bluuebunny/crossref_metadata_2025 huggingface dataset:
Using ground-penetrating radar to map agricultural subsurface drainage systems for economic and environmental benefit
Authors:   USDA-ARS – Soil Drainage Research Unit, USA, Allred Barry , Koganti Triven ,   Aarhus University, Denmark
Published: March 2023

Due to economic and environmental considerations, there exists a need for effective, efficient, and nondestructive methods for locating buried agricultural drainage pipes. Ground penetrating radar (GPR), a proximal soil sensing method, can potentially provide a means for drain line detection. This chapter details the evolution of research, through a series of studies conducted over the past twenty years, which focused on farm field mapping of subsurface drainage systems using GPR. The chapter first describes the evaluation of GPR against other proximal soil sensing methods. It then considers the factors potentially impacting GPR drainage pipe detection, goes on to examine GPR assessment of agricultural drainage pipe conditions and associated functionality implications, the effects of GPR antenna orientation relative to drain line directional trends and the integration of GPR with Real-Time Kinematic (RTK) Global Navigation Satellite System (GNSS) technology. A section on drainage mapping with a multichannel, stepped-frequency, continuous wave 3D-GPR system is also provided which is then followed by a review of complementary employment of GPR and unmanned aerial vehicle (UAV) imagery for drainage system characterization. The chapter concludes with a summary and recommendations for future research.
The effects of environmental pollution on humans in international agreements
Authors: علي د. طارق عبد المجيد محمد
Published: March 2023

The result of progress and development in several fields, such as science, technology, industry, and transportation, has led to pollution and deterioration of the ecosystem and the occurrence of disasters that threaten human life. Therefore, attention must be paid to the environment and work to protect it from pollution. Given the importance of the topic of environmental protection, we address in this study two important topics, firstly, protecting the environment from pollution in the human dimension. Secondly, the most important dangers of environmental pollution resulting from it, and mentioning the most important international agreements that were formulated to protect the environment. One of the most important findings that I have reached through going into this research paper is that protecting the environment from the dangers of pollution is a shared responsibility among all human societies, that ecosystems are interconnected with each other, and that disruption of these systems threatens the natural balance of the environment, which affects all organisms living, including humans. In addition to the fact that the environment and pollution are man-made due to development, activities, exploitation of natural resources, and depletion of the environment in a way that exceeds the capacity of the environment, which leads to the deterioration of the ecosystem, and therefore everyone is called to bear the responsibility of protecting and preserving the environment.
Cause of distress of an old building through analytical and micro‒analytical methods ‒ a case study
Authors: Preetha Rajappan , Kumari Kalpana , Sakthi Balakrishnan , Harikumar Chandrasekharan Nair , Abdul Gani Haneef Ibrahim
Published: March 2023

The case study pertains to the methods such as nondestructive, semi-destructive, chemical, electrochemical and micro-analytical, utilized to assess the cause of cracking and spallation of a reinforced concrete building near to the eastern coastline of India. Cause of degradation of the structure is assessed to arrive at the appropriate repair methodology. From the analysis methods, direct cause of failure could not be attributed to a single cause since many factors co-exist such as structural cracking, carbonation and presence of chloride and the synergistic effect; hence concludes that an appropriate repair methodology has to be evolved to address each issue.
A discussion on the beam on elastic foundation theory
Authors: Yelce Tunay Uzbay , Balcı Erdem , Bezgin Niyazi Özgür
Published: March 2023

A railway track is a structural composure of many elements. Railway track analyses requires analyses for the interaction between these elements and the interaction between the track and the vehicle passing over the track. Various design models have been developed to simplify the analysis of railway tracks and to establish appropriate design criteria. Winkler's representation of the subgrade support as a continuous structure with independent springs was adapted to railway tracks by Zimmermann that further evolved into what is known as the Beam on Elastic Foundation Theorem (BOEF) today. A soil and structure interaction model based on BOEF theorem, frequently used by engineers to analyze the response of continuously supported structures on bearing layers, provides estimates for the distribution of deflections, bearing pressure, shears and moments along a continuously supported structure, such as a plate, by subgrade. This study aims to provide an in-depth and an explicit solution to the 4th order differential equation of BOEF and serve as a resource for those who are interested in this topic. This study will also present the historical development of the BOEF model, its use in railway track analysis, as well as its underlying assumptions in terms of structural behavior.
Keabsahan Akta Notaris Yang Tidak Dibacakan Oleh Notaris Di Depan Para Penghadap Dan Para Saksi Pada Saat Penandatanganan Minuta Akta
Authors: Yunian Rizky
Published: March 2023

