bluuebunny/crossref_metadata_2025_split huggingface dataset:
Extended Reach Drilling - new solution with a unique potential
Authors: Vestavik O. , Egorenkov M. , Schmalhorst B. , Falcao J. 
Published: March 2013

Abstract
The Reelwell Drilling Method (RDM) is a new drilling method, developed and qualified for commercial use during recent years. RDM is a multi-purpose drilling method with a unique flow arrangement. RDM is based on using a conventional drill string combined with an inner string to form a dual conduit drill string. This arrangement allows the return fluid, containing drill cuttings from the bottom of the well, to be transported back through the inside of the drill string.
RDM has the potential to increase the envelope for Extended Reach Drilling (ERD) for several reasons:
– Torque and Drag reduction, due to use of a flotation technique of the drill string. – Elimination of the dynamic Equivalent Circulating Density (ECD) gradient, since the ECD is screened from the formation. – Optional Hydraulic Weight On Bit (WOB), due to a piston type arrangement at the drill string.
The following presents a case study for an ultra ERD RDM application. In this case, the RDM arrangement involves the use of a special dual conduit aluminium drill string and the use of two different density fluids in the well during drilling. A calculation example of a fully buoyant drill string is also presented. This situation indicates that the well can be drilled with very high operational margins on the equipment and at the same time, the wear will be very low. The simulations indicate that the extreme ERD well of 15.8 km depth can be drilled with good margins, mainly due to flotation of the drill string. It is shown that the well can be cased and lined, using conventional flotation techniques in combination with RDM.
Autonomous Robotic Drilling Systems
Authors: Søndervik Kenneth 
Published: March 2013

Abstract
Over the last decades we have seen many improvements in drill floor automation. Common for many of these have however been more in line of "make a machine to duplicate manual labor". This is about to change. Over the last 5 to 6 years more and more companies and resources have been focusing on creating fully automatic systems, and in the last couple of years we have seen the introduction of fully robotized systems.
This paper will highlight some of the vast improvements seen in Health and Safety as well as efficiency measured in both time and money when using robotics in the drilling operations. This will be true for most, if not all, drilling structures designed for land or offshore operations either used for drilling for hydrocarbons or not.
We will discuss how fully robotized drill floor, and even small partly intelligent tools can make a big difference, for both safety and cost savings.
This effectiveness and safety aspect will be further improved when using autonomous decision making systems. With autonomous system we mean that the systems itself will have the ability to decide how to perform a given task more safely and with a higher efficiency than a preprogrammed task.
Automated Alarms for Smart Flowback Fingerprinting and Early Kick Detection
Authors: Ali Tarab H. , Haberer Sven M. , Says Ian P. , Ubaru Charles C. , Laing Moray L. , Helgesen Olav , Liang Max , Bjelland Bente 
Published: March 2013

Abstract
Recent events and studies show that wellbore stability and geopressure events continue to plague the oil industry with issues that affect the safety of people and the environment. In addition, events such as kicks and lost circulation also create significant loss of time and productivity, commonly referred to as non-productive time (NPT). Deepwater studies have shown NPT related to kicks, and lost circulation can amount to 4.5% of the total well construction time. Consequently, early kick and lost circulation detection is crucial to eliminating detrimental effects on human and environmental safety, in addition to minimizing NPT.
Kicks frequently happen during connections, and flowback fingerprint monitoring has been used for more than a decade across the industry to aid in kick detection. However, setting alarm thresholds and identifying abnormal flowbacks has been a manual process that relies heavily on the experience and intuition of the engineer who performs this critical safety monitoring. This manual process frequently misses early signs of influx, and thus greatly increases the well remediation time.
This publication focuses on the development and deployment of an automated flowback monitoring technology. The new solution aids drillers and drilling engineers by generating intelligent alarms relevant to current well conditions for early kick and loss detection, which can result in detecting kicks up to one connection earlier than the existing manual method. This paper demonstrates the benefits of Smart Flowback Fingerprinting over existing practices and how it can significantly reduce safety risks and NPT.
Implementation of PMCD to Explore Carbonate Reservoirs from SemiSubmersible Rigs in Malaysia results in Safe and Economical Drilling Operations
Authors: Jayah M Noreffendy , A Aziz Intan Azian , Mathews Travis , Voshall Allan , Rojas Rodriguez Freddy 
Published: March 2013

