bluuebunny/crossref_metadata_2025_split huggingface dataset:
Factors Affecting the Financing Policy of Commercial Banks in Ethiopia
Authors: Shibru W/Michael , Kedir Hamdu , Mekonnen Yonas 
Published: March 2016

Determining the optimal capital structure is one of the most fundamental policy decisions faced by financial managers. Since optimal debt ratio influences firm’s value, different firms determine capital structures at different levels to maximize the value of their firms. Thus, this study examines the relationship between leverage and firm specific (profitability, tangibility, growth, risk, size and liquidity) determinants of capital structure decision, and the theories of capital structure that can explain the capital structure of banks in Ethiopia. In order to investigate these issues a mixed method research approach is utilized, by combining documentary analysis and in-depth interviews. More specifically, the study uses twelve years (2000 - 2011) data for eight banks in Ethiopia. The findings show that profitability, size, tangibility and liquidity of the banks are important determinants of capital structure of banks in Ethiopia. However, growth and risk of banks are found to have no statistically significant impact on the capital structure of banks in Ethiopia. In addition, the results of the analysis indicate that pecking order theory is pertinent theory in Ethiopian banking industry, whereas there are little evidence to support static trade-off theory and the agency cost theory. Therefore, banks should give consideration to profitability, size, liquidity and tangibility when they determine their optimum capital structure.
C1 Lateral Mass Screw Migration Causing a Delayed Unilateral Hypoglossal Nerve Lesion
Authors: Hollern Douglas , Shafi Karim , Miller Andrew , Woods Barrett , Heller Joshua , Vaccaro Alexander 
Published: March 2016

Case:
We present the case of a fifty-eight-year-old woman who was initially treated with a C1 to C7 anterior-posterior cervical decompression and fusion for an epidural abscess and returned two years postoperatively with four days of progressive dysphagia and tongue deviation. She was diagnosed with a unilateral hypoglossal nerve (cranial nerve XII) palsy secondary to compression from a C1 lateral mass screw.

Conclusion:
This is the first reported case that we are aware of describing a delayed cranial nerve palsy secondary to cutout and cephalad migration of a C1 lateral mass screw resulting in a neurologic deficit due to impingement on the hypoglossal nerve.
The Design, Development, and Testing of a Standardized Treatment System for Oilfield Brines
Authors: Kohler T. E. , Heckman S. W. , Watson R. W. , Adewumi M. A. , Rabosky J. G. 
Published: March 2016

ABSTRACT
The petroleum industry in the eastern United States is dominated by a large number of independent producers. In Western Pennsylvania alone, there are about 1000 producers who operate 45,000 wells. Although most of the producers are small independent businesses, they provide a majoreconomic base for many of the state's counties. In addition to the current economic situation in the oil and gas industry resulting from the decline in crude oil prices, it is anticipated that additional economic duress would result from the necessity to comply with National PollutantDischarge Elimination System (NPDES) discharge standards and Clean Streams Law Part II Water Quality permit requirements.
The standardized oil field brine treatment process addressed by this research was designed to meet certain discharge criteria set by DER. The treatment process consists of several sequential unit operations: oil-water separation, aeration and pH adjustment, settling, secondary aeration, and filtration. A comprehensive chemical analysis of the input and effluent streams was conducted to determine the effectiveness of the treatment process.
Results indicate the capability of the process to adequately address the problem of oil field brine treatment. The treatment facility is being field tested. In addition to the field testing of the facility, a mathematical model has been developed for scale-up purposes and is being tested using the inputs form the field test.
Field Verification of Lead Angle and Azimuth Rate of Change Predictions in Directional Wells Using a New Mathematical Model
Authors: Maidla E. E. , Sampaio J. H. B. 
Published: March 2016

ABSTRACT
A general rock-bit interaction model was developed to determine the bit walk-rate and the best estimate of the lead angle required while kicking off a directional well.
The model was used by a computer program and was validated using the data from 15 directional wells drilled in the offshore Campos Basin area in Brazil. The results showed that the bit walk predictions were good for most of the well trajectories. Due to lack of the appropriate geological information on the history wells, additional field examples are necessary to further validate the model. The results on the lead angle computations showed that it is possible, sometimes, to avoid direction corrections through the appropriate prediction of this angle.
The Effect of Wettability on Estimation of Reserves
Authors: Cockcroft P. J. , Guise D. R. , Waworuntu I. D. 
Published: March 2016

