bluuebunny/crossref_metadata_2025_split huggingface dataset:
Utilization of Electrical Plasma for Hard Rock Drilling and Casing Milling
Authors: Kocis Igor , Kristofic Tomas , Gajdos Matus , Horvath Gabriel , Jankovic Slavomir 
Published: March 2015

Abstract
Worldwide, the research groups have been dealing with several innovative drilling technologies. Their common aim is to significantly decrease the overall price of the drilling process, particularly to keep the high constant speed, energy efficiency and shorter drilling time. There are above twenty innovative non-contact technologies at different maturity such as: laser, water jet, plasmatorch, ultrasonic, microwave, and several others. However few of them reached Proof-of-the-Concept in laboratory and are currently developed in outside testing sites. This paper presents one of such activities – development of technology based on electrical plasma for hard rock drilling. During its development, another application was identified – milling of steel casing and cement for well Plug&Abandonment operations. Both of these applications are developed by the team of engineers led by the authors.
The electrical plasma-based tool changes completely from its inception the paradigm of the drilling as well as casing milling. The most important advance in comparison to conventional plasmatorch technology is that the electrical arc with temperatures of tens of thousands of degrees Kelvin heats directly the surface, especially the radiation component, with minimalized heating of intermediate gas (the intermediate gas flow in conventional plasmatorches reduces the efficiency of heat transfer into the rock). Moreover, the arc creates area-wide, relatively homogeneous heat flow from spiral arc on the whole surface for high-intensity disintegration process. Compared to conventional plasmatorch technology, electrical plasma-based technology allows the use of electrohydraulic phenomenon, generating shock waves for the destruction and transport of disintegrated material. System also allows obtaining electrical and/or optical characteristics of the arc in the interaction with the rock to derive indirect sensory information (e.g. online spectroscopy for logging while drilling.).
This paper includes the nature of challenges in both application areas – hard rock drilling and casing milling, the description of the developed solutions, the results obtained until now, possibilities of some spin-off technologies using the same core technology concluded by expected impacts. The technology has been tested on various rock types including sandstone, limestone, halite, granite and quartzite. Currently, the demonstration prototype is being tested for drilling of testing borehole in the quarry.
Innovative Hybrid Bit Delivers Breakthrough in a Deepwater Exploration Well on the West Coast of Ireland
Authors: Holub Chase M. , Chiniwala Barzin , Montgomery Jonathan , Buske Robert J. 
Published: March 2015

Abstract
The new hybrid drilling technology which combines the two primary rock failure modes of crushing and shearing was effectively deployed in the challenging drilling environment on the west coast of Ireland. It improved drilling efficiency by reducing the mechanical specific energy (MSE) and mitigating stick-slip and excessive torsional oscillations.
The 12¼-in. section was drilled through a relatively homogenous cretaceous limestone sequence with a small percentage of chert bands. The limestone became progressively harder with depth but remained drillable using the PDC bit. The initial bit, an eight-bladed PDC design, was considered the best choice to drill through the limestone sequence. The initial rate of penetration (ROP) through the top of the limestone was 20 to 30m/hr. After 30 to 40m of drilling, the ROP decreased rapidly to 0 to 2 m/hr over a 10m interval. The bit was pulled. When on surface, the dull condition of the bit confirmed the presence of interbedded chert.
When the hybrid drill bit was run into the hole it drilled an average of 5 to 7m/hr with an instantaneous ROP of 22 to 24m/hr. Isolated chert bands occasionally reduced the ROP to a 3 to 4m/hr range. However, the bit returned to the average ROP upon exiting the chert. The operator, therefore, selected a second identical bit to complete the section. Both hybrid bits endured similar wear on the PDC and TCI cutting elements without any evidence of bearing or seal damage.
The hybrid cutting action generated smoother rotation and lower vibrations throughout the drilling system which improved ROP and extended bit life. The bit thus provided a viable solution to drilling firm limestone with interbedded chert stringers.
Reliable High-speed Mud Pulse Telemetry
Authors: Emmerich Wojciech , Akimov Oleg , Brahim Imed Ben , Greten Alexander 
Published: March 2015

