bluuebunny/crossref_metadata_2025 huggingface dataset:
Systematic screening for PRKAR1A gene rearrangement in Carney complex: identification and functional characterization of a new in-frame deletion
Authors: Guillaud Bataille M , Rhayem Y , Sousa S B , Libé R , Dambrun M , Chevalier C , Nigou M , Auzan C , North M O , Sa J , Gomes L , Salpea P , Horvath A , Stratakis C A , Hamzaoui N , Bertherat J , Clauser E
Published: October 2013

Background

Point mutations of the PRKAR1A gene are a genetic cause of Carney complex (CNC) and primary pigmented nodular adrenocortical disease (PPNAD), but in 30% of the patients no mutation is detected.

Objective

Set up a routine-based technique for systematic detection of large deletions or duplications of this gene and functionally characterize these mutations.

Methods

Multiplex ligation-dependent probe amplification (MLPA) of the 12 exons of the PRKAR1A gene was validated and used to detect large rearrangements in 13 typical CNC and 39 confirmed or putative PPNAD without any mutations of the gene. An in-frame deletion was characterized by western blot and bioluminescence resonant energy transfer technique for its interaction with the catalytic subunit.

Results

MLPA allowed identification of exons 3–6 deletion in three patients of a family with typical CNC. The truncated protein is expressed, but rapidly degraded, and does not interact with the protein kinase A catalytic subunit.

Conclusions

MLPA is a powerful technique that may be used following the lack of mutations detected by direct sequencing in patients with bona fide CNC or PPNAD. We report here one such new deletion, as an example. However, these gene defects are not a frequent cause of CNC or PPNAD.
Spanking and Child Development Across the First Decade of Life
Authors: MacKenzie Michael J. , Nicklas Eric , Waldfogel Jane , Brooks-Gunn Jeanne
Published: October 2013

OBJECTIVE:

To examine the prevalence of maternal and paternal spanking of children at 3 and 5 years of age and the associations between spanking and children’s externalizing behavior and receptive vocabulary through age 9.

METHODS:

The Fragile Families and Child Well-Being Study, a longitudinal birth cohort study of children in 20 medium to large US cities, was used. Parental reports of spanking were assessed at age 3 and 5, along with child externalizing behavior and receptive vocabulary at age 9 (N = 1933). The data set also included an extensive set of child and family controls (including earlier measures of the child outcomes).

RESULTS:

Overall, 57% of mothers and 40% of fathers engaged in spanking when children were age 3, and 52% of mothers and 33% of fathers engaged in spanking at age 5. Maternal spanking at age 5, even at low levels, was associated with higher levels of child externalizing behavior at age 9, even after an array of risks and earlier child behavior were controlled for. Father’s high-frequency spanking at age 5 was associated with lower child receptive vocabulary scores at age 9.

CONCLUSIONS:

Spanking remains a typical rearing experience for American children. These results demonstrate negative effects of spanking on child behavioral and cognitive development in a longitudinal sample from birth through 9 years of age.
1-MCP nos aspectos fisiológicos e na qualidade pós-colheita de maçãs Eva durante o armazenamento refrigerado
Authors: Fante Camila Argenta , Boas Ana Carolina Vilas , Costa Adriano Carvalho , Silva Edson Pablo , Oliveira Marcelo Caetano de , Lima Luiz Carlos de Oliveira
Published: October 2013

O objetivo deste estudo foi verificar o efeito de doses específicas do composto 1-metilciclopropeno (1-MCP), após a colheita, nos aspectos fisiológicos e na qualidade físico-química de maçãs Eva durante o armazenamento refrigerado. Após a aplicação dos tratamentos com diferentes doses de 1-MCP (0, 10, 50, 100 e 500mg L-1), os frutos foram armazenados em câmara fria 0,5°C (±0,5) por até 135 dias. O armazenamento refrigerado juntamente com a aplicação de 1-MCP resultou em uma menor produção de etileno, principalmente nos frutos tratados com as doses de 10, 50 e 100mg L-1. O grupo controle perdeu 45% de sua firmeza, enquanto os grupos tratados perderam, em média, 27% de sua firmeza. O parâmetro C de cor identificou frutos com cor mais intensa aos 135 dias de armazenamento e o ângulo Hue mostrou que, quando tratados com as doses de 10 e 50mg L-1, os frutos apresentaram-se mais amarelados, evidenciando melhor ação do 1-MCP em baixas concentrações. Frutos que não foram submetidos aos tratamentos apresentaram maior relação sólidos solúveis e acidez, demonstrando assim maior atividade metabólica.
Bond behaviour of deformed bars in self-compacting lightweight concrete subjected to lateral pressure
Authors: Wu Xi , Wu Zhimin , Zheng Jianjun , Zhang Xue
Published: October 2013