ABSTRACT
Estimations of reserves, especially by the volumetric method, is usually undertaken assuming water-wet conditions. However, in South East Asia, some initial reserves estimates have been grossly overestimated. One of the reasons for this, particularly in carbonates reservoirs of this region, is the effect of different wettabilities. Reserves estimation is important at any stage in the production cycle, but in frontier regions such as in South East Asia where initial production costs can be very high, care must be taken. This wettability effect can manifest itself in the form of 100 % oil-wet or mixed or fractional wettability. Petrophysical data is of primary importance to the estimation of volumetric reserves, and an examination of different wettabilities on log and core results is undertaken. The effect of wettability on saturation exponent, cementation exponent and formation factor commonly overlooked until the reservoir production is mature. Capillary pressure and relative permeability can be changed quite substantially with different wetting phases, with subsequent influences on transition zone height, hydrocarbon-water contacts, producibility and residual oil saturation. These changes are discussed with examples from different reservoirs. Reserves estimation is also undertaken by decline curve analysis, material balance, and at times, reservoir simulation. The effects of different wettabilities on these methods of reserves estimation are examined and presented.
Bambra 3: An Innovative Drilling/Construction Project
Authors: Rampling R. J. , Miller R. L. 
Published: March 2016

ABSTRACT
Development of previously marginal fields in the Carnarvon sedimentary basin in Western Australia has been made possible by the use of monopod production platforms. The Bambra 3 project sought significant cost reduction through integration of the construction and drilling activities. During the project a method of fast installation of piles was developed and tested.
Introduction of Subsea Cuttings Disposal System for Drilling of Riserless Tophole Section on Subsea Templates
Authors: Tungesvik S. , Knutsen S. 
Published: March 2016

Abstract
Accumulation of drill cuttings from predrilling subsea template wells often require subsea dredging before the platform jacket may be installed, such location clean up work is time and cost consuming. The development of a subsea disposal system designed to transport the cuttings away from the subsea template for disposal outside the future jacket installation area, has proven to be a successful development seen both from a technical and an economical point of view.
Developing a Platform Strategy and Predicting Torque Losses for Modeled Directional Wells in the Amauligak Field of the Beaufort Sea, Canada
Authors: Lesso W. G. , Mullens E. , Daudey J. 
Published: March 2016

Abstract
Nine exploration wells drilled by Gulf Canada Resources Ltd. have defined the Amauligak Field in the Beaufort Sea, Canada as being roughly 3 by 12 kilometers in size. An oblong offshore field like this normally would be developed with several platforms. Due to the expense of development structures in the Arctic, it is worthwhile to evaluate drainage of the field from a single platform with extended reach wells. Previous experience gained from the directional wells in the field highlighted problems with excessive drill string torque. This led to concern that the planned extended reach wells would be beyond normal driliability. An accurate prediction of torque losses for these planned wells was necessary to prove the feasibility of the single platform concept.
This paper demonstrates a technique used to predict the total torque losses expected in drilling directional wells. It is based on an analysis of expected drill string side-forces using field derived friction data which has been documented in previous papers (1,3,4). To successfully predict losses on future wells, a simulation of possible corrections to the directional plan, sidetracks and dog-leg severity must be added to the original directional plan. The method described here, simulates survey data with variations on inclination and azimuth that are matched to the corrections and dog-leg severity found in the nearby wells., These effects can increase torque losses by up to 70% above the "ideal" plan.
A 50 well scenario was developed for the field from a 60 slot platform. Ideal directional plans were made and then altered to minimize collision possibilities. A design case directional path with corrections and dogleg severity was simulated, applied to the ideal plan and associated torque losses predicted. The value of these losses were used to size drill string components and top drive equipment. The results of this study demonstrated the feasibility of using a single platform to develop the field.
Field Measurement of Strain and Temperature While Running and Cementing Casing
Authors: Morgan D. R. 
Published: March 2016

Abstract
One of the problems arising from the reservoir: compaction and subsidence of the Ekofisk field is casing deformation. In order to better understand the stresses in the casing as the result of subsidence, strain gauges were run on the 9-5/8 in. (244mm) casing of a deviated well at Ekofisk.
Three sets of sensors spaced at appropriate intervals were run. Each set of sensors included four strain gauges oriented to measure axial strain, four strain gauges oriented to measure radial strain and a temperature gauge. A measure of annulus pressure variations can be inferred from the radial strain measurements, since the pressure inside the casing was known. Bending stresses due to running casing in a deviated well are shown by an increase in the tension measured by one axial gauge and a decrease in tension at the diametrically opposing gauge.
Measurements were made showing the temperatures and stresses in the casing while the casing was being run in the well, while circulating prior to cementing, and during and after cementing the casing. This data shows the forces acting on a casing while running through doglegs and the stresses which occur due to the rapid changes in temperature and pressure during and after cementing. The temperature and pressure changes which occur while cement cures were also measured.
High-Temperature Performance of Rotary-Shouldered Connections
Authors: Maney J. J. , Strozier C. A. 
Published: March 2016