This study aims to analyze and identift the validity of the Notary deed that was not read out by the Notary before the applicants and witnesses; and, to analyze and identify the role of the Notary Supervisory Board in terms of enforcing UUJN regarding the behavior of a Notary who does not read the Notarial deed that they have made. This is a qualitative normative legal research as it examines legal norms related to the validity of notarial deeds which were not read out by the notary before the applicants and witnesses at the time of signing the minutes of the deed. The results of the study concluded that the Notary is obliged to guarantee the certainty of the day, date, month, year, and facing time listed or mentioned at the beginning of the Notarial deed, as proof that the parties face and sign the deed and all procedures for making the deed have been carried out according to the applicable legal regulations in UUJN. In the case of the notarial deed not being read to the applicants and witnesses due to the notary's negligence is certainly in contrary to the UUJN provisions, which undoubtedly will have legal implications for both the deed and the notary concerned. The reading of the deed that is not carried out by a Notary will result in a decrease in the value of proving an authentic deed to become a private deed as stated in Article 16 paragraph (9) UUJN.
Design Communication Processes in the LISA Cohort Study
Authors: Netto-Rocha Constança , Marques Daniela Sofia
Published: March 2023

The basis of this project is a health literacy cohort study (LISA) being developed in the county of Leiria. The study aims to reach and monitor the adult population of the county over time. Counting with a multidisciplinary team, the study stakeholders asked the designers to develop the study’s brand so it could be more advertisable to the population, turning the communication between the stakeholders and the public easier. The development of the brand identity and elements of communication used some graphic design approaches. These approaches were reinforced by the opinions given by the interviewed sample of the population, that answered some of the study’s questions. The interviews held by designers allowed the team to receive information about what was expected the study to be, and how and where to better communicate the LISA’s Study. Trough the aforementioned process resulted in the current finalized outcomes of the study’s brand and communication materials. Both printable and digital communication elements (i.e., roll-up, id cards, flyers, QR Code, and website) were developed and disseminated according to the brand's strategy. Concluding, the communication elements created are seen as the first phase of this project, leaving a second phase related to the design and structuration of the Study to be developed, and published in future articles.
Improving student engagement through employability themed group work
Authors: Fairfax Simon A.
Published: March 2023

In an ideal world, universities and their departments are able to reach out to employers for collaborative, employer-set, authentic assessment which align industry expectations with an assessment that tests the intended learning outcomes of a module. This is a large and ambitious undertaking for practical reasons. The author identified three practical challenges as: sourcing willing employers, relevance and level-setting, and scalability, i.e., use in modules with large numbers of students. As module leader, each of these challenges were addressed and solutions identified allowing the employability project to be embedded into a module with 150 participating students contributing 30% towards the overall module mark.
El empleo de metodologías de código abierto para las investigaciones costeras: comparativa de las técnicas de detección de cambios
Authors: Gómez Pazo Alejandro
Published: March 2023

Coastal studies have a great relevance historically. This increase in the last with the new technologies and the possible global change impact. In this context, open-source tools represent a key element in these investigations. The present project analyzes the advantages and problems of open-source tools for estimate coastal variations and volumetric changes. For this purpose, a small sector of the Galician coast was used as an example. The open-source approaches have produced similar results to those obtained with proprietary software (ratios ≥ 0.97). In some cases, these methods improve processing times and allowing to users better possibilities for customization and decision-making.
Building a System to Solve the Challenges of Drilling Hot Hard Rock for Geothermal and Oil and Gas
Authors: Pink Anthony , Patterson Adam , Thoresen Karl Erik
Published: March 2023

Objective Scope

Geothermal energy is gaining attention worldwide as an attractive and vastly underutilized renewable energy source due to its abundance, baseload capability, resiliency, and reliability. While there are many types of geothermal energy concepts, the holy grail of geothermal – that would enable geothermal drilling and production in most places in the world – is hard rock or superhot rock concepts. Developing these systems requires drilling into granitic basement formations, often at temperatures exceeding 300º C. There are two main technological challenges associated with hard, hot rock concepts. Firstly, very hard rock, such as granite or basalt, limits the rate of penetration (ROP). Secondly, the temperature of the drilling system exceeds the operational limits of electronic tools like measurement while drilling (MWD) and Rotary Steerable. This paper discusses the modeling, design, and testing of a drilling system that solves both challenges.

Methods

Our approach to the ROP problem was to optimize the drilling system for drilling cold hard rock from 0º to 175º C and optimize the system for drilling hot hard rock where temperatures exceed 175º C. We will discuss the design and performance of both PDC drill bits and Hybrid Particle Impact/PDC bits in hard rock formations and the best application of the two methodologies moving forward. Our approach to the temperature problem was to model the entire wellbore and drillstring and investigate the effects of, but not limited to, the starting temperature of the fluid, flow rate of the fluid, type of fluid, impact of the thickness, type of insulation on the inside of the drillpipe, the diameter of the pipe, and continuous circulation. The objective of the modeling was to understand the relative impact of changes to the system on the temperature of the drilling fluid and the most cost-effective way to deliver a 150º C fluid to the bottom of the hole.

