bluuebunny/crossref_metadata_2025_split huggingface dataset:
Inducing Axial Vibrations in Unconventional Wells: New Insights through Comprehensive Modeling
Authors: Wilson J. K. , Noynaert S. F. 
Published: March 2017

Abstract
Axial Excitation Tools, or AETs, are known to help improve ROP in modern horizontal wells. These devices instigate an axial vibration in the drillstring, which then propagates along the length of the horizontal assembly. The improvement in ROP is thought to originate from a more effective WOB transfer due to this induced axial movement from the AET. However, the exact mechanics of how these tools affect the drillstring is not known due to a lack of adequate modeling. Additionally, little work has been done to examine the potential consequences of inducing an axial resonance within the drillstring while utilizing these types of tools. This study explores these questions through advanced dynamic modeling.
Using a newly-developed, validated, comprehensive drillstring model, the dynamic response of the drillstring, due to the axial excitation provided by an AET, is examined via a forced-frequency approach. The resulting sensitivity analysis illustrates the dependence of the system on the various operational and structural characteristics of the drillstring. Parameters examined include applied WOB, wellbore trajectory, design characteristics of the AET, and various boundary conditions. Nonlinear time- domain simulations are also conducted in order to quantify how AETs affect the axial force transfer to the bit.
It is shown that various operational parameters will have a noticeable impact on the dynamic response of the drillstring when inducing axial vibrations while drilling. This observation suggests the necessity to properly plan for the use of AETs in order to avoid unnecessary failures of downhole components and subsequent non-productive time (NPT). While the modeling itself is advanced, the outputs are designed to help visualize the response of the system in a "user-friendly" manner, reducing the learning curve and bridging the gap between the "tech-savvy" and non-technical personnel.
This study presents an efficient way of determining the potential of harmful vibrations when drilling with an Axial Excitation Tool. The modeling approach shown is comprehensive and provides new insights into the fundamental operation of these types of tools and how axial excitations help to improve drilling efficiencies. Results presented show that induced vibrations do not simply "reduce friction," as is so often claimed; instead, these tools generate a dynamic axial force, oscillating about the average value, which may help work past "tight-spots" along the well. In turn, this would give the impression of reduced friction along the wellbore based on hook load measurements.
CO2 Self-Healing and Resistant Cement Technology From Laboratory to the Field
Authors: Engelke B. , de Miranda C. R. , Daou F. , Petersen D. , Aponte S. A. , Oliveira F. , Ocando L. M. , Conceição A. C. , Guillot D. 
Published: March 2017

Abstract
In a joint effort, an oil and gas operator and a service company have undertaken research to help overcome well integrity and cementing fluids challenges in the presalt wells of Brazil where some fields present high levels of CO2 in reservoir fluids. Results are provided from the laboratory phase to cement placement evaluation.
The new approach is to provide a cementing system that is not only resistant to CO2 attack but also has a self-healing capability in the presence of fluids containing CO2. The validation of the CO2 selfhealing and resistant cement technology was initiated at laboratory level. Then, a yard test with real-time field parameters was performed, proving that the new slurry can be mixed and pumped using conventional cementing equipment. Finally, an onshore well in Brazil served as a test well for deploying and evaluating the new CO2 self-healing and resistant cement system in the field.
The technology consists of an engineered particle size distribution (EPSD) blend containing a reactive material that swells upon contact with CO2. This swelling allows the closure of microfissures and/or the reduction of the microannulus, which heals the cement sheath and reestablishes the integrity of the well. Then, a large-scale yard test was performed to evaluate real-time field parameters such as the fluidity and homogeneity of the dry blend and the mixability of the slurry using conventional cementing equipment. After the success of the yard test, the technology was deployed in Brazil. During the field test, 8 m3 [50 bbl] of 1,900 kg/m3 [15.8 lbm/gal] CO2 self-healing cement was pumped downhole and placed in the annular space between a 7-in. casing and a 8.5-in. open hole to promote casing support and zonal isolation in the production zone.
The CO2 self-healing and resistant cement overcomes the deficiencies of conventional Portland cement in carbon dioxide environments and presents an advantage over other available technologies designed to withstand CO2 attack by maintaining zonal isolation and long-term well integrity. Moreover, this technology can be applied in any field in the world where CO2 is regulated and/or entails risk for operators or the general public.
New Innovative Underreamer Technology Simultaneously Drilled and Reamed with Two Activated Reamers
Authors: Grymalyuk S. , Schimanski M. 
Published: March 2017

