bluuebunny/crossref_metadata_2025_split huggingface dataset:
World's Deepest Single-Trip Multistage Fracturing through 2-7/8-in. 7,400-m Coiled Tubing String: Method Development and Learnings from Norway
Authors: Keong Azwan , Jaimes Nelson , Mussenov Adlet , Graterol Hector , Østebø Bjørn , Sørensen Max , Maj Karsten , Caline Yann 
Published: March 2023

Abstract
The Valhall and Hod chalk fields have seen the rise of single-trip multistage fracturing (STMF) that allows stimulating two to four zones in a single day in contrast to the average of one zone every 2 to 3 days for conventional applications. Recent advancements focus on lowering operational costs while bringing wells on production faster. One way of doing this is to further improve the STMF method by the introduction of fracturing through coiled tubing (FTCT).
Conventional multistage fracturing operations use the plug-and-perforation method to complete each stage separately. With a sliding sleeve completion, coiled tubing (CT) is used to manipulate sleeves; then, proppants are pumped down the wellbore without CT in the well. Conversely, STMF uses a bottomhole assembly (BHA) with sleeve shifting tool and multiset packer for selective proppant stimulation down the CT-tubing annulus. Any underflush of proppants is cleaned by CT forward circulation. FTCT builds upon the STMF method, but proppants are pumped through CT. The underflush proppants are reverse circulated out of CT through a BHA without a check valve.
FTCT was first used in a well at 5,000-m measured depth (MD) using a 6,700-m 2 7/8-in. CT. Data from this operation were used to match the friction calculation. In the second well at 6,500-m MD, intervened with a 7,400-m-long CT, 10 zones were stimulated using FTCT, and 2 zones with conventional fracturing. FTCT only required 8.5 hours whereas conventional fracturing took 75.6 hours per zone. The underflush volume was 50% less and removed through reverse cleanout that is 4 hours faster per stage compared to STMF. In the third well at 6,700-m MD, the well was killed with 1.35-SG heavy brine due to a leak in the completion. Proppant was pumped through CT and displaced with 1.04-SG brine. An increase in pumping pressure during reverse cleanout, compounded with the difference of fluid density, led to the collapse of CT section above the BHA. The collapse created difficulties for the BHA to unset, thus creating a mechanical sticking point, and hindered the ball drop release mechanism for the BHA. Awareness of pressure limitations of CT at the thinnest section is essential to improve the reverse cleanout design since high initial forces are required to reverse circulate.
FTCT requires careful pressure analysis, especially when attempting operations in deep horizontal wells. Most standard CT cleanout simulation software lacks complete hydraulic modeling capabilities for reverse cleanout of crosslinked fluids with proppants. Data gathered from the three operations are thus important to improve the method. This study highlights associated challenges, considerations during design, operational benchmarks, and learnings from the world's longest FTCT operation in the North Sea.
Recover Stuck Drill Pipe in an Uncontrolled Well with Abrasive Cutting Technique on Coiled Tubing – Case Study
Authors: Mesa Nestor , Perez Camilo , Aldana Eddisson , Sanchez Carolina , Silva Oswaldo 
Published: March 2023

Abstract
Drilling low-pressure formations represent challenges. In the present paper, an operational situation became an issue when during the drilling of a deviated well, the circulation was lost, and the BHA got stuck, followed by a gas inflow observed in the return line. After a well control procedure and several failed attempts to control the well and recover the drilling BHA, another problem occurred when the drill pipe got plugged, making it impossible to continue pumping control pills.
The scenario described above was presented to the Coiled Tubing and Thru Tubing companies with the request of a proposal to help solve three specific goals to achieve remove the plug in the inner of the drill pipe, getting communication between the drill pipe and the open hole to be able to pump Lost Control Material (LCM) and control de well, perform a cut of the drill pipe in case the pipe couldn't be recover after control the gas inflow.
With an interdisciplinary group, the problem was analyzed, and a proposal was submitted, including three runs with Coiled Tubing and Thru Tubing tools. The first run a cleanout of the drill pipe with a downhole motor and taper mill. The second run will be with an abrasive punching BHA to establish communication with the annuls, and the third run will be for an abrasive cutting that will allow the recovery of the drill pipe above the free point. The job preparation includes the engineering program with the operational parameters and flow chart and the logistic preparation with the resources such as coiled tubing equipment, thru-tubing BHAs, chemicals, and fluids, among others.
During the operation, other discussions and revisions forced a change in the plan from the initial proposal, performing two of the three runs for the cleanout and abrasive cutting, which represented a benefit by controlling the well with the slurry pumped working as a LCM that helped control the gas inflow.
With a conclusion of a successful cut and drill pipe recovery, the operation data and analysis of the preparation vs. the execution are presented in the paper.
Addressing Challenges in Setting Thru-Tubing Whipstock in UBCTD
Authors: Almusallam Ali Abdulhadi , BinAmmar Yousef Abdulmohsen 
Published: March 2023

