bluuebunny/crossref_metadata_2025_split huggingface dataset:
Drilling Riser Conductor Monitoring: A Practical Approach for Operational Integrity Verification
Authors: Diestler Jeff , Park Mike , Das Samik 
Published: June 2014

Abstract
With an increase in the number of drilling operations in harsh environments and ultra deepwater, combined with the limited availability of drilling rigs and qualified personnel, it is increasingly important to maximize safety and operability while minimizing structural damage to the riser, wellhead and conductor system. Great efforts to improve drilling equipment, safety features and overall structural integrity of drilling riser systems have occurred in recent years. Subsequently, trends have shifted the focus of integrity concerns from the drilling riser onto the wellhead and conductor system. The integrity of the wellhead and conductor system is of utmost importance – as it provides a vital barrier to contain hydrocarbons and drilling mud inside of the drilling system. A structural breach of this system could have catastrophic consequences and must be avoided at all cost.
Significant challenges remain in accurately predicting and tracking actual fatigue damage on wellhead and conductor systems. This papers details the findings of several monitoring campaigns designed to track the actual vibration of the BOP and LMRP stack due to riser VIV, and its contribution to wellhead and conductor strength and fatigue concerns. The measurements have been used to provide operational guidance, validate design tools and thus provide a more realistic fatigue and strength data set for wellhead and conductor systems.
The paper will discuss the monitoring application including state of the art sensor systems with practical attachment systems that can be retrofit installed via ROV or diver. Furthermore, is discusses data processing methodologies and software with the aim to provide operational guidance to the drilling team (while providing uninterrupted continuation of drilling operations). Furthermore, detailed engineering studies are presented that correlate conductor fatigue as a function of drilling riser VIV and stack excitation. Two case studies illustrate the application of these technologies.
Through research findings and field application, this paper summarizes the operational benefits of an integrity monitoring systems for the wellhead and conductor system from an operator perspective. The target is to increase the understanding of Drilling Riser VIV and its effect on the wellhead and conductor systems. This provides assurance to the operator that the system has not been compromised during a specific drilling campaign and that any risk and uncertainties have been captured and has been evaluated.
In-Situ Analysis of the Microscopic Thermal Fracture Behavior of PDC Cutters using Environmental Scanning Electron Microscope
Authors: Zhan Guodong (David) , Patin Alexander , Pillai Raju , Gilleylen Russell , Castagna Marc 
Published: June 2014

Abstract
While significant advancements have been made in the field of Polycrystalline Diamond Compact (PDC) cutter technology over the years, understanding of the thermal fracturing behavior of these cutters is still limited. Traditionally, analysis of thermal fracturing was conducted by heating the cutter to the fracture point in normal atmospheric or vacuum/inert conditions, and then allowing it to cool down and polishing it for easy observation prior to microscopic analysis. This method limits findings, as the environmental conditions do not accurately reflect those experienced downhole, and this process does not allow for an in-depth understanding of the precise fracturing behavior of the cutter.
To gain a more in depth understanding of thermal fracturing behavior and its causes, a specialized environment was prepared that allowed in-situ observations of fracturing behavior in simulated drilling conditions. This included equipping a Scanning Electron Microscope (SEM) with a heating-stage furnace accessory to allow for real-time observations and filling the chamber with a simulated atmosphere consistent with downhole conditions. Cutter cross-sections were selected and polished using new methods to ensure maximum clarity and then heated to fracturing temperatures, with the SEM recording all changes as they occurred.
The observed thermal fracturing behavior, analysis of the microstructure degradation and EDS chemical analysis led to some valuable insights into cutter failure mechanisms. In the unleached areas of the cutters, fracturing began at significantly higher temperatures than expected, while the cobalt binder compound began melting at lower temperatures than commonly accepted. In addition, fracturing behavior was not universal, but began with a few major cracks appearing in the PDC structure, from which a network of smaller cracks progressed outwards through the cutter. With deep leached cutters, microcracking appeared in the diamond grains rather than intergranular fracturing, degrading the integrity of the cutter and indicating that graphitization, not fracturing, is the primary thermal failure mechanism of these cutters.
The data from these tests provides valuable insights into how PDC cutter and deep leach technology can be effectively used in the field. Due to the lower melting point of the cobalt binder compound, the temperatures used in manufacturing can be adjusted to ensure maximum cutter stability. In addition, these tests demonstrate a greater-than-expected wear resistance for deep leach cutters and a higher fracturing or degradation temperature of both unleached and deep leached cutters, meaning that they are suitable for a wider range of applications.
Innovative Dual-Diameter PDC Bit Design Provides Unique Solution to Successful Drilling of Challenging Volcanic Interval
Authors: Teasdale Paul , John Gareth , Davis Ron , Baudouin Nicolas 
Published: June 2014