The purpose of this paper is to present an experimental investigation into the bond behaviour between deformed bars and self-compacting lightweight concrete (SCLC) under lateral pressure. SCLC pull-out specimens made with two types of lightweight aggregate were tested under two orthogonal lateral pressures p1 and p2, perpendicular and parallel to the transverse rib of deformed bars respectively. It was found that, under uniaxial lateral pressure, the ultimate bond stress increases with an increase of p2 but is independent of p1. Under biaxial lateral pressures, the ultimate bond stress increases monotonically with an increase in p1 and/or p2. The slip at the ultimate bond stress is an increasing function of lateral pressure for specimens failing by splitting, but basically remains constant for specimens failing by pull-out. The ratio of residual to ultimate bond stress is mainly related to the ratio of cover depth to bar diameter. It was also found that the lightweight aggregate type has little influence on the bond behaviour of deformed bars. Based on the experimental results, empirical formulae for the ultimate bond stress, the slip at the ultimate bond stress and the ratio of residual to ultimate bond stress are formulated. Finally, a bond stress–slip model is proposed and verified with experimental results.
Soft skills of senior contracts managers in Northern Ireland
Authors: Fletcher Simon M. , Gunning Joseph G. , Coates Ronald
Published: October 2013

This paper describes an investigation of the soft management skills of senior personnel within construction companies in Northern Ireland. A literature review was undertaken to identify issues relating to soft management skills, and is summarised within the paper. Data were collected using eight semi-structured pilot interviews to identify the major issues required for inclusion in a subsequent on-line questionnaire. Each interview was analysed through cognitive mapping, using Banxia Decision Explorer software. The questionnaire asked respondents to indicate, on a five-point Likert scale, if they considered they had adequate soft management skills training and was circulated through the Construction Employers' Federation (N.I.). SPSS software used in the analysis of the 47 usable responses identified stress management, communication, people management, negotiation and presentation as the main soft management skills currently lacking. These soft management skills gaps are not widely recognised, the major emphasis of employers being on hard skills. Recent research at Queen's University, Belfast found that construction management education throughout the UK and Ireland also focuses primarily on developing hard management skills. Bridging of these soft management skills gaps will help improve day-to-day running of construction organisations.
Elderly Homeless Veterans in Los Angeles: Chronicity and Precipitants of Homelessness
Authors: van den Berk-Clark Carissa , McGuire James
Published: October 2013

Objectives. We compared the characteristics of chronically homeless and acutely homeless elderly veterans to better understand precipitants of homelessness.

Methods. We conducted interviews with 33 chronically and 26 acutely homeless veterans aged 65 years and older receiving transitional housing services in Los Angeles, California, between 2003 and 2005. We asked questions regarding their sociodemographic characteristics and other social status measures. Other precipitants of homelessness were acquired via observation and open-ended and structured questions.

Results. Both veterans groups were more similar than different, with substantial levels of physical, psychiatric, and social impairment. They differed significantly in homelessness history, with chronically homeless veterans having more homelessness episodes and more total time homeless. They were also less educated and had smaller social networks. In response to open-ended questioning, elderly homeless veterans revealed how health and substance use issues interacted with loss of social support and eviction to exacerbate homelessness.

Conclusions. Assessment of a range of factors is needed to address risk factors and events leading to homelessness. Further research with larger samples is needed to confirm the characteristics and needs of the elderly homeless veteran population.
Housing Retention in Single-Site Housing First for Chronically Homeless Individuals With Severe Alcohol Problems
Authors: Collins Susan E. , Malone Daniel K. , Clifasefi Seema L.
Published: October 2013

Objectives. We studied housing retention and its predictors in the single-site Housing First model.

