bluuebunny/crossref_metadata_2025 huggingface dataset:
Fibrous roller-compacted concrete with recycled materials – feasibility study
Authors: Angelakopoulos Harris , Papastergiou Panos , Pilakoutas Kypros
Published: March 2015

This paper presents fundamental work done to enable fibre reinforcement of roller-compacted concrete (RCC). Procedures for mixing and casting two types of steel fibres in RCC were developed. Fresh properties, uniaxial compressive and bending behaviour were examined in a pilot study dealing with cement content, fibre type and dosage. It was found that different fibre types and dosages require different moisture contents. It is concluded that low cement content (less than 300 kg/m3) steel-fibre-reinforced roller-compacted concrete (SFR-RCC) mixes do not have sufficient paste and are prone to fibre agglomeration, hence SFR-RCC mixes richer in paste and at optimum moisture content are recommended. Mixes with cement content of 300 kg/m3 coped better with fibre reinforcement. Despite causing some loss in compressive strength, fibres help enhance the flexural performance and even SFR-RCC mixes with recycled masonry and concrete aggregates performed equally well as natural aggregate mixes. A full-scale trial has been conducted to confirm the findings. This paper is followed by a companion paper dealing with a comprehensive parametric study leading to the development of σ–ε models for SFR-RCC.
Study on waterproof mechanism of polymer-modified cement mortar
Authors: Wang Ru , Ma Daoxun , Wang Peiming , Wang Gaoyong
Published: March 2015

In order to clarify the effect and influence mechanism of polymers on the waterproof performance of cement mortar, the effects of three polymers on capillary water absorption, impermeability, porosity and cracking of cement mortar were studied. The correlation between porosity and waterproof performance was analysed and the waterproofing mechanism of polymer-modified mortar was explored. The results show that waterproof performance, characterised by capillary water absorption and impermeability, was significantly improved by all three polymers but to different extents. The cracking weighted value declined and open porosity decreased with an increase in polymer dosage. The penetration depth of water into mortar and the capillary water absorption showed linear and exponential growth, respectively, with an increase in open porosity. The polymers were found to improve pore structure and refine porosity of >50 nm and thus weaken the negative effect of porosity on the waterproof performance of mortar.
Evaluation of short- and long-term properties of heat-cured alkali-activated fly ash concrete
Authors: Shekhovtsova Julia , Kovtun Maxim , Kearsley Elsabe P.
Published: March 2015

Short- and long-term properties of alkali-activated fly ash concrete, namely, compressive, flexural and splitting tensile strengths, modulus of elasticity, Poisson ratio, early-age and drying shrinkage, creep and durability performance have been investigated in this paper. Blended ordinary Portland cement–fly ash concrete was used as a reference. The average compressive and flexural strengths of alkali-activated fly ash concrete at 28 d were 45 MPa and 5·8 MPa, respectively; drying shrinkage and creep values were about 360 and 200 microstrain, respectively, at 1 year. The total early-age shrinkage during the first 24 h of curing was lower for alkali-activated fly ash concrete at 1460 microstrain compared to 2800 microstrain for blended cement concrete. The use of this non-Portland cement containing material for producing precast concrete units can utilise high volumes of fly ash and potentially reduce the carbon footprint of the final product.
Családi gazdaságok termék nyomon követése a Közvetlen Számítógépi Leképezés módszerével
Authors: András Tankovics
Published: March 2015

Az agrifood folyamat hálózatok szerepl?inek szektorok között átível? nyomon követése jelenleg nem teljesen megoldott feladat. Munkámmal a Kaposvári Egyetem Folyamatinformatikai Kutató Csoportjának a folyamat hálózatok egyszer?sített dinamikus tömegmérlegeken alapuló vizsgálatára irányuló kutatásaihoz kapcsolódtam. Kutatási témám a folyamatlánc elején lév? legkisebb szerepl?k, a növénytermeszt? családi gazdaságok rendszerbe való csatlakozási lehet?ségeinek vizsgálata volt. Tanulmányoztam a hazánkban, nagy számban jelen lev? családi gazdaságok számára el?írt adatszolgáltatási kötelezettségeket. Megismertem a kis mez?gazdasági termel?k munkafolyamatait, és a gyakorlatban alkalmazott adatrögzítési módszereit. Ezen információkat felhasználva kidolgoztam egy ideiglenes adatrögzítési megoldást, amely alkalmas ezen gazdaságok összes olyan adatának rögzítésére, amely szükséges a nyomon követési rendszerbe való csatlakozáshoz. Az adatszolgáltatási eljárás megvalósítása nem jelentett nehézséget az általam vizsgált gazdaságoknak. Megállapítottam, hogy az általunk alkalmazott metodika szerint megvalósítható a legkisebb szerepl?k komplex nyomon követési rendszerbe integrálása is.
Strategic planning and decision support in small-medium wood enterprises using database technology
Authors: Andreopoulou Zacharoula , Koliouska Christiana , Tsekouropoulos Georgios
Published: March 2015

