bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cemented Versus Open Hole Completions: What is Best for Your Well?
Authors: Appleton Joel , Rivenbark Mark 
Published: January 2013

AbstractFor many years, the industry has relied on cemented and perforated liners to complete multistage stimulated oil and gas wells. However, the boom in tight oil and gas plays in North America and elsewhere have seen the emergence of open hole multistage system completions as a competitor to the traditional cemented liner.Open hole multistage system completions found favor due to the efficiencies and cost savings realized by operator companies. These systems also made possible many more stages at an economic price point. But what about initial and ultimate recovery comparisons? Do open hole completions perform better or worse than cemented liners?This paper will explain the differences between these competing completion options and present multiple case studies that have demonstrated operational, economic and production variances between cemented and open hole completions. This review will include a discussion of as important components to evaluating these competing completion techniques.
The Importance of Saturation History for Tight Gas Deliverability
Authors: Spain David R. , Merletti German , Webster Mike , Kaye Lindsay 
Published: January 2013

Abstract
Contemporary thinking on the origin of "basin centered" gas highlights the importance of proximity of mature source rocks to many low permeability gas reservoirs. The quality of gas charge determines the efficiency of the system; this is largely dependent upon source rock characteristics (oil versus gas prone) as well as the time sequence associated with hydrocarbon migration and reservoir unroofing. Examples exist where tight gas accumulations exhibit production of both condensed water and formation water. This can occur where low permeability reservoirs exist downdip or updip of pervasive gas saturation, where the source rock is not in proximity to the reservoir or where source rocks are lean or limited relative to the capacity of the reservoir rocks. Water production can also occur where the reservoir system has been breached, buried, or tilted and water has been imbibed to partially replace gas, thereby trapping a residual gas phase.
Dynamic rock typing "focuses on using petrophysical properties including rock type, porosity and effective permeability at reservoir conditions to divide the reservoir into flow units" (Liu et al, 2012); however, this should be done within the context of their saturation histories. Given the dynamic nature of some gas accumulations over a geologic timescale, it is important to model the relative permeability controls on gas and water deliverability using both drainage and imbibition models. A comparison of drainage versus imbibition models highlights the importance of saturation history, since minor variations in saturation can result in large changes in fractional flow and deliverability - depending upon whether drainage or imbibition conditions apply. Tight gas petrophysical studies must go beyond volumetrics and should consider both static (storage) and dynamic (flow) properties within the context of the petroleum system and the evolution of the current day pore geometry and fluid saturation distribution.
New Method for Inferring Fracture Aperture and Matrix Permeability Simultaneously Using Spontaneous Imbibition Data
Authors: Lu Juhong , Cheng Changhui , Li Kewen 
Published: January 2013

Abstract
It has been found experimentally that the relationship between the imbibition rate and the reciprocal of recovery by spontaneous water imbibition has two linear parts in rocks with fractures but has only one linear part in rocks without fractures. One of the two linear parts may represent the fracture property and the other may represent the matrix or the set of smaller fractures. A method to infer the effective fracture aperture (or permeability) and the matrix permeability simultaneously has been developed using the experimental data of spontaneous water imbibition in gas-saturated (dried) rocks. The mathematical model has been derived theoretically based on the fundamental laws of fluid flow in porous media. These include Darcy's law, material balance, and continuum equation. The theoretical model characterizes the relationship between imbibition rate and the reciprocal of recovery in both fractures and matrix. Several spontaneous water imbibition experiments have been conducted in rocks with different permeability, with and without fractures. Experiments have also been conducted in coal samples with fractures because of the importance in the production of coal bed methane. The values of the effective fracture aperture and matrix permeability of the core samples were inferred using the mathematical model derived in this study.
Applying Petrophysics and Systematic Completion Science to Increase Potential: A Terryville Field Tight Gas Case History
Authors: Modeland N.. , Buller D.. , Middaugh R.. , Wyszynski J.. , Sumrow H.. , Eckerman S.. , Graham J.. 
Published: January 2013