ABSTRACT
High temperature make-up and break-out tests were conducted on full size 6–1/4" (15.88 cm) OD × 2–3/4" (6.99 cm) ID NC46 rotary shouldered connections to determine changes in performance between room temperature and 500°F (260°C).
The tests measured the slope of the torque vs. rotation curve and the torque required to initiate additional circumferential movement after the tool joint connection had been made up to 20.500 Ibf–ft (27.794 N-m) make-up torque at room temperature (move torque).
Results of room temperature tests indicated that the move torque was essentially equal to the make-up torque and the slopes of the torque vs. rotation curves were similar.
High temperature tests produced significantly different results. A used connection was torqued to 48,200 Ibf–ft (65.350 N-m) without failure, while a new connection only reached a maximum torque of 25.600 Ibf–ft (34.709 N-m) before failure; a value which is significantly less than the API torque to yield value of 44.871 Ibf–ft (60.837 N-m).
It was found that increased thread interference from the rough surface finish typically found oh the thread flanks of "used" connections was responsible for the change in performance. The problem of downhole make-up was successfully overcome in the field by implementation of new break-in procedures and through use of a special high temperature thread compound. This compound was developed to increase the coefficient of friction at high temperatures in new connections to provide additional resistance to downhole make-up during the critical break-in period.
Estimation of Pressure Peaks Occurring When Diverting Shallow Gas
Authors: Santos O. L. , Bourgoyne A. T. 
Published: March 2016

ABSTRACT
A model diverter system was constructed on a 381 m (1250 ft) well to experimentally study dynamic loads occurring during a shallow gas flow. Numerical methods for calculating diverter design loads were developed and verified using experimental data obtained. Surface pressures occurring as the mud is expelled from the well were found to be significantly higher than the steady-state pressures previously used to select the working pressure of diverter components.
Composite Cutter Bits Extend Application Range of Conventional PDC Bits in Western Canada
Authors: Schnell D. M. 
Published: March 2016

ABSTRACT
While polycrystalline diamond compact (PDC) bits have been used successfully in Western Canada, they have lacked consistency in many applications. Even when they performed better than conventional roller cone bits, PDC bits were not always an economic success, clearly indicating that development of new cutter technology was required to improve the consistency and economics of synthetic diamond bit performance.
Combining many thermally stable synthetic diamond cutters into a composite cutter, also known as a Mosaic cutter, was a novel approach in drill bit cutter technology. However, the method of cutter manufacture had to be refined in order to make full use of the concept. The resulting drill bits, which use a combination of PDC and composite cutters, have proved successful in extending the PDC bit application in at least one lithological section.
Xls: A New Shale Parameter for Resistivity Log Evaluation
Authors: Hardwick A. 
Published: March 2016

ABSTRACT
Excess conductivity in shaly sandstones complicates the interpretation of resistivity logs for water saturations. A new laboratory procedure has been developed to provide rapid, yet highly accurate assessment of excess conductivity effects in core samples. The basis of the technique is conductivity measurements on samples saturated with dilute brine.
Enhancing Through-Tubing Formation Evaluation Capabilities with the Dual-Burst Thermal Decay Tool
Authors: Jeckovich G. T. , Olesen J-R. 
Published: March 2016

ABSTRACT
The determination of hydrocarbon saturation through tubing and/or casing requires an accurate knowledge of formation capture cross section and porosity. In many cases an openhole porosity log is not available and the presence of tubing prevents running a compensated neutron porosity tool into the borehole.
The Dual-Burst* TDT service has recently been enhanced to provide a real-time wellsite value of the formation porosity. This neutron porosity is based on the ratio of capture gamma rays accumulated in selected gates late after the long burst in the near and far detectors. Corrections are performed for borehole status (open or cased); borehole size; and for borehole and formation fluid salinities, obtained internally from the borehole and formation thermal neutron decay rates. The environmentally corrected ratio is then transformed into porosity according to one of three lithology-dependent transforms. A laboratory data base consisting of more than 750 different cases covering a wide range of porosities, borehole geometries, lithologies, formation and borehole fluid salinities has been analyzed to establish the porosity algorithm. Field examples are presented to compare this new porosity to openhole neutron porosity data over a wide range of borehole conditions.
Previous publications have demonstrated that the Dual-Burst TDT formation capture cross-section measurement is accurate and independent of standard borehole conditions. In this paper, we demonstrate through the use of examples that the appropriate choice of the neutron pulsing and gating scheme and the use of the diffusion model extend the validity of the formation capture cross-section measurement to areas where it has been questionable in the past. More precisely, examples are shown of logs recorded before and after gravel packing operations, through drillpipes and in concentrical casings. The effect of a large cement annulus, as well as the absence of cement, is studied in known laboratory test formations.
Resistivity Index and Capillary Pressure Measurements Under Reservoir Conditions Using Crude Oil
Authors: Longeron D. G. , Argaud M. J. , Bouvier L. 
Published: March 2016