Abstract
Drilling hard, abrasive volcanic rock has presented significant technical challenges to bit manufacturers over the years, creating a dilemma for operators designing a strategy to efficiently drill difficult volcanic intervals.
This paper will focus on the development of a unique concentric two-stage, dual-diameter PDC bit coupled with a low-speed, high-torque motor, providing an alternative solution for drilling a challenging section featuring a hard volcanic layer for a major international operator in a remote location West of Shetland.
The paper reviews the design concepts of the bit that allows an initial smaller pilot hole to be drilled, relieving the stress of the surrounding rock. The larger reamer section subsequently enlarges the hole to the desired diameter through stress-relieved rock, thus requiring less energy to remove a comparative volume of rock. The unique design concept was tested in an in-house pressurized drilling laboratory with basalt samples of varying compressive strengths to evaluate its performance in these challenging rock types. Alternate bit designs with a variety of cutter geometries and cutter layouts were also evaluated and an optimum design was selected for the field test to deliver lower vibrations and increased ROP.
A strategy was formulated to drill the interval in a single run with the optimal dual diameter PDC bit and a low-speed, high-torque mud motor. Downhole dynamics data recorders were placed in the BHA to capture downhole dynamic activity to evaluate performance and provide information to help further optimize performance through the interval.
On the subject well, the new dual-diameter PDC design successfully drilled the entire 12 ¼-in hole section in a single run, including 67 m of volcanics. The design achieved a record ROP for the section, saving five days of drilling time and resulting in significant cost savings for the operator.
In addition to providing measurable stability and drilling efficiency benefits in conventional applications, the unique concentric dual-diameter PDC bit also provides a technical solution to operators looking at more cost-effective means of drilling these challenging formations in a high-cost drilling environment.
Transferring Knowledge Through Decision Support: A Case Study in Drilling
Authors: Gundersen Odd Erik , Kucs Richard , Sheehy Tim , de Holden Mabel Susana 
Published: June 2014

Abstract
The new generation is primed to take on this challenge and lead the industry into the future. However, the industry will not simply pass the reigns to an unready resource, as experience is a critical component to success. Decision support systems can be an important source for sharing knowledge and experience, but they need to provide the right information at the right time.
We discuss how decision support software can and should both enhance the situation awareness of its users, as well as help transfer knowledge. Our view is based on Mica Endsley's model of situation awareness. We explain how oil well drilling monitoring can be understood according to this model, and we seek to define what exactly a situation related to the oil well drilling process is. Furthermore, we discuss knowledge transfer in relation to oil well drilling and the situation awareness model. Then, we show how the software we have developed performs in this regards both through an analysis and a use case that describes a commercial trial. Finally, the results of the commercial trial are discussed and some future work is considered.
Technology Application and Process Optimization for Success in Riserless Drilling
Authors: Groetsch Ryan , Mathur Rohit , Boyd Andrew , Williams Roger 
Published: June 2014

Abstract
Deepwater wells traditionally feature two or three riserless sections that present a unique set of issues. Any oversight in managing these issues could increase the risk to the wellbore and jeopardize the safe delivery of the entire project. Recent successes in an operator's field in the Gulf of Mexico indicated improvements could be made to a process that has been commonplace for the industry. In this case, many complications often encountered during riserless drilling were overcome by utilizing technologies that had been previously used in later sections of the wellbore.
These riserless sections have very soft, unconsolidated sediments, potential shallow water flow, torque-and-drag implications, positional uncertainty and close proximity potential to other wells in the field. This close proximity brings along another set of complications such as very large holes with concentric reamers, precise dogleg severity control, magnetic interference, and anti-collision issues. Any combination of these conditions may exist in a well.
Operators may want to consider adapting existing technology as a more cost-effective, efficient, and safe solution to riserless drilling complications. This paper presents case histories from successful deployments of available technologies to meet the demands of riserless drilling challenges. Technologies in focus are rotary steerable systems, gyro measurement while drilling (MWD), survey management and acoustic measurements in large hole sizes.
The oil and gas industry strives to manage risk, minimize non-productive time (NPT), increase efficiency, and reduce overall cost. The technologies and processes presented in this paper proved to be efficient in riserless drilling applications and helped the operator achieve overall project success. These technologies can be run separately or in conjunction, depending on the application.
Steering Efficiency and Directional Responsiveness - Definitions, Considerations, Drilling Systems Effects and Contributions to Performance Drilling Improvements
Authors: Mensa-Wilmot Graham , Gagneaux Jay , Langdon Sheldon , Benet Paul 
Published: June 2014