Abstract
In Underbalance Coiled Tubing Drilling (UBCTD), well pre-setting can be defined as the required drilling or work-over activity to set the last casing string at the top of a productive layer. This cost can be avoided by utilizing a thru-tubing casing exits (whipstock). This paper will address the challenges and enablers for direct wells’ intervention without pre-setting.
To close the gap between sending existing wells for pre-setting and direct well intervention with UBCTD, an extensive case-by-case analysis on UBCTD candidates is carried out. In essence, the approach was selected on the basis of utilizing existing technologies to their full potential or re-designing the tools to be able to fulfill the requirements. Since some candidates don't tolerate failures and allow for only one attempt, tools were always subjected to the highest level of quality checks and deployed in the best possible conditions.
Setting thru-tubing whipstocks in a typical well will require a low to medium inclination, rigid cement behind the casing and enough room below end of tubing. One of the main challenges in UBCTD is weight transfer for milling a window through the metal, especially in high inclination. Applying excessive weight on the window could agitate and dislocate the whipstock. Consequently, this could result in having stuck incidents while passing through the window during tripping. Thus, for such an application, the whipstock has been empowered with stronger slips for robust casing engagement.
In another challenge for cases with limited room below end of tubing, the window milling BHA was redesigned to be shorter. Also, close monitoring on the milling parameters was employed to ensure smoothness of the window and to avoid losing it and, indeed, losing the well. Such practice becomes standard to observe the milling parameters and benchmark them to guarantee the best window possible. This approach allows entry on wells with poor or absent cement behind the casing.
Utilizing the current wells’ assets as they are, and avoiding re-entry or mechanical pre-setting can save tremendous cost. Salvaging wells can be tricky with multiple choices and this would be always be a great opportunity with the tools and process upgraded. Thru-tubing whipstocks can now be handled in different fashions based on case-by-case applications.
Efficient and Reliable Multilateral Coiled Tubing Intervention Technique for Acid Stimulation: A Case History in the Middle East
Authors: Alnasser Hassan Basim , Okeke Ugochukwu Maria , Zhang Zhiheng , Veen Ronnie Van Der , Chishti Sadaf Shoukatali , Umirshin Saken 
Published: March 2023

Abstract
In recent years, multilateral wells have become more predominant enabling either improved recovery or injectivity depending on the well type. The process of timely accessing the correct lateral with coiled tubing (CT) is still one of the greatest challenges relative to the well intervention. This paper presents a case history in which a flawless 2.375-in CT intervention was performed to stimulate laterals with a proprietary multilateral entry bottom hole assembly (BHA) that steered the CT efficiently into the laterals.
The injector well has a natural and un-natural lateral, both of which required stimulation. A proprietary hydraulic multilateral entry tool was selected for the job which reliably locates and enters multiple lateral junctions in a single run. The special working mechanism of the tool circumvents any need for an electrical control or steering system. Along with this tool, a casing collar locator (CCL) was incorporated into the BHA, powered by a proprietary CT conductor telemetry system. Real time data enabled confirmation relative to access into the correct lateral to save time without the need to tag the bottom. A gamma ray (GR) sub can also be incorporated into the BHA to correlate depth where needed.
A major challenge for multilateral intervention is time on location. The multilateral entry tool searches for the lateral by rotating 360° until it reaches the desired kick off angle which is confirmed by a surface pressure indication signifying that the correct lateral has been located. The simple yet effective operational mechanism of the multilateral tool allows each lateral to be found and entered in less than 30 minutes once it is positioned at the window. Depth correlation is confirmed with use of either the CCL or GR subs or a combination of the two and the multilateral entry tool is resettable easily by pressurizing, which enables any number of laterals to be located & stimulated. The job was completed safely as per program with more than 4,000 bbl of acid pumped to stimulate both the laterals. The entire operation was conducted efficiently, flawlessly, and post injectivity results of the stimulation resulted in significant incremental injection drainage capability.
This combination of BHA's options and the efficient mechanism of the multilateral entry tool to find and enter multiple laterals quickly and reset without the need to pull out of hole, enables the Operator to intervene in any number of branches of a multilateral well in a timely and efficient manner. This is a very important case history for other complex multilateral wells in the region which could benefit from this technology and approach
Utilizing Manually Tracked Variables to Derive Complex Equations in Real-Time Platforms
Authors: Ott Waylin B , Fairley Robert T , Thomas Travis G , Pursell John C , Ables William C , Guzman Manuel L 
Published: March 2023

