bluuebunny/crossref_metadata_2025 huggingface dataset:
Knowledge, attitudes and practices of obstetrical ultrasound in Conakry, Guinea
Authors: S. Y. Telly , Leno Daniel William Athanasse , Camara Moussa Kantara , Hyjazi Yolande , Keita Namory
Published: January 2017

Background: The authors report an initial assessment of the practice of obstetrical ultrasound in Conakry in order to make suggestions to improve the quality of services in Guinea.Methods: It is about a cross-sectional study of three months (August 1st to October 31st, 2013) conducted in Conakry. The study population consisted of health personnel performing fetal ultrasounds in Conakry and who agreed to participate in the survey. The data collected were about the socio-professional characteristics of the service providers, their knowledge and attitudes. The data were analyzed in a simple descriptive statistical analysis way. The results were analyzed according to the norms and standards issued by the French Fetal Ultrasound College and the National Technical Committee for Prenatal Diagnosis Ultrasound.Results: Twenty one service providers over twenty-six (80.8%) were male (80.8%) aged 40-49 years old (46.2%), obstetrician-gynecologists (76.9%), working in a public hospital (46.2%) and not having an ultrasound degree (59.2%). Eight service providers over twenty-six ((30.8%) affirmed knowing the recommended period for a fetal biometry. The majority (60%) indicated measuring the nuchal translucency and 85.2% (22/26) the craniocaudal length. The anatomical landmarks were not correctly identified in 75.2% of cases for the biparietal and the head circumference and in 63.8% of cases for abdominal circumference. Nine service providers over twenty-six (34.6%) affirmed explaining the limitations of ultrasound. Eighteen devices over twenty-six (69.2%) had more than 9 years of age, 73% (19/26) of them did not have a vaginal probe and 65.3% (17/26) did not have a pulsed wave Doppler.Conclusions: Improving the quality of the practice of obstetrical ultrasound in Guinea goes through training of service providers, establishing distribution and compliance with norms and standards as well as quality control of ultrasound devices.
Role of serum LDH in preeclampsia as a prognostic factor – a cross sectional case control study in tertiary care hospital
Authors: Mary Vinitha Padmini , Chellatamizh M. , Padmanaban S.
Published: January 2017

Background: LDH is an intracellular cytoplasmic enzyme. It is ubiquitous to all the major organ systems. Cellular enzymes in extracellular space have no metabolic function, although they serve as indicators of disturbances in cellular integrity. Serum LDH is abnormal in many disorders, therefore total serum LDH is highly sensitive but nonspecific test. In preeclampsia also LDH may be elevated and can indicate the prognosis for both mother and fetus. We conducted this study to examine the relationship between lactate dehydrogenase concentration and the severity of the disease and the occurrence of its complications.Methods: 200 pre-eclamptic women (121 with mild and 79 with severe pre-eclampsia) and 200 healthy normotensive controls were studied prospectively at Government Kilpauk medical college and hospital between January and December 2015. Demographic, hemodynamic, and laboratory data were compared among the three groups. The symptoms and complications of severe pre-eclampsia along with fetal outcome were analyzed according to the levels of LDH.Results: Severely pre-eclamptic patients were significantly younger, with low gravidity and parity. On the other hand, they had significantly increased systolic and diastolic pressure and liver enzymes, uric acid, urine albumin, and LDH levels. The symptoms and complications of pre-eclampsia along with perinatal mortality were increased significantly in patients with LDH >800 IU/l compared with those who had lower levels.Conclusions:  Lactate dehydrogenase is a useful biochemical marker that reflects the severity of pre-eclampsia. In our study, LDH has been evaluated as a biochemical marker for preeclampsia and as a prognosticator of the disease severity. Detection of high-risk patients with increased levels of LDH mandate close monitoring and management to prevent maternal and fetal morbidity and mortality.
Risk factors of thrombocytopenia in pregnancy
Authors: Begam Ayisha , TL Sujatha , Nambisan Bindu , KP Vasanthakumari
Published: January 2017

Background: Thrombocytopenia in pregnancy occurs due to several etiologies which include both pregnancy specific and non pregnancy related causes. It is second only to anemia as the most common hematological abnormality encountered in pregnancy. Better antenatal care has led to increased detection. Once diagnosed, it is important to further evaluate and to determine the cause to optimize management. Several studies have been undertaken across the world; however there are very few studies in Kerala hence this study. The aim of this study was to determine the risk factors of thrombocytopenia in pregnancy.Methods: This was a case control study undertaken in the Department of Obstetrics and Gynecology, Medical college Hospital, Trivandrum, Kerala. Using purposive sampling, a sample size of 96 cases and 96 controls were included in this study. “Cases” were antenatal women with thrombocytopenia and “controls” were consecutive women without it. Study period was 18 months and analysis was done using SPSS version 22.Results: In 49% of subjects ,the cause was identified as gestational thrombocytopenia,39.5% cases were due to hypertensive disorders of pregnancy.10.4% was due to ITP. SLE, AFLP, Dengue infection, HUS and APLA were rare causes of thrombocytopenia in our hospital. Of the 96 cases enrolled in the study,88 were diagnosed during pregnancy. Amongst the hypertensive disorders,16.7% was due to gestational hypertension,10.4% due to preeclampsia and 7.4% were due to HELLP syndrome.82.3% of patients with thrombocytopenia in this study were asymptomatic.Conclusions: Thrombocytopenia should be evaluated by making a practice of routinely checking the platelet count and peripheral smear in early pregnancy and also in third trimester to enable early diagnosis since most cases may be asymptomatic.
Prevalence of Bronchial Asthma among School Children in Urban and Rural Areas and Associated Risk Factors: A Cross Sectional Study from Western Uttar Pradesh, India
Authors: Prakhar Sharma Nitin Kumar , Naresh Kumar ,
Published: January 2017