Methods. Participants (n = 111) were chronically homeless people with severe alcohol problems who lived in a single-site Housing First program and participated in a larger nonrandomized controlled trial (2005–2008) conducted in Seattle, Washington. At baseline, participants responded to self-report questionnaires assessing demographic, illness burden, alcohol and other drug use, and psychiatric variables. Housing status was recorded over 2 years.

Results. Participants were interested in housing, although a sizable minority did not believe they would be able to maintain abstinence-based housing. Only 23% of participants returned to homelessness during the 2-year follow-up. Commonly cited risk factors—alcohol and other drug use, illness burden, psychiatric symptoms, and homelessness history—did not predict resumed homelessness. Active drinkers were more likely to stay in this housing project than nondrinkers.

Conclusions. We found that single-site Housing First programming fills a gap in housing options for chronically homeless people with severe alcohol problems.
High Utilizers of Emergency Health Services in a Population-Based Cohort of Homeless Adults
Authors: Chambers Catharine , Chiu Shirley , Katic Marko , Kiss Alex , Redelmeier Donald A. , Levinson Wendy , Hwang Stephen W.
Published: October 2013

Objectives. We identified predictors of emergency department (ED) use among a population-based prospective cohort of homeless adults in Toronto, Ontario.

Methods. We assessed ED visit rates using administrative data from the Institute for Clinical Evaluative Sciences (2005–2009). We then used logistic regression to identify predictors of ED use. Frequent users were defined as participants with rates in the top decile (≥ 4.7 visits per person-year).

Results. Among 1165 homeless adults, 892 (77%) had at least 1 ED visit during the study. The average rate of ED visits was 2.0 visits per person-year, whereas frequent users averaged 12.1 visits per person-year. Frequent users accounted for 10% of the sample but contributed more than 60% of visits. Predictors of frequent use in adjusted analyses included birth in Canada, higher monthly income, lower health status, perceived unmet mental health needs, and perceived external health locus of control from powerful others; being accompanied by a partner or dependent children had a protective effect on frequent use.

Conclusions. Among homeless adults with universal health insurance, a small subgroup accounted for the majority of visits to emergency services. Frequent use was driven by multiple predisposing, enabling, and need factors.
Homelessness During the Transition From Foster Care to Adulthood
Authors: Dworsky Amy , Napolitano Laura , Courtney Mark
Published: October 2013

Objectives. We estimated the incidence of homelessness during the transition to adulthood and identified the risk and protective factors that predict homelessness during this transition.

Methods. Using data from the Midwest Evaluation of the Adult Functioning of Former Foster Youth, a longitudinal study of youths aging out of foster care in 3 Midwestern states, and a bounds approach, we estimated the cumulative percentage of youths who become homeless during the transition to adulthood. We also estimated a discrete time hazard model that predicted first reported episode of homelessness.

Results. Youths aging out of foster care are at high risk for becoming homeless during the transition to adulthood. Between 31% and 46% of our study participants had been homeless at least once by age 26 years. Running away while in foster care, greater placement instability, being male, having a history of physical abuse, engaging in more delinquent behaviors, and having symptoms of a mental health disorder were associated with an increase in the relative risk of becoming homeless.

Conclusions. Policy and practice changes are needed to reduce the risk that youths in foster care will become homeless after aging out.
Relationship Among Adverse Childhood Experiences, History of Active Military Service, and Adult Outcomes: Homelessness, Mental Health, and Physical Health
Authors: Montgomery Ann Elizabeth , Cutuli J. J. , Evans-Chase Michelle , Treglia Dan , Culhane Dennis P.
Published: October 2013

Objectives. We determined whether a report of adverse childhood experiences predicts adult outcomes related to homelessness, mental health, and physical health and whether participation in active military service influences the relationship between childhood and adult adversity.

Methods. Using data from the 2010 Washington State Behavioral Risk Factor Surveillance System, we tested by means of logistic regression the relationship between adverse childhood experiences and 3 adult outcomes—homelessness, mental health, and physical health—as well as differences among those with a history of active military service.