Abstract
PETRONAS has been drilling carbonate reservoirs offshore Sarawak since the 90's. However, with more prospects being explored, the challenges have escalated as the company has embarked into exploring the remaining carbonate pinnacles where the primary objective is to identify the gas or oil water contacts of the prospects. Some of these carbonate reservoirs are characterized by the presence of large karsts and fractures, leading to a frequent scenario of total mud losses and kicks. Conventional drilling practices are not considered a safe or economical option to drill the carbonate sections. Additional problems associated with the drilling operation in these zones includes poor hole cleaning, low ROP, high vibrations and stuck pipe events.
Implementing the Managed Pressure Drilling (MPD) variant called Pressurized Mud Cap Drilling (PMCD) allowed the drilling team to reach targeted total depths on several wells. Upon encountering unsustainable losses the wells were converted over to PMCD. Light Annular Mud (LAM) was injected into the annulus and a sacrificial fluid (SAC) was pumped down the drillstring allowing drilling to continue to total depth.
By successfully implementing the PMCD technique, the operator was able to reduce risk and reach the exploration targets successfully. Lessons learned surrounding operational techniques, pressure limitations of the drilling system and continuous training and development of the operating team have expanded the application for the operator.
The authors present lessons learned of wells drilled to date and key lessons learned as the Operator evolves to improve execution of PMCD.
A New Standard in Wireline Coring: Recovering Larger Diameter Wireline Core through Standard Drill Pipe and Custom Large Bore Jar
Authors: Farese Travis , Ahmed Hammad , Mohanna Assaad 
Published: March 2013

Abstract
Wireline retrievable coring is a unique technology offering capabilities to full bore core, drill and convey logs in a continuous operation without tripping out of hole. This technology saves considerable time compared to multiple conventional coring runs. The time and cost savings increase significantly where there is a need to drill between coring intervals as applies in hole sections with multiple objectives.
However, one of the constraints with large diameter wireline coring systems is the requirement to pick up specialty drill pipe. This specialty drill pipe provides an internal diameter large enough to accommodate the retrieval of the inner components utilized to cut 3 to 3.5 inch diameter core. A further constraint with large diameter wireline coring systems is the inability to run a jar within the drill string due to internal diameter limitations.
A new wireline retrievable system capable of acquiring 3 inch diameter core utilizing standard drill pipe was designed for an application in Middle East. In addition, custom large bore coring jars were designed and deployed to meet the operator's stuck pipe prevention standards. A total of 215 ft. of core was cut on the first trial well in 8 3/8 inch hole size achieving 98.6% core recovery, excellent core quality and 74-hrs of rig time savings compared to conventional coring operations.
The improvement in this technology has drastically increased the efficiency of large diameter wireline retrievable coring technology, decreased the stuck pipe risk and greatly reduced the minimum amount of core needed for the technology to be economically justified.
Qualification and Field Trial of a Metal Expandable Well Annular Barrier
Authors: Drechsler Jan Roar , Eikeskog Øystein , Hazel Paul , Vasques Ricardo , Filev Boris , Bårdsen Johnny , Hjorteland Øyvind 
Published: March 2013