Results, Observations and Conclusions

This paper will discuss the results, observations, and conclusions of testing and running PDC drill bits and Particle Impact Drilling/PDC hybrids in hard formations. The results will derive from lab testing and geothermal drilling projects. The paper will also discuss the field testing and running of components of a drilling system optimized to deliver as cool a fluid as possible to the bottom of the wellbore.

Novel/Additive Information

The results shown in this paper suggest that we have solved, or are very close to solving, two of the major challenges which prevent geothermal energy from being economically viable worldwide and not just restricted to the small geographic areas where you have very high temperature gradients associated with volcanic activity. The results would also have significant benefits for oil and gas wells where the bottom hole temperatures exceed 175º C.
Cuttings Return Analysis by Visual Imaging: Novel Technology to Support Drilling Automation
Authors: Grossi Caroline D , Hummels Yuri H , Meleiros Luiz Augusto da Cruz , Scheid Claudia Miriam , Calçada Luís Américo , Waldmann Alex Tadeu Almeida , De Sa Carlos , Martins André Leibsohn
Published: March 2023

In recent years, image acquisition of process variables has become a common practice as an essential monitoring tool for industrial systems. The rise of data analysis models and high performance computers enables the development of systems to support real time decision and automation initiatives. This work aimed to develop a comprehensive methodology to acquire, process and interpret shale shaker video images to support detection of problems associated with poor hole cleaning and wellbore instability. To achieve this goal, experiments in different operational conditions were performed in a pilot-scale vibrating screen using a sand suspension with xanthan gum at 0.1% to emulate the slurry flow in actual sieves. Such experiments aimed to evaluate how some of the main operational variables influence the area of the sieve filled with solids, the moisture content of the solids, and their flow velocity. The proposed methodology used a U-Net convolutional neural network to perform the semantic segmentation of the sieve’s images to estimate the percentual area filled with solids in the shale shaker. An image database with 11,140 pictures and their respective templates was created from 26 experiments. The templates were built using image processing techniques, and 75% of them were used for training, 10% for validation, and 15% for testing. The neural network evaluation metrics were accuracy for training, F1-Score, and MeanIoU for testing. In addition, the estimated values were compared to the experimental data. The estimated velocity, expressed in cm/s, was further compared to experimental data. The results obtained using the U-Net showed high segmentation ability, with an average accuracy of 97%, mean F1-Score of 92%, and mean IoU of 91%. According to these results, it can be concluded that the proposed image-based technique is a promising tool for monitoring important process variables in drilling operations. Additional experiments with different shape particles result in effective guidelines to detect wellbore instability events. In future work, the authors expect to improve the segmentation technique to obtain better estimations of the process variables and the implementation of the procedure in integrated real time diagnosis systems. This work shows an innovative approach to support the drilling process, allowing to evaluate, quantify and characterize the drilling cuttings that returns to the surface. This initiative is committed to helping to reduce the well construction costs, non-productive times (NPTs) and to guarantee drilling operations more efficient and safer. Besides, provides additional relevant information to support the future views of autonomous drilling and unmanned rigs.
Becoming an HPHT World Class Project, the Valemon experience 2012-2017
Authors: Paulus Steven Leonardus , Shen Hendry , Beeh Hany Ahmed
Published: March 2023

The objective of this case study is to share essential learnings from the planning and execution of the first drilling and completion campaign in the Valemon field throughout the period of 2012-2017 with a total delivery of 17 wells. The case study will give an overview of the Valemon field, geology of the area and well design. The development of well trajectory became longer and more challenging as the geology targets moved farther away from the platform. Several major challenges and learnings were experienced during execution such as enabling one run strategy in 17-1/2" section, updating well path strategy to improve borehole stability, managing overburden gas responses in 12-1/4" section, and section target depth strategy for 12-1/4" section.