Objective: To find the prevalence of asthma in the age group of 6 –13 years & to identify the risk factors increasing the prevalence of asthma in Urban and Rural area school children in Western Uttar Pradesh. Methods. This is a cross sectional community based study conducted by interviewing the parents of randomly selected 1287 children in the age group of 6-13 years using a modified International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire. Results: Out of 1287 children, 746 children belong to urban area and 541 children were in rural area. Prevalence of bronchial asthma in Urban School children was 11.93% and 9.79% for Rural Children respectively. The prevalence of asthma was higher among girls (11.96%) compared to boys (10.32%). There was an inverse linear trend with increasing age. A statistically significant association of bronchial asthma with breast feeding, type of diet, indoor plants, family history of asthma, allergy, type of domestic fuel used and heavy vehicle smoke was observed. There was no association of bronchial asthma with age, gender, birth weight and family history of smoking. Conclusion: There is a high prevalence of bronchial asthma among children living in urban areas with a high prevalence among girls. Advice for exclusive breast feeding, avoidance of domestic fuel smoke and heavy vehicle smoke may reduce the risk of asthma and should be encouraged.
Comprehensive NICU Parental Education: Beyond Baby Basics
Authors: Mosher Sara L.
Published: January 2017

Abstract

Educating NICU families during their child’s hospitalization and prior to hospital discharge is an integral task for staff from the moment an infant is admitted to the unit. Staff has the responsibility of providing parents with a myriad of education regarding the intensive care environment and information concerning their child’s medical condition. With first-time parents, staff teaching topics extend to also include training on how to perform basic newborn care such as diapering, bathing, feeding, and numerous other primary parenting responsibilities. True comprehensive education, however, should include information about and evidence on the significance of parental self-care in not only their own health and emotional stability but also the cognitive and behavioral development of their child prior to leaving the comfort of their NICU support network. Recommendations for this essential education are presented so NICU providers can best prepare parents for this critical responsibility.
Palliative Care in the NICU and Why Education Matters
Authors: Discenza Deborah
Published: January 2017

Abstract

Palliative care in the NICU gets a bad rap to the point where it is not even clearly described to families. There is a strong need for education and dispelling the myths that surround this very important type of support.
Growth Performance of Mono Sex and Mixed Sex Climbing Perch (Anabas testudineus)
Authors: Helmizuryani Helmizuryani , Muslimin Boby
Published: January 2017

Many factors influence fish growth like rearing by sex. This study aims to determine the growth of theClimbing perch of the different sexes. This research was conducted at hatchery business unit at MulyaPlaju, from May to July 2015. Fry spawning fish came from the wet Laboratory Faculty of Agriculture,University of Muhammadiyah Palembang. They were maintained separately between the male and thefemale and the gender-mix between male and female, reared in nets with a density of 30 individualseach net; each treatment was repeated three times. During the research, fry feed used artificial feedwith 30% protein compotition.  The results showed that there was growth of female was faster than ofmale and of mixed sex. The growth of fish was 1,40 cm and weight of 4.56 gr, while survival rate ofthem was 100%. Keywords : growth, Anabas testudineus, mixed sex,  mono sex
Industrial-sized Cyber Attacks Threaten the Upstream Sector
Authors: Jacobs Trent
Published: January 2017

The oil and gas industry is coming to terms with a cyber threat landscape that has expanded beyond data breaches and the theft of intellectual property. The latest battlefront is in the field where critical drilling and production assets are at risk of being disrupted or destroyed, thanks to their highly vulnerable control systems.

The industry has experienced only a few cases of these so-called cyber-to-physical attacks but the US Department of Homeland Security predicts that by 2018 cyber attacks against oil and gas infrastructure around the world will cost almost USD 1.9 billion. One of the most dire warnings comes from the multinational risk adviser and insurance firm Willis Group, which in 2014 reported that “a major energy catastrophe, on the same scale as Piper Alpha, Phillips Pasadena, Exxon Valdez, or Deepwater Horizon, could indeed be caused by a cyber attack.” The company noted in its report that insurance providers generally will not cover such events. The concern over control systems has come to the forefront because of the widespread use of digital oilfield technology that began about 2 decades ago. Driven by significant gains in efficiency and production, companies eagerly moved to tether nearly every facet of operational networks to the Internet, either directly or through corporate networks. On the plus side, the industry gained invaluable real-time data, various operations became automated, and engineers working in office buildings could remotely control offshore operations.

