Determination of the suitable drilling operating parameters in different geological formations El-Sharara Oil Field (South-Western Libya)

Purpose. The objective of this study is to determine the best operating conditions for the most notable drilling parameters (i.e. weight on bit (WOB), rotary drilling speed (RPM), and characteristics of drilling fluid) using field data obtained from El-Sharara Oil Field. Methods. The used data has been extracted from daily drilling reports of well named (NC-186/K04h) field. Such data contains information about the geological formations, casing strings, drill-bits, fuel consumption, flow rate of drilling fluid and other drilling parameters. Findings. The results reveal that, the lower geological formations of El-Sharara Oil Field, the harder are the upper formations. Therefore, it is recommended to apply heavy loads (i.e. WOB of 45000 lb) with low drilling speed (i.e. 100 rpm) in the lower formations; and to apply small loads (i.e. WOB of 19000 lb) with high drilling speed (i.e. 160 rpm) in the upper formations. Originality. This study evaluates the performance of drilling operation based on the interaction between rock formations and machine drilling parameters. Practical implications. Understanding such interaction between rock formations and machine drilling parameters will remarkably improve the rate of penetration (ROP) in the related geological formations. Consequently, the overall drilling costs will be reduced in terms of drilling time, life of drill-bit and fuel consumption.Мета. Визначення оптимальних експлуатаційних умов для технологічних параметрів буріння – осьового навантаження на долото (ОНД), швидкості обертального буріння (ШOБ), характеристик бурового розчину на основі емпіричних даних, отриманих на нафтовому родовищі Ель-Шарара. Методика. У роботі вивчені та систематизовані дані експлуатації нафтової свердловини NC-186/K04h, що містять інформацію про геологічні формації родовища, обсадних колонах, бурових коронках, витрат палива і бурової рідини та інших параметрах буріння. Результати. Дослідження показало, що, чим нижче розташовані нафтоносні геологічні формації Ель-Шарара, тим міцніше породи верхніх формацій. Рекомендовано застосовувати велике навантаження (ОНД – близько 104 кг), при низькій ШOБ (100 об/хв) у нижніх формаціях; і мале навантаження (ОНД – 86 кг) при високій ШOБ (160 об/хв) – у верхніх формаціях. Встановлено кореляційний взаємозв’язок комплексу технологічних параметрів буріння з умовами геологічних формацій родовища. Наукова новизна. Для умов нафтового родовища Ель-Шарара дана наукова оцінка ефективності буріння на основі встановлення взаємозв’язку параметрів формацій і бурових установок. Практична значимість. Врахування взаємозв’язку геологічних формацій і параметрів механічного буріння дозволить суттєво підвищити швидкість проходки свердловин, при цьому загальні витрати на буріння будуть скорочені за рахунок зменшення часу буріння, споживання палива та збільшення терміну служби бурових коронок.Цель. Определение оптимальных эксплуатационных условий для технологических параметров бурения – осевой нагрузки на долото (ОНД), скорости вращательного бурения (СВБ), характеристик бурового раствора на основе эмпирических данных, полученных на нефтяном месторождении Эль-Шарара. Методика. В работе изучены и систематизированы данные о эксплуатации нефтяной скважины NC-186/K04h, которые содержат информацию о геологических формациях месторождения, обсадных колоннах, буровых коронках, расходе топлива и буровой жидкости, а также других параметрах бурения. Результаты. Исследование показало, что, чем ниже расположены нефтеносные геологические формации Эль-Шарара, тем тверже породы верхних формаций. Рекомендуется применять большую нагрузку (ОНД – около 104 кг), при низкой СВБ (100 вр/мин) в нижних формациях; и малую нагрузку (ОНД – 86 кг) при высокой СВБ (160 вр/мин) – в верхних формациях. Установлена корреляционная взаимосвязь комплекса технологических параметров бурения с условиями геологических формаций месторождения. Научная новизна. Для условий нефтяного месторождения Эль-Шарара дана научная оценка эффективности бурения на основе установления взаимосвязи параметров формаций и буровых установок. Практическая значимость. Учет взаимосвязи геологических формаций и параметров механического бурения позволит существенно увеличить скорость проходки скважин, при этом общие затраты на бурение будут сокращены за счет уменьшения времени бурения, потребления топлива и увеличения срока службы буровых коронок.The authors declare that the paper has not been originated under any project and no funding has been raised for this research

Gravitational and gauge interactions

Imperial Users onl

Effect of Oil Production and Drilling Operations on the Ecology of Phytoplankton in the OEI Study Area