Continuous learnings from sessions such as Improve Well on Paper (IWOP), Drill Well on Paper (DWOP), Subsurface Action Review (SAR), Subsurface After-Action Review (SAAR), operational procedures after action review, experience reports, and post well meetings enabled the project to reduce the time and cost per well. It took 160, 111, and 166 days respectively to complete the first three wells. The last well was delivered in 62 days. By the end of the campaign in November 2017, the Valemon project delivered four (4) extra wells compared to the original plan of thirteen (13) wells, while spending 500 million NOK-2017 (Norwegian Kroner with 2017 currency) or 60 million USD-2017 (United States Dollar with 2017 currency) less than the planned budget. Moreover, the entire drilling campaign was completed without any well control incidents.
Improving the Accuracy of a Kick-detection System by Reducing Effects of Rig Operational Practices
Authors: Joshi Deep R. , Yalamarty Sai Sharan , Cheatham Curtis A. , Kamyab Mohammadreza , Winklmann Kelly , Ross Trish , McCormack Patrick
Published: March 2023

Novel methods are presented that update a real-time cloud-based kick-detection system introduced in SPE-208770-MS to handle false kick identifications caused by rig operations. A common weakness in kick-detection systems is false indications of kicks due to rig operations and drilling practices that cause changes in tank volumes. In this work, we will discuss the modifications made to the existing real-time kick-detection system to handle rig operational practices and reduce false positives.

The existing kick-detection system analyzes the trends in the drilling data such as tank volumes, flow rates, and pump rates to detect well control events. Extensive field use of this system showed that the rig operations such as transfers between tanks, tank swaps, and adding material to the active tanks have a severe impact on the false-positive rates. Two approaches were developed to handle such operational practices: - Transfer identification: identify transfers between monitored tanks - Comment watcher: Evaluate the rig-memos to check if they might identify an operation that explains the variation in the tank volumes.

These approaches were tested with historical wells and live wells. Transfers were identified in several historical wells with help from the operator subject matter experts (SMEs). Thresholds such as the rate of transfer and the window size were tuned to optimally identify transfers. The tuned algorithms correctly identified transfers between monitored tanks with more than 85% accuracy. This workflow was added to the existing kick-detection framework. The efficiency of the kick detection logic depends on dynamically adjusting various thresholds. If any transfers were identified, the thresholds were reset which helped further reduce the false positives by 20% - 25%. For the comment watcher, a keyword library was developed with help from the operator SMEs. This library contained a list of keywords that the rig crew frequently uses in the rig memos to describe the operations. Each keyword from the library was mapped to an alarm type to be suppressed. A workflow was implemented to identify if a rig memo contains a keyword and suppress the respective alarm. The comment watcher feature was then implemented on historical wells along with the transfer identification. These updates resulted in a 40% reduction in false positives while maintaining a 100% true positive identification rate.

This work improves the accuracy and efficacy of a previously presented (SPE 208770) real-time cloud- based kick-identification system by detecting and avoiding the impact of rig operations. Features such as transfer identification and comment watcher are added to determine if the changes in the tank volumes can be attributed to rig operations. This update was tested on historical wells and live wells. Working together, these features helped reduce the false positives by up to 40%.
A Control-Oriented Lumped Parameter Drillstring Dynamic Model for Real-Time Vibration Mitigation and Drilling Optimization
Authors: Zhang Yifan , Ashok Pradeepkumar , Chen Dongmei , van Oort Eric
Published: March 2023

Drilling is an essential operation for subsurface hydrocarbon/geothermal energy extraction or underground waste fluid/gas storage. Efficient drilling is the key to an economically viable operation. Axial, torsional, and lateral oscillations that are excited in the drillstring by various surface/downhole sources (like the application of the weight-on-bit (WOB), rock cutting process, bottom-hole-assembly (BHA) resonance, downhole tool operation, drilling fluid dynamics, etc.), are the prime causes of downhole tool failure, material fatigue, bit wear/damage, and insufficient surface-to-bottom energy transfer. Since the 1960s, a wide variety of models have been developed to analyze drillstring dynamics and optimize the well/drillstring design. With the advance of drilling engineering, sensor technology, and data science, a fast and comprehensive drilling system dynamic model is in need for real-time drilling optimization and automation.

In this study, a control-oriented physics-based lumped parameter model (LPM) is developed to investigate the fully coupled drillstring dynamics in all three directions. Various boundary conditions (wellbore-drillstring interaction, bit-rock interaction, presence of stabilizers/centralizers) and system input actuations (surface WOB/hookload, surface rotational speed (RPM)/torque, mud motor operational parameters, etc.) are defined in the modeling framework. Simulations are run for different drillstring scenarios in a vertical and an actual L-shaped wellbore configuration. System dynamic responses illustrate various amplitudes, frequencies, and modes of fully coupled drillstring vibrations at different depths when simulated with different drilling parameters. Another significant observation is the emergence, propagation, and transition of lateral vibration modes between forward, backward, and chaotic whirl patterns. Based on the tradeoff between accuracy and complexity, the proposed dynamic model can be adapted for real-time model-based control, and can also be deployed for well design purposes or digital twinning applications.
Design and Calculation of Process Parameters in Bullheading and Pressurized Mud Cap Drilling
Authors: Liu Yaxin , Upchurch Eric R. , Ozbayoglu Evren M. , Baldino Silvio , Wang Junzhe , Zheng Danzhu
Published: March 2023