Results. Adverse childhood experiences separately predicted increased odds of experiencing homelessness as an adult and mental health and physical health problems. Childhood adversity increased the likelihood of adult homelessness and poor physical health among individuals with no history of active military service and the likelihood of mental health problems among individuals with a history of active military service.

Conclusions. The relationship between childhood adversity and adult adversity changes in degree when history of active military service is controlled, which has implications for Armed Forces recruitment strategies and postmilitary service risk assessment.
Twenty-Five Years of Child and Family Homelessness: Where Are We Now?
Authors: Grant Roy , Gracy Delaney , Goldsmith Grifin , Shapiro Alan , Redlener Irwin E.
Published: October 2013

Family homelessness emerged as a major social and public health problem in the United States during the 1980s.

We reviewed the literature, including journal articles, news stories, and government reports, that described conditions associated with family homelessness, the scope of the problem, and the health and mental health of homeless children and families. Much of this literature was published during the 1980s and 1990s. This raises questions about its continued applicability for the public health community.

We concluded that descriptions of the economic conditions and public policies associated with family homelessness are still relevant; however, the homeless family population has changed over time. Family homelessness has become more prevalent and pervasive among poor and low-income families. We provide public health recommendations for these homeless families.
Community-Level Characteristics Associated With Variation in Rates of Homelessness Among Families and Single Adults
Authors: Fargo Jamison D. , Munley Ellen A. , Byrne Thomas H. , Montgomery Ann Elizabeth , Culhane Dennis P.
Published: October 2013

Objectives. We modeled rates of family and single-adult homelessness in the United States in metropolitan and nonmetropolitan regions and as a function of community-level demographic, behavioral, health, economic, and safety net characteristics.

Methods. We entered community-level characteristics and US Department of Housing and Urban Development point-in-time counts for a single night in January 2009 into separate mixed-effects statistical analyses that modeled homelessness rates for 4 subpopulations: families and single adults in metropolitan and nonmetropolitan regions.

Results. Community-level factors accounted for 25% to 50% of the variance in homelessness rates across models. In metropolitan regions, alcohol consumption, social support, and several economic indicators were uniquely associated with family homelessness, and drug use and homicide were uniquely associated with single-adult homelessness. In nonmetropolitan regions, life expectancy, religious adherence, unemployment, and rent burden were uniquely associated with family homelessness, and health care access, crime, several economic indicators, and receipt of Supplemental Security Income were uniquely associated with single-adult homelessness.

Conclusions. Considering homeless families and single adults separately enabled more precise modeling of associations between homelessness rates and community-level characteristics, indicating targets for interventions to reduce homelessness among these subpopulations.
Predictors of Medical or Surgical and Psychiatric Hospitalizations Among a Population-Based Cohort of Homeless Adults
Authors: Chambers Catharine , Katic Marko , Chiu Shirley , Redelmeier Donald A. , Levinson Wendy , Kiss Alex , Hwang Stephen W.
Published: October 2013

Objectives. We identified factors associated with inpatient hospitalizations among a population-based cohort of homeless adults in Toronto, Ontario.

Methods. We recruited participants from shelters and meal programs. We then linked them to administrative databases to capture hospital admissions during the study (2005–2009). We used logistic regression to identify predictors of medical or surgical and psychiatric hospitalizations.

Results. Among 1165 homeless adults, 20% had a medical or surgical hospitalization, and 12% had a psychiatric hospitalization during the study. These individuals had a total of 921 hospitalizations, of which 548 were medical or surgical and 373 were psychiatric. Independent predictors of medical or surgical hospitalization included birth in Canada, having a primary care provider, higher perceived external health locus of control, and lower health status. Independent predictors of psychiatric hospitalization included being a current smoker, having a recent mental health problem, and having a lower perceived internal health locus of control. Being accompanied by a partner or dependent children was protective for hospitalization.