As the enterprise management plays vital role in the overall performance of a company, it is recognized the need for application of quality improvement tools and techniques such as database technology. A DataBase Management System (DBMS) is an IT application, which contains information about the company in various levels. Enterprises can use DBMS to plan and standardize their practices and increase overall efficiency in the company. It is an essential management tool for Small and Medium-sized enterprises (SMEs) because in such companies the entrepreneur-owner is personally responsible for managing the activities of the company without being an expert. This modern information technology tool is the basis of the application of marketing principles and techniques via electronic media and more specifically the internet. The purpose of this paper is to explore how implementation of modern information technology tools, such as DBMS, simplifies SME management. That DBMS design approach can be a useful tool while designing similar applications in SME in wood sector and also in various issues in primary and secondary production sector.
Mapping solution of Interscale Landscape Diversity Modelling Methodology
Authors: Fülöp Györk -
Published: March 2015

Interscale Landscape Diversity Modelling Methodology (INLAND) was set up in order to carry out landscape diversity modelling tasks. The modelling has dual aims: sampling and mapping. In the confines of this paper I introduce the mapping solution, with the description of the modelling needs, and the application of the output results. INLAND methodology defines landscape diversity as the (human/social) perception of spatial heterogeneity. INLAND also intends to model landscape diversity continuously through-out spatial scales. The automated assessment tools of INLAND carry out the modelling tasks relying on Earth Observation (satellite remote sensing) imagery. With the use of sampling tool – objective parameters can be extracted from input data sources. Mapping solution visualises landscape diversity in a map format in order to provide basis for monitoring, and planning tasks – in comfort with the requirements of European Landscape Convention (2000, Florence). Examples of the application of INLAND maps are also introduced along a case study (Rostock region – Mecklenburg-Vorpommern, Germany).
Creating a Virtual Learning Environment
Authors: Hampel György , Dancsházy Kinga
Published: March 2015

Creating a virtual learning environment may be useful to acquire knowledge in some circumstances. A Learning Management System is essential to manage a virtual learning environment. There are numerous steps of creating an e-learning curriculum. In the described three-year international project the goal was to develop an e-learning system with the following logical development scale: (1) Specification of the needs of the target group; (2) Development of the on-line toolkit; (3) Development of the training material; (4) Training of the e-tutors; (5) Development of the methodology to test the training material; (6) Pilot testing on the target group; (7) Accreditation of the modules; (8) Dissemination and promotion activities. This paper contains a brief description of the above mentioned development process which resulted in an e-learning material that can be used to prepare agrarian specialists to prepare for today’s modern world and to be a successful member of the information society.
Process simulation of integrated biohydrogen production: hydrogen recovery by membrane separation
Authors: Koók László , Szabó Ákos , Bakonyi Péter , Tóth Gábor , Bélafi-Bakó Katalin , Nemestóthy Nándor
Published: March 2015

In this project, the production of biohydrogen, as a renewable and sustainable energy source was studied. Biohydrogen was manufactured by using E. coli strain in a batch dark fermentative process integrated with membrane gas separation. Two different methods were applied: Firstly, the amount of the produced gas and component concentrations were measured, but CO2 and H2 gases were not separated. In the second experiment CO2 was removed from the gas mixture via chemical sorption (reacting with NaOH). Both methods use continuous product removal in order to enhance the biohydrogen formation. In addition, process modeling was carried out with a simulation software (SuperPro Designer, Intelligen Inc.) so that experimental and computational results could be compared. CO2 and H2 flow rates and fluxes were calculated on the basis of the membrane permeation data obtained by using pure gases and silicone (PDMS) hollow-fiber membrane module (PermSelect – MedArray Inc.).
Features during labor in women with chronic hepatitis B
Authors: Shoonaeva N D
Published: March 2015

Aim. To examine the course of labor in women with chronic hepatitis B.Methods. The course of labor was studied in 391 female patients with chronic viral hepatitis B, included in the study group (mean age 22.7±2.5 years), who delivered off in the National Maternity Hospital (Bishkek). The control group included 59 healthy women in labor (mean age 22.5±1.3 years).Results. The vast majority of patients - 53 (89.8%) of the control group and 328 (83.9%) of the study group - had delivered off at term. Post-term births were registered in both groups. Operative delivery by cesarean section was performed in 13.0% of chronic viral hepatitis B cases - by 4.5% higher compared to control group. In the study group, planned cesarean section was performed in 21 (5.4%) patients, the main indication was burdened obstetric history - in 8 (2.0%) patients; 5 (1.3%) patients had multiple indications. Emergency operations were conducted in 30 (7.7%) patients. Indications were premature rupture of membranes - 15 (3.8%) of cases, fetal hypoxia during labor and multiple indications - 10 (2.6%) cases each. The average blood loss at cesarean section in the group of patients with chronic viral hepatitis B was 870±15.2 ml, compared to 700±10.2 ml in the control group, which can be associated with low coagulation seen in hepatitis. Comparative analysis of the complications rate in the control group revealed that delayed rupture of membranes was the most frequent - 11 (18.6%) cases, followed by intrauterine fetal hypoxia - 5 (8.5%) cases, early postpartum bleeding - 4 (6.8%) cases, hypertensive disorders at labor and retained placenta - 3 (5.1%) cases each. In the group with chronic viral hepatitis B, premature rupture of membranes occurred in 51.5% of cases, (relative risk 2.8). Early postpartum bleedings were seen in 38.9% of the cases at the main group (relative risk 5.7).Conclusion. The above data gives us every reason to include women with chronic viral hepatitis B at high-risk group for possible bad pregnancy and childbirth outcomes both for the mother and the fetus.
Clinical features of chronic hepatitis C and efficacy of antiviral treatment in Caucasian and Mongoloid patients
Authors: Malov S I , Dulguun B , Malov I V , Stepanenko L A , Miroshnichenko I A , Nymadawa P
Published: March 2015