This study aims to provide the design and calculation method of key parameters in bullheading/PMCD operations. An improved gas migration velocity model in closed well conditions was developed based on the combination of the equation of motion (bubble flow) and Taylor bubble correlation (slug flow). A detailed derivation of the model can be found in our companion work (Liu et al. 2023). Experiments of Taylor bubble countercurrent behavior in an eccentric 6 in. × 4 in. annulus were conducted. Fluid rheology, annulus inclination, and internal pipe rotational speed were varied to provide a clearer understanding of Taylor bubble physics under non-Newtonian countercurrent flow and its implications for effectively managing upward gas migration that can occur in a wellbore during drilling operations in fractured or vugular rock formations. Computational Fluid Dynamics (CFD) simulations were performed to estimate the velocity of Taylor bubble in vertical annuli with downward fluid flow and a new closure relation for distribution parameter, C0, was proposed. The drift flux model embedded in the new gas migration velocity model was applied to simulate the dynamics of bullheading/PMCD. Good agreement between the model and published data was obtained. The effect of different bullheading rates on surface pressure and gas fraction in PMCD operation was examined.
Automated Offsets for Drill Bit Performance Evaluation, Analysis, and Monitoring At-Scale
Authors: Skoff Gregory , Fink Dave , Poor Andrew , Gjertsen Ole , Wolfram Preston , Santana Roberta , Ford Robert
Published: March 2023

Utilizing big drilling data requires an innovative approach. The service company’s drill bits business is largely based upon an in-house drilling record system (DRS) that captures global bit record performance data. The DRS contains over 1.8 million wells drilled worldwide since 1980 with nearly 5.4 million total BHA runs from over 100 countries. In the last 10 years alone, over 1.4 million bit runs drilling over 2.8 billion ft of formation have been recorded. To utilize this vast amount of data for drill bit performance evaluation, analysis, and monitoring, the innovative approach described in this paper was developed and implemented.

Traditionally, the performance of a drill bit run–often measured in terms of drilled footage and ROP–has been evaluated versus similar offset runs. Offset runs are chosen in various ways, but are typically done manually by bit engineers, meaning that offset run selection is subjective based on personal experience and bias. Furthermore, people often only evaluate the performance of test bit designs. Instead, we wanted to analyze and monitor the performance of all drill bit runs. To alleviate these biases and enable a wider breadth of considered runs, an objective offset run selection workflow was developed and implemented within DRS. Offset runs are selected based on a sophisticated filtering and scoring routine that considers many characteristics such as geographic location, time, wellbore and drilling system design, along with lithology. As new data enters DRS continuously, this workflow runs on a regular basis using an automated pipeline.

The performance evaluation results of the automated offset selection workflow are available to all data analysts (engineers and salespeople) both inside DRS and extensible applications to aid in performance monitoring and new product development target-setting. Product performance is now objectively evaluated at-scale across geographies and always utilizing apples-to-apples comparisons. The workflow has proven itself quite useful and delivered business value already but also exemplifies the need for both enhanced data quality and improved bit record data capture rate. These are ongoing efforts to further enhance and improve this workflow.

Automated workflows like this one can help our industry by eliminating repetitive biased tasks and allowing people to focus on more creative processes leveraging objective data. Developing new drill bit designs, material selections, or component selections to overcome new challenges are creative processes which contribute to increased drilling performance and lower costs for the industry.
Drilling Three-Mile Laterals Tighter and Safer with a New Magnetic Reference Technique
Authors: Pare Andrew , Cosca Nico , Berarducci Alec , Crookston Glenna , Paynter Ryan
Published: March 2023

Three-mile laterals have become more common over the last five years of onshore US drilling. They are especially commonplace in the Appalachian and Permian basins and are used to overcome limited surface access for drill pads and for economic reasons. These long laterals pose significant wellbore positioning and anti-collision challenges. Horizontal position error grows at 2% (or more) of the lateral length per degree of wellbore azimuth error. This work addresses these wellbore positioning challenges with a new and significant improvement in magnetic field determination. With this procedure, multi-well pads with tightly spaced three-mile laterals can be drilled without compromising anti-collision standards or horizontal placement goals.

