bluuebunny/crossref_metadata_2025_split huggingface dataset:
New Cutter Technology Redefining PDC Durability Standards for Directional Control: North Texas/Barnett Shale
Authors: Baker Ryan , Shen Yuelin , Zhang John , Scott Robertson 
Published: February 2010

Abstract
The Bamett Shale play in the Fort Worth basin has become a substantial source of natural gas development and production in the United States. However, successfully drilling to the producing horizontal section requires an ever increasing amount of directional control. It's critical to optimize borehole placement and maximize total lateral footage within the producing horizon to enhance project economics. Additionally, in the vertical/build and hold section the operator must drill the sharp, abrasive Atoka sandstone and Bend conglomerate. These formations usually require several bits/trips to complete the entire section. These formations have historically been drilled with roller cone bits because standard polycrystalline diamond compact (PDC) bits/cutters do not have the required wear and impact resistance to withstand the punishment of the downhole environment without sustaining dramatic penetration rate (ROP) reductions. The operator required new cutter technology to efficiently drill the hardest, most abrasive sections of the Pennsylvanian Atoka sandstone and Bend conglomerate (~80% sandstone). The PDC bit body also needs to provide superior directional control to efficiently deliver the complex borehole geometries.
To solve these issues, the service provider initiated a research and development effort to analyze the levels of frictional heat generated at the rock/cutter interface. The resulting high temperature at the cutting tip is a major factor limiting PDC application in challenging hard/abrasive formations. Additionally, PDC's are now expected to drill longer intervals at deeper depths further intensifying thermal degradation and micro-chipping. The multifaceted analysis was aimed at increasing the three key functional properties that dictate PDC cutter life including thermal stability, wear resistance and impact strength. Generally, wear resistance and thermal stability are required for drilling sandstone, siltstone and other abrasive formations, while formations with higher rock strength and interbedded sections require a more impact resistant cutter.
Understanding the Contribution of Primary Stability to Build Aggressive and Efficient PDC Bits
Authors: Fuselier Danielle M. , Vempati Chaitanya R. , Oldham Jack , Patel Suresh G 
Published: February 2010

Abstract
A rigorous engineering and research effort combined with targeted field testing has delivered a new generation of PDC technology. This technology is intended to be utilized to drill both the hard-to-drill rock applications and the fast drilling top hole applications around the world.
In the fast drilling environment, the bit passes from the softer formation to harder interbedded stringers. In the hard-to- drill rock environments, the bit is drilling at low depths of cut (DOC). In both of these environments, it is critical to the overall performance in both rate of penetration (ROP) and distance drilled that the drill bits exhibit stability that is dependent on how the cutting structure interacts with the formation (primary stability) and keeps the bit from being perturbed when drilling.
This paper investigates how increasing primary stability can improve both the aggressiveness and efficiency of the bit and gain performance that cannot be achieved with bits that use damage mitigating features as part of the design methodology to stabilize or otherwise protect the cutting structures in these drilling environments. This paper also outlines a comprehensive product development effort with testing both in a laboratory setting as well as in the field. Using aggressive cutting structures to drill these two environments can increase performance if the bit has a strong primary stability signature as demonstrated by the test protocols used in this development effort. During laboratory testing, the new generation of PDC technology achieved on average 45% faster ROP compared to standard bits while increasing stability and efficiency. This improvement correlated to the field as the new concept bits drilled intervals 30% longer and 25% faster compared with the average performance of runs drilled with PDC bits.
Successful Development and Field Qualification of a 95/8 in and 7 in Rotary Steerable Drilling Liner System that Enables Simultaneous Directional Drilling and Lining of the Wellbore
Authors: Torsvoll A. , Abdollahi J. , Eidem M. , Weltzin T. , Hjelle A. , Rasmussen S. A. , Krueger S. , Schwartze S. , Freyer C. , Huynh T. , Sorheim T. 
Published: February 2010