Aim. To present the comparative clinical characteristics of chronic hepatitis C infection and to estimate the effect of antiviral treatment in Caucasian and Mongoloid patients, considering interleukin-28B gene polymorphism in study populations.Methods. Population and genetic study including 1520 healthy subjects and 267 patients with chronic viral hepatitis of Caucasian and Mongoloid race analyzed interleukin-28B gene polymorphism. 433 patients with chronic viral hepatitis C were followed up. Combined antiviral treatment by pegylated interferon alfa-2a and ribavirin was administered for 48 weeks. The rates of early and sustained virologic response were the endpoints for assessing antiviral treatment effect. 82 Caucasian patients and 42 Mongoloid patients have completed the full course of antiviral treatment and 24 weeks of follow-up.Results. The following clinical features of chronic hepatitis C were revealed in Mongoloids: more extensive liver fibrosis, older age, longer infection duration and higher total cholesterol levels (due to triglycerides). These factors negate the expected better effect of antiviral therapy effect, associated with higher prevalence of interleukin-28B favorable genotypes in Mongolian population. The presence of the C-allele of rs12979860 gene and T-allele of rs8099917 gene reaches 89.6 and 91.7% respectively in Mongolian population, which is comparable with those in China, Japan and Korea, and is typical for the whole of Asia. Combined treatment with pegylated interferon alfa-2a and ribavirin in patients with genotype 1 of hepatitis C virus led to sustained virologic response in 78.5% of Mongoloid and in 56.1% of Caucasian patients; groups were totally comparable.Conclusion. Mongoloid patients with chronic hepatitis C reached sustained virologic response to antiviral treatment with pegylated interferon and ribavirin significantly more frequently compared to Caucasians, in cases of no aggravating factors and minimal liver fibrosis.
Adrenergic mechanisms of myocardium contractility regulation in genetic model of Alzheimer’s disease
Authors: Leushina A V , Nurullin L F , Petukhova E O , Zefirov A L , Mukhamedyarov M A
Published: March 2015

Aim. Study is aimed to investigate contractility impairments and receptor mechanisms of adrenergic regulation of myocardium inotropic function in Alzheimer’s disease model on transgenic mice.Methods. Experiments were performed on isolated preparations of atria and ventricles myocardium of mice. Transgenic mice of B6C3-Tg(APP695)85Dbo Tg(PSENI)85Dbo genotype were used as animal model of Alzheimer’s disease. Contractile responses of myocardium were registered by conventional myographic technique in isometric conditions. To evaluate the expression of adrenergic receptors, immunofluorescence staining of myocardium with specific antibodies was performed.Results. Transgenic mice showed not only a decreased effect of norepinephrine on myocardium inotropic function but also the inversion of the effect of norepinephrine - the use of 10-5-10-4 M of norepinephrine decreased myocardium inotropic function. Immunofluorescent staining showed decrease of expression of β1- and especially β2-adrenergic receptors ventricular myocardium of transgenic mice comparing to wild type mice. Adrenergic deregulation was registered in ventricles, but not in atria. The features of adrenergic regulatory mechanisms of myocardial contractility in transgenic APP/PS1 mice aged 8-10 months are specific, although somewhat similar to wild type mice aged 8-10 months, and are evidently due to Alzheimer’s disease. The inversion of norepinephrine inotropic effect (from positive to negative) may be explained by switching the intracellular cascade pathway of β2-adrenergic receptors effects to another type of G-protein.Conclusion. The results indicate that peripheral adrenergic mechanisms of myocardial contractility regulation are impaired in studied transgenic mice model of Alzheimer’s disease. Obtained data widen our understanding of Alzheimer’s disease pathogenesis, as well as our conception of relations between cardiovascular diseases and neurodegeneration.
Effect of benzimidazole derivative containing dioxonium ethane cycle on the outcomes of emotional stress induced by physical overload in animals
Authors: Kataev A V , Gizatullin T R
Published: March 2015