Abstract
The ability of cement to achieve a pressure seal across the reservoir section for the life of a well becomes ever more difficult to achieve because of increasing depths and more complexity in well design and operations. Mature fields with depleted zones combined with the desire and ability for extended reach wells exacerbates the challenge of delivering a cement-only, fit-for-purpose liner.
To address this challenge, an operator and service company have joined forces to design, develop, and qualify a hydraulically expandable metal well annular barrier (WAB) assembled on the outside diameter (OD) of a liner while maintaining full-bore inner diameter (ID). Intended initially for use in Norway's Valemon field, the operator is also exploring options for other applications in the Snorre and Brage fields, also offshore Norway.
This paper discusses the design, development, and qualification of the metal WAB, including: review of the design, material selection to achieve the required expansion, the unique outer seal design to deliver the pressure differential requirements, and intended applications to date. The final qualification process exceeds the industry-established guidelines in ISO standard 14310 (which defines requirements for packers and bridge plugs for the oil and gas industry).
The Next Step in Conventional Reciprocating Mud Pump Technology
Authors: Berryhill Gregg , Shelton Andy 
Published: March 2013

Abstract
Recent developments in reciprocating mud pump technology provide added value for operators, drilling contractors, and MWD/LWD (measurement while drilling/logging while drilling) service providers. Utilizing current proven conventional triplex (3-cylinder) pump designs and adding two cylinders provides an increased performance envelope, reduces pulsations on the rig structure and piping, and substantially increases data rate-transfer bandwidth during MWD/LWD operations.
Current data rate transfer for MWD/LWD when using reciprocating pumps are limited to frequencies below the first dominant frequency. Using a comparable horsepower quintuplex (5-cylinder) pump increases the data transfer rate 66% over current triplex reciprocating pumps. Due to the shorter stroke of a comparable horsepower quintuplex pump, the pump can also be operated at higher stroke rates that produce an additional 33% gain in frequency bandwidth. This is achieved through increased frequency of the additional pump cylinders and the ability to operate the pump at higher pump speeds.
The inherent design attributes of conventional quintuplex pumps reduce fluid flow variation (pulse) versus comparable horsepower triplex pumps. The five operating cylinders are timed at 72° whereas conventional triplex pumps are timed at 120° intervals per 360° of pump rotation. The additional cylinders reduce flow variation of the quintuplex to 7 percent versus a 23 % flow variation for conventional triplex pumps.
This paper focuses on advantages of using a conventional five cylinder design horizontal mud pump versus an equivalent horsepower conventional three cylinder design. For comparison a EQ-2200 will be tested versus a E-2200.The discussion includes specification comparisons, weights, external envelope dimensions and comparisons of fluid flow variation (pulse) performance that translates into reduced vibration on the rig and increased MWD/LWD data rate transfers.
The EQ-2200 is a 2,200 horsepower quintuplex pump and the E-2200 is a 2200 horsepower triplex pump. Both pumps are crankshaft-slider driven and both are rated at 7500 PSI working pressure.
Though both series have equivalent horsepower, in contrast, the pulse signature of the EQ series is greatly reduced compared to that of the E series, thereby increasing the performance envelope for MWD/LWD operations. In addition weights and dimensional envelopes of the EQ series are less than the E series.
Pore Pressure Evolution, Core Damage and Tripping Out Schedules: A Computational Fluid Dynamics Approach
Authors: Zubizarreta Izaskun , Byrne Michael , Sorrentino Yelitza , Rojas Elinor 
Published: March 2013

Abstract
During coring operations, while tripping out of the hole, core is submitted to a relatively sudden decrease in pressure, leading to fluid expansion and movement out of the pore space. The rapidly expanding fluids can generate fractures and damage the core. Tripping out core represents a delay to well drilling operations, therefore, project economics dictate "efficient" tripping out schedules given high daily rig costs. Ideally, core tripping out rates should be established for each particular core; however common practice is based on generic rules of thumb. The resulting schedules can lead to unjustifiably long tripping out operations or core damage if the process is too fast. There is a lack of clarity and consensus regarding tripping schedules impacting on both the integrity of the core and the economics of coring/drilling operations.
With these high daily rig costs in mind, a more scientific and quantitative approach, tailored to each case is required. The application of Computational Fluid Dynamics (CFD) is used to model transient pressure differentials in a gas reservoir core during retrieval.
The results of theoretical and field case simulations support and confirm empirical evidence that the pressure differentials created in a core during retrieval, are very low for relatively high permeability rock, and that most core tripping schedules based on rules of thumb significantly overestimate time, to the detriment of drilling efficiency. As the core permeability decreases, the time required for the core internal pressure to approach the external pressure increases, requiring longer equilibration times. The model realisations demonstrate that tensile failure criteria are more likely to be reached during the final stages of tripping out.
This study demonstrates that CFD can accurately predict the pressure differentials created in a core during retrieval to surface and enables proper planning of tripping times based on the assessment of potential damage by pressure release.
Performance of Thermal Cements with Different Weighting Materials
Authors: Caritey Jean-Philippe , Brady Jason 
Published: March 2013