Abstract
Many oil and gas operators around the world are faced with drilling operational risks when entering the matured field phase. Narrow drilling margins, hole collapse and lost circulation are among the challenges that must be dealt with safely and economically.
This paper describes a successful approach to overcoming these challenges developed through close cooperation between the operator and the oilfield services company. By providing an overview of the concept, technology and operating principles of the 9⅝ in and 7 in advanced steerable drilling liner system, the paper highlights the development and the testing process leading to the successful execution of the world's first steerable drilling liner application in the Norwegian sector of the North Sea.
The paper also discuss description of the testing and qualification of the two liner drilling sizes (9⅝ in and 7 in) at the service company's experimental test rig.
Williston Basin - A History of Continuous Performance Improvements Drilling Through the Bakken
Authors: Djurisic Alejandro , Binnion Adrian , Taglieri Anthony , Thompson Jim , Menge Mathias , Fleischhacker Curtis , Hood James 
Published: February 2010

Abstract
The Williston Basin has become one of the more lucrative oil reservoirs in North America over the past few years. The main reservoir occupies about 200,000 square miles of the subsurface of the Williston Basin, covering parts of Western North Dakota, Eastern Montana, and Southern Saskatchewan.
The Bakken Formation was first discovered in 1951, but efforts to extract oil from it have historically been difficult. Efficient production of the Bakken has been achieved with long horizontal wells drilled through reservoirs at depths ranging from 8,000 ft to 10,500 ft (2,438 m to 3,200 m) true vertical depth (TVD). The target reservoir depths and the extended lateral wellbore lengths, require more powerful rigs to meet the operational demands of these well designs. The increased cost and tight economics associated with this play present a strong incentive to improve the drilling performance by reducing drilling time and cost. As a result, a strong focus was placed on improving drilling efficiency in the 9,000 ft to10,000 ft (2,743 m to 3,048 m) lateral wellbore sections, which have the largest impact on the overall well cost.
This paper will introduce the challenges encountered when drilling these wellbore designs and outline the approach taken to optimize the drilling process. The usage of high-performance drilling motors, a review of previously used bottom hole assembly (BHA) concepts, and the benefits of gathering additional real-time downhole drilling data to validate or change best practices will all be discussed. The data presented has been gathered over the past 18 months, mainly in Dunn County of North Dakota, and will show rate of penetration (ROP) improvements of about 50% over this time period. This improvement in drilling efficiencies has proven to reduce the overall drilling time and has impacted the economics of this play significantly.
RCM Principles Provide Predictive Asset Maintenance Benefits, Cost Savings
Authors: Breland Frank , Guy James , Masters Max , Kinert Nathan , Menon Ashe 
Published: February 2010

Abstract
Since its inception, the drilling industry has grown accustomed to a "fire fighting" culture, facing and solving problems as they occur. A study on reliability-centered maintenance (RCM) proposes to move the industry toward a "fire prevention" culture by transferring technologies from industries like aerospace, automotive and downstream petroleum, to develop smarter equipment monitoring and management systems that enable the improved design, construction, and maintenance of rig equipment. RCM principles have yet to be applied in the drilling industry because of the harsh conditions and repeated movement equipment is subjected to over a typical lifecycle.
This study involves identifying equipment on drilling rigs using field-proven radio frequency identifier (RFID) tags, and acoustic and vibration sensors, to measure operational deviations from the baseline. The RFID tags ensure accurate historical data is obtained regarding equipment location and movement. To establish trends, real-time rig equipment data is collected and charted. A web-based application is used to monitor and manage equipment maintenance. Failures that result in maintenance-related downtime are added to the database and the trend is updated. A data analysis model developed using statistical analysis software narrows down potential causes and identifies problem sources.
This study clearly demonstrates that significant economic benefits can be realized by applying RCM practices using smart equipment monitoring and management systems for better preventive rig equipment maintenance. Moreover, RCM application using rig equipment data helps achieve asset maintenance goals, including greater safety, longer life, and higher equipment availability and reliability, while simultaneously enabling better quality product development with greater cost effectiveness.
Applying RCM concepts to predictive asset management and maintenance adds the following to the drilling industry technical knowledge base:
– Industry-proven RCM practices are applied in the drilling industry using rig equipment data to achieve substantial cost savings and other important asset maintenance goals. – Technology transfer concepts are used to identify milestones, measure deliverables and assess the economic benefit from RCM application in the drilling industry.
Correlations between operating conditions and equipment wear are developed by considering formation characteristics and revealing operational differences (e.g. top drive mean-time to failure when drilling in hard vs. soft formations).
Improving Horizontal Well Performance with PDC Bits Designed to Increase Aggressiveness through the Run
Authors: Beuershausen Chad , Schwefe Thorsten , Weinheimer Cara , Kramer Mark 
Published: February 2010