Abstract
Few unconventional plays become successful by accident. Relying solely on what has historically been performed to dictate completion development without using resources available to gather the necessary petrophysical information about a play can often lead to disappointing production results. Misinterpreting well results can potentially lead to incorrect assumptions, which can require years to rectify. In the Terryville field of northern Louisiana, which is home to several productive tight gas sandstone layers, determining the correct development strategy was crucial to the economic sustainability for one emerging operator. By investing research, time, and money into the front end of the play’s development, a strategic plan was deployed that allowed an entire field (which might have only looked marginally economic in a favorable gas price environment initially) to be a profitable success story, even during a time of decreasing North American gas prices. By resurrecting old well logs for new rock model analysis, new insight was obtained from the field without any additional expense for drilling and logging operations. Some new vertical well logs were acquired as well, which helped fill in data gaps across the field. The information gleaned from these petrophysical rock models revealed potential in targets that might have otherwise been overlooked or regarded as uneconomical. Some of these targets proved worthy of lateral completions and have produced results that outperform many of the wells in the nearby Haynesville shale gas play. With a better understanding of the reservoir rock mechanics, decisions have been made more confidently about both well construction (where to land and in what direction) and well completions (how to stimulate for optimal results). By continually calibrating and improving the rock modeling of the field using post-completion science (i.e., tracer logs and pressure matching), the knowledge of the reservoir continues to be refined. This case history details the technology examples and resultant production that continue to make the Terryville field a success.
Challenges to Geosteering and Completion Optimization of Horizontal Wells in the Cotton Valley Formation, East Texas
Authors: Liu S.. , Lucas J. L. , Plemons P. A. , Zhou X.. , Zett A.. , Spain D. R. , Rabinovich M.. , Pour R. A. , Zhou Q.. 
Published: January 2013

Abstract
Cotton Valley tight gas sands in the east Texas Basin of North America consist of very fine-grained, well-sorted quartz arenites and subarkoses that are overprinted by significant diagenetic processes. Stratigraphic variations in rock type control gas production. Hydraulic fracturing delivers economic gas production.
Recently, horizontal wells over 4,000 ft long consisting of more than twelve hydraulic fracturing stages have been drilled. The good gas producing rock type reservoirs are usually less than 14 ft thick and exhibit strong diagenetic overprint. Low gas prices challenge the use of sophisticated geosteering logs. Using a very basic Gamma Ray (GR) log and very limited offset pilot well data, chasing such thin and variable sand bodies over a distance of 4,000 ft in a marginal marine sedimentary environment is daunting. Apart from this, horizontal wells that target thin layers present unique challenges to completion optimization.
Quad-combo log data, including azimuthal density image data, was acquired using a Logging While Drilling (LWD) tool. Extensive log modelling was performed by combining the horizontal well logs with logs from its two offset vertical wells, and consistent interpretation was achieved. Log modelling has helped the post-drill well diagnosis in geosteering, completion design, and production performance. It has also supported formation evaluation.
This paper will highlight an integrated study workflow in tight gas sands using open-hole and cased-hole data. It will demonstrate the geosteering challenges, explain the log modelling process, and display the formation evaluation results. Geomechanical study, together with hydraulic fracturing data and production log data will be used to confirm that good gas producing rock types are easier to fracture, and they contribute better to production.
Eagle Ford Shale Well Control: Drilling and Tripping in Unconventional Oil and Gas Plays
Authors: Ridley K.. , Jurgens M.. , Billa R. J. , Mota J. F. 
Published: January 2013