Most commonly in the US land market, tightly spaced laterals are 1-2 miles in length and make use of In-Field Referencing (IFR-1) magnetic models built from airborne geophysical surveys to ensure proper positioning and avoid well collisions. For more challenging pad designs, such as three-mile laterals, a new method has been developed to combine an IFR-1 magnetic model with a near-well magnetic theodolite measurement to build a more precise magnetic model and positioning tool code. Specifically, the declination error terms in the ISCWSA (Industry Steering Committee on Wellbore Survey Accuracy) Error Model can shrink beyond the IFR-1 tool code specifications. This reduces the horizontal uncertainty in the ellipse of uncertainty (EOU) by upwards of 40% when compared to the MWD tool code standard.

A study was conducted on a typical well and pad design for three-mile laterals in the Marcellus Shale in Pennsylvania. We find that the horizontal uncertainty with the MWD tool code at two and three miles of reach to be 206 feet and 303 feet, respectively. With the new tool code enabled by this body of work, we calculate the horizontal uncertainty at two and three miles of reach to be 120 feet and 174 feet, respectively. These results clearly show that this technique enables three-mile laterals to be drilled more safely and more tightly together. It is preferable for well pad design and lateral spacing to be determined by drilling and reservoir economics rather than collision concerns. Well planners and reservoir engineers can now safely access more of the reservoir from a single pad with longer laterals.

This work is novel because it combines a ground based, near-well, magnetic measurement with an airborne derived IFR-1 model. This allows for a greater reduction in positioning uncertainty than has been available in the past. The application of this method to three-mile laterals is also new and has a profound impact on being able to plan optimally spaced wells and avoiding collisions.
Gas Migration Model for Non-Newtonian Fluids Under Shut-In Well Conditions
Authors: Liu Yaxin , Upchurch Eric R. , Ozbayoglu Evren M. , Baldino Silvio , Zheng Danzhu , Wang Junzhe
Published: March 2023

Addressing gas migration in a static mud column during the shut-in period is a major concern in Pressurized Mud Cap Drilling (PMCD). Significant discrepancies have been found between the field data and existing correlations for gas migration velocity, since the latter are based on either small-scale experiments or overly simplified assumptions, resulting in overly conservative estimations. To meet the Light Annular Mud (LAM) requirement for managing gas migration and to monitor the transient pressure experienced throughout the PMCD operation, an improved gas migration velocity model was developed by combining the equation of motion (bubble flow) and Taylor-bubble correlation (slug flow). In the bubble flow model, the effects of non-Newtonian fluid properties and drill pipe rotation are considered through a modified drag coefficient (CD) that incorporates the bubble Reynolds number (Reb) and dimensionless shear rate (Sr). The effect of bubble swarm is taken into account through a void fraction (αg) term. The slug flow model is based on a Taylor bubble correlation in terms of Eötvös number (Eo) and inverse viscosity number (Nf). For the first time, the dependence of Taylor bubble velocity on drill pipe rotation has been shown and correlated as a function of Sr. Predictions of the gas migration velocities in PMCD operations are made and successfully compared with the existing models and test-well experimental data. The drift flux model embedded in the new gas migration velocity model was applied to simulate the gas migration in a test well. Good agreement between the model and measured pressure results in the full-scale test-well experiments can be obtained. Its companion work (Liu et al., 2023) provides the design and calculation method of key parameters in bullheading/PMCD operations.
Rotary Steerable Drilling Dynamics and Associated BHA Changes to Improve Overall BHA Performance and Reliability
Authors: Jones Steve , Sugiura Junichi , Johnson D. Wayne
Published: March 2023

During the advanced development phase of a push-the-bit rotary steerable system (RSS), downhole drilling dynamics were captured utilizing high-frequency embedded drilling dynamics sensors distributed throughout the bottom-hole assembly (BHA).

The RSS development testing was conducted in a challenging pocket of the Delaware Basin in the Permian Region of North America. This specific Delaware area has proven difficult to drill with conventional steerable motors due to rapid shoulder wear on the bit and sliding difficulties (Sugiura et al. 2022).

The initial RSS BHAs were designed based on the directional objectives of the well. As the runs and wells progressed, the multiple embedded drilling dynamics sensor data, BHA/bit component wear and reliability, and drilling performance were all analyzed. From these learnings, systematic BHA changes were implemented and measured. This process continued until the drilling pace, reliability and repeatability were at an acceptable level for the project.

This paper details the drilling dynamics, drilling parameters, BHA configurations, formations, and logic for BHA/drilling parameter changes in the 12 ¼-in. intermediate section.
Case Study of the World's First Offshore Implementation of a Drilling Automation Platform with Multiple Closed-Loop Applications
Authors: Ronquillo Nahum , Birgisson Kjartan , Ørevik Morten , M Zurhan M Syahmi , A Murad M Syazwan , Khazali-Rosli Khairul Amir , Abd Mokhti M Ridzuan , Jamal Jasrudin , Bailey Jason , McEwan Doug , Ng Damien
Published: March 2023

Drilling automation technology has been successfully deployed and in operation for several years. While the technologies covered in this paper had already been deployed separately in other regions, this case study is not only Malaysia's first drilling automation project but also the world's first deployment that includes the automation platform combined with two third-party closed-loop control applications (Apps). The study details the technologies, their implementation approach, and key performance indicators (KPIs) to measure the success of the project.