Abstract
Mud pulse telemetry (MPT) has been the dominant measurement-while-drilling (MWD) data transmission technology for more than three decades. Continuous development has enabled the oil and gas industry to drill deep and complex well paths and deliver valuable real-time measurements. With the advent of recent logging-while-drilling (LWD) technologies, the amount of information collected downhole has considerably increased the demand for real-time transmission bandwidth. Driven by this demand, new developments in downhole and surface equipment have made higher data rates available. In addition, reliable high-speed MPT (HSMPT) is needed when utilizing a complex LWD bottom hole assembly (BHA) to deliver answers while drilling.
Transmitting data at high rates introduces new challenges for MPT due to the higher signal attenuation and distortion that occurs when drilling very deep wells with high-density, high-viscosity oil-based muds. This paper describes improvements to the MPT system to overcome these challenges. Optimized surface signal processing and enhanced telemetry sequences are used to automatically tune adjustable filters at the receiver.
These adaptive filters respond to new drilling conditions, adjust for changes in the MPT channel, and test their performance automatically, thereby enabling field personnel to easily make decisions when optimizing decoding quality. Advanced manual options complement these automated processes. The new system has been successfully run in challenging fields in the North Sea. Compared to offset runs, the automated system has significantly increased reliability. Examples of the improved decoding capability and operational performance are provided.
This paper will highlight the necessary changes to further improve reliability for high-speed telemetry to enable real-time log density measurements. The MPT system can enable answers while drilling without having to limit the drill rate in critical sections.
Strain-Gauge Bending-Moment Measurements Used to Identify Wellbore Tortuosity
Authors: Marland Chris , Greenwood Jeremy 
Published: March 2015

Abstract
To determine wellbore tortuosity, the industry uses different methods. Well trajectories can be calculated between survey stations in the wellbore with the resolution of the tortuostity dependent on the survey frequency. Friction factors within the wellbore can be back calculated from surface torque-and-drag information and used as empirical indicators of tortuosity change over the open-hole section. Neither of these previous methods however provides sufficient resolution to accurately quantify the severity and location of the wellbore macro- and micro-tortuosity. The use of downhole strain gauges to identify variations in hole condition and wellbore tortuosity, as well as how they effect the bending stresses in the bottomhole assembly (BHA), has enabled a significantly more accurate method of quantifying this tortuosity.
Downhole strain gauges are used to measure compression and tension, torque, bending moment, and bending-moment direction at specific locations within the BHA. These measurements are used in the following manner to derive the actual downhole values for the following properties: weight on bit uses downhole tension and compression; overpull uses downhole tension; the downhole torque is used to determine how much of the surface power is reaching the BHA and drillbit; and the bending moment of the BHA is used to determine the bending stresses being applied to the BHA. In addition to these accepted methods, the bending moment is used by this new approach to show details of the location and severity of wellbore tortuosity and highlights how the measurement is influenced more by changes in the wellbore trajectory than by the application of compression or tension to the BHA.
Brittle Longitudinal Splits of P-110 Couplings Due to Local Material Defects and Insufficient Control of Material Properties During Manufacturing of High Collapse P-110 Casing
Authors: Koneti Srinivasa , Gokhale Samit 
Published: March 2015

Abstract
Brittle longitudinal splits of P-110 couplings in shale operations cause immense financial loss to oil and gas operators. Unfortunately, there seems to be an increasing trend in these coupling failures, particularly in operations where high-collapse grades of P-110 casing is used.
A common method employed by manufacturers to increase the collapse capacity of P-110 material is to push the yield strength up close to the maximum requirement specified in API Specification 5CT for P110 grade. Sometimes, the yield strength even exceeds the upper limit specified in API 5CT, which increases the hardness of the material, making the couplings more susceptible to environmentally-assisted cracking like hydrogen stress cracking (HSC).
This paper presents case studies of such split coupling failures. In one particular case, metallurgical analysis was performed on both the split couplings and the non-failed couplings from the same string. The analysis indicates a clear trend that correlates the higher coupling strengths to the failure instances.
Split coupling failures can also be caused by local material defects even when the overall fracture surface presents signatures similar to those observed on environmentally-assisted cracking. Case studies of such failures are also presented along with discussions on forensic testing methodology used to identify the cause of failure.
This paper discusses metallurgical testing methods that can be used to identify the local material defects which contribute to longitudinal splits. This paper also presents manufacturing guidelines and specification requirements needed to control the manufacturing processes of the high-collapse P-110 couplings to mitigate split coupling failures.
Drilling Modeling and Simulation: Current State and Future Goals
Authors: Sugiura Junichi , Samuel Robello , Oppelt Joachim , Ostermeyer G. P. , Hedengren John , Pastusek Paul 
Published: March 2015

Abstract
The process of drilling a borehole is very complex, involving surface and downhole drilling systems, which interact with the drilling fluid and the surrounding rocks. Modeling and simulating every aspect of the drilling process and drilling system is still considered too complex to be realized. However, many areas of modeling and simulation are currently undergoing very aggressive development. These areas include rig systems, downhole dynamics, rock-bit interaction, drilling/formation fluid, and the Earth model. High-fidelity models in these well-defined areas have demonstrated some success. Lately, drilling modelling and simulation has become one of the key factors for advancing drilling systems automation/control, intelligent managed pressure drilling and drilling optimization by understanding and/or predicting downhole dynamics.
Modeling the magnitude and spatiotemporal distribution of uncertainty in the actual drilling process poses serious challenges in constructing high-fidelity models of the entire drilling system. However, the advancement of technology may dramatically improve the future of such an attempt to accurately model and simulate the whole drilling process.
The topics presented in this paper include the current state of drilling process simulation software and simulators, the challenges of modelling drilling systems for automation and control, adaptive simulations for downhole drilling systems and the operator's perspective on drilling modelling. This paper examines the current state of drilling modelling and simulation and identifies its future goals.
Drilling with Liner Technology Enables Successful Sidetrack through Depleted Sands in Shallow Water Gulf of Mexico
Authors: Bridgeman Wayne , Salminen Chuck , Rosenberg Steve , Karimi Moji , Shahri Mojtaba P. 
Published: March 2015