Aim. To study the outcomes of emotional stress induced by physical overload, and to assess the effects of benzimidazole derivative containing dioxonium ethane cycle of 2-[1-(1,1-dioxyethenyl 3) benzimidazolyl-2-thio] acetic acid potassium salt.Methods. Behavioral responses were studied in experimental animals getting graduated physical exercise (swimming test) which was used as a model for physical and emotional stress. White scrub rats with a body weight of 120-180 g were used as research object. Physical overload was induced by making animals swim 30 minutes daily for 28 days. Animals were distributed into three groups of 10 animals each: the control group, the group of physical activity, and the group of physical activity exposed to the studied substance (50 mg/kg).Results. Animals exposed to physical activity showed an increase in adrenal glands weight white blood cell count and reduced the mobility ratio and the overall research activity, as well as increased emotional anxiety, indicating stress. Benzimidazole derivative showed to be effective controller of chronic stress. Physical activity in animals exposed to study substance did not lead to an increase of white blood cell count and adrenal glands weight. Animals exposed to study substance increased mobility ratio and the overall research activity by 1.5 times, and the rate of emotional anxiety in animals has decreased by 2 times compared to the group that was exposed to physical activity without benzimidazole derivative administration. Free radical oxidation processes were more intense in brain homogenates of animals after physical activity, which was seen as increased levels of reactants interacting with thiobarbituric acid and decreased total antioxidant activity. In animals exposed to study substance, these indicators increased compared to animals exposed physical activity without administration of study substance, and were comparable to controls.Conclusion. The use of the study substance prevents the negative effects of emotional stress and physical overload.
Ischemic and nonischemic manifestations of antiphospholipid syndrome
Authors: Tukhfatullina S I , Gaynetdinova D D
Published: March 2015

Hypercoagulability syndrome is an actual multidisciplinary problem of the last decade. Blood clotting disorders leading to hypercoagulability syndrome may manifest as different diseases in neurology, obstetrics, rheumatology, surgery, including diseases of pregnancy. Antiphospholipid syndrome is the most common form of hypercoagulability syndrome, which often develops at a young age, in children and even infants, with female-male ratio of 5. Causes and pathogenesis of antiphospholipid syndrome are not fully clear. This problem is especially important for pregnant women. Almost a third of refractory pregnancy losses are associated with antiphospholipid antibodies formation. Main manifestations of this condition include thrombotic events during pregnancy and the postpartum period, including cerebral pathology in both mother and child. Central nervous system damage in this condition may have both ischemic (cerebrovascular accident) and nonischemic (primary immune-mediated damage of the nervous system) genesis. The variety of neurological disorders associated with antiphospholipid syndrome is very wide, from cerebrovascular disorders, migraine and migrainous headaches to chorea and seizures. Headaches are the most common reason for pregnant women to seek neurologic help. Pregnancy associated with high titers of antiphospholipid antibodies often end as early gestation stage stillbirth. Children born to mothers with antiphospholipid syndrome in 20% of cases develop neurological symptoms of ischemic and non-ischemic origin. Thus, antiphospholipid syndrome requires special attention for early and timely diagnosis, especially in women planning pregnancy and in pregnant women for the preventing serious complications, both in mother and fetus.
The role of IL-36γ/IL-1F9 in developing erythroderma in patients with psoriasis
Authors: Zaslavskiy D V , Chuprov I N , Sydikov A A , Ibragimov K U , Wolkenstein P , Skrek S V , Nasyrov R A
Published: March 2015

Erythroderma is the term used for naming any inflammatory skin disease affecting over 90% of cutaneous surface. Numerous etiologic factors may background erythroderma; however, this condition is most often associated with such underlying diseases as eczema, drug hypersensitivity syndrome, cutaneous epidermotropic lymphoma, photosensitization. Being the most severe clinical form of psoriasis, psoriatic erythroderma may be a life hazard in patients with psoriasis, requiring admission and systemic treatment. The paper reviews modern data on psoriasis and psoriatic erythroderma pathogenesis. The biological role of IL-36γ/IL-1F9 - novel specific marker of psoriasis - is described in detail. Data of researches of this marker in different forms of inflammatory skin disease are discussed. Unlike other earlier described markers of psoriasis, for example, S100 A7, A8, A9 proteins, IL-36γ was highly specific to psoriasis, and rarely found at other inflammatory skin diseases (atopic dermatitis, contact dermatitis). The role of IL-36γ in diagnosing erythroderma in patients with psoriasis is described. The most specific and promising marker for distinguishing psoriatic erythroderma from other forms of erythroderma, IL-36γ can be detected at early stages of the disease, allowing to administer early causative treatment, improving treatment effect and preventing complications.
Efficiency analysis of the early years of the first level trauma center in the Chelyabinsk region
Authors: Shishkin E V
Published: March 2015

Aim. To assess the efficiency of first level trauma center on the base of «Chelyabinsk Regional Hospital». Methods. The data were copied out from the medical charts of road accidents victims. The majority of patients who were admitted to the first level trauma center are young people of reproductive and working age, mostly males. In most of the cases, patients suffered from combined injuries involving multiple body regions (T00-T07). Results. Admission in every fourth patient of the trauma center was inappropriate, as patients had isolated injury not accompanied by shock. In 26.8% of the studied group, no surgery was performed, also stressing inappropriate admission. Spinal and brain injuries requiring neurosurgical aid were detected only in 36.8% of cases. The analysis showed miscommunication between trauma centers of levels I and II. Significant violations of road traffic accidents victims’ hospitalization orders, as well as the presence of inappropriate patients, were discovered. Conclusion. The findings highlight problems associated with trauma centers low functioning as a whole system, requiring introduction of real-time monitoring of their activities, as well as management decisions aimed at optimizing the communicative process between trauma centers, as well as with other medical institutions, which include trauma centers.
Reasons for inappropriate ambulance calls by adult urban population
Authors: Paykov V L , Ishmetov R P , Akchurina I I
Published: March 2015