Abstract
In late 2010, Shell began an Eagle Ford appraisal program at Piloncillo Ranch in South Texas. These wells are 8,500’ – 9,500’ TVD horizontals, with an average total depth of 14,500’ MD. Their primary target is the Cretaceous Eagle Ford shale. The Shell leases are located in the gas-condensate window. Shell is currently running a five rig development program. Initially, reservoir pressures were thought to be in the 12.5 ppg range, but Diagnostic Fracture Injection Tests (DFITs) showed the actual pore pressure to be greater than or equal to 14 ppg.
Initially, underbalanced drilling techniques were used to drill the 14-14.5 ppg formation with 11 ppg oil based mud. The Eagle Ford has no natural fractures in this area. As more wells were drilled, however, completion fracturing of offset wells began to cause well control problems, as induced fractures were encountered in horizontal sections during drilling. Initially, it was thought that additional casing strings would be required to deal with the higher pressures and flow capability of the 14-14.5 ppg fracture; however, through well control modeling and experience with underbalanced drilling in other tight gas environments, tripping and heavy pill spotting procedures were developed that allowed the wells to be drilled with the initial casing program.
This paper will describe the development of fit for purpose well control techniques used to drill underbalanced horizontal wells in the Eagle Ford shale gas play. It will discuss how the characteristics of tight shale formations in horizontal wells resulted in a different approach to well control and tripping procedures. Several simple techniques for establishing an understanding of real time data have helped to make decisions in the field with current information: Institute a dual density system to stop reservoir flow and prevent up-hole lossesCreate a Horner Plot for distinguishing ballooning from reservoir flow if losses are experiencedCreate a mud weight vs. influx flow plot for predicting flow changes with mud weightAscertain how the influx rate and location affect the time at which it would a take a well to unload to dry gas
The paper will also describe the software modeling used to determine influx responses and the methodology developed around it. This methodology is applicable to other tight shale formations drilled horizontally and developed around the globe. These procedures can significantly reduce non-productive time and minimize serious well control events on horizontal shale wells when properly followed.
Sensitivity Analysis on Parameters Affecting the Thickness of the Gas Hydrate Zone in the Gulf of Oman
Authors: Afazeli Erfan , Gerami Shahab , Badakhshan Amir 
Published: January 2013

Abstract
According to a recent seismic survey in the Gulf of Oman (GOO), hydrate bearing layers were detected through observation of significant bottom simulating reflector (BSR), flat spot and bright spot attributes. In addition, favorable geological conditions indicate possibility of gas hydrate formation in this region. Quantification of the hydrate resource using geological and geophysical techniques, while continuously improving is subject to very large uncertainties. Uncertainty associated with estimation of the thickness of the gas hydrate stability zone (GHSZ) is a source of error in prediction of the volume of hydrate-bound gas and gas production from gas hydrate reservoirs. In this paper we present a conceptual model of the thickness of the GHSZ varying over a wide range of input variables within the study area and use it along with sensitivity analysis to quantify the impact of these variables on the thickness of the GHSZ in the gas hydrate accumulations of the GOO. Using Milkov and Sassen's model, the thickness of the GHSZ is modeled on the basis of the GOO region properties for three kinds of gas hydrates with gas composition containing 100% methane, 95% methane and 90% methane. The results of sensitivity analysis show that geothermal gradient is the most effective parameter changing the thickness of the GHSZ, then seabed temperature and gas composition have the greatest impact, respectively. Furthermore, the results reveal that gas composition has indirect impact on the degree of influence of other parameters. Evaluating the source of the gas in the GOO, particularly at the beginning of the life of the reservoir which very limited information is available for engineering calculations is the usefulness of this sensitivity analysis.
Support Vector Machine Model: A New Methodology for Stuck Pipe Prediction
Authors: Chamkalani Ali , Pordel Shahri Mojtaba , Poordad Saeed 
Published: January 2013

AbstractStuck pipe is a common worldwide drilling problem, resulting significant increases in non-productive time and overall well cost. Many oil and gas reservoirs are mature and are becoming increasingly depleted of hydrocarbons which make stuck pipe more severe risks. This is due to the fact that decreasing pore pressure increases the chance of stuck pipe. Minimizing the risks of stuck pipe while drilling has been the goal of many operators recently. This paper describes a robust support vector regression (SVR) methodology that offers superior performance for stuck pipe prediction either mechanically or differentially using available drilling parameters. A new model is developed using drilling parameters such as measured depth, mud weight, plastic viscosity, yield point, gel strengths, PH and solid percent from different wells. The method incorporates hybrid least square support vector regression and Coupled Simulated Annealing (CSA) optimization technique (LSSVM-CSA) for efficient tuning of SVR hyper parameters. The algorithm is applied to classify the stuck types, i.e., differential stuck or mechanical stuck. Performance analysis shows that LSSVM classifier has high accuracy. Using intelligent system would help drilling industry to reduce Non-Productive Time (NPT) during operation in complex zones.
Cycloidal algebras
Authors: Han Jeong , Kim Hee , Neggers J. 
Published: January 2013