Conclusions. Health care need was a strong predictor of medical or surgical and psychiatric hospitalizations. Some hospitalizations among homeless adults were potentially avoidable, whereas others represented an unavoidable use of health services.
Prediction of Buried-Hill Productive Carbonate Reservoirs Using Electrical and Acoustic Image Logs, Ordovician Formation, China (II)
Authors: Zhou Feng-Ming , Si Zhao-Wei , Lin Fa-Wu , Liu De-Fang , Yang Hong , Wang Da-li , Zhao Xian-Ran , Yan Ping , Wei Guo , Zhao Hai-Peng
Published: October 2013

Electrical and acoustic image logs in 18 wells were integrated for prediction of buried-hill productive carbonate reservoirs in a field in China. The logs showed that the reservoirs are associated with paleotopographic features in a very complex and heterogeneous fracture/vug/cave karst system that provides their fluid-flow pathways and storage capacity. The fluid-flow pathways were provided mainly from high-angle permeable fractures and vugs with good connectivity that were caused by a long period of weathering and leaching. The storage components of the reservoirs were composed predominantly of the secondary development of a complex mixture of solution-enhanced fractures, vugs and pores, and occasionally of karst caves. The reservoirs had also undergone karstic erosion and fracturing during the Ordovician.

In addition to detecting and classifying buried-hill carbonate reservoir types, the combination of log data with data from 16 well production tests allowed us to establish reliable fracture and vug property ranges for a series of reservoir types and to calibrate the productivity of the various reservoir types by production test and core analysis, or local production experience from similar buried-hill carbonate reservoir fields. The main contributors to oil reserves and production are from the three types of buried-hill carbonate reservoirs, a fracture reservoir, a fracture-vug-breccia reservoir and a vug-breccia reservoir.

For the prediction of buried-hill productive carbonate reservoirs in the case study, firstly, the structural faults and fractures were detected from seismic data to better understand the fracture/vug/cave karst system in the field scale. Secondly, the fractures and vugs in the 18 wells were recognized and classified from borehole electrical and acoustic image logs to indicate the types of reservoir. Thirdly, the fluid-flow pathways and storage capacity of the reservoirs were quantitatively defined through the fracture and vug properties to analyze the relationship between the reservoir types and production. Finally, from the multiwell correlation of the fracture and vug properties with reservoir production, the levels of the productivity of the reservoirs were predicted. The approach used in this case study improves on the conventional approaches to the definition of the fluid-flow pathways of the reservoirs by adding hydraulic fracture aperture, fracture porosity and connected porosity to the fracture and vug properties, which have a close relationship with the reservoir production in the field.
Centralized Process Control System: A Choice for Optimizing Mature Field Facilities
Authors: Amanu Deny Kalfarosi , Chairunissa Cindy
Published: October 2013

As the Aceh Production Organization (APO) fields continue to mature and production declines, cost and personnel efficiencies become increasingly challenging. Process Control System (PCS) centralization and plant remote monitoring capability are critical elements toward reducing operator surveillance and achieving unmanned field operation. A robust Supervisory Control & Data Acquisition (SCADA) system is also a must to ensure reliable & secure real-time online monitoring, production data reporting, and remote troubleshooting.

Previously all the sites in APO have local PCS equipment consisting of individual Distributed Control System (DCS) and SCADA. To achieve centralization in PCS, local DCS was connected via an inter-field network. On top of it, central SCADA servers were built to directly collect data from DCS instead of local SCADA equipment.

To minimize project cost, the modification was done by utilizing existing network infrastructure. A key aspect of the new configuration was to ensure that the system was not compromised from a cyber-security standpoint.

The PCS centralization in APO supported unmanned operations in 4 out of 7 fields with modification cost US$ 180K, with total saving US$200K/year through reduced operator surveillance.

This paper outlines the series of PCS centralization and upgrade activities, including engineering concept selection, challenges faced, optimization, economic analysis, and implementation strategy.
CO2 Flooding WAG Safety Control Technology
Authors: jun Wang , Feng Wang , Deping Zhang , Guojun Yin , Ruosheng Pan , Shuai Xing
Published: October 2013

Under the conditions of injecting pure CO2, the corrosion rate of strings in CO2 injection wells is very low, while in WAG process, because CO2 is mixed with water, corrosion rate of downhole strings is high. Hence, we need to take some anticorrosion measures. Because of the fluctuations in pressure and the changes in temperature due to frequent changes of gas injection and water injection, both of these two processes will cause load changes of the tubing, as well as reduce the tubing seal behavior. WAG technology should be optimized.