But the computer hardware that makes all of this possible was never designed to be connected to the Internet. Known collectively as Industrial Control Systems (ICS), they were built to run in isolation and thus have no security measures that guard against run-of-the-mill malware, let alone a targeted cyber attack launched by a sophisticated hacker.

“Security was not important for anyone; what was important was to have those systems operational,” said Ayman Al Issa, chief technologist and senior adviser of industrial cyber security at Booz Allen Hamilton. He added, “Based on our experience, it is easy to attack those systems—it is easy to attack thousands of them.”

Al Issa explained that the control systems are used not only in the oil and gas industry but in nearly every industry and utility sector around the world. Recent attacks on control systems in Europe prove that the digital oil field is at risk. The long list of assets using these exposed control systems includes drilling rigs, subsea wellheads, flowmeters, production facilities, pipelines, and artificial lift installations.

The industry is working on multiple fronts to address vulnerabilities, but cybersecurity experts working in the industry say it will be years before adequate safeguards are in place. Until then, oil and gas companies must face the reality that the hacker community has the advantage.
Vietnam Still Holds Much E&P Opportunity
Authors: Parshall Joel
Published: January 2017

As oil companies struggle with the collapse in crude prices and industry upheaval, assessing the future of exploration and production (E&P) in specific countries requires a longer term vision of a market in which prices will have stabilized and rebounded to a level yet undetermined. Seen in this lengthier view, Vietnam holds substantial E&P opportunity because of its resource potential, its expanding economy and surging internal energy demand, the diverse group of global operators active in the country, and the interest of national oil company Petrovietnam in expanding partnerships with international E&P players.

At the same time, a limitation on this upside lies in the dispute between Vietnam and China over territorial waters, which is affecting international investment in some E&P prospects. While sporadic tensions have arisen between the countries, Vietnam and China remain in discussions over the disputed areas. A peaceful resolution could benefit both countries and the oil and gas industry. Notably, well to the north of the disputed waters, Petrovietnam and China National Offshore Oil Company have a joint exploration agreement covering the Gulf of Tonkin.

In the decades since the end of the Vietnam War, exploration and development in Vietnam have grown by leaps and bounds. With 4.4 billion bbl of oil reserves, the country now ranks No. 3 in the Asia- Pacific region, trailing only China and India.

Always an Interest

“Vietnam has always been an interest among international oil and gas companies,” said Suraya Tulot, Vietnam EP upstream researcher at IHS. “It is an opportunity that companies are looking at, especially the independents.”

Almost all of Petrovietnam’s domestic upstream activity has been offshore in shallow water. From the beginning, the Cuu Long Basin has been the center of Vietnamese E&P. However, activity has spread to the Nom Con Son, Song Hong, Phu Khanh, Phu Quoc, and Malay-Tho Chu basins, as well as others, and deepwater development is getting under way.

“Vietnam is relatively underexplored,” Tulot said. “While the focus has been on Cuu Long, there are opportunities in the Nam Con Son and Song Hong basins and elsewhere.” Petrovietnam’s Ky Lan 1X gas discovery in the Song Hong Basin late last year is one example. That success has piqued interest among other companies. Eni and KrisEnergy have recently acquired exploration blocks in the vicinity.
E&P Notes (April 2016)
Authors: Jacobs Trent , Rassenfoss Stephen
Published: January 2017

E&P Notes

Onshore Support for Mexico’s Deepwater Blocks Lacking

Trent Jacobs, JPT Senior Technology Writer

The deepwater blocks Mexico plans to lease to international operators in December are among the deepest, most remote, and geologically challenging in the world. But the difficulties of developing these areas will start onshore, where adequate and secure port facilities are few and far between.

“This is where the issue is about deep water,” said Chris Garcia, the Mexico international account director and deepwater adviser at Schlumberger. “Logistics are going to be very challenging, much more so than on the American side.”

 

New Technology To Cut Electric Costs, Not Production

Trent Jacobs, JPT Senior Technology Writer

Everhart Energy Technology, a startup company based in Beverly Hills, California, has developed a system it believes will help small to medium-sized operators cope with the reality that, while oil prices have fallen, their electric bills have not.

Installed between a pump jack lift and its power source, the system regulates the power being transmitted to the electric motors and also captures the kinetic energy generated on the pump’s down stroke—similar to how a hybrid vehicle works. The technology was invented in South Korea for industrial and commercial equipment and Everhart, founded in 2014, has secured the rights to apply it in oil fields in the United States.

 

Statoil Gets a Jump on Offshore Costs

Stephen Rassenfoss, JPT Emerging Technology Senior Editor

One of the latest offshore innovations from Statoil is nothing flashy, which is the point. A drawing shows a plain, steel jacket, standing in water 110 m deep, topped with a flat metal deck.