Abstract
The maturation of fields in the Gulf of Mexico shelf means that many future sidetracks and recompletions will require drilling through depleted formations. The difficulty of drilling through such formations is especially high when adjoining zones are over-pressured since the mud weight required to maintain overbalance creates significant risk of differential sticking and lost circulation in the depleted zone. Three dump waterflood wells drilled conventionally in 2012 encountered significant problems while drilling the depleted zones. These included lost returns while cementing, hole pack-off and in one case, differential sticking which required the drill string to be severed and a sidetrack to be performed. The three wells incurred an average of 258 hours of associated NPT, which negatively affected project economics and led the operator to evaluate other drilling methods for such depleted sections.
Following a detailed and collaborative planning process between the operator and an integrated service provider, it wasdecided to sidetrack an existing well and use drilling with liner (DwL) method to drill through two depleted sandstone intervals bounded by over-pressured shale zones and cement the liner to facilitate the completion of a dump flood well. There were no observed losses while drilling the entire 577 ft. interval, and also during the cement job with the liner lap testing successfully. An additional benefit was the exceptionally low formation damage observed during the subsequent frac-pack completion as compared to the previous wells. Overall, this operation suggests that DwL is an enabling technology for drilling depleted sands.
In this paper the authors will describe the planning process in detail and will continue to describe how drilling with liner technology was successfully implemented to drill a sequence of depleted sands and over-pressured shale formations in a field where conventional drilling had presented many problems.
Alternate Weighting Material for High Pressured Jurassic Wells in Kuwait - Case Histories of Successful K-Formate Mn3O4 Drilling Fluids
Authors: Jumah Al-Foudari Saud , Al-Muhailan M.S. , Rajagopalan Arun , Al-Qadhi Fahad Khaled 
Published: March 2015

Abstract
Deep wells drilled into the Jurassic formations of Kuwait have long utilized oil based mud (OBM) with barite as the weighting material. However, barite caused considerable damage to the reservoir sections, resulting in reduced production rates. The high oil content in the OBM also prevented recording of good quality image logs, which was necessary to identify the micro-fractures in the reservoir. To overcome these issues, it was necessary to use a water based mud (WBM) with non-damaging weighting material suitable for high pressure conditions.
The existence of high pore pressures and a requirement for mud weights up to 18.5 lb/gal in these wells ruled out the use of conventional WBM. Laboratory tests conducted using a fluid based on Potassium Formate (K-Formate) brine weighted with Manganese Tetraoxide (Mn3O4) as an alternate weighting material. This fluid was successfully applied in a number of deep wells, resulting in increased production rates, up to three times higher than the wells drilled with OBM. Damage to the reservoir was considerably reduced as the wells were easily activated. High quality image logs were also recorded which was not previously possible with OBM. K-Formate-Mn3O4 fluid is a non-corrosive, biodegradable, environmentally friendly fluid, capable of long term storage without degradation of mud properties and recyclable, which reduces fluid cost in subsequent wells.
This paper will review the case histories of twelve deep exploratory wells where the K-Formate-Mn3O4 fluid was applied successfully. Issues including, high rheology encountered while increasing the mud weight using Mn3O4, fluid related complications in drilling and solutions developed to overcome the problems will be discussed in detail. Lessons learned in each deep high pressured well, mud loss scenarios and well control issues will be discussed.
K-Formate-Mn3O4 based drilling fluid has been highly successful in drilling high pressured Jurassic reservoirs in Kuwait. Following the success of the fluid in these wells, it is now being planned to apply in all future deep exploratory wells.
Drilling Technique Improves Directional Steering Control in Very Weak Formation and Reduces Wellbore Collision Risk
Authors: Ogwumike John , Ajijolaiya Yemi , Appleton Edmund , Schrader Hartmut Hans , Foekema Nico , Ruszka Jon , Wilson Harry , Adams Adeniyi 
Published: March 2015

