other computers. The software can be accessed via any modern web browser across all kinds of computers and any other smart devices (tablets, phones).

Two automatic design workflows shall be illustrated in detail:

Automatic Well Trajectories Automatic Casing Design
Evacuation Procedure Modeling and Optimization for Offshore Structures
Authors: Dillon-Gibbons Craig , Kilner Andrew , Thurumella Hemant , Carra Chris , Ryan Victoria
Published: April 2022

Disconnectable FPSOs are important systems employed by operators in regions that are subject to hurricanes and cyclones. A key to the successful disconnect of the mooring and riser systems is a robust evacuation procedure. To this end, this paper presents an evacuation procedure developed for an FPSO with a disconnectable internal turret mooring system. The advantage of the developed evacuation procedure is that by combining the forecast site wind and wave data, the analysis showed an increase in the number of times the facility could evacuate safely and, at the same time, provided increased uptime.

To test the evacuation procedure, an evacuation procedure modeling tool was developed that evaluated the procedure using historical hurricane/cyclone information such as the track position, forward speed, wind speed and wind radius, as well as 60 hour site wind and wave forecast data. Evaluated storms ranged from major cyclones to tropical storms that developed close to the offshore location of interest. The program performed evaluations from initial formation of the weather system through to the disconnect and sail away of the FPSO. An evacuation disconnect was deemed successful if all required evacuation procedures took place within the designated time constraints, as well as the disconnect operation occurring within wind and wave height limitations. Furthermore, the overall evacuation was considered successful if the FSPO was subsequently able to sail out of the hurricane path and not experience wind conditions of greater than 34 knots.

The tool was used to assess an example evacuation procedure for a disconnectable FPSO facility at 3 locations in the GOM and develop an understanding of the critical operations in the procedure and where optimizations could be made. Sensitivity analyses were conducted to understand the impact of changes in disconnect duration, vessel sailing speed, the disconnect and reconnect limits. Additionally, an assessment was conducted to understand the typical duration that the field would be shut-in when a disconnect was completed, and thereby understand how long it took for the FPSO to return to site and recommence normal operations.