The spare design is indicative of the disciplined approach to offshore development that led to a 52% decrease in the estimated break-even cost for its Oseberg Vestflanken 2 project, of which the platform is a key part. The lower break-even made it possible to move forward with development of three small oil and gas fields at a time when depressed prices are forcing mass cancellations of offshore projects globally.
Operations Excellence Begins in Design
Authors: Wilson Adam
Published: January 2017

This article, written by Special Publications Editor Adam Wilson, contains highlights of paper IPTC 18566, “Operations Excellence Begins in Design,” by Wesley R. Qualls, ConocoPhillips, prepared for the 2015 International Petroleum Technology Conference, Doha, Qatar, 7-9 December. The paper has not been peer reviewed.

Achieving production and availability targets is paramount to the ultimate success of any liquefied-natural- gas (LNG) project. Both are important factors in any life-cycle economic analysis. The focus on true operational excellence must begin early in the design phase and remain endemic throughout. This paper focuses on common design pitfalls and oversights within the LNG industry and presents several methods or techniques to avoid them. While the techniques and methods presented are not new to the oil and gas industry, they are often not used within the LNG industry.

Introduction

The first and foremost consideration in almost any process design is defining feed conditions and product specifications properly. Ideally, this should occur well before beginning process design, but, unfortunately, this is not always the case. Because most recognize the importance of defining feed pressure, feed temperature, and product specifications, these particular variables are generally well-defined. However, accurately characterizing feed compositions and quantifying feed contaminants remain common industry oversights. The lack of diligence in these areas can and does lead to numerous operating problems, some of which are difficult and costly to address.

Many critical project considerations are involved in the process, equipment, and piping design. Design oversights with this type of work process are common, often resulting in late design changes and rework. To avoid added cost and schedule delays, many smaller design oversights discovered later in design are simply accepted. A question frequently and understandably asked in later project phases is, “Will it work?” Seldom in later project phases is the question asked, “Will it work well?” Naturally, once the perceived cost of correcting a problem becomes greater than the perceived benefit, the focus on operations excellence cannot endure.

Therefore, it is of paramount importance to eliminate as many design oversights as possible early in the project timeline.

Feed Contaminants

While it may be intuitively obvious that it is necessary to identify and quantify feed contaminants, the effort does not always receive sufficient attention. If contaminants (e.g., methanol, glycols, oxygen, corrosion inhibitors, compressor oils, acids, chlorides, salts, aerosols, iron sulfide, and dust and other particulates) are identified and quantified properly from the outset, the processes and equipment to remove them, and in some cases to recover them, may be properly selected and sized early in design. Otherwise, equipment must be added, modified, or replaced late in design or after operation begins.
New Approach Tests Cement-Sheath Integrity During Thermal Cycling
Authors: Wilson Adam
Published: January 2017

This article, written by Special Publications Editor Adam Wilson, contains highlights of paper SPE 173871, “Cement-Sheath Integrity During Thermal Cycling: A Novel Approach for Experimental Tests of Cement Systems,” by J. De Andrade, SPE, and S. Sangesland, SPE, Norwegian University of Science and Technology, and J. Todorovic, SPE, and T. Vrålstad, SPE, SINTEF Petroleum Research, prepared for the 2015 SPE Bergen One Day Seminar, Bergen, Norway, 22 April. The paper has not been peer reviewed.

Well cement is placed into the annulus between casing and formation to provide structural support and zonal isolation throughout the well life cycle. Nevertheless, operators in the North Sea have been concerned about the ability of the cement sheath to maintain sealing integrity because of the increasing number of reported failures in mature wells. A new laboratory setup is designed to allow visualization of the development of possible leak paths throughout the cement sheath when exposed to pressure-and temperature-related varying loads.

Experimental Setup

The new laboratory setup presented in this work allows pressurization while maintaining the capability to perform a detailed study of the creation and propagation of cement-sheath failures upon thermal cyclic loads.

The cell is shown in Fig. 1.

The applied formation materials were Saltwash North sandstone and Mancos shale.

Some of the current features of the cell are specified as follows:

Cell is X-ray transparent.

Temperature is controlled (from inside the casing) during cement setting and cyclic tests.

There is independent control of pressure inside casing on cement and confining pressure (around the rock) during cement setting and cyclic tests.

Maximum pressure is set at approximately 35 bar, while the allowable temperature range is set between −1°C and 150°C.

All components of the cell can be reused for several test samples.

In particular, the X-ray transparency is important because it allows for visualization of leak paths without the need to release pressure from the cell, or remove the internal test sample for a computed-tomography (CT) scan, or perform the traditional invasive method of cutting the test sample cross section. This was achieved by constructing the cell from aluminum, which has suitable radiolucent characteristics and allows the radiant energy to pass toward the test sample with little attenuation. The material also provides a lightweight cell to facilitate handling.
Viscosity and Stability of Dry CO2 Foams for Improved Oil Recovery
Authors: Carpenter Chris
Published: January 2017

This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper SPE 179690, “Viscosity and Stability of Dry CO2 Foams for Improved Oil Recovery,” by Chang Da, Zheng Xue, Andrew J. Worthen, Ali Qajar, Chun Huh, Mascarona Prodanovic, and Keith P. Johnston, The University of Texas at Austin, prepared for the 2016 SPE Improved Oil Recovery Conference, Tulsa, 11–13 April. The paper has not been peer reviewed.