Abstract
This paper presents and discusses the results of the field application where a new integrated expandable under reamer technology was implemented in the North Sea. An operator faced issues with wellbore stability and equivalent circulating density (ECD) while drilling a 12¼-in. section in a challanging formation. Placing the reamer close to the bit removed the need for an additional rathole elimination run, avoiding the risks associated with it and saving rig time.
The on-command digital, expandable under reamer is fully integrated into the bottom hole assembly (BHA) and can be monitored and controlled from the surface. The under reamer tool has unlimited activation cycles that provide the capability of selective reaming. The flexible placement of multiple reamers in the BHA enables near-bit and main reaming applications, and a combination of both. When used for near-bit reaming service, the reamer can reduce the rat-hole length to 4 m. Significant time savings and safety improvements can be achieved by simultaneously operating the main and the near-bit reamer.
In one run, the entire section was simultaneously drilled and underreamed to TD. The first 3,491 ft (1064m) were drilled while simultaneously opening the hole to 13½-in. with the main underreamer. The remaining 233 ft (71m) were drilled and reamed with both the main and the near-bit reamers activated. The rathole length was reduced to 33 ft (10m) in the same drilling run, saving 3 days of rig time. The 10¾-in. liner was then run to the desired depth. Minimal vibrations were recorded in the interval where both reamers were activated and stick/slip was nominal. After the run, an inspection of the reamer blades showed good performance and little wear.
The paper will summarize and describe the results and features in detail, and demonstrate how they can help the operators to reduce operational risks and save cost.
From Laboratory High-Pressure, High-Temperature Technology to Field Success: A Case Study on New Anti-Balling Coating Development
Authors: Yu B. , Goodman A. , Hayes B. , Stevens J. , Vondenstein T. , Callais R. , Harvey J. , Honeycutt J. , McEvers J. , Lindsey J. 
Published: March 2017

Abstract
Bit balling and balling on other bottom hole assembly (BHA) components is a common concern when drilling shale with water-based mud (WBM) because it limits drilling efficiency or in extreme cases can stop drilling, causing costly non-productive time (NPT).
Among many strategies which have been created to mitigate the above balling problem, an effective approach is coating the tool surfaces with hydrophobic materials that are generally characterized by high water contact angle. This approach has been pursued by bit manufacturers with some success; however, poor coating durability is still a common concern. Additionally, previous applications are often guided by surface hydrophobicity evaluated at ambient conditions. Elevated temperatures and wellbore pressures can potentially cause the behavior to change and limit effectiveness. Therefore, evaluating the surface hydrophobicity under conditions that closely simulate downhole conditions becomes essential.
To address these challenges, this paper reports the recent success on a new anti-balling coating technology and the novel high-pressure, high-temperature (HPHT) laboratory tests used to develop it. The laboratory-level HPHT apparatus developed in this study is capable of measuring key parameters including the contact angle and interfacial tension at extreme conditions of up to 500 °F and 30,000 psi. It is also demonstrated how pressure and temperature have an impact on the surface hydrophobicity.
The newly developed coating technology combines good surface hydrophobicity at HPHT conditions with superior wear performance. The development results were later demonstrated in several shale applications (Marcellus Shale, West Virginia in 2014; East Cameron, Gulf of Mexico in 2015), where the coating technology was applied onto 8 ½" diamond bits that at one time drilled up to 10,000 ft in a single run without requiring a trip while still maintaining coating functionality.
This development work provides drilling operations with an effective solution to improve the performance in balling-prone shale applications. Additionally, the body of work demonstrates the importance of material testing in conditions matching real-world applications and how this approach leads to improved material selection for solving downhole problems.
Integrating Human Factors into Well Control
Authors: Odgaard Jacob , Morton Tim 
Published: March 2017