Technical and procedural measures necessary to ensure the safe and efficient use of the system are explained. The project's measured KPIs were collected and analyzed throughout multiple wells and are presented in the paper to measure the performance and success of the project.

Throughout the execution of the project, the automation platform successfully coordinated control ownership of the two Apps. A comparison by the drilling contractor of KPIs with and without the automation technology successfully validates the benefits in performance and consistency.
Cloud-Based Real-Time Well Engineering: Coupling Torque-And-Drag and Uncertainty Modeling
Authors: Chi Yuandao , Kemajou Vanessa , Rajan Anil , Samuel Robello
Published: March 2023

Surface hookload and torque values serve as good indicators for some undesirable scenarios or anomalies during drilling, such as stuck pipe, buckling, and inadequate hole cleaning. However, to detect these risks, it requires drilling engineers to perform the friction factor calibration manually and regularly, which costs more effort and poses significant uncertainties on the detection. In this paper, a cloud-based real-time well engineering webapp has been developed to monitor and forecast tripping frictions and drilling performance. Results of field tests were presented to prove the successful testing of this cloud- based real-time workflow. Real-time hookload and torque values were streamed smoothly to the web application interface. Rig activity, friction factor, and mechanical specific energy (MSE) were also evaluated and displayed in real-time with predicted uncertainty zone. It has been demonstrated that this cloud-based web application supports a multi-tenancy architecture and multiple wells can stream simultaneously with no down time. This new workflow made it possible for drilling engineers to monitor live drilling wells anywhere and anytime while enabling the rig personnel to make significant improvements to operations and make timely and accurate decisions.
Gas Bullheading Study in an Instrumented Well
Authors: Samdani Ganesh Arunkumar , Rao Sai Sashankh , Moganaradjou Yashwant , Almeida Mauricio A. , Kunju Mahendra K. , Santos Otto , Gupta Vishwas Paul
Published: March 2023

Bullheading involves pumping produced fluids back into the formation using a kill-fluid. A key operational parameter is the required bullheading rate which depends on surface pressure, available horsepower, and erosion limits. There is wide variation in current guidelines for bullheading rates, especially for large-diameter wellbores. Therefore, a well-scale bullheading test program was conducted using a 5200-ft-deep vertical well with 9-5/8"x2-7/8" casing/tubing annulus located at LSU test well facility. The tubing was instrumented with 4 downhole pressure gauges and fiber optic DTS/DAS to obtain data on the downhole flow dynamics and determine bullheading efficiencies. In a typical test, a large nitrogen cap placed at the top of the annulus was bullheaded by pumping fluid in annulus with continuous returns taken from the tubing side. Tests were conducted with varying fluid rates (50 to 500 gpm), initial gas-cap size (30-60 bbl), gas pressurization method and kill fluids (water and synthetic base mud). It was observed that the bullheading process involves simultaneous gas compression, gas bubble breakage, gas dispersion, and gas displacement, unlike the typical assumption of bullheading a large gas slug. The breakage of the initial gas slug depended on the surface pressure and the extent of gas-liquid mixing. The minimum water flowrate required for gas bullheading matched to water velocity just above small bubble velocity in water. Increase in water flowrate increased the bullheading efficiency, e.g., bullheading with 350 gpm required <50% water volume compared to 150 gpm water flowrate. Experiments with a highly pressurized initial gas cap and a larger initial gas cap volume resulted in relatively more efficient bullheading due to lower slip velocity resulting from higher average gas-holdup in the gas-swarm. In one test, the gas was bullheaded for some time and then allowed to migrate upward in a shut-in well. It was observed that the gas migration velocity (0.71 ft/sec) was higher than the gas slip velocity during bullheading (0.3-0.6 ft/sec). Contrary to the popular belief, the gas also did not carry its pressure while migrating in a shut in well. The experimental observation of bubbly flow instead of slug flow during bullheading under sufficiently higher surface pressure helped understand the multiphase flow dynamics of bullheading and it can help provide realistic bullheading guidelines based on well conditions.
Drill-Off Tests for Drilling Optimization: Pitfalls and How to Avoid Them
Authors: Chhantyal Khim , Kyllingstad Åge , Hetland Anders T. , Thor Birgisson Kjartan
Published: March 2023