Carbon dioxide (CO2)/water foams are of interest for mobility control in CO2 enhanced oil recovery (EOR) and as energized fracture fluids or as hybrid processes that combine aspects of both processes. It is challenging to stabilize ultradry foams with extremely high internal-phase gas fraction given the high capillary pressure and the rapid drainage rate of the lamellae between the gas bubbles. However, the authors demonstrate that these ultradry CO2- in-water foams may be stabilized with surfactants that form viscoelastic wormlike micelles in the aqueous phase.

Introduction

In this study, the authors extend the study of ultradry CO2/water foams composed of worm-like micelles to higher temperatures by adding an electrolyte, potassium chloride (KCl), and a cationic surfactant, decyldimethylamine (C10DMA), to the primary surfactant, sodium lauryl ether sulfate (SLES). The continuous-phase viscosity and surface shear viscosity of this formulation were found to be approximately two orders of magnitude higher when worm-like micelles were formed at room temperature. The foam morphology was measured at high pressure with microscopy, and a long lifetime of foam bubbles was demonstrated. The morphology of the worm-like micelles was also characterized by cryogenic transmission electron microscopy.

The authors have been able to manipulate foam stability for various specialty applications such as EOR where low water consumption, foam stability and extended life span, and conformance of the foams are crucial. In particular, these high-quality stable foams have been developed and tested at laboratory scale in high-salinity and high-temperature conditions to mimic the actual reservoir condition. These high-quality, highly stable foams have been generated and tested by use of sandpacks at the laboratory scale. In this work, a numerical simulation of foam injection into a layered reservoir is performed.
Drilling Slump in North Dakota Allows Rapid Flaring Reduction
Authors: Rassenfoss Stephen
Published: January 2017

Natural gas flared in the Bakken has abruptly declined this year, reaching 8% in April, a striking change from the days when more than one-third of the gas from the oil-rich formation was burned.

“In 2014, flared volumes in the state reached 0.35 Bcf/D, equal to almost half of total volumes that were either flared or vented in the United States,” according to a report by the US Energy Information Administration (EIA).

The percentage of gas flared in April was half of what it was at the end of last year, and the volume is the lowest since 2011, according to totals reported by the state.

During the Bakken boom in 2014, nighttime pictures from space served as a sign of the times, showing the light from the many flares in the sparsely populated state that otherwise would look mostly dark. While lights are still visible, they are not as bright.

The EIA reported flaring in the state “has declined sharply since 2014,” based on numbers from the North Dakota Industrial Commission’s Department of Mineral Resources.

The volume of gas flared is down because more is flowing to market via the state’s expanded network of pipeline and processing facilities. The amount burned looks even smaller as a percentage because the total amount of gas produced has been rising in North Dakota, which set a record for output in March.

The accelerated rate of decline was a bit of a surprise. Last fall, North Dakota regulators stretched out the timetable for a reduction in flaring to 10% of the total gas production by 2020, after the industry asked for more time to deal with issues slowing the expansion of pipelines and processing facilities.

North Dakota officials are wary about declaring victory. “In the near term we expect to have a high level of gas capture in North Dakota,” said Justin J. Kringstad, director of the North Dakota Pipeline Authority, who closely follows the business. “But over the long term it is something we are continuing to look at.”
Guest Editorial: Low Prices Trigger Much-Needed Change Through a Holistic Approach
Authors: Jackson Dan
Published: January 2017

Guest editorial

Change in the oil and gas industry often comes slowly. However, as months of low oil prices turn into years, it is necessary now. Oil producers have taken to cutting billions of dollars in expenditure, which has forced providers and contractors to slash rates and delay and even cancel projects.

The upstream industry in particular needs to fundamentally transform the way it works to survive and thrive. While cost-cutting can be an effective plan in the short term, the industry needs to take a longer-term focus and change the fundamentals of the way it operates. To compound matters, the days of triple-digit oil prices appear well and truly over, with the World Bank estimating that a barrel of oil will only rise to USD 60 by 2020.

Regardless of the oil price, the sector needs to rethink established ways of working in order to better handle increasingly complex projects. The high crude price in recent years helped the industry gloss over inefficiencies and enjoy success in the short term. But the recent slump has fully exposed shortcomings, and shone a spotlight on the fact that the offshore industry was on an unsustainable path and in need of guidance to standardize processes to lead the industry through a turbulent time.

Taking a Holistic Approach

A reason why projects are not completed on time and on budget is the disconnect between operators and contractors. A recent report from Ernst & Young on oil and gas megaprojects showed that 21% of project failures came down to management processes and contracting and procurement strategies; 65% were due to people, organization, and governance; and 14% of failures were due to external factors such as government intervention and environment-related mandates.

The existing model of contracting is piecemeal with specialist designers, contractors, and projects managers coming on board one at a time, with no one group bringing the whole project together at the front end to deliver efficiencies and control that should be standard in the offshore sector.