Paper by Kenneth W. Fucik and Sayed Z. El-Saye

The Immigration Shadow Docket

Each year, the Board of Immigration Appeals (BIA)—the Justice Department’s appellate immigration agency that reviews decisions of immigration judges and decides the fate of thousands of noncitizens—issues about thirty published, precedential decisions. At present, these are the only decisions out of approximately 30,000 each year, that are readily available to the public and provide detailed reasoning for their conclusions. This is because most of the BIA’s decision-making happens on what this Article terms the “immigration shadow docket”—the tens of thousands of other decisions the BIA issues each year that are unpublished and nonprecedential. These shadow docket decisions are generally authored by a single BIA member and consist overwhelmingly of brief orders and summary affirmances. This Article demonstrates the harms of shadow docket decision-making, including the creation of “secret law” that is accessible to the government but largely inaccessible to the public. Moreover, this shadow docket produces inconsistent outcomes where one noncitizen’s removal order is affirmed while another noncitizen’s removal order is reversed—even though the deciding legal issues were identical. A 2022 settlement provides the public greater access to some unpublished BIA decisions, but it ultimately falls far short of remedying the transparency and accessibility concerns raised by the immigration shadow docket. The BIA’s use of nonprecedential, unpublished decisions to dispose of virtually all cases also presents serious concerns for the development of immigration law. Because the BIA is the final arbiter of most immigration cases, it has a responsibility to provide guidance as to the meaning of our complicated immigration laws and to ensure uniformity in the application of immigration law across the nation. By publishing only 0.001% of its decisions each year, the BIA has all but abandoned that duty. This dereliction likely contributes to well-documented disparities in the application of immigration law by immigration adjudicators and the inefficiency of the immigration system that leaves noncitizens in protracted states of limbo and prolonged detention. This Article advances principles for reforms to increase transparency and fairness at the BIA, improve the quality, accuracy and political accountability of its decisions, and ensure justice for the nearly two million noncitizens currently in our immigration court system

Chaotic behavior of a coupled system of the Riccati map

In this paper, We present the equivalent discrete system of coupled Riccati map. We study some the dynamic behavior such as (xed points and their asymptotic stability, the lyapunov exponents, chaos and bifurcation) of the system. Numerical simulation is presented to ensure the analytical results

Optička svojstva soli polianilina i baze polianilina punjenog s KBr, Co(CH3COO)2 i pikričnom kiselinom

Polyaniline was prepared by chemical methods. The composites were prepared by the hot pressing of polyaniline base with different percentages of KBr, Co(CH3COO)2 and picric acid. The diffused reflectance of polyaniline doped with 10, 15, 25 and 50 wt% of KBr, picric acid and cobalt acetate, was measured at room temperature in the wavelength range from 500 to 1800 nm. The energy gaps of the samples were then deduced as well as the position and number of the indirect transitions which were found to be dependent on the concentration percentage of the doping materials. The energy gaps of all samples decrease by increasing the concentration percentage of the doping materials.Polianilin smo pripremili kemijskim postupkom. Mješavine smo postigli vrućim tiskanjem polianilina s raznim postocima KBr, Co(CH3COO)2 i pikrične kiseline. Mjerili smo difuznu reflektanciju polianilina s 10, 15, 25 and 50 tež% KBr, pikrične kiseline i kobaltnog acetata na sobnoj temperaturi za valne duljine 500 do 1800 nm. Odredili smo energijske procjepe te položaje i broj posrednih prijelaza. Ustanovili smo za sve uzorke pad energijskih procjepa pri povećanju koncentracije dodataka

Optička svojstva soli polianilina i baze polianilina punjenog s KBr, Co(CH3COO)2 i pikričnom kiselinom

Polyaniline was prepared by chemical methods. The composites were prepared by the hot pressing of polyaniline base with different percentages of KBr, Co(CH3COO)2 and picric acid. The diffused reflectance of polyaniline doped with 10, 15, 25 and 50 wt% of KBr, picric acid and cobalt acetate, was measured at room temperature in the wavelength range from 500 to 1800 nm. The energy gaps of the samples were then deduced as well as the position and number of the indirect transitions which were found to be dependent on the concentration percentage of the doping materials. The energy gaps of all samples decrease by increasing the concentration percentage of the doping materials.Polianilin smo pripremili kemijskim postupkom. Mješavine smo postigli vrućim tiskanjem polianilina s raznim postocima KBr, Co(CH3COO)2 i pikrične kiseline. Mjerili smo difuznu reflektanciju polianilina s 10, 15, 25 and 50 tež% KBr, pikrične kiseline i kobaltnog acetata na sobnoj temperaturi za valne duljine 500 do 1800 nm. Odredili smo energijske procjepe te položaje i broj posrednih prijelaza. Ustanovili smo za sve uzorke pad energijskih procjepa pri povećanju koncentracije dodataka

Validated stability indicating methods for determination of nitazoxanide in presence of its degradation products

AbstractThree sensitive, selective and reproducible stability-indicating methods are presented for determination of nitazoxanide (NTZ), a new anti-protozoal drug, in presence of its degradation products. Method A utilizes the first derivative of ratio spectra spectrophotometry by measurement of the amplitude at 364.4nm using one of the degradation products as a divisor. Method B is a chemometric-assisted spectrophotometry, where principal component regression (PCR) and partial least squares (PLS) were applied. These two approaches were successfully applied to quantify NTZ in presence of degradation products using the information included in the absorption spectra in the range 260–360nm. Method C is based on the separation of NTZ from its degradation products followed by densitometric measurement of the bands at 254nm. The separation was carried out on silica gel 60F254, using chloroform–methanol–ammonia solution–glacial acetic acid (95:5:1:1 by volume, pH=5.80) as a developing system. These methods are suitable as stability-indicating methods for the determination of NTZ in presence of its degradation products either in bulk powder or in pharmaceutical formulations. Statistical analysis of the results has been carried out revealing high accuracy and good precision