Abstract
A substantial development effort, backed by drilling simulator and field testing, has delivered a directional PDC drill bit optimized for drilling the curve and lateral sections of horizontal wells. The PDC drill bit employs a new technology that controls the aggressiveness of the PDC in specific portions of the well and delivers reduced drilling and operating costs.
With an increased focus on fewer days on a well necessitated by reduced natural gas prices in the North American land market, the need to reduce cost and eliminate bit trips has increased substantially over the past year. Operators in North America Oil/Gas Shale plays have migrated to drilling a combined curve and lateral section with a single bit to reduce operating expenses and rig time. With these changes, the PDC drill bit must maintain toolface control in the curve section, while being able to attain an increased rate of penetration (ROP) in the lateral section.
To maintain toolface control and achieve the desired build-up rates, the axial and lateral aggressiveness of the bit must be managed. To do this, the aggressiveness (Mu) of the PDC drill bit is initially controlled at the kick-off point from the vertical section through the curve section. As the PDC bit drills the curve section, the feature that controls the torsional oscillations is systematically reduced allowing the aggressiveness, thus the ROP, to increase for the lateral section. In atmospheric lab testing, the aggressiveness was increased from 0.38 (curve) to 0.64 (lateral) for the new design. This represents an increase of 68% in the aggressiveness from the beginning of the curve to the end of the lateral section. This has been substantiated in field performance.
The goal for this innovative feature is to control the torsional oscillations at the beginning of the curve section of the well, where control drilling is generally used to achieve the desired build-up rates. Once in the lateral section, the predominant method of drilling changes from sliding to rotating thus the need for the bit to have increased aggressiveness.
This paper demonstrates how selectively managing the torsional oscillations of the PDC drill bit in the curve and lateral sections can increase on-bottom drilling time and decrease operating expenses due to increased toolface control and increased rate of penetration. By efficiently managing the bit's torsional response, a single PDC drill bit can be used in both sections, which allows for a single bottomhole assembly to be run without a trip.
Improved Drilling Performance and Economics Using Hybrid Coiled Tubing Unit on the Chittim Ranch, West Texas
Authors: Littleton B. , Nicholson S. , Blount C. 
Published: February 2010

Abstract
A significant performance and cost improvement was achieved with the application of hybrid Coiled Tubing (CT) drilling equipment and techniques on the Chittim Ranch in Maverick county Texas. During this drilling program, 233 wells were grass-root drilled using the hybrid CT unit. Coiled tubing drilling equipment and techniques reduced the average time to complete a well by 60% when compared to conventional rotary rig drilling. This increase in drilling performance coupled with a turnkey contract resulted in a 14% (33% adjusted for inflation) cost reduction per well when compared to the most recent conventional drilling data from this area.
This paper will review the process used in choosing a CT solution, the hurdles overcome, the problems encountered, and the lessons learned in managing and operating this CT Drilling (CTD) campaign. The paper will also provide an overview of CT coring performed in one of the wells during the CTD campaign.
The drilling performance increase was realized using a top-set rig to set surface casing and a hybrid "Big Wheel" CT rig to drill the production hole. Finalized project data demonstrated that field performance using CTD met and in some areas exceeded project goals.
Case Study: API Box Boreback Stress Relief With Truncated Threads Can Cause Premature Connection Fatigue Failure
Authors: Gerdes Michael B. , Lee Kang 
Published: February 2010