Aim. To study the reasons for inappropriate ambulance calls made by adult urban population. Methods. Emergency calls of 1016 patients, 917 of them - aged 18 years and older who sought emergency medical help for different reasons, registered 8:00 to 20:00 from January 1 to September 30, 2014 and served by the first author. Reasons for inappropriate ambulance calls were studied using specially designed questionnaire, which was used to carry out the survey in 298 patients in their places of residence. Results. The examination of the call cards revealed that majority of the calls - 826 (90.1%) - were productive, including emergency aid and inappropriate ambulance calls - 457 (49.9%) cases. Females made inappropriate ambulance calls more frequently compared to males - 277 (60.6%) and 180 (39.4%), respectively. Males under the age of 60 years (mean age 56.6 years) performed inappropriate ambulance calls more frequently compared to elderly males, with no such age-related difference in females. According to the survey, the reasons for seeking for emergency medical care were: «it was far to get to the outpatient clinic» (28 cases, 9.4%), «did not know the phone of the outpatient clinic» (7 cases, 2.3%), «for a timely aid and a doctor’s appointment» (16 cases, 5.4%), «because of the symptoms requiring treatment» (51 cases, 17.1%), «exacerbation of a chronic disease» (34 cases, 11.4%), «unaware of the fact that he/she should visit an outpatient clinic» (10 cases, 3.8%), «a non-working day» (17 cases, 5.7%), «known that he/she will be dismissed form an outpatient clinic» (23 cases, 7.7%), «nonresident» (11 cases, 3.7%). All of the above is the evidence of the population ignorance of the mechanisms of providing primary health care (66.1%). In addition, several patients indicated «long time is needed to get the appointment to a doctor» (25 cases, 8.4%), «not able to reach outpatient clinic» (12 cases, 4.0%), «do not trust doctors of the outpatient clinic» (45 cases, 15.1%), «the call to the outpatient clinic was not accepted» (11 cases, 3.7%) and «having problems of getting to a doctor» (8 cases, 2.7%) as the reason. In the latter cases, these reasons were indicators for malpractice of the outpatient clinics (33.9%). Conclusion. Reasons for inappropriate ambulance calls made by adult urban population, according to a survey - unawareness of the appropriate facility providing primary health care (66.1%) and outpatient clinics malpractice (33.9%).
The Impact of Adding High pH Fluid to Sea Water on The Sandstone Rock Charge During EOR Process
Authors: Attia M. , Mahmoud M.A.
Published: March 2015

Many researchers investigated the effect of the ionic strength and the chemistry of the injected water on the oil recovery from sandstone reservoirs. They concluded that as the salinity of the injected water decreased the oil recovery increased. They studied the effect of changing the salinity of the injected water on the zeta potential. The Zeta potential decreased in case of aquifer water compared to the sea water. The new application that we used has the ability to do better than the low salinity water flooding in increasing the oil recovery from sandstone reservoirs without diluting the sea water. Sea water dilution is a costly process, the cost of the new fluid system is low and in terms of recovery it will do better than the low salinity waterflooding. The new EOR fluid system will remove the damage caused by the low salinity water and sea water flooding and also it will prevent the formation damage.

In this paper we will study the effect of adding high pH fluid (chelating agent) to sea water on the sandstone rock charge. Zeta potential was measured for Berea sandstone rock with different fluids and different concentrations of the chelating agent which was added to sea water. Also the effect of the chelating agent on the surface tension and oil recovery was evaluated.

The results of zeta potential showed that adding high pH chelating agent to sea water decreased the value to -33 mV less than the low salinity water (5,767 ppm) which changed the zeta value to -12mV. In addition, the zeta potential of sandstone rock will be affected by the iron concentration in the fluid. Low salinity water with 1000 ppm iron changed the value to 7 mV. But, in case of adding the chelating agent to the same fluid the effect of iron did not appear and the charge decreased to -24mV. The decrease in zeta potential value indicates more water wet rock surface and in turn, high oil recovery will be achieved. The chelating agent diluted in sea water yielded lower surface tension compared to sea water and low salinity water. The oil recovery increased by 30% after sea waterflooding when we used 5 wt% of Na4EDTA chelating agent diluted from initial concentration of 40 wt% using sea water. The recovery increase can be attributed to the change in the rock surface charge, rock dissolution, IFT reduction mechanisms.
Design Optimization of Electric Centrifugal Pump by Multiple Surrogate Models
Authors: Adhav R. , Samad A. , Kenyery F.
Published: March 2015