Abstract
Human Factors encompass elements which influence our behaviour. In a work environment they embrace many areas, for example; environmental and organisational, the design and functionality of equipment, process and procedures, individual characteristics of personnel, their skills and competencies.
It is generally acknowledged many of the world's worst oil field incidents have been attributable to Human Factors including well control events like the Montara and Macondo blow outs and many others. It is notable that some well control incidents initially appear straightforward but are frequently exacerbated by human error, increasing risk and costs, and in the worst cases resulting in blowouts.
The oil field has been a little late in realising the importance of Human Factors but there is now recognition they are essential in successfully resolving well control events. The inclusion of Human Factors in managing well control events was also a recommendation of the OGP 476 report in 2012.
The corporate well control manual was refreshed to include Human Factors in the management of well control incidents. This required mapping the well control process, assigning personnel specific roles, defining contingencies, etc. whilst acknowledging the effect Human Factors has on the personnel involved. The intention was not to create a rigid structure but to rather provide a framework to guide the front line in dealing with a well control event. New policies and procedures were subsequently developed and included in the update.
It is recognised this new philosophy will require an ongoing commitment impacting well control procedures, client liaison, bridging documents, the assessment and assurance of teams, well control training etc. It is further acknowledged this is just a first step and there will be continued development and refinement of the management tools as the system beds in.
The Floating Factory Concept: Engineering Efficiencies Up Front to Reduce Deepwater Well Delivery Cost
Authors: Hebert James 
Published: March 2017

Abstract
Deepwater drilling needs improved efficincy. Since well delivery cost is a major component of deepwater projects, a 20% reduction in well delivery cost may pull deepwater projects back over the economic threshold. However, sustainability requires looking beyond market cycle price consessions and focus on longer term technology and innovation to drive down the well duration and cost. Accordingly, the industry needs to apply engineered soultions to increase operational efficiency and safety as compared to existing 6th Gen drillship designs.
This paper introduces a next generation drillship design concept, featuring a factory-like approach to well construction, grounded with input from operators and third-party service providers. Capitalizing on Lean methodologies, the design combines improved safety with automation and robotics to reduce bottlenecks and minimize controllable flat time for the entire well life cycle with a reduction in well duration and cost by 15 to 30%.
The author examines the distinctive vessel layout including a large flat and un-obstructed work deck, a high variable load capacity of 27,500 short ton (ST), and increased personnel on board capacity to improve the off-line transition from the drilling to completion phases. In addition, the reorganized drill floor replaces the standard derrick and substructure with a Dual Multi-purpose Tower (DMPT), employing robotic pipe manipulators capable of handling 180-ft stands. To meet future well design requirements, the hoisting system is engineered for at least a 1,500 ST static hook load at the elevators. Further, independent mud and brine systems with 11,000-bbl and 17,000-bbl capacities, respectively, with off-line tank and suction line cleaning, improve well displacement safety and efficiency. Moreover, a unique power distribution network improves both thruster availability and also allows maintenance while operating efficiently in an open buss configuration, thereby stretching the dynamic positioning (DP) operating envelope.
The target of this efficiency and safety-centric initiative is to reduce the operator's well cost and allowing future optimization of 40,000-ft-plus well designs in 13,200-ft water depth.
Transformation of Mindset - Cost-Effective Collaborative Well Engineering & Operation Delivers Record Horizontal Appraisal Well in the Barents
Authors: Hollinger Gerald , Trauner Stephan , Dupuis Christophe , Wendt Anke Simone , Breivik Dag H. , Myrvoll Odd Helge 
Published: March 2017