Abstract
A rotary shouldered connection (RSC) can be modified with two stress relief features to improve its fatigue performance: 1) A stress relief groove on the pin and/or 2) A boreback feature on the box, commonly called a box boreback. Both are API approved stress relief features, whose only purpose is to mitigate stress concentration caused by unengaged threads in the connection. However, under certain operating conditions the box boreback feature as traditionally machined can actually reduce the fatigue life of the connection. Prompted by recognition of unique failure locations in the box of numerous BHA connection types, the authors performed finite element analysis to better understand the fatigue mechanisms driving the failures.
In a typical API box boreback, the crests of the last four or five threads are cut short, resulting in truncated threads. Regarding the box boreback feature, API Specification 7-2 (API, 2008) controls for three primary dimensional variables by connection type & size: 1) Cylinder diameter 2) Depth to last thread scratch 3) Depth to end of cylinder. A machined boreback will be technically acceptable adhering to these dimensional requirements, which allow for truncated threads, but this method is not optimal. The approach does offer two commercial advantages for the tool owner as it is both simpler to execute and leaves greater material behind for future recuts. API 7-2 also allows for a box stress relief groove, but this feature is rarely used commercially for similar reasons. To quantify the impact of the box boreback on fatigue life, the authors modeled a failed NC46 drill collar connection with the feature and compared with hypothetical configurations of the same connection.
SATB2 haploinsufficiency in patients with cleft palate
Authors: Writzl Karin , Lovrečić Luca , Vojtaššák Ján , Peterlin Borut 
Published: January 2010

Abstract
De novo translocation interrupting the transcription unit of SATB2 gene has been associated with cleft palate only (CPO). We tested for the presence of the copy number of SATB2 gene in a sample of 92 patients with CPO using a quantitative real-time PCR approach. In one patient (1%, 95% CI = 0.2%–6%), a 19 Mb de novo deletion encompassing the SATB2 gene was detected. These results suggest that SATB2 gene deletions do not play an important role in the etiology of cleft palate.
Aorta transplantation in young apolipoprotein E-deficient mice: Possible model for studies on regression of atherosclerotic lesions?
Authors: Tonar Zbyněk , Bobková Dagmar , Witter Kirsti , Matějka Vít , Havlíčková Jana , Lánská Věra , Poledne Rudolf 
Published: January 2010

Abstract
Syngeneic transplantation of murine aorta segments with advanced atherosclerotic lesions in defined recipients is a valuable model for regression studies. To date, this model has not been used to study the regression of initial atherosclerotic lesions. The aim of this study was to evaluate a microsurgical technique of syngeneic heterotopic transplantation of the thoracic aorta of young apolipoprotein E-deficient (ApoE-/-) mice to the abdominal aorta of wild-type recipients. Stereological quantification methods were tested in order to assess changes in structure and volume of the aortic wall including the involvement of immune cells in changes of the atherosclerotic lesions. The animals were euthanised one month after surgery and histological analysis including stereological quantification of changes in both the grafts and adjacent aorta segments was performed. The overall survival rate of the recipients was 62.5%. No regression of initial atherosclerotic lesion was achieved and neointima formation and elastin degradation prevailed in all transplanted specimens. The volume of the arteriosclerotic lesions was higher (p<0.001) and elastin length density was lower (p<0.001) in transplanted ApoE-/- samples as compared to adjacent segments. In transplanted grafts, T- and B-lymphocytes, macrophages and neutrophilic granulocytes formed non-random clusters within the vessel wall and they were colocalised with the sutures. The reproducibility of the promising regression model was derogated in young mice by the striking dependence of the results upon the operation technique. Stereological assessment has proven to be accurate, correct and reproducible; it has provided us with robust quantitative estimates, which can be achieved with a reasonable effort.
Fluconazole, caspofungin, voriconazole in combination with amphotericin B
Authors: Kalkanci Ayse , Dizbay Murat , Sari Nuran , Yalcin Burce , Fidan Isil , Arman Dilek , Kustimur Semra 
Published: January 2010

Abstract
Combined antifungal therapy has been suggested to enhance the efficacy and reduce the toxicity of antifungal agents. The aim of the study was to investigate the in vitro synergistic activity of caspofungin, voriconazole, and fluconazole with amphotericin B against ten isolates of Candida parapsilosis and Candida albicans strains which were resistant to azoles or amphotericin B. Three different antifungal combinations (amphotericin B [AP] — caspofungin [CS], amphotericin B — fluconazole [FL], and AP — voriconazole [VO]) were evaluated for in vitro synergistic effect by the microdilution checkerboard and E-test methods. For the majority of strains, the combination test showed indifferent activity. Via the E-test method, synergistic activity was seen in 3 strains in response to AP-CS combination treatment and in one strain after administration of AP-FL; however, no synergy was observed in response to combination treatment with P-VO. Antagonistic activity was the result in 1 strain treated with AP-CS as well as in 6 strains treated with AP-FL and AP-VO combinations. Via the microdilution test, no synergistic activity was seen after treatment with all 3 combinations. Antagonistic activity was the result in 2 strains with AP-CS, in 6 strains with AP-VO and in 5 strains with AP-FL combinations. Agreement between the checkerboard and E-test methods was observed to be approximately 72%. These combinations may be used in the case of antifungal resistance.
Genitourinary tuberculosis in a 54-year-old woman: diagnostic difficulty
Authors: Agca Harun , Baylan Orhan , Ozyurt Mustafa , Acar Ali , Demirpek Ugur , Haznedaroglu Tuncer 
Published: January 2010

Abstract
Genitourinary tuberculosis (GUTB) is an extrapulmonary manifestation of tuberculosis seen in 1.2% of all cases of tuberculosis. The clinical case of a 54-year-old woman diagnosed with GUTB is presented. Cloudy urine, abdominal pain, and microscopic hematuria led us to investigate for Mycobacterium tuberculosis. Although cultures were negative, positive Ehrlich-Ziehl-Neelsen (EZN) staining and a positive polymerase chain reaction (PCR) revealed the diagnosis of M. tuberculosis complex (MTC), which was confirmed by treatment success. It has been shown that PCR is a reliable and rapid method for establishing or supporting the diagnosis of tuberculosis and can be used in a routine diagnostic algorithm when conventional methods fail to identify MTC.
A microarray gene analysis of peripheral whole blood in normal adult male rats after long-term GH gene therapy
Authors: Qin Ying , Tian Ya-Ping 
Published: January 2010

AbstractThe main aims of this study were to determine the effects of GH gene abuse/misuse in normal animals and to discover genes that could be used as candidate biomarkers for the detection of GH gene therapy abuse/misuse in humans. We determined the global gene expression profile of peripheral whole blood from normal adult male rats after long-term GH gene therapy using CapitalBio 27 K Rat Genome Oligo Arrays. Sixty one genes were found to be differentially expressed in GH gene-treated rats 24 weeks after receiving GH gene therapy, at a two-fold higher or lower level compared to the empty vector group (p < 0.05). These genes were mainly associated with angiogenesis, oncogenesis, apoptosis, immune networks, signaling pathways, general metabolism, type I diabetes mellitus, carbon fixation, cell adhesion molecules, and cytokine-cytokine receptor interaction. The results imply that exogenous GH gene expression in normal subjects is likely to induce cellular changes in the metabolism, signal pathways and immunity. A real-time qRT-PCR analysis of a selection of the genes confirmed the microarray data. Eight differently expressed genes were selected as candidate biomarkers from among these 61 genes. These 8 showed five-fold higher or lower expression levels after the GH gene transduction (p < 0.05). They were then validated in real-time PCR experiments using 15 single-treated blood samples and 10 control blood samples. In summary, we detected the gene expression profiles of rat peripheral whole blood after long-term GH gene therapy and screened eight genes as candidate biomarkers based on the microarray data. This will contribute to an increased mechanistic understanding of the effects of chronic GH gene therapy abuse/misuse in normal subjects.