Abstract
Many threshold metrics in the well intervention industry's standard operating procedures (SOP) require monitoring and tracking of difficult-to-sensor operational components. Gathering this important job data is challenging due to the cost and/or availability of technology. This paper will outline how manually tracked parameters can be applied to complex equations inside derived channels and used to make real- time decisions.
Traditionally important variables such as return rate, density, and viscosity are tracked and documented manually. These metrics are needed to calculate thresholds such as annular velocity, Reynolds number, and bottoms-up time to surface, all of which are required to ensure debris is effectively transported to the surface during coiled tubing operations. Using the previously mentioned derived metrics in a live platform, users can set up warnings and alarms to make real-time decisions. This methodology enables the user to easily capture manually tracked variables in a singular job data set for post-job evaluation.
Because the industry has traditionally relied on handwritten and manually tracked data, the acceptance of digitally calculated results based on manual inputs has become commonplace. What was once minutes of calculation time to obtain a snapshot view of job-specific variables is now instantly available and tracked throughout the job so that time-sensitive decisions can be made using snapshots and tracked deviations from the SOP thresholds. Readily available information enhances overall job performance. Real-time availability of job metrics to the equipment operator and remote engineering support makes completions
cleaner, reduces stuck instances and non-productive time (NPT), optimizes chemical usage, and maintains rate of penetration (ROP).
True identification of annular velocity in singular and multi-sized casings, measurement of turbulent flow, and fluid balance status determine the ability to remove cuttings from a wellbore, which reduces the overall job time and the production testing costs post-intervention. Job performance metrics can be set and analyzed during operations. Any changes to the project scope can be assessed onsite or remotely to ensure acceptable deviations will not negatively impact the project outcome.
In previous years, technical papers have outlined how to optimize coiled tubing drillout efficiencies using SOPs, complex equations, and thresholds regarding fluid metrics, circulation times, differential pressures, and annular velocities. Still, these papers included manually tracked channels to document metrics for specific projects. Using the previously mentioned methods, manually tracked channels will display trends in complex equations, resulting in an improvement of the quality of data in a real-time platform and overall operational enhancement.
Modeling of Quadruple Tank System using Machine Learning Algorithms
Authors: M Aravindan 
Published: March 2023

Abstract
Modeling is essential for understanding the input and output behavior of quadruple tank system, analysis and design of controllers. Precise mathematical model for multi loop system-based Quadruple Tank Process (QTP) is a challenging task, due to strong interaction between pump inputs and output liquid level sensor values. Traditional methods such as transfer function and state space model limitations are removed through the proposed Model. Transfer function model can never be applied to multiple input and multiple output QTP system. State space model never address the internal state of QTP system. In this paper, Machine Learning based Quadruple Tank Process model is proposed such as Gaussian Process Regression Quadruple Tank Process (GPR-QTP) model and Support Vector Machine Quadruple Tank Process (SVM-QTP) model for runtime input and output sensor level data from laboratory based QTP station. Regression technique is performed with pump inputs and output liquid level data which can change in experimental environments such as ambient temperature and tube condition change, due to unknown disturbances and due to change in power supply to the pumps. The regression technique is verified with R-square values of proposed models. GPR-QTP and SVM-QTP models are developed using MATLAB software. From experimental results, GPR-QTP and SVM-QTP models perform better than conventional transfer function and state space model and validated through performance analysis such as Mean Absolute Error (MAE), Root Mean Squared Error (RMSE), R-squared (R2) and Mean Squared Error (MSE). GPR-QTP and SVM-QTP models provides an accuracy of about 98%.
WITHDRAWN: Fake News Detection Using Ensemble Techniques
Authors: Malhotra Pooja , Malik Sanjay Kumar 
Published: March 2023

Abstract
Fake news is misinformation or distorted news that is spread over social media with the intent of harming an individual, organization, or government body. Collecting news from an internet platform is simple because it is quick, user-friendly, and constantly updated. However, this information is also subject to personal preferences or interests, which can negatively affect individuals or organizations. As a result, it is critical to detect the spread of fake news by computational methods. Semantic web approaches also plays an important role in detecting false news since they are used to understand the data that is available online in the same manner that humans do. As a result, this research examined various learning models for classifying whether the information is true or false using a fake and real news dataset. Around 40,000 items were analyzed, including approximately 20,000 from each fake and actual news dataset. Ensemble learning models such as support vector machine, logistic regression, CatBoost, XgBoost, multinomial, Naive Bayes, and random forest were used and evaluated using recall, accuracy, false rejection rate (FRR), F1 score, precision, negative predictive value (NPV), false discovery rate (FDR), and Matthews' correlation coefficient. Based on these evaluations, the best learning models were hybridized and computed alongside the passive-aggressive classifier and deep Auto_ViML model. Following computation, it was determined that the deep Auto_ViML model had the highest accuracy, precision, recall, and F1 score of 99%. In contrast, the hybrid learning model had the best value of false rejection rate of 71%. In comparison, the support vector machine was computed in 0.000245 seconds.
Multi Band Spectrum Sensing in Cognitive Radio Networks Using USRP 2943R in Labview
Authors: D sumithra sofia , A Shirly Edward 
Published: March 2023