Abstract
As the world's demand for energy continues to grow, exploration and production activity increasingly involves operations in high-pressure, high-temperature (HPHT) conditions. HPHT domains include geothermal, steam-injection, and ultradeep wells. These environments introduce difficult technical challenges. A major concern is the set-cement integrity. To maintain zonal isolation throughout the life of an HPHT well, the cement sheath must perform reliably at temperatures that can exceed 315°C [600°F]. When exposed to temperatures higher than 110°C [230°F], set Portland cement undergoes strength retrogression unless additional silica is incorporated in the cement formulation. This phenomenon has been studied extensively. However, less attention has been paid to the effects of other additives on the stability of set Portland cement in an HPHT environment—weighting materials in particular. Weighting materials have largely been assumed to be inert with respect to set Portland cement; however, the present study reveals that this assumption may be false in HPHT environments in which well temperature exceeds 260°C [500°F]. Some weighting agents may react with the set Portland cement, causing strength loss and increased permeability. Fortunately, this effect can be prevented, and the set-cement integrity can be preserved.
System Reliability and Metrics for High-Speed Networked Drillstring Telemetry and Along String Evaluation
Authors: McCubrey Raymond , Johnson Aaron , Adsit Rhys , Veeningen Daan , Pixton David 
Published: March 2013

Abstract
High-bandwidth downhole data transmission via a wired or networked drill string system provides an alternative to conventional wireless telemetry to obtain real-time downhole data during well construction operations. With an unprecedented rate at three orders of magnitude faster (57,600 bps) than wireless systems, networked drillstrings offer twoway broadband communication. In addition, real-time pressure and temperature measurements are uniquely available from multiple discrete measurement stations along the drillstring.
Industry-wide adoption of this technology necessitates the system to lower well construction expenditure through increased efficiency, improved wellbore quality and reduced risk exposure to be considered as a viable alternative to conventional strings. In addition, system reliability must be demonstrated with useful metrics. Mean Time Between Failure (MTBF) is one such metric used in the industry to measure reliability. High values of a system MTBF generally indicate a reliable product when combined with other metrics.
This paper provides historical trends of MTBF, and other reliability metrics in the case of high-speed networked telemetry drillstrings. The data and most conclusions are based on a reliability study from 65 wells that were drilled from 2008 to 2011. Results show increasing trends in reliability. Future improvements to network drillstring are discussed and their effect on reliability through these estimates is forecasted.
Validation of a modified McGill Pain Questionnaire for orthodontic patients
Authors: Iwasaki Laura R. , Freytag Larissa E. , Schumacher Charles A. , Walker Mary P. , Williams Karen B. 
Published: March 2013

ABSTRACT

Objective:
To assess better and more efficiently the aspects of pain experienced by adolescent orthodontic patients, the McGill Pain Questionnaire-Short Form (MPQ-SF) was modified (MMPQ-SF) and validated.