ABSTRACT
Experimental data of resistivity index and oil-brine capillary pressure on sandstone and carbonate rock samples from 4 reservoirs are reported. Laboratory equipment using actual fluids at reservoir conditions has been developed. The capillary drainage was achieved with the porous-plate method and fluid saturation along the core was checked for uniformity by conductivity measurements with a four-electrode system. For each rock sample, the resistivity index and capillary pressures were measured first with refined oil and then with crude oil. In addition, wettability indices were determined using Amott's tests. The resistivity/water-saturation law is well fitted by Archie's law except for vuggy carbonates. In this case, the resistivity/water-saturation plot consisted in two straight line segments in log-log coordinates. The Archie's n-exponent values obtained with crude oil were different than those determined with refined oil except in one case. The n-value increases as the rock becomes more oil-wet. The maximum increase of n-value, from 1.68 to 2.19, was observed for one carbonate, initally neutral and becoming oil-wet during drainage with the crude oil.
Thin Oil Columns: Most People Think Horizontal Wells, Obagi Field Case Suggests the Contrary
Authors: Chugbo A. I. , Roux G. D. , Bosio J. C. 
Published: March 2016

ABSTRACT
The OBAGI Field is situated onshore NIGERIA. Among the numerous productive layers, one is a thin 36 ft thick disk-shaped oil column. This unconsolidated deltaic sand is produced, making the best possible use of the natural geological features to limit gas and water coning. Permeability is 2 darcys and bottom hole oil viscosity 0.8 cp.
In that area, such an oil disk is considered as almost impossible to produce economically, because of immediate coning problems.
In fact, in this type of sand, it is our experience that shaly streaks are always present. If they can be accurately located it is always possible to position the perforations so that they are adequately protected from early invasion by water and gas.
Some wells can produce up to 3500 bbl/day, that is 10 times more than the theoritical critical rate derived from Darcy's law in a supposed homogeneous sand.
This shows that although shale interbeds cannot be correlated from one well to the other, their abundance is such that as one disappears laterally, another one develops not far above or below it: this results in a low vertical permeability and limits coning.
Shale lamination is difficult to pick up on the logs, and even the Gamma ray can be misleading as a shale indicator. Fortunately, some other tools have a good vertical resolution and proved very useful in detecting shale streaks.
An interesting feature of this field is that a horizontal well, now expected by some people in the industry to be the best way to produce a thin layer of unconsolidated sand with a coning problem, would probably not be as successful in OBAGI because of the low vertical permeability.
In fact, ELF NIGERIA has already recovered 21 × 106 bbl of oil (that is 19 % of the original oil in place), and expects to obtain a final recovery of 30 %.
Why Waterflood Works: A Linearized Stability Analysis
Authors: King M. J. , Dunayevsky V. A. 
Published: March 2016

ABSTRACT
The stability of the transient waterflood problem has been examined. The treatment includes both the effects of relative permeability and of capillary pressure. The analysis is formulated for a Buckley-Leverett type base state, although with capillary corrections. This base state is obtained for arbitrary water/oil relative permeabilities and capillary pressure functions, using the method of matched asymptotic expansions.
The stability analysis is performed in a coordinate system co-moving with the base state; the transformation is a combined stretching and uniform translation in position. The growth rate of a perturbation is found to depend upon both the spatial position and the time of initiation of the instability. The long and short wavelength asymptotics are obtained analytically, the latter using a WKB-type approach. Finite wavelength stability is studied numerically.
The pertubration evolution is found to be a competition between a temporal algebraic instability and an exponential decay, in regimes of practical interest. The success of waterflood can be understood since the algebraic instability remains finite at all wavelengths (short wave growth rates are independent of wavelength), in distinction to the strong exponential instability exhibited by an adverse mobility miscible flood. Essentially, the stretching of the Buckley-Leverett base state is as fast as the growth of the instability, changing the exponential instability to an algebraic one. For highly adverse mobility ratio immiscible floods, the exponential instability remains, although it is spatially localized due to the effects of relative permeability.
The method of analysis is also applied to the motion of a steady state solution, with relative permeability and capillary pressure, for comparison to the results of previous researchers. An exponential instability arises, instead of the temporal instability, demonstrating the inadequacy of such base states for the examination of waterflood stability.