Abstract
As the number of primary users are increased in huge number detecting the presence of more than one primary user in the cognitive area network will increase the quality of the spectrum usage for continuous usage. In Dynamic spectrum sharing the cognitive user often undergo the process of leaving the primary user spectrum as soon as the primary user occupies the spectrum. This immediate leaving from the primary user spectrum will affect the ongoing communication of the cognitive user. So cognitive users need to monitor the neighboring multiple primary user spectrum to manage the discontinuity in the communication. In this paper we have implemented the multi band spectrum sensing of the primary user using Two National Instruments USRP 2943R Transceivers (1.1GHz-6Ghz) to sense the spectrum using energy-based spectrum sensing technique in LabVIEW Platform. The primary user spectrum sensing is done based on the threshold value updated manually and adaptive method. The results are very promising for high threshold values compare to low threshold values.
Dynamic Changes of Soil Parameters and Bacterial Communities during Bioremediation of Multiple Heavy Metals Contaminated Tailings by Compound Bacterial Flora
Authors: Wang Huan , Xue Lingui , Huo Yanli , Ma Yecheng , Li Jiahui 
Published: March 2023

Abstract

Many researchers have paid attention to solving the problem of multiple heavy metals pollution in the tailings area. However, the studies only stay at the laboratory level, which cannot completely demonstrate an efficient approach to remediate polluted environment due to tailings. This study aimed at investigating the effects of compound bacterial flora we constructed to remediate the tailings area of Linze County, Zhangye City, Gansu Province due to the accumulation of numerous heavy metals such as Pb, Cd and Mn. The remediation effects of different treatment groups were evaluated by monitoring the physical and chemical properties of soil and studying the bacterial community structure during the remediation process. Compared with the control (TCK), after 84 days of restoration, parameters of the tailings soil inoculated with the compound bacterial flora were improved, pH was decreased from 7.74 to 7.02, EC (electrical conductivity) was decreased by 21.15% ~70.49%, and activities of alkaline phosphatase, sucrase and urease were increased by 95.94%~99.64%、88.42%~98.43%、83.28%~86.95% respectively. Among the 43 identified core optional taxonomic units (OTUs), Proteobacteria (44.9%), Actinobacteriota (21.7%), Bacteroidota (17.9%) were the dominant bacterial phyla, and Sphingobacterium (20.2%), Arthrobacter (8.5%), Sphingomonas (6.1%) were the dominant bacterial genus. The results of alpha diversity showed that the bacterial diversity and richness of the treatment groups inoculated with compound bacterial flora were significantly higher than controls (TCK and HCK). The correlation analysis of RDA, VPA and Spearman showed that soil pH, WHC, EC, POR, TEMP and heavy metals had significant effects on the composition and distribution of bacterial communities. Our study monitored the changes of soil physical and chemical properties and bacterial community structure during the whole remediation process, which will provide a reference basis for the remediation approach to the soil polluted by multiple heavy metals.
Going virtual for professional development: when to do it, how to do it well, and what don’t we know - a scoping review
Authors: Bonsall Joanna M , Massart Annie , Edwards Roger A 
Published: March 2023

Abstract
Background:
Since the COVID-19 pandemic began in 2020 there has been a massive shift from in-person to virtual professional development. While the benefits of virtual sessions are obvious during a pandemic, there are many other benefits to virtual options, especially for professionals who live at great distances from the event and/or practice in resource-limited circumstances.
Objective:
In this scoping review, we describe the evidence for the benefits and drawbacks of virtual professional development. We describe the necessary components for successful conversion of in-person professional development to virtual events and how networking can be incorporated into virtual events successfully.
Design:
A literature search of peer-reviewed articles from 2000 through 2021 was undertaken using the databases PubMed, ERIC, and CINAHL.
Results:
Our review found that there was a significant decrease in both cost and environmental impact for virtual events, particularly for those participants who would have needed to travel long distances for in-person events. Combined simultaneous virtual and in-person sessions allowed participation from those who would have otherwise been unable to participate while still allowing the establishment of regional connections. Processes that led to successful conversion of in-person events included extensively testing and educating about the technology, training presenters on how to modify teaching for a virtual format and having facilitators moderate discussions. Networking was successful if participants either focused on a common project or had specific common interests; appropriate facilitations was also important for success.
Conclusions:
Advantages of virtual professional development, including reduced cost, reduced environment impact, and reaching attendees who would not otherwise be able to participate, should prompt ongoing use past the COVID-19 pandemic. Understanding when and how to effectively use of virtual professional development options is important to reduce barriers to professional development participation and maximize advantages of the virtual environment.