Oil companies and contractors, therefore, need to work together better to understand the drivers and develop the best blueprint to take the project forward into execution with a common purpose. The benefits of a holistic approach mean that all aspects of a project are taken into consideration from the beginning to ensure that it can be delivered on time, on budget, and with certainty.
Understanding Completion Performance: Software-Guided Work Flows and Models
Authors: Carpenter Chris
Published: January 2017

This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper SPE 179172, “Understanding Completion Performance in Niobrara-Codell Reservoirs Through the Use of Innovative Software-Guided Work Flows and Models,” by K.J. Wallace, Encana Oil and Gas; P. Reyes Aguirre, Schlumberger; E. Jinks and T.H. Yotter, Encana Oil and Gas; and Raj Malpani and Felipe Silva, Schlumberger, prepared for the 2016 SPE Hydraulic Fracturing Technology Conference, The Woodlands, Texas, USA, 9–11 February. The paper has not been peer reviewed.

This paper describes a comprehensive field study of eight horizontal wells deployed in the stacked Niobrara and Codell reservoirs in the Wattenberg Field (Denver-Julesburg Basin). The overall goal was to understand the geometry of the hydraulic fractures (propped) and the producing volume with respect to completions design, target reservoirs, and well spacing. Through this understanding, the asset can be developed more effectively and economically.

Field Description

The Wattenberg Field is a basin-center petroleum accumulation located northeast of Denver, from which hydrocarbons have been extracted over the last 50 years. Development in the Wattenberg Field began in 1970 from vertical J-Sandstone wells, with production of the Niobrara following in 1976. In 2009, horizontal development began in the Niobrara formation. The Upper Cretaceous sequence from Codell to Niobrara is the current focus of horizontal development in the Wattenberg Field.

Petrophysical Model

A robust 3D mechanical Earth model (MEM) provides the framework for data integration and physical simulations. In this work flow, the MEM calculates or approximates a number of input parameters. Each of these variables is defined both spatially and stratigraphically and is housed in a 3D geocellular model. Because many of the input calculations are dependent on other variables, a set of variable relationship definitions keeps the model dynamic so that, during the tuning process, all initially established data relationships are honored.
Shift Toward Permian Drives Rising Rig Count
Authors: Parshall Joel
Published: January 2017

Don’t look now, but the United States rig count has inched up in recent months, and the driver has been the old reliable of onshore oil production, the Permian Basin of west Texas and New Mexico.

While some observers might see the scenario as a simple case of drillers responding to the recovery of oil prices over the spring and summer, the fact that rig growth occurred chiefly in the Permian indicates there is more to the story. And along with a similar, smaller shift of gas rig activity toward the Marcellus and Utica basins in Pennsylvania and Ohio, the statistics suggest what the geographic footprint of an eventual, long-term recovery may look like in the US.

The number of active oil rigs nationwide rose to 407 for the week ending on 2 September, according to Baker Hughes, up from 316 for the week of 27 May. Of the additional 91 rigs, 65 were activated in the Permian Basin. Beginning from a low point of 132 rigs operating in the week of 29 April, the basin has added 70 rigs, and it currently has more than 50% of the horizontal oil rigs operating in the US, up from 15% in 2011.

A smaller growth trend has emerged in Oklahoma, where 10 rigs were added between 13 May and 2 September to bring the statewide total to 66. The increase has centered on the SCOOP (South Central Oklahoma Oil Province) and STACK (Sooner Trend, Anadarko [Basin], Canadian [County], and Kingfisher [County]) plays.

On the US natural gas side, the 88 rigs operating at the beginning of September reflected little change since spring. However, a shift in deployment had added six rigs to the Marcellus since 5 August and four rigs to the Utica since 20 May. The total number of rigs operating in the two basins were 27 and 14, respectively.
Model for a Shale-Gas Formation With Salt-Sealed Natural Fractures
Authors: Carpenter Chris
Published: January 2017

This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper SPE 175061, “Model for a Shale-Gas Formation With Salt-Sealed Natural Fractures,” by Hoagie Merry and C.A. Ehlig-Economides, University of Houston, and Pang Wei, Sinopec Research Institute of Petroleum Engineering, prepared for the 2015 SPE Annual Technical Conference and Exhibition, Houston, 28–30 September. The paper has not been peer reviewed.

Most multiple-transverse-fracture horizontal wells in shale-gas formations remain in transient bilinear or linear flow for very long periods. However, there are often reported cases of shale wells that exhibit boundary-dominated flow in a very short period, which implies a stimulated rock volume (SRV) much smaller than would be expected. This paper offers an alternative explanation for the early boundary-dominated flow related to dissolution of salt-sealed natural fractures in the shale.

Introduction

Operators producing gas from the Haynesville, Marcellus, and Horn River shale formations have observed that produced water is more saline than the injected fracturing fluid. Additionally, the fraction of injected water that flows back when the well is put on production— termed load recovery—is low.

This study investigates the possibility that salts removed by flowing back injected low-salinity water-based fracturing fluid may be a mechanism for increasing the effective permeability in shale-gas wells within a limited volume surrounding the created hydraulic fractures. The study offers strong evidence that salt may be a key factor in productivity and ultimate gas recovery from shale-gas wells.