According to affecting factors of corrosion of WAG process in CO2 flooding, studies of corrosion prevention measures of wellhead equipment, downhole strings and casing are carried out. Based on different conditions of string mechanics in the WAG process, considering different working conditions, the CO2 WAG process is optimized to reduce fatigue failure due to the fluctuations of pressure and temperature on the strings.

The safety control technology of CO2 WAG is widely used in CO2 flooding test in Daqingzi oilfield. In the CO2 WAG process, the technology optimizes injection strategy and corrosion prevention measures in CO2 WAG injection process, protects wellhead equipment and downhole strings of the CO2 injection effectively, as well as ensures safe and smooth operation of CO2 injecting wells.
Economic Small Scale LNG Plant Implementation with Cluster LNG Technology
Authors: Lee JungHan , Antara Dwi Suasti , Kim Julie
Published: October 2013

Recently gas has been more important role over coal and fuel oil in global energy sources, and the trend is expected to continue at least for 20 ~ 30 years. Southeast Asian countries are also coping with the trends and opportunities. Gas demands in the region have been increased and expected to increase rapidly with the relatively low price over fuel oil. However, the new emerging gas consumers are somewhat different from those of conventional large quantity LNG. The new consumers need more flexible and diverse supply of LNG for their specific needs. At the same time, there are many potential gas producers who endeavor to monetize their stranded gas fields by supplying LNG to nearby markets. New multi-producer and multi-consumer market requires different approaches in LNG production and distribution, and small scale LNG would be more appropriate for the new environment. Cluster LNG, which is based on increased pressure LNG liquefaction, has advantage in reducing liquefaction power, consequently overall CAPEX and OPEX. On the contrary, the produced LNG should be stored in increased pressure containment system. Nonetheless, it does not cause inconveniences to end-users as long as the integrated liquefaction, transportation, and regasification system is provided. At the same time, the increased pressure LNG system has superior carbon dioxide (CO2) emission index. The first Cluster LNG plant is being implemented in Indonesia. The plant would produce 5 mmscfd equivalent LNG and the produced LNG will be transported by LNG trucks to typically 300 ~ 500 Km away multiple industrial customers. The plant is expected to start operation around the end of 2014. High efficiency Cluster LNG will have overall competitiveness in CAPEX and OPEX compared with conventional LNG. Extensive applications of the innovative technology may bring paradigm changes in Southeast Asian LNG industry from long-term perspective.
Low Permeability Fractured Reservoir Drive Co2 Plugging Technology
Authors: Feng Wang , Yingan Zhang , Chuntao Yu , Xuechao Jin
Published: October 2013

Reservoir permeability of CO2 flooding test area in Block Da Qing Zi Jing in Jilin Oilfield is about 3.0~5.0 mD with poor physical properties, such as thin and multilayer reservoir, developed fractures, and strong heterogeneities. Therefore, commingled gas injection indicates there are large differences of gas injection between reservoirs, gas oil ratio increases in some oil wells. In order to inhibit the gas channeling, control flow pressure gradient and ensure the miscible displacement, profile control technique is an effective way to enlarge swept volume and enhance flooding EOR. According to reservoir characteristics, the gelling intensity could reach to 20000mpa.s under acidic condition. The system has the features of shearing resistance property, scouring resistance. Plugging efficiency of the core was higher than 92.0%. Based on the mechanisms of dual plugging of gel and foam, blocking gas channeling channels and enlarging swept volume of gas injection can be achieved. This technique had been applied in profile control test in five wells in CO2 test area of block Da QingZiJing and success rate is 100%. Injection pressure increases by 70.0%. Gas -liquid ratio decreases and oil production rate in the well group increases by 40.0%, the results show that profile control techniques can effectively plug gas channeling and enhance CO2 flooding EOR.
Co2 Flooding Lifting Technology in Oil Well with High Gas-Oil Ratio in Low Permeability Oilfield
Authors: