bluuebunny/crossref_metadata_2025_split huggingface dataset:
Design and Qualification of an Ultra-High Pressure Perforating System
Authors: Mhaskar Nauman , Sloan Mark , Myers William , Harvey William 
Published: June 2012

Abstract
With the steadily increasing demand for oil and gas, operators have been forced to explore deeper and hotter areas to find the most prolific reservoirs. This paper hightlights the design and qualification steps performed during development of a 7.0-in. O.D. 16 shots per foot (SPF) 30,000 psi perforating gun system. Finite-element modeling was used to optimize the gun design for 30,000 psi external pressure, and 400° F. As part of the qualification requirements, ballistic survival testing was conducted using low-debris gravel pack shaped charges.
Comprehensive knowledge of the post-perforated condition of the gun body is required, as its failure may lead to an expensive fishing operation and possible damage of the oil well casing. Survival testing was conducted under two different conditions, no load on the gun body and the second contion with a tensile load equivalent to the weight of 1,500 ft of perforating guns.
The methodology of finite-element modeling is discussed along with experimental data obtained by collapse testing of perforating hollow carriers (HC) of different diameters and shot densities. Data from computer simulations and physical testing in the lab are presented to provide better insight into the behavior of perforating guns under external pressure. The data from the survival tests showed virtually no change in the swell of the HC when subjected to a high tensile load as compared to the no-load condtion. This testing method provides insight into the behavior of perforating systems under different loading parameters.
The results described in this paper highlight the need to apply rigorous methods for design and qualification of ultra-high pressure gun systems when exploring new oilfield frontiers characterized by extremely harsh environmental conditions.
A Solution to the Problems Associated with Tight-Clearance Boreholes: the Close Tolerance Press-Fit Stop Collar
Authors: Wimberg J. A. , Tkach S. A. , Marque J. M. , Domingue K.. , Buytaert J.. , Harless K.. 
Published: June 2012

Abstract
With the continual development of offshore drilling operations comes new ways to approach old challenges. For any operator in a mature field, it is commonplace to enhance value by sidetracking existing wellbores to unswept areas within the reservoir where using a new drill would not be economically feasible. However, this approach often involves inherent risk. By using an existing wellbore, hole size and casing combinations are limited to the largest outer diameter (OD) casing string the operator can exit from and still safely case and cement the objective with a high probability of success. A bicenter drilled or under-reamed hole in combination with the use of noncoupled tubular connections (flush connections) is often required to construct a wellbore of sufficient size that does not constrict eventual production rates. Tight annular clearances and subsequent enlarged holes create standoff problems for subsequent cementing operations. In addition, sidetracks commonly drilled with only limited casing strings require efficient use of the minimal amount of casing sizes available. This often requires washing, rotating, or reaming casing to bottom when borehole conditions deteriorate. This paper describes a creative solution to the challenge of achieving casing standoff in an enlarged borehole while being robust enough to ream lengthy distances and retain the flexibility to properly centralize a tubular string for a quality cement job.
Improvement of Hole Cleaning Through Fiber Sweeps
Authors: Cheung Erik , Takach Nicholas , Ozbayoglu Evren , Majidi Reza , Bloys Ben 
Published: June 2012

Abstract
Hole cleaning is often more difficult during drilling of inclined wells. The resulting poor removal of cuttings can lead to problems such as borehole pack-off and excessive ECD, which are both difficult and expensive to resolve. Fluid sweeps are commonly implemented when normal circulation cannot adequately remove cuttings from the borehole. Field reports have indicated that specialized fibrous-type materials enhance cleaning performance when added to fluid sweeps. Yet, understanding of the behavior of this improvement remains inexact.
This paper presents a comparative experimental investigation of the hole cleaning performances of fiber sweeps, conducted with different drill pipe rotation speeds and fiber concentrations. Experiments were carried out in an inclined flow loop apparatus with an inner rotating drill pipe. The hole cleaning performance of fiber-containing sweep fluids using different fiber concentrations (0%, 0.05%, 0.1%, and 0.2%, by weight) and varying drill pipe rotation speeds (0 to 90 rpm) was evaluated. Sweep efficiencies were compared in terms of the measurement of cuttings bed heights before and after circulating the sweep fluid.
The results indicate that significant improvement associated with higher fiber content requires a commensurate increase in drill pipe rotation speed. With lower or no pipe rotation speed, increasing fiber concentration yields less dramatic returns. Pairing high fiber content with rapid pipe rotation resulted in enhanced performance over the control sweep, which contained no fiber, but relatively low concentrations did not surpass the control.
With the increasing need in the industry to drill extended reach or otherwise inclined wells, there is greater potential to develop problems stemming from inadequate hole cleaning. This research gives insight into the specific interaction of sweep fiber and pipe rotation with the cuttings bed, and with each other. Deeper understanding of fiber sweeps would inform in-field decisions when dealing with poor hole cleaning.
Multidisciplinary Approach and Engineered Solution Sets New North Sea Performance Benchmarks
Authors: Cockram Mark , Ritchie Allan , Norge BG , O’Keefe John , van der Laan Rene , Sundfør Erik , Larsen Olav , Kleimeer Peter , Rapp Tom , Shotton Peter , Gjertsen Ole Jacob 
Published: June 2012

AbstractTo efficiently develop reserves in the Norwegian North Sea, the operator must drill a challenging 12¼" directional borehole through a Chalk formation with high stick-slip potential. In Gaupe North, a negative vertical section was required in the initial kickoff to properly line up the well path before entering the reservoir target. The reservoir is comprised of channel/sheet sandstones interbedded with shale sequences with different pressure regimes and nearby reservoir depletion issues. The 8½" wellbore must penetrate an unstable organic shale just above the reservoir, infamous for causing hole stability problems and stuck pipe events. The regulatory agency requires this shale to be drilled in an 8½" section, requiring long exposure time, which increases risk for hole problems when running the production liner. The objective was to efficiently drill these trouble-zones and deliver two horizontal producers in a cost effective manner using an integrated engineering solution.To achieve the objective, a sophisticated multidisciplinary approach was employed including: bit/BHA offset analysis to reduce stick-slip in the chalk; BHA/RSS and drilling fluids modeling/planning; and drilling parameter plots to identify optimum RPM/WOB. Also, a real-time parameter analysis system was deployed to optimize ROP without compromising hole cleaning or well integrity.The synergy provided by a fully integrated service provider increased drilling performance and was a major contributor to the success of the Gaupe wells performance. Well 6/3-A-1H broke the previous Rushmore index for subsea development wells in the region and set a Norwegian record for wells in this class. Both wells (15/12-E-1H & 6/3-A-1H) achieved positive P10 curves and saved a total of 18 days vs AFE. Compared to an analogous UK North Sea field, significant increases in ROP were achieved resulting in the wells being drilled 20+ days faster than benchmark. The average increases in ROP for the two Gaupe wells were approximately 146%, 47% and 148% in the 17½", 12¼" and 8½" sections respectively.
Challenges in Setting Cement Plugs in Deep-water Operations
Authors: Bogaerts M.. , Kanahuati A.. , Khalilova P.. , Moretti F.. , Voon E.. , Dighe S.. 
Published: June 2012

Abstract
Offshore cementing poses many challenges across the world as drilling operations move towards deep-water and ultra-deep-water. As a new initiative of continuous improvement, a deep-water cementing peer review process was started early 2011. To this date, this team has reviewed more than 1200 deep-water cementing jobs in more than 30 countries worldwide.
Plug cementing makes up nearly 53% of all the deep-water jobs reviewed. The majority of the cement plugs placed are for plug and abandonment purposes; however a significant part is for loss circulation, kick-off, or squeeze. Although plug cementing comprises a big portion of deep-water cementing, it often does not get the same level of attention as primary cementing.
Specialized plug cementing software is used to design all cement plugs set in deep-water operations. The software simulates fluid interfaces, contamination during placement (both when the fluid is travelling down the pipe and when it is being placed in the annulus) and while pulling out of hole. As a final result, it provides the top of uncontaminated cement. Aside from proper job placement, good slurry design is very important. Cement slurries used for plug cementing need to be designed according to the objectives of the job. Several case histories will show lessons learned from the analysis of plug cementing operations in deep-water operations.
As the industry and local regulations gets more stringent on the evaluation and acceptance of the barrier for well integrity, the success of setting a cement plug the first time is becoming ever more critical. Getting it right the first time easily saves several days of NPT resulting in savings of millions of dollars, especially in this deep-water environment. Appropriate focus on sound engineering practices and the use of the specialized software has improved reliability of setting cement plugs in deep-water and helps operators avoid costly remedial operations.
A Novel Tubing Movement Workflow Increases Efficiency and Planning for Deepwater Frac-Pack Operation
Authors: Boisvert Ian , Strobel Marshal , Szatny Michael 
Published: June 2012

Abstract
The frac-pack completion has become one of the prominent completion types for deepwater formations throughout the world. The vast majority of frac-pack stimulation treatments are pumped through complex sand control tools in wells with large gravel pack assemblies. The forces created by these stimulation treatments have increased as treatment size, water depth, and total depth have increased offshore. To plan appropriately for these deepwater completions, engineers expend a significant amount of effort to ensure that the tools are robust enough to accommodate the treatment demands. This planning and simulation can be a very time consuming process; moreover, it may evaluate only a limited range of potential frac-pack scenarios.
To reduce time and limit uncertainty, a novel tubing movement workflow has been developed. A commercially available workflow software suite was used to connect a commercially available fracture design component and a commercially available casing and tubing simulator. This workflow uses formation parameters and a wellbore input file to process hundreds or thousands of stimulation injection schedules to determine tubing movement, pipe forces, and weight transmitted downhole. The entire process is completed within a significantly shortened time span, depending on the computer speed and the number of iterations desired. The results of the workflow enable the determination of optimal workstring and service tool characteristics. A sample case study is included.
Transformational Reduction in Non-productive Time through Implementation of Broadband Networked Drill-string and Modified Drilling Practices in an Extended Reach Drilling Campaign
Authors: Veeningen Daan , Fear Martyn , Energy Husky , Willson Stephen 
Published: June 2012

AbstractHistorically, extended reach offshore wells in Trinidad & Tobago were characterized by wellbore instability and hole cleaning challenges. These phenomena had become almost impossible to manage effectively in the highest angle wellbores, leading to levels of non-productive time (NPT) that threatened the economic viability of the latest development.Wellbore instability exacerbated the hole cleaning challenge, fueled by a new instability mechanism at highest wellbore inclinations. This led to pack-offs and stuck pipe incidents. Additionally, poorly understood and generally insufficient hole cleaning practices increased stuck pipe risk, and also caused the equivalent circulating density (ECD) to rise, resulting in mud losses due to the narrow window between mud density required for wellbore stability, and formation fracture gradient.The solution to these problems was found through advanced downhole measurements of borehole stability and hole cleaning, transmission of those data back to surface via a high frequency medium ("networked or wired" drill-pipe), deployment of subject matter experts into the rig team for critical phases of the operation, and introduction of unconventional drilling and decision-making practices to mitigate the problem phenomena.This paper describes the transformational efficiency improvement that was achieved by this combination of new technology, improved workflows, and multidisciplinary expertise deployed to the rigsite. The methodology was implemented on the third well, resulting in a reduction of NPT from 47% and 48% on the first two wells, to 10% on the third, clearly expressing the enhanced control of these drilling phenomena on the third well.Recommendations offered are relevant to many extended reach drilling campaigns, and may be critical to the success of ultra-ERD wells.
Application of Mechanical Specific Energy Techniques in Reducing Drilling Cost in Deepwater Development
Authors: Amadi Kingsley , Iyalla Ibiye 
Published: June 2012