Abstract
Through a tightly integrated collaboration between an operator and a service company, the world's northernmost horizontal well was successfully drilled and tested. Set in the Barents Sea at 73° latitude 350km from Hammerfest, this project de-risked a future commercial field development plan for the Wisting field, which holds some of the largest known oil reserves in the Barents Hoop Area.
All three major well objectives were achieved: (1) proving drillability by landing the horizontal well approximately 250m from the seabed (a record for subsea wells) and geosteering for 1400m across several fault blocks, (2) performing a well test within a long interval of reservoir exposure (over 460m) to prove the added productivity of horizontals, (3) acquiring appraisal information: reservoir data in new blocks, estimated oil / water contact (OWC), geomechanical properties, etc.
This well was outside the envelope achieved before, and such an extended reach drilling (ERD) operation required a customized well engineering approach at every step.
In addition, the hole design was adopted to cater for the drillstem test (DST) string. Different casing designs, string designs and operating parameters were screened in dedicated studies, looking at equivalent circulating density (ECD), torque and drag, hole cleaning, prior experience and contingencies.
A combined 3D subsurface, pressure and stress model was built, calibrated to drilling observations, core data and leak off tests and then used as input for subsequent studies (mud window, rock strength for drill ability).
The geometry required a constant 9°/30m dogleg from kickoff (no tangent section) to land at reservoir depth. Any interval where that performance was not achieved would have resulted in overshooting the reservoir (too deep).
An oil-based mud design was adopted for several reasons, and a dedicated lost circulation material (LCM) strategy established to manage potential losses in the reservoir matrix, in fractures or faults.
Important planning and operational considerations were given to safety and logistics, and no issues resulted in this remote and environmentally sensitive area.
The mud motor strategy selected after careful engineering simulations landed the well at the reservoir depth, before geosteering near-horizontally for the required 1400m. The partnership has gained invaluable information about the drill ability of such wells in Wisting.
Several fault blocks could be accessed with a long horizontal, giving a positive impact on the field economics.
Reliable Mud-Pulse Telemetry System for High-Resolution Real-Time Logs
Authors: Greten Alexander , Brahim Imed Ben , Emmerich Wojciech , Akimov Oleg 
Published: March 2017

Abstract
For drilling directional wells and exact reservoir navigation, a broad spectrum of measurement-while-drilling (MWD) and logging-while-drilling (LWD) measurements, as well as drilling optimization-related measurements, are available. The data they generate are used for accurate characterization of the formation while drilling and for steering within the reservoir. Additional data is needed for a safe drilling process, and for achieving a high rate of penetration (ROP) while drilling the reservoir. The oil and gas industry has developed many technologies that enable real-time transmission of this data from downhole to surface. For decades, mud-pulse telemetry (MPT) has been the most common transmission system for MWD and LWD data. Depending on the geology and the complexity of the well, a multitude of MWD and LWD measurements are required simultaneously on surface. The number of desired logs increases as applications become more challenging and performance is pushed to maximize penetration rates. The additional data required from new and existing measurement technologies pushes the envelope of reliable and fast transmission of data via MPT.
To achieve real-time data rates that can accommodate all measurements, deliver the required resolution, and simultaneously achieve the planned ROP, a highly sophisticated and flexible telemetry system is required. This paper describes an MPT system that delivers high data rates and high reliability. The system includes a robust mud pulser and an improved, self-adjusting surface system. To overcome decoding challenges, the system has flexible options like diverse signaling types, various modulation schemes, and adjustable signal frequencies.
With this system it is possible to drill wells that have a very high real-time data demand without limiting the ROP or reducing the amount of transmitted information. This MPT system helps achieve the desired data density in MWD and LWD logs, and in borehole images.
This paper shows how the system enables data transmission from some of the most complicated instrumented bottom hole assemblies (BHAs), how it improves real-time logs and images, and how it lifts ROP ceilings while simultaneously increasing reliability.
A Systems Approach to Well Control Barrier Management During Drilling Operations
Authors: Thorogood John L 
Published: March 2017

Abstract
Well barrier verification is having the confidence and being able to prove that "the folk on the rig will do the right thing and the equipment will function as intended when called upon to do so". This paper describes a method of achieving that aim by analyzing well control barrier systems in a logical and complete manner with regard to the technical, operational and organizational elements so that the results can be used as the basis for a straightforward means of barrier verification during operations.
BowTie diagrams, while a useful illustrative starting point, are limited in their ability to depict well control barriers as systems consisting of individual elements that interact with each other. Portraying them as systems enables the processes, people and equipment required for effective well control to be analyzed in a way that is both logical and complete. Further examination of the elements reveals the critical aspects that must be checked to verify barrier effectiveness. Operationalising the verification process is done by extending and formalizing established practices of wellsite supervisor oversight and cross-checking complemented with periodic inspections.
The analysis is resource intensive because each operational mode must be considered separately to ensure completeness. Once this work is done, general themes within critical aspects emerge that enable the verification tasks to be grouped into a set of logical activities that include: conversations with crew members to verify knowledge, criteria for drills to check on team capability and periodic inspections to ensure equipment integrity. Although difficult to achieve, the process must be carried out in a way that engages the crews in a sense of self-preservation to avoid becoming a box ticking exercise.