Abstract
Directional drilling control in top-hole sections through very weak shallow sediments is challenging. The formation tends to wash out, reducing steering control. The lack of reliable steering results in well kick-off-points planned deeper than optimal, especially for extended-reach wells or under multi-well platforms where early well separation is advantageous. Additionally, when drilling in close proximity to existing wells, well collision risk increases.
As a result of these challenges, a major operator and international service company have developed, and proven, a hybrid drilling technique enabling reliable steering control in sediments which previously proved difficult to directionally drill through. The technique employs an automated rotary steerable system (RSS) and gyro-while-drilling tool operating in a directional jetting mode without rotation.
The wells are drilled from an offshore platform through dual conductors. In addition to the well collision risks normally associated with multi-slot platforms, dual conductors mean that the second well drilled from each conductor is initially in very close proximity to the first well.
Until this technique was developed, the top-hole sections were drilled with steerable motors because RSS were unable to steer consistently in the very weak shallow sediments. When the collision risk was passed, and the formations became firm enough for the RSS to operate, the steerable motor bottom hole assembly (BHA) was replaced with the RSS.
The hybrid RSS jetting technique provides several advantages; a single BHA run can drill to section TD, shallower kick-offs are possible and predictable steering control reduces the risk of collision. The lower energy of the non-rotating jetting system is also believed to reduce damage to an offset well in the event of collision.
The paper explains how the hybrid system was developed, and describes how it is applied and optimised in practice with real examples. Opportunities for further research are presented which may enable offset wells to remain on production, saving significant production loss and avoiding risk associated with well shut-in and start-up.
Design, Qualification, QAQC and Operational Performance of Completion Fluid, Reservoir Drill-in Fluid and Breaker - Tamar, Offshore Israel
Authors: Healy John , Sanford Jack , Hopper Tim , Dufrene Kerby , Fink Josh , Balderrama Christian , Steve Vickers , Mackenzie Grant 
Published: March 2015

Abstract
A case history from Offshore Israel is presented that describes the successful delivery of five (5) ultra-high rate gas wells (+250 MMscf/D) completed in a significant (10 TCF) gas field with 7 in. production tubing and an Open-Hole Gravel Pack (OHGP). Maximizing gas off-take rates from a gas reservoir with high flow capacity (kh) requires large internal diameter (ID) tubing coupled with efficient sand face completions. When sand control is required, the OHGP offers the most efficient as well as the most reliable, long-term track record of performance. A global study of ultra-high rate gas wells was made to select and finalize the design concept after which the commensurate engineering rigor was applied. This paper will highlight the design, qualification, Quality Assurance / Quality Control (QA/QC) and operational performance of the completion fluids inclusive of the Reservoir Drill-in Fluid (RDIF) and the breaker. Completion fluids are critical to the success and production efficiency of an OHGP. The completions were installed with minimal operational issues (Average NPT ≈4%). Production commenced on March 31, 2013. All wells have performed to expectations with maximum well rates up 340 MMscf/D.
Well Advisor - Integrating Real-time Data With Predictive Tools, Processes and Expertise to Enable More Informed Operational Decisions
Authors: Israel R. , Mason C. , Whiteley N. , Gibson K. , Dobson D. , Andresen P.A. 
Published: March 2015

Abstract
An increasing proportion of oil and gas production comes from the technically-challenging, deep-water/offshore environment, where drilling and completions teams continue to focus on enhancing safety and operational integrity and where the costs of non-productive time during well construction can be quite significant. BP identified opportunities to address these three issues through extending its use of real-time data and launched the BP Well Advisor (BPWA) Project to develop and deploy this technology to aid in further enhancing drilling performance.
This paper will share the lessons that the company has learned from this project and provide an introduction to the range of functionality within the technical solutions currently being developed and deployed. It will also discuss how the company and its project collaborators have worked together to deliver the well advisor as a solution package inclusive of the underlying technology, business transformation processes, solution deployment, training and support. This approach has been a key component of the project's success to date and has built a solid platform to support its planned future activities.
The objective of the well adviosr project is to facilitate the management and exploitation of real-time data. The system being developed integrates this real-time data with other predictive tools and processes to support delivery of the right information, in the right place at the right time. This helps the operational teams to make timely and well-informed decisions as they work to deliver safe and reliable wells. The project's key areas of operational focus are enhancing operational safety, improving well construction efficiency and life of well reliability.
The well advisor project has demonstrated success in helping the company to enhance all three areas of operational performance listed above, and efforts are ongoing to expand the system's technical capabilities and regional deployments globally. One highlight of the project to date has been its successful application to casing running where over 291 casing/liner strings in 4 major regions have now been run without a stuck pipe incident. This success alone is estimated to have saved over 250 days of non-productive time (NPT) based on historical data associated with stuck casing incidents prior to its introduction. Other functionality being deployed monitors cement placement, blow-out preventer (BOP) health, pressure tests and rigsite fluid management.
This paper will conclude with a summary of operational performance benefits derived to date from the implementation of the well advisor and give a preview of new functionality being considered for potential future deployments.