Abstract
This paper examines the application of mechanical specific energy optimisation techniques in cost reduction through prediction of optimum ROP using real-time drilling parameters data and intrinsic formation data acquired during the actual drilling process. In fields where offset well data exist accurate field penetration rate benchmark can be established aiding cost Optimisation. In recent times, the global number of deep water wells drilled has risen with the oil price, however growth is patchy and the actual spending on wells is rising rapidly. Spending surge on drilling cost impacts on the bottom line performance and sustainability of E&P business. Therefore the need for drilling performance improvement as operational cost reduction initiatives has become a critical industry goal. This study show that in most cases, drilling progress could be raised by 30 – 60% compared to best offset well performance. It also highlights drilling flounder (point at which the penetration rate stops responding linearly with increasing weight on bit) during the drilling process enabling informed decisions towards improving the drilling process with the overall goal of achieving lowest cost per foot drilled.
A Numerical Model for Predicting the Rate of Sand Production in Injector Wells
Authors: Azadbakht S.. , Jafarpour M.. , Rahmati H.. , Nouri A.. , Vaziri H.. , Chan D.. 
Published: June 2012

Abstract
In this paper, a numerical model for volumetric prediction of sand production in injector wells is presented. Sanding in injector wells is mainly associated with the back-flow and cross-flow generated during shut-in in addition to the waterhammer pressure pulsing in the wellbore due to fast flow rate changes. Emphasis is given to the geomechanical aspects of sanding such as rock fatigue due to cyclic pressure changes and the concomitant degradation of bonding between the sand grains. This model is robust in capturing the key parameters in the sandstone behavior such as stress-dependent elasticity, hardening, softening and dilatancy. Rock degradation is considered to be the necessary condition for sand production which is assumed to obey the erosion mechanics. The model is calibrated and validated using physical model tests carried out under various stresses and fluid flow conditions. The numerical model has been utilized to analyze sanding potential in a cased and perforated injector which will be presented to demonstrate the field application of the proposed concepts.
Marine Well Containment Company Progress
Authors: Massey Marty 
Published: June 2012

Abstract
Following the Deepwater Horizon incident, ExxonMobil, Chevron, ConocoPhillips and Shell recognized the need to improve containment capability for a potential deepwater well control incident in the U.S. Gulf of Mexico.
This led to the formation of a not-for-profit, independent company, Marine Well Containment Company, which would develop, maintain and advance well containment systems for the deepwater U.S. Gulf. Following formation, MWCC gained six additional members (for a total of ten member companies): BP, Apache, Anadarko, BHP Billiton, Statoil and Hess. This coming together signified unprecedented industry collaboration and is a key reason that drilling has resumed in the U.S. Gulf of Mexico.
As the leader in deepwater well containment in the U.S. Gulf of Mexico, the company is committed to being continuously ready to respond to a well control incident in the Gulf and is committed to advancing its capabilities to keep pace with its members’ needs. Membership is open to all oil and gas operators in the U.S. Gulf of Mexico.
Biochemical markers of bone metabolism in gingival crevicular fluid during early orthodontic tooth movement
Authors: Barbieri German , Solano Patricia , Alarcón Jose Antonio , Vernal Rolando , Rios-Lugo Judith , Sanz Mariano , Martín Conchita 
Published: June 2012

Abstract

Objective:
To evaluate the expression of an activator of nuclear factor-kappa (RANK), osteoprotegerin (OPG), osteopontin (OPN), and transforming growth factor ß1 (TGF-ß1) in gingival crevicular fluid (GCF) of teeth subjected to orthodontic forces.

Materials and Methods:
A randomized, pilot clinical trial including 10 healthy volunteers was conducted using a split-mouth design. Orthodontic elastic separators were placed between the second premolar and first molar, with the contralateral quadrant serving as a control. The GCF samples were collected from the tension and compression sites at baseline, 24 hours, and 7 days after the placement of separators. The GCF sample volumes were measured using a Periotron 8000, and total protein concentrations were determined. Levels of RANK, OPG, OPN, and TGF-ß1 were also analyzed using a multiplex enzyme-linked immunosorbent assay.