A drill-off test is a special drilling test where the drawworks is locked and the string elasticity causes the bit to penetrate the formation at a decreasing weight on bit (WOB). It is often used as a tool for finding how the rate of penetration (ROP) varies as a function of WOB and for finding optimal drilling parameters. This paper sheds a critical light on the use of drill-off test by discussing various errors and pitfalls usually ignored today. The paper starts by presenting a simple but widely used method for converting surface hookload data into an ROP vs. WOB curve, commonly known as a drilling performance curve. Next, it discusses and tries to quantify various error sources, such as hookload sensor errors, residual wellbore drag, and formation inhomogeneities. The paper uses real field data and a comprehensive simulation model to illustrate the magnitude of the various errors and how they affect the drilling performance curve. Finally, the paper suggests ways to check the accuracy and validity of the drill-off tests. The analysis shows that the variable wellbore friction is an error source that depends on many parameters, such as string length, wellbore inclination, rotational string speed, and ROP. It also shows that it is possible to model the errors and apply correction formulas to improve the quality and accuracy of WOB and ROP. Although friction-related errors can be reduced by applying proper corrections to the estimated WOB and ROP, there is still a need to check the validity of the drill-off test results with other types of drilling tests. The paper presents several proposals for alternative and complementary drilling tests, such as drill-on test (here defined as a test where WOB is continuously increased), steady state (constant WOB) drilling test, combo test, and sinusoidal perturbations test.
Time-Lapse Evaluation from Ultrasonic Pulse-Echo and Pitch-Catch Configuration and Sonic Logging Data for Potential Formation Creep and General Annulus Solids Segregation
Authors: Obando Palacio Guillermo Andres , Govil Amit , Agrawal Gaurav , Gupta Shilpi , Delabroy Laurent , Kristiansen Tron Golder
Published: March 2023

Verification of annular well barrier elements is an essential process during the well construction and plug and abandonment phases. This topic has been the subject of many publications and is governed by regulations in different countries around the world. In this paper we focus on the evaluation of shale creep barriers. We describe how sonic and ultrasonic pulse-echo and pitch-catch configuration data are used to monitor the evolution of formations creep around the casing to eventually form annular barriers.

Multiple annulus logging evaluations were performed across wells from the Valhall, Ula, Alvheim, and Jette fields on the Norwegian Continental Shelf (NCS). This was done using ultrasonic pulse-echo and pitch-catch configuration data as well as traditional sonic logs. The logging data were collected, reprocessed, and compared as part of a collaborative effort between the operator and a service company. In this study we examine the progression of annular solids through time from formation creep.

Our intention was to study the ability of shales creep to form barriers, and to simplify the well design and achieve isolation around the production casing without the need for conventional cementing operations.

The log data provide information of annulus material with a detailed map of the axial and azimuthal variations of the annulus contents. Crossplotting state-of-the-art measurements also helps to identify the material accumulating in the annulus as published in many other industry papers. This approach has garnered interest over the years as a novel solution during well abandonment operations. The results provide solid evidence of shale creep-forming barriers and has been used by the operator to further refine their zonal isolation strategy.

Comparing ultrasonic data with a particular interest on the progression of formation creep, has become a popular subject within the NCS. Innovative use of historical logging data holds a great potential to help make decisions that result in reduced cost and environmental impact. Because of this novel usage and analysis of ultrasonic logging data, the operator was able to make informed decisions faster, saving rig time and cost while reducing the carbon footprint.
Drilling Parameter Optimization in Real-Time
Authors: Mal Anwesha , Oedegaard Sven Inge , Helgeland Stig , Navabi Josef , Skogestad Jan Ole , Bjoekevoll Knut Steinar , Lien Morten , Weltzin Tore , Rudshaug Bjørn
Published: March 2023

There is an increased demand for contactless and/or low touch activities as well as a requirement for most product delivery and services to be such. This paper aims to demonstrate how drilling parameter optimisation in real-time provides a drilling team with an Edge based solution that can continuously improve performance and avoid problems without the need of subject matter experts. Results from testing the Edge-System on multiple wells from several operators are presented related to auto-calibration of real-time prediction models and for optimization of drilling parameters. This system based on cloud technology with Model based reasoning in Artificial Intelligence (AI) is able to give real-time and forward advice for operational parameters, ref SPE-204074-MS

The key enabler for such system is "automatic" auto-calibration of models which is used for multiple forward-looking and what-if calculations to find optimal drilling parameters within the well envelope ahead.

A simplified configuration has been made so that the rig-team can operate and maintain the system without the need for subject matter experts. "Automatic" Auto-calibration at stable conditions and/or during ramping conditions removes the need for subject matter experts. Such a system helps reduce operational costs as the rig-team can operate the system without the need of back-office support. Comparison will be made to document operational improvements.