Abstract
In this paper we introduce for an arbitrary algebra (groupoid, binary system) (X; *) a sequence of algebras (X; *)n = (X; ∘), where x ∘ y = [x * y]n = x * [x * y]n−1, [x * y]0 = y. For several classes of examples we study the cycloidal index (m, n) of (X; *), where (X; *)m = (X; *)n for m > n and m is minimal with this property. We show that (X; *) satisfies the left cancellation law, then if (X; *)m = (X; *)n, then also (X; *)m−n = (X; *)0, the right zero semigroup. Finite algebras are shown to have cycloidal indices (as expected). B-algebras are considered in greater detail. For commutative rings R with identity, x * y = ax + by + c, a, b, c ∈ ℝ defines a linear product and for such linear products the commutativity condition [x * y]n = [y * x]n is observed to be related to the golden section, the classical one obtained for ℝ, the real numbers, n = 2 and a = 1 as the coefficient b.
Groups of homeomorphisms on C(X) and pointwise limits
Authors: McCoy R. 
Published: January 2013

Abstract
This study looks at some subgroups of the group H(C(X)) of homeomorphisms on the space C(X) of continuous real-valued functions on a topological space X, where C(X) has the compact-open topology. The main result shows that, for certain spaces X, the subgroup of H(C(X)) generated by the algebraic and vertical homeomorphisms on C(X) is dense in H(C(X)) with the pointwise topology. Also, for X equal to the unit interval, a subgroup of H(C(X)) is developed using integration of the members of C(X), and this subgroup is used as an example and to illustrate certain properties that subgroups of H(C(X)) can have.
Composition, Temperature and Frequency Dependent Magnetic, Dielectric and Electrical Properties of Magnesium-Zinc Ferrites
Authors: Rahman M Mahbubur , Sheak Md Shahin , Pervin Soheli , Uddin Nasir , Ahmed Farid , Hossain Md Abul , Rahaman Mashudur , Bashar M Shahriar , Hossain Tofazzal , Akhter Shireen 
Published: January 2013

Polycrystalline spinel MgxZn0.3Cu0.7-2xFe2+xO4, where x = 0.10, 0.20, 0.25, 0.30 and 0.35 ferrites (hereafter abbreviated as Mg-Zn) have been prepared by conventional double sintering technique. The samples were sintered at 1250°C in air for 6 hours. Measurements have been done at temperature and frequency ranges of 0 - 350°C and 0 - 500 kHz, respectively. In this work, some extrinsic magnetic properties such as Curie temperature, initial permeability, loss factor, quality factor, dielectric constant and resistivity of the samples have been studied. The Curie temperature and loss tangent of the samples decreased with increase in Cu-content whereas permeability, Qfactor, resistivity and dielectric constant have been noticed to be increased with the increase in Cucontent. The decrease in Curie temperature related to fact of weakening the strength of exchange AB interaction. Maxwell-Wagner type of interfacial polarization might have found correlated with the normal dielectric behavior of the samples, however no relaxation peaks were observed in the dielectric dispersion curves of the Mg-Zn samples in virgin state or doped state. DOI: http://dx.doi.org/10.3329/jbas.v36i2.12963 Journal of Bangladesh Academy of Sciences, Vol. 36, No. 2, 199-212, 2012
Substrate Temperature Effect on the Structural and Optical Properties of Znse Thin Films
Authors: Bhuiyan M R A , Miah M A H , Begum J 
Published: January 2013