Materials and Methods:
Internal and external expert panels developed a MMPQ-SF with 15 descriptors and 4-point Likert severity scales (MMPQ-SF15). Seventy-five subjects undergoing orthodontic treatment gave informed consent. Sixty-one subjects completed the MMPQ-SF15, a visual analogue scale (VAS), and the present pain index (PPI) 24 hours after an orthodontic visit. Respondents were grouped by gender and treatment stage: initial (15 female, 7 male), middle (10 female, 7 male), and end (16 female, 6 male). MMPQ-SF, VAS, and PPI scores were compared by Spearman correlation analysis. Underlying constructs were explored by factor analyses. Construct validity of the MMPQ-SF was tested by analysis of variance.

Results:
MMPQ-SF15 and VAS (r  =  0.78, r2s  =  0.61, P &lt; .0001), MMPQ-SF15 and PPI (r  =  0.84, r2s  =  0.71, P &lt; .0001), and VAS and PPI (r  =  0.70, r2s  =  0.48, P &lt; .0001) were correlated positively and significantly. A two-factor solution (localized and generalized/emotional pain; Kaiser-Meyer-Olkin  =  0.88) showed that 11 descriptors (MMPQ-SF11) accounted for 64% of response variability. Generalized/emotional pain values were significantly higher during the initial stage of treatment compared to the middle (P  =  .011) and end stages (P  =  .014).

Conclusions:
MMPQ-SF, particularly MMPQ-SF11, demonstrated utility in assessment of localized and generalized/emotional aspects of pain in adolescent orthodontic patients and correlated well with VAS and PPI. Future application of the MMPQ-SF11 to measure orthodontic pain more specifically could lead to more appropriate management of this important facet of therapy.
Induction of hairy roots in Arnica montana L. by Agrobacterium rhizogenes
Authors: Petrova Mariya , Zayova Ely , Vlahova Mariana 
Published: March 2013

Abstract
The induction of hairy roots in Arnica montana L. by Agrobacterium rhizogenes mediated system was established. The frequency of genetic transformation varied from 4.8 to 12% depended on method of infection. The cefotaxime at concentration of 200 mg/l proved to suppress effectively the growth of A. rhizogenes after co-cultivation. Among the three tested nutrient media: Murashige and Skoog (MS), Gamborg’s (B5) and Schenk and Hildebrandt (SH), MS medium was superior for growth and high biomass production of transformed roots compared to other culture media. After culturing for 40 days the fresh weight of clone T4 increased 7.6 fold over the non-transformed roots. The transfer of rol A, rol B and rol C genes into Arnica genome was confirmed by PCR analysis. Established genetic transformation techniques in A. montana efficiently provided and generated a large number of transformed roots — an excellent system for studying gene function and could be used for the production of secondary metabolites synthesized in roots.
Evaluation of Stability of Potential Betaadrenolytics in Various Solutions by thin Layer Chromatography and by Kinetics of Hydrolysis
Authors: Stankovičová M. , Bezáková Ž. , Mokrý P. , Csöllei J. , Pažitná M. , Liptáková B. , Ševčíková Z. , Dvořáková – Kotlíková S. 
Published: March 2013

Abstract
The aim of this work is the study of stability and kinetics of hydrolysis of the chosen compounds, derivatives of 2-hydroxy-3-[2-(4-methoxyphenyl)ethylamino]propyl-4- [(alkoxycarbonyl)amino]benzoates and 2-hydroxy-3-[2-(2-methoxyphenyl)ethylamino] propyl-4-[(alkoxycarbonyl)amino]benzoates with potential ultra-short beta-adrenolytic activity. The studied compounds are different in the position of the substituent on the benzene ring in the side chain as well as in the aromatic ring in position 4 with alkyl- (methyl- to butyl-) carbamate. Thin layer chromatography and UV-area spectrophotometry are used in order to establish the stability of these potential pharmaceuticals. The stability studies of the compounds were examined in acidic and alkaline media, in buffers and due oxidation at room and at elevated temperature chromatographically, and Rf values of incipient products and degradation products were detected. Kinetics of acid and base hydrolysis in various solutions at temperatures 80 °C and 100 °C were examined through UV-area spectrophotometry. Kinetic parameters such as rate constant k, half-life period t1/2 and usable life t90 were determined.