In this paper, an effort has been made to maximize the efficiency of ESP by using surrogate models for optimization. Inlet and outlet blade angles are selected as design variables. Initially, a pump stage simulation is performed using Navier Stokes solver which include rotating impeller and stationary diffuser. The steps of the simulations are: generate geometry, grid and solve. The surrogate models were response surface approximation, Kriging and radial basis neural network. A hybrid genetic algorithm has been implemented to find optimal design. The multiple surrogate approach was used to reduce uncertainty in optimal point search. The initial CFD generated results were used to generate surrogates and the surrogates were used to give optimal point via genetic algorithm. Design of experiments were used to find the designs and low fidelity based surrogates were constructed to reduce the number of simulation runs. The optimization procedure sufficiently reduces the design time. Hence, the approach shows an optimal design of ESP and selection method of right surrogate for the shortening of computational cost.
A Case Study - Living the HSE Vision and Values - Delivering Success in an Environment of Uncertainty
Authors: Karish John , Siokos George
Published: March 2015

Ensco plc is an international drilling contractor which, has experienced significant growth since its creation only 27 years ago to its current position as the second largest offshore drilling organization worldwide. In 2011/12 it doubled its size through the acquisition of another similarly sized drilling organization.

Despite this significant growth, and while being challenged by many issues from inside such as integration, and from the outside such as having to do business in a difficult market and in many different national cultures, it has achieved acknowledged excellent performance. Ensco plc was voted as the number one performer by a cross section of operators in an independent customer survey in 2010, 2011, 2012 and 2013.

This paper will describe these processes and the leadership that has driven this success. They are not new; what Ensco has done is integrate existing and well known concepts in a way that has led to this success. The processes are multi-faceted and integrated and include: –Creation of a safety culture that emphasis accountability and responsibility for all to create a safe work place.–Safety Systems development with an implementation process focused on consistent implementation across the fleet–Verification on how well they used, noting of lessons learned and application across the fleet–Training and development in critical safety tools and processes–A strong safety leadership development process for leaders in critical positions–A strong and visible senior executive at all safety development programs and through other media–A focus on developing engineering and technical solutions that have common elements across the fleet, making their management easier.

This paper will explore these factors; it will focus on the leadership and people aspect, rather than the technical and engineering solutions.

Underpinning Ensco's safety performance to date has been an unshakeable belief by its leaders and people in its Vision and Core Values.

The very visible leadership of Ensco's leaders is perhaps the most striking of the elements that will be discussed, without which, many of the other factors would be more difficult.

Of note, and key to the paper is that Ensco's journey over a decade has come about at the best of times in the industry as well as the worst. This is important to consider given the current difficult and challenging market in which the oil and gas industry, and drilling in particular, finds itself.

Finally, the paper will provide a brief over-view of some key underpinning theory and principles that have guided Ensco's safety program design and development.
Tandem ESP-Packer Dumpflood Completion – A Successful Alternative to Conventional Encapsulated ESP systems – Field Case Study
Authors: Al-Hajeri Nasser , Anthony Elred , A-Sharhan Ghazi , Jha Ajay
Published: March 2015

Dumpflooding from a strong Aquifer to support pressure to another depletion-drive reservoir is not new to the oil industry, neither to the region. In cases where the natural Aquifer pressure is insufficient to deliver adequate volumes to meet pressure support requirements, or the Injectivity of the target reservoir is relatively low, artificial lift is required. This was the case in the North Kuwait Asset where Injectivity was poor owing to the relatively low natural fracture density of the Carbonate reservoir being flooded.

Since the conventional encapsulated (POD) systems required one (1) seal-bore packer, one (1) encapsulated ESP system, and one (1) ESP-packer, it was decided to test an alternate and simpler system that required only two (2) ESP packers that would achieve the same result.

Deployment of this new tandem-ESP-packer system proved less complex and required less rig time than the encapsulated ESP system. Both packers were set simultaneously in one operation with the ESP function test to surface-pit giving excellent results. After opening the SSD's, the ESP operating parameters, measured at surface, indicated optimum pump performance at expected injection rates.

The Tandem-ESP-Packer Dumpflood completion system provides fewer sealing interfaces than the conventional encapsulated ESP system, and therefore fewer opportunities for leaks. Additionally, it affords a very simple one-trip system for less complex deployment, and retrieval, when necessary. This alternate system also provides easily-deployed, immediate pressure support in areas of the reservoir/field while awaiting the installation and commissioning of major surface Injection facilities.
Managing Wellbore Instability in Horizontal Wells through Integrated Geomechanics Solutions: A Case Study from a Carbonate Reservoir
Authors: Khan Khaqan , Abdulaziz Ahmad Azly , Ahmed Sajjad , Ahmed Mujahed
Published: March 2015

Saudi Aramco is one of the pioneers in optimizing hydrocarbon production and reducing development cost using latest technologies aimed to increase gas production and enhance gas recovery. The case study discussed here shows results from an integrated approach used to drill wells in the minimum horizontal stress direction to create multiple transverse fractures during stimulation that helps enhancing production. The real challenge involved in drilling such horizontal wells is to maintain wellbore stability (especially in a transition zone from high porosity to low porosity and vice versa) mainly due to wellbore breakouts and differential sticking. Due to variably depleted reservoir pressures together with geological and structural complexities, pre-drill geomechanical models need to be updated in real-time, which require extra vigilance, in terms of optimizing mud weight while drilling, to address both formation breakouts and risk of differential sticking. If these problems are not addressed in a timely manner, initial signs of wellbore instability can aggravate with time leading to stuck pipe and loss of tool downhole.