Interactions Between Fluids, Salt, and Shale

Several fracturing-fluid/formation interactive phenomena relate strongly to the material-balance model that the authors have developed. These phenomena include the imbibition and entrapment of injected fracturing fluid, the increase in salinity of the fluid in contact with the shale, and the deterioration of shale samples.

Several researchers have studied the relationship between the low load recovery of hydraulic-fracturing fluid and the elevated salinity of the fluid that does return. Many authors have proposed relationships between the surface area of the formation exposed to fracturing fluid, the characteristics of the fluid, the wettability of the rock, and the distribution or characteristics of the natural-fracture system. These findings are examined in detail in the complete paper.
Positron-Emission Tomography Offers New Insight Into Wormhole Formation
Authors: Carpenter Chris
Published: January 2017

This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper SPE 180051, “New Insight Into Wormhole Formation in Polymer Gel During Water Chase Floods Using Positron-Emission Tomography,” by B. Brattekås, University of Stavanger; M. Steinsbø, A. Graue, M.A. Fernø, and H. Espedal, University of Bergen; and R.S. Seright, New Mexico Petroleum Recovery Research Center, prepared for the 2016 SPE Bergen One-Day Seminar, Bergen, Norway, 20 April. The paper has not been peer reviewed.

Polymer gel is frequently used for conformance control in fractured reservoirs, where it is injected to reside in fractures or high-permeability streaks to reduce conductivity. Polymer-gel behavior is often studied in corefloods, where differential pressure and effluents from fracture and matrix outlets give information about gel deposition during placement and flow paths during chase floods. The work presented in this paper uses complementary positron-emission-tomography (PET)/computed-tomography (CT) imaging to quantify the behavior and blocking capacity of gel during chase waterflooding.

Introduction

Channeling of injected fluids through a highly permeable fracture network, and the following early fluid breakthrough, may be mitigated by placing a highly viscous polymer gel in the fracture. With polymer gel in place, higher differential pressures may be achieved during chase floods, which can contribute to increased sweep efficiency in the porous matrix adjacent to the fracture network.

A polymer gel is formed when a gelant solution is exposed to elevated temperature for a given time, known as the gelation time. Previous work has investigated how the gel state during placement (gel or gelant) influenced the gel behavior during chase floods. The complete paper provides a detailed discussion of previous models for fluid leakoff. In this work, the authors study the extrusion of formed polymer gel through fractures, and its resistance to pressure during subsequent waterfloods.

PET imaging is based on the decay of positron-emitting radionuclides. In this work, PET was used to visualize flow of radioactive water through a gel-filled fracture, to augment global measurements, and to increase the understanding of filter-cake formation during formed-gel placement and wormhole formation during chase floods.

A discussion of the experimental setup, including limestone- and sandstone-core-plug preparation, polymer-gel placement, the chase-flood procedure, and the PET-imaging process, is provided in the complete paper.
Determination of H2S Partial Pressures and Fugacities in Flowing Streams
Authors: Carpenter Chris
Published: January 2017

This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper SPE 179921, “Determination of H2S Partial Pressures and Fugacities in Flowing Streams for a More-Accurate Assessment of Integrity Threat in Sour Systems,” by Christopher Harper, Kanan Taghiyev, and Peter Wilkie, Baker Hughes, and Douglas Hall, Chevron, prepared for the 2016 SPE International Oilfield Corrosion Conference and Exhibition, Aberdeen, 9–10 May. The paper has not been peer reviewed.

An Excel-based tool was developed that uses cubic-equation-of-state (EOS) and thermodynamic electrolyte-chemistry modeling to assess sour-production streams from a reservoir, through production tubing, pipelines, and facilities to an export pipeline within a range of temperature and pressure conditions. The approach is need to assess the integrity risk posed to system components in the Alba field in the North Sea.

Theory and Methodology

To accurately determine multiphase sulfide concentrations, and therefore hydrogen sulfide (H2S) partial pressures and the resulting integrity threat in sour-production streams, it is first important to understand the pH-dependent distribution of the three species of sulfide that may be present in an aqueous solution. Many commercially available EOS software packages do not take into account aqueous pH- and speciation-driven aqueous sulfide solubility. They merely assume that the gas-phase and oil-phase H2S remains as H2S in all three phases and, as such, that the aqueous solubility is limited by the solubility of the H2S species in water.

The three species of sulfide that may be present in an aqueous solution are H2S, HS−, and S2−. How much of each species is present (as a fraction) is dependent largely upon the aqueous pH. H2S is the only species of sulfide that exists in all three phases; some aqueous sulfide must speciate to H2S before H2S is found in the oil and gas phases. Therefore, in an oil-production system in thermodynamic equilibrium, with an aqueous pH of 9.5 or higher, all sulfide must be in the water phase and oil and gas phases must be completely free of H2S. However, this would be very unusual in an oil- production system or reservoir where typical aqueous pH values are much lower.