Zinc selenide (ZnSe) thin films were deposited on to chemically and ultrasonically cleaned glass substrates at different substrate temperatures from room temperature to 200°C keeping the thickness fixed at 300 nm by using thermal evaporation method in vacuum. The structural properties of the films were ascertained by X-ray diffraction (XRD) method utilizing a diffractometer. The optical properties were measured in the photon wavelength ranging between 300 and 2500 nm by using a UV-VIS-NIR spectrophotometer. The XRD patterns reveal that the films were polycrystalline in nature exhibiting f.c.c zincblende structure with average lattice parameter, a = 5.6873Å. The grain size, strain and dislocation densities of the films have bee calculated. The optical transmittance and reflectance were utilized to compute the absorption coefficient, band gap energy and refractive index of the films. The band gap energy of the films was extracted from the absorption spectra. The direct band gap energy of the films slightly increases with substrate temperature.DOI: http://dx.doi.org/10.3329/jbas.v36i2.12969Journal of Bangladesh Academy of Sciences, Vol. 36, No. 2, 233-240, 2012
Reid, Thomas
Authors: Cuneo Terence 
Published: January 2013

AbstractThomas Reid (1710–96) defended the view that there is a plurality of moral first principles which are self‐evident to the conscientious agent. Reid further claimed that these moral principles are not part of the natural order described by science. It is because of these commitments that Reid's view is often described as a version of moral intuitionism (seeIntuitionism, Moral). While not inaccurate, this description conceals important ways in which Reid's view differs from that of later intuitionists, such as W. D. Ross (seeRoss, W. D.). For, unlike Ross, Reid's defense of moral intuitionism appeals primarily to the nature of science and human agency. Only if we have a proper understanding of both these subjects, Reid argues, can we develop a satisfactory theory of morals.
Recognition
Authors: Williams Robert R. 
Published: January 2013

AbstractPaul Ricoeur points out that no theory of recognition exists in the way that one or more theories of knowledge or truth exist. This absence of theoretical insight stands in contrast to the coherence that allows the word “recognition” to appear in a dictionary as a single lexical unit. Lest anyone think that the term “recognition” has some obvious coherent sense, Ricoeur asks, “What do Kant's synthesis ofrecognitionin transcendental deduction, Bergson's account ofreconnaissanceas the mnemonic act par excellence, and Hegel's account ofAnerkennenas a process that culminates in an ‘I' that is a ‘We' have in common?” (2005: 18).
Microsurgical anatomy of the infratemporal fossa
Authors: Joo Wonil , Funaki Takeshi , Yoshioka Fumitaka , Rhoton Albert L. 
Published: January 2013

AbstractThe objective of this study is to clearly and precisely describe the topography and contents of the infratemporal fossa. Ten formalin‐fixed, adult cadaveric specimens were studied. Twenty infratemporal fossa were dissected and examined using micro‐operative techniques with magnifications of 3–40×. Information was obtained about the inter‐relationships of the contents of the infratemporal fossa. The infratemporal fossa lies at the boundary of the head and neck, and the intracranial cavity. It is surrounded by the maxillary sinus anteriorly, the mandible laterally, the pterygoid process anteromedially, and the parapharyngeal space posteromedially. It contains the maxillary artery and its branches, the pterygoid muscles, the mandibular nerve, and the pterygoid venous plexus. The course and the anatomic variation of the maxillary artery and the branches of the mandibular nerve were demonstrated. The three‐dimensional (3D) relationships between the important bony landmarks and the neurovascular bundles of the infratemporal fossa were also shown. The skull base anatomy of the infratemporal fossa is complex, requiring neurosurgeons and head and neck surgeons to have a precise knowledge of 3D details of the topography and contents of the region. A detailed 3D anatomic knowledge is mandatory to manage benign or malignant lesions involving the infratemporal fossa without significant postoperative complications. Clin. Anat., 2013. © 2013 Wiley Periodicals, Inc.
Protoporphyrin IX/Cobyrinate Derived Hybrids – Novel Activators of Soluble Guanylyl Cyclase
Authors: Chromiński Mikołaj , ó Proinsias Keith , Martin Emil , Gryko Dorota 
Published: January 2013

AbstractCobyrinate/protoporphyrin IX molecular hybrids were prepared through application of the CuOAc catalyzed azide‐alkyne cycloaddition (CuAAC) "click" reaction. The synthesis involved selective preparation of cobyrinate and PpIX derived building blocks possessing respectively terminal alkyne and azide moieties, followed by a CuOAc catalyzed cycloaddition reaction. Synthesized molecules activated soluble guanylyl cyclase and showed strong linker‐length/activation dependence.