To address above issues, an integrated approach was applied during well planning and execution phases using prior drilling experience in conjunction with a geomechanical analysis to make recommendations for the planned well. While drilling, potential uncertainties in the geomechanical model due to formation heterogeneity and varying in-situ stresses, were further addressed by updating the model using real-time logging while drilling (LWD) data along with real-time drilling geomechanics (RTDG) support and advanced mud logging technology. In addition, advanced cutting return-monitoring technology was implemented which helped monitor proper hole cleaning and minimize the risk of stuck pipe due to compressional formation failure at the wellbore. Based on this analysis, revised drilling practices and recommendations were made to address the wellbore instability issues. The case study presents results from a challenging well using this integrated approach showing significant improvement in well safe delivery within planned drilling time and achieved the planned target gas rate.
Horizontal Drilling in Kuwait for Development of a Complex Carbonate Reservoir
Authors: Zaidi Salman , Pathak Ashok Kumar , Al-Hamadi Hajer Bader
Published: March 2015

Approximately 75% of the proven conventional oil reserves in the Middle East occur in carbonate reservoirs like Mauddud in North Kuwait. Today, this reservoir is the focus of aggressive development through drilling of horizontal wells.

Mauddud in North Kuwait is heterogeneous with varying rock and fluid properties between crest and periphery. A major challenge in its development is the presence of high permeability streaks that are random, inconsistent and unpredictable. Though typical of carbonates this causes early breakthrough into producers and cycling of injection water into patterns resulting in poor sweep efficiency and oil recovery. The reservoir is under active water flood for over 10 years.

Horizontal wells is not something new to KOC yet their objective, completion and integration with development plan is more holistic now than before. Mauddud today is at a point where its character, quality and condition favors development by horizontal and multi-lateral wells. The objective of drilling new horizontal wells is to have large contact area of the reservoir and the good news is that, despite early mixed results, we are beginning to see their positive impact. Modeling studies have indicated that a combination of pattern and peripheral water flood would help maintain reservoir pressure and achieve reasonable oil recovery.

Encouraging production results from recent horizontal completions at the periphery of Mauddud structure, where rock quality is not good, is the beginning of a new phase of development in the life of this reservoir. The incremental production benefit is expected to be around 2-2.5 times the vertical.

The paper discusses the typical design considerations, problems in drilling, lessons learnt, their benefit over offset vertical wells and test results of some of these wells drilled in Mauddud Reservoir.
Numerical Modeling of Flow and Temperature Distribution in Heterogeneous Wellbore Medium
Authors: Irawan Sonny , Bathaee Mahmood
Published: March 2015

The mathematical model for flow and temperature distribution for the water alternating gas (WAG) process had been developed. Water alternating gas (WAG) injection has been a popular method for commercial gas injection projects worldwide. The injection of water and gas alternatively offers better mobility control of gas and hence, improves the volumetric sweep efficiency.

The model is generated for the injection well with one cycle of water and one cycle of injected gas. There are some considerations for the three phases modeling in this study. The scope of the model is to develop the flow model for cylindrical, gravity segregation, turbulency effect due to the high injection rate, incompressible water, slightly compressible oil, compressible gas, IMPES method and with ignoring the tangential flow. The energy balance equation for the three phases could be expanded after the saturations from the flow part had been obtained. These are the conditions for solving the equation for temperature distribution: Cylindrical, implicit method, convection and conduction with ignoring tangential temperature gradient.

In order to solve the governing equations, an analytical method had been used for the two and three phase systems around the wellbore; then a program had developed to do the iteration for implicit parts. The water, gas and oil pressures and saturations had been obtained in addition with the system temperature for homogeneous and heterogeneous media.
Improving the Accuracy of Cement Bond Evaluation by Improving the Borehole Fluid Impedance Measurement in Ultrasonic Scanner Tools
Authors: Tello Lucio N. , Azuaje Dimas C.
Published: March 2015

Ultrasonic scanning tools measure the cement acoustic impedance at higher radial and vertical resolution than radial cement bond and sector tools. The cement impedance measurement is affected by variations of the borehole fluid contained in the well. Until now, ultrasonic tools estimated the value of the fluid impedance by measuring the slowness and multiplying this value by the density which is a constant reading at the surface. Occasionally, the slowness measurement is acquired during a logging down pass. An error is introduced when the fluid changes from one type to another, because both slowness and density change with the fluid; however, density will change in larger percentages than slowness. This causes the estimated fluid impedance to have a substantially different value than the actual one. Not surprisingly, this difference in fluid impedance causes the cement evaluation to differ as well.