Abstract
Downhole drilling tools1,2, continue to see improvements in reliability, leading to extended mean times between failures (MTBF). Drive systems, specifically positive displacement motors (PDM), rotary steerable tools (RSS), and turbines have seen extensive improvements in MTBF. Consequently, technical successes on directional drilling programs, where such drive systems are commonly used have also improved. However, these gains do not always translate into meaningful operational success4, which is needed to drive down drilling costs. This situation is caused by some of the industry's perceptions and approach to drilling system design. Additionally, it is influenced by how projects are analyzed, and sometimes interpreted, with regards to performance drilling expectations.
This paper will discuss three types of success – technical, mechanical, and operational. It will also identify and discuss the reasons why gaps still exist between technical and operational success. In addition, evaluation processes developed to bridge the gap between technical and operational success will be discussed. Multiple case histories, highlighting the impact of the concepts and evaluation processes to be discussed in the paper, will be presented.
Automated MPD and an Engineered Solution: Case Histories from Western Canada
Authors: Medina Leiro , Baker Justin , Markabi Mazen , Rojas Jimmy , Tarique Zoro , Dow Blaine 
Published: June 2014

Abstract
Managed pressure drilling allows operators to address key technical risks such as narrow pore pressure and fracture gradient windows, influx management, sensitive wellbore stability environments and navigation of steep and unknown pore pressure ramps. In these applications, MPD may be the determining factor of delivering or not delivering the well.
Historically in North America land, operators have executed simplified forms of equipment-centric MPD in well-known basins. However, as unconventional development expands and new basins open up, subsurface pressure regimes present challenges that require a more intense engineered approach to MPD drilling, at least until the field is known. Applying engineering support alone does not guarantee success, though. MPD systems are designed to offer different degrees of pressure management precision and control. Depending on the complexity of the reservoir and geometry of the well design, an MPD solution appropriate for the application is also required.
The authors discuss the foundation of MPD automation using as an example, two systems with different degrees of automation control. Each was used for two distinct MPD projects in Western Canada. After determining the technical requirements of each basin, the appropriate MPD system was selected. In both instances, intensive drilling engineering design work was required to ensure the selected system was utilized successfully to drill these difficult wells. Each case unearthed unique lessons that allowed the drilling team to collectively evolve a step-change approach to MPD.
Multi-Machine Control Leads to Improved Rig Layout
Authors: Engum Erlend A , Haavind Erik , Enes Ståle , Holck Jesper 
Published: June 2014

Abstract
The 6th and 7th generation drilling rigs are increasingly using more automated and integrated control systems to reduce the number of operators needed on the drill floor, enhance safety, increase operational efficiency and predictability and reduce wear and tear on the equipment. A comprehensive multi machine, sensor and camera control system has been installed on several rigs currently in operations in the Gulf of Mexico. This system allows one to two operators to control and monitor all the tools in the tripping or stand building sequence with the ease of using one joystick.
This follow-up case study collects experiences of a rig using multi-machine control (MMC) by interviewing the rig crew, studying the drilling contractors KPIs and analysing logged data
Findings and lessons learnd have led to improved machine design and rig floor layout on the next generation drilling rigs. This paper also summarizes how the use of multi-machine controls and assembly line focused rig design together improves the effects automation has on staffing and efficiency of pipe logistics.
Degradable Fiber Pill for Lost Circulation in Fractured Reservoir Sections
Authors: Droger Nicolas , Eliseeva Ksenia , Todd Larry , Ellis Chelsea , Salih Omer , Silko Nikita , Fu Dan , Meyer Arnoud , Bermudez Raul 
Published: June 2014

Abstract
Lost circulation is one of the main causes of nonproductive time during drilling and impacts the success of cementing operations. Losses into the reservoir not only impact drilling, they potentially impact the reservoir, due to influx of quantities of drilling fluids that are potentially damaging, or will influence the production rate. Existing solutions are based mainly on particulates, which often are added to drilling fluids to plug fractures or to build up filtercake to cure fluid losses. When particulates are applied for curing losses in reservoir sections, it is desirable that the plugging materials maintain stability for sufficient time to allow well completion but eventually self-degrade to leave undamaged formation for future hydrocarbon production. The main challenges are the design of the lost-circulation material to cure losses into fractures of various widths and to provide plug stability and cleanup within a desired time frame over a broad bottomhole temperature range.
Fibers have shown good fracture-plugging behavior. Parameters affecting fiber performance include, but are not limited to, fluid viscosity, fiber concentration, fiber geometry, flow rate, effect of the wall, and fracture width. To effectively apply fibers as lost-circulation applications, a novel, fiber-laden fluid was designed for easy preparation on surface, allowing compatibility with bottomhole assemblies (BHAs). The decrease in velocity inside the fracture enables fibers to bridge and then plug the fracture, thus regaining circulation. The fibers are specially designed to degrade in an adjustable time frame sufficient to ensure plug stability until the well is completed. With time, the plug undergoes further degradation, leading to nondamaged formation for production.
This novel degradable solution has been successfully proven during field trials in various drilling scenarios ranging from severe to total losses with effective and efficient loss mitigation, without issues on placement through BHA and bit nozzles, and mitigating further reservoir damage.
Drilling with Induced Vibrations Improves ROP and Mitigates Stick/Slip in Vertical and Directional Wells
Authors: Clausen J. R. , Schen A. E. , Forster I. , Prill J. , Gee R. 
Published: June 2014