At very low pH values, three-phase H2S distribution is driven by temperature and pressure alone: Increasing pressure reduces gas-phase H2S and increases oil- and water-phase H2S, whereas increasing temperature increases gas-phase H2S and reduces oil- and water-phase H2S (Fig. 1).
DEVELOPMENT OF ECOLOGICALLY SAFE TECHNOLOGY OF WASTE MYCELIA RECYCLING
Authors: Yegorova Oksana
Published: January 2017

Chitosan is a cationic polymer derived by deacetylation of chitin obtained from crustaceans. Biodegradable and mucoadhesion properties of chitosan have recently led to increasing the interest. Chitosan can be used as raw material for the manufacture of films, membranes and fibers, in such branches as medicine, agriculture, veterinary medicine, biotechnology, cosmetics and pulp, and paper industry. Previously it was investigated that in Aspergillus Niger cell wall constituents, chitin comprises of 42 % and also researchers confirmed that the chitosan content of fungi depends on fungal strains, mycelial age, cultivation medium and conditions [1]. In the paper the results of the study of physical and chemical properties of obtained samples of chitosan are shown. The influence of initial parameters of the process on the quality of chitosan is investigated. Use of the biomass to produce chitosan on the basis of the developed methodology is shown. It is found that the resulting chitosan is characterized by low values of ash content, moisture content and the value is within 75–82 %. A further development of the scientific basis for the creation of an efficient, competitive and environmentally safe technologies for utilization mycelial biomass of the fungus Aspergillus Niger with the production of a valuable product is chitosan, which is in contrast to the known allows to reduce production costs by 10–80 % (by using not concentrated solutions of chemicals and low temperature process. This leads to reducing the cost of reagents and electricity. The calculation was performed on indicators such as net present value, internal rate of return and payback period.) The use of the developed technological schemes in practice allows utilization of mycelial waste with the aim of obtaining from them valuable product of chitosan, and to ensure the improvement of ecological situation in the region.
TYPES OF ANGIOPATHY IN EXPERIMENTAL AUTOIMMUNE DISEASE IN RATS
Authors: Iegudina Yelizaveta , Yakovlenko Pavel , Syniachenko Oleg , Mikuksts Viktoriya
Published: January 2017

The purpose and objectives of this work were to study the nature of the heart, lungs and kidneys angiopathy in rats with a model of systemic autoimmune disease, carrying out comparisons of the results with extravasal morphological manifestations of the pathological process, the state of vascular endothelial function and activity of pro-inflammatory cytokines in the blood. The experiment was conducted on 40 non-linear rats. To simulate the disease animals were injected by complete Freund's adjuvant, a solution of splenic deoxyribonucleic acid cattle, mercaptopurine, methyluracilum and with food rats constantly received sulfate cadmium, lithium hydroxybutyrate and ammonium molybdate. Within two months from the start of the study animals were taken out of the experiment on the background of intraperitoneal nembutal anesthesia. Histological sections of the heart, lung and kidney tissue were stained with hematoxylin -eosin, alcian blue and by van-Gieson, becoming the PAS-reaction. In the animals with the proposed experimental model of systemic autoimmune disease observed morphological characteristics of lesions of the heart blood vessels, lungs and kidneys, the nature of the manifestations of which were interconnected with each other, which confirms the common pathogenetic angiopathy constructions at various diseases in clinical practice. In the genesis of cardiac, pulmonary and renal vessels lesions act the activation of pro-inflammatory cytokines and violation of vascular endothelial function, which has a certain practical significance. In clinical practice, not only purely systemic vasculitis, and other autoimmune diseases should be treated as angiopathy.
PREDICTION OF THE DURATION OF HOSPITAL TREATMENT OF PATIENTS WITH CATARACT
Authors: Kovtun Mihail , Kochina Marina , Lapkina Inna
Published: January 2017

The aim of the paper was to evaluate and determine the duration of the hospital treatment of patients with cataract.

Materials and methods of the investigation. 629 case histories were analyzed and 60 patients’ forms were also analyzed. The assessment of case histories was done according to the scheme: sex, age, the stage of cataract, the duration of hospital treatment, the cause of treatment which lasts more than 1 day (postoperative complication, treatment of concomitant eye diseases, patient’s desire), the type of complication. 60 surveyed patients with cataract required surgical treatment in order to work out the model of the duration of hospital treatment. The questionnaire contained several questions, which answers allow evaluating the social status of patients, somatic and optic status, peculiarities of the main disease and also the duration at the hospital after the operation.

Results. It has been demonstrated that patient’s age, his or her financial status, the number of concomitant somatic and eye diseases are the main peculiarities for the prognosis for long-lasting stay at hospital after surgical treatment. Undetermined logics was used to create the model of prognosis of the duration of hospital treatment based on еру results of patients’ questionnaire, the method of clustering was used to receive undetermined rules.

Conclusions. Ophthalmologic status of the patient, the presence of concomitant eye diseases, such as myopia alta, glaucoma, diseases of retina, and optic nerve and concomitant somatic disease play an important role in the choice of the type of treatment. The most informative indices for hospital treatment of patients with cataract after surgery are patient’s age, his/her financial status, the number of concomitant somatic and eye diseases.