In this paper we present the results of the field testing program of the newly developed mud chamber for the ultrasonic radial scanner tool. Instead of calculating the impedance indirectly from the slowness measurement, the mud chamber measures the fluid impedance directly. The tool takes this measurement in situ, during logging, and with greater accuracy than before. In addition, we present the algorithm that computes changes in the cement impedance which are due to variations of the impedance in the fluid column. Observations in laboratory tests and logs obtained during field testing show that the fluid column commonly has variations in the acoustic impedance and its density. Under the new measurement, phantom communicating channels are not displayed and actual channels are correctly detected. The effect is accentuated in instances where stratigraphic fluid columns with different densities are present. The new mud chamber eliminates the uncertainties of small channels by detecting the presence or absence of cement.
Oil Recovery Enhancement in Middle East Heavy Oil Field using Malonic Acid based Deep Eutectic Solvent
Authors: Al-Weheibi I. , Al-Hajri R. , Al-Wahaibi Y. , Jibril B. , Mohsenzadeh A.
Published: March 2015

This study investigates the potential of chemical solvent called deep eutectic solvents (DES) to recover the residual heavy oil left after waterflooding. For the first time to our knowledge, the effectiveness of two DESs - choline chloride-malonic acid of molar ratios 1:1 and 1:0.5 - in enhancing heavy oil recovery was thoroughly investigated. As preliminary investigations, the two solvents were characterized by measuring density, viscosity, conductivity and pH at different temperatures (20 – 80°C). In order to investigate the EOR potential of the solvent, measurements of interfacial tension, wettability alteration, spontaneous water imbibition, emulsification, core flood and formation damage tests were conducted at different temperatures. The core flood test was carried out at reservoir condition (pressure = 1200psi, temperature = 45 - 80 °C) using Berea sandstone core samples and fluids from the field of interest (formation brine and crude oil). Results of the core flood test showed the solvents produced 7-14% of the residual heavy oil after brine flooding as tertiary recovery stage and both DESs displayed better performance in enhancing the oil recovery at higher temperatures. Measurements of absolute permeabilities before and after injection of DESs/brine solutions showed no damage to the formation. Wettability alteration was found to be the dominant mechanisms for the tertiary oil recovery enhancement.
Maximizing Reservoir Exposure in the Thin Limestone of Ahmadi Formation, Bahrain
Authors: Suleiman Sameh , Al-Ansari Yusuf , Shah Razza , AlTawash Feras , Samaroo Rajeev , Al-Alqum Wael , Jawad Waleed
Published: March 2015

Lately, stratigraphically thin reservoirs are being exploited more and more to meet an ever-growing need to increase reservoir recovery. In Bahrain, the AB3 layer of the Ahmadi formation has a true stratigraphic thickness (TST) of 8 to10 ft. Gamma ray and resistivity stand relatively constant at 12gAPI and 45ohm.m, respectively, and there is good conductivity contrast between the Ahmadi limestone and the underling mudstone and overburden shale. The Ahmadi formation is also known to have faults and high dips, contributing to the geological challenge for geosteering wells in the region.

To address the challenges, a bed-boundary mapper (also includes core petrophysical measurements like gamma ray and resistivity) has routinely been incorporated into the bottom-hole assembly (BHA) along with surveying and rotary steerable technology. Given the lean nature of the BHA meant that drilling operations were cost-effective and that measurements were as close to the bit as feasibly possible, ideal for both formation evaluation and well placement.

During drilling, inversion data from the bed-boundary mapper was used to estimate both reservoir thickness and formation dip. These dips correlated with those estimated from the seismic model. The inversion information was also used to estimate the vertical displacement of faults and directed the next geosteering decision for either returning the trajectory to the reservoir or to the reservoir “sweet spot”. Even in this high penetration rate drilling environment (+200 ft./hr), these core measurements, located close to the bit, allowed for quick and efficient well-placement decisions to be taken at the right time.

Using these drilling, evaluation, and geosteering practices, more than 30 horizontal producer wells have been drilled in the Ahmadi formation to date. Reservoir net-to-gross averages 91%, with wellbores typically placed in the middle of these thin reservoir sections. The method has shown to improve reservoir exposure and well productivity when compared to geometric drilling and evaluation methodologies.
Distribution of New Horizontal Wells by the Use of Artificial Neural Network Algorithm
Authors: Ali Diyar H. , Al-Jawad Mohammed S. , Van Kirk Craig W.
Published: March 2015

It is an established fact that substantial amounts of oil usually remain in a reservoir after primary and secondary processes. Therefore; there is an ongoing effort to sweep that remaining oil. Field optimization includes many techniques. Horizontal wells are one of the most motivating factors for field optimization. The selection of new horizontal wells must be accompanied with the right selection of the well locations. However, modeling horizontal well locations by a trial and error method is a time consuming method. Therefore; a method of Artificial Neural Network (ANN) has been employed which helps to predict the optimum performance via proposed new wells locations by incorporating reservoir properties and production data of previous wells.

This study used the Artificial Neural Network (ANN) that has been programmed in a manner to predict the cumulative oil produced for a certain grid by providing the corresponding properties of the grid. The network has been validated with real data collected from a number of drilled hypothetical wells. Furthermore; the validated network used to simulate the field parts that have not been drilled yet, to predict the corresponding cumulative oil for each grid. Field-scale simulation has been carried out and new horizontal wells have been allocated using the validated prepared data by the Artificial Neural Network Algorithm and an approved Iraqi reservoir model. Finally, different optimization scenarios have been investigated on the overall field recovery performance.