Abstract
For years drillers have been taught to mitigate all vibrations in the drillstring while drilling to maximize Rate of Penetration (ROP), limit bit damage, and extend bit life. While limiting lateral vibrations and stick/slip are proven ways to improve performance and maintain directional control, in recent years it has been conclusively proven in the field that inducing axial agitation with specialized downhole tools can significantly improve lateral reach. Currently, however, the benefits of downhole oscillation tools have not been thoroughly studied for other performance gains, such as improved ROP in non-directional wells.
An extensive research study, including lab and field testing, found that a low-frequency, benign axial vibration can increase the ROP significantly in all well types. Initial laboratory experiments were performed by inducing axial vibrations into the drilling process on a small scale drill bit in hard rock. Dramatic improvements in ROP and drilling efficiency were observed, with the added benefits of improved bit life and an unexpected reduction in stick/slip. This lab experiment was later tested in the field by utilizing a proven downhole oscillation tool in an active Bottom Hole Assembly (BHA) to create the effect that was simulated in the lab. The field tests showed the same results as the lab tests: significant performance gains were observed in several test wells using the downhole oscillation tool as compared to offset data. In addition, this same downhole oscillation tool showed drastically improved directional control when run above a Rotary Steerable System (RSS) tool, and stick/slip was practically eliminated with no negative effect on bit life or BHA reliability.
High-speed sensor data collected at the bit during both the lab and field tests will further demonstrate the validity of the theory. Testing for a hard-rock application with roller cone bits is forthcoming, as the data indicates possible performance gains in this environment as well.
Overall, the study revealed many benefits, such as improving well placement, reducing Non-Productive Time (NPT) and time to Total Depth (TD) by preventing BHA component damage through beneficial axial vibrations from the downhole oscillation tool. The data indicates that "benign vibration" can drastically improve drilling performance.
Nanosilicas as Accelerators in Oilwell Cementing at Low Temperatures
Authors: Pang Xueyu , Boul Peter J. , Jimenez Walmy Cuello 
Published: June 2014

Abstract
Accelerators are important cementing additives in deepwater wells where low temperatures can lengthen the wait-on-cement (WOC) time, potentially increasing the cost of operations. The cement set accelerators traditionally used for shortening WOC times are inorganic salts, such as CaCl2. These accelerators are known to have the potentially negative side effect of increasing the set cement permeability. Nanosilicas, on the other hand, can be advantageous compared to conventional cement set accelerators because they reduce the permeability while increasing the mechanical strength of cement-based materials. For this reason, nanosilicas are known to be particularly good candidates as replacement materials for traditional salt accelerators.
This study investigates the feasibility of using different sizes and aspect ratios of nanosilicas as cement hydration accelerators under low-temperature conditions 59°F (15°). The nanosilica activities are herein defined through their comparative advantages with traditional accelerators as well as through the advantages and disadvantages of the different nanosilicas resulting from their various sizes and shapes. While hydration of oilwell cement is known to be accelerated by the addition of nanosilica, the effects of nanosilica particle shape on cement hydration kinetics has not been previously investigated. The isothermal calorimetry experiments conducted in this study reveal that just as smaller nanosilica particle sizes increase the cement set acceleration so do higher nanosilica aspect ratios.
The effects of slurry density on the relative merits of CaCl2 and nanosilica are also investigated. In regular-weight slurries, the effectiveness of nanosilica acceleration appears to be weaker than that of CaCl2, especially during early ages (≤ 3 days). In lightweight slurries, the effectiveness of nanosilica acceleration can be much stronger than that of CaCl2, especially when mid- to long-term properties (≥ 2 days) are considered. Smaller particle sizes and higher aspect ratios enhance the acceleration effect of nanosilica. The compressive strength development of lightweight oilwell cements with and without accelerators was also investigated. Lightweight cements accelerated with nanosilica displayed 7-day compressive strengths up to 136% higher than those accelerated with CaCl2.