Results:
The control sites remained unchanged throughout the study. In contrast, the concentration of OPG significantly decreased at the compression site by 24 hours, and the amount and concentration of RANK differed significantly between the control, compression, and tension sites after 7 days. A significant increase in absolute TGF-ß1 levels was also detected at the compression site versus the control and tension sites after 7 days.

Conclusion:
Bone metabolism is affected by application of force to the teeth by elastic separators. Both increased expression of bone resorptive mediators (eg, RANK and TGF-ß1) and decreased expression of a bone-forming mediator (eg, OPG) on the compression side were detected.
Multi-dimensional instability of electrostatic solitary waves in ultra-relativistic degenerate electron-positron-ion plasmas
Authors: Masum Haider M. , Akter Suraya , Duha Syed , Mamun Abdullah 
Published: June 2012

Abstract
The basic features and multi-dimensional instability of electrostatic (EA) solitary waves propagating in an ultra-relativistic degenerate dense magnetized plasma (containing inertia-less electrons, inertia-less positrons, and inertial ions) have been theoretically investigated by reductive perturbation method and small-k perturbation expansion technique. The Zakharov-Kuznetsov (ZK) equation has been derived, and its numerical solutions for some special cases have been analyzed to identify the basic features (viz. amplitude, width, instability, etc.) of these electrostatic solitary structures. The implications of our results in some compact astrophysical objects, particularly white dwarfs and neutron stars, are briefly discussed.
Effectiveness of Rape Protection Against Pests in the Years 2006-2009 in Poland
Authors: Walczak Felicyta , Golinowska Maria , Tratwal Anna , Bandyk Andrzej 
Published: June 2012

Effectiveness of Rape Protection Against Pests in the Years 2006-2009 in Poland
Long-term research on the intensification of economically significant pests in rape cultivation has been conducted by the Plant Protection Institute - National Research Institute (PPI - NRI) Poznań, Poland. This research has allowed for a determination of the economic effectiveness of chemical plant protection against pests. The research was conducted during the 2006-2009 time period. Results showed that the economic effectiveness expressed in approximate profitability indexes E1 and E2 in rape cultivation in Poland was diversified. The values were influenced by the selling prices of rape, intensification of pest occurrence, and yield. To prevent losses in yields, chemical crop protection has been implemented. In 2006, rape underwent an average of two treatments against pests: one against diseases and one reducing weed infestation. The primary rape-attacking pests from 2006 to 2009 were: rape pollen beetle (Meligethes aeneus F.), cabbage stem weevil (Ceutorhynous quadridenz Penz), cabbage seed weevil (Ceutrohynorus assimillis Payk.) and pod gall midge (Dasyneura brassicae Winn.).
Effect of Reniform Nematode, Rotylenchulus Reniformis as Biotic Inducer of Resistance Against Root-Knot Nematode, Meloidogyne Incognita in Potato
Authors: Osman Hamida , Youssef Mahmoud , El-Gindi Abd-El-Moneim , Ameen Hoda , Abd-Elbary Nagwa , Lashein Asmahan 
Published: June 2012

Effect of Reniform Nematode,Rotylenchulus Reniformisas Biotic Inducer of Resistance Against Root-Knot Nematode,Meloidogyne Incognitain PotatoA greenhouse experiment was conducted to evaluate the preinoculation of reniform nematode,Rotylenchulus reniformisfor inducing resistance againstMeloidogyne incognitain potato plants. Potato plants were inoculated with reniform nematode three days before the same plants received a root knot nematode inoculation. There was a reduction in the population parameters of the root knot nematode compared to plants given only a single inoculation. The studied potato plants which had two inoculations, also had enhanced growth parameters. The activity of the enzymes; peroxidase, polyphenol oxidase, and chitinase increased in the inoculated plants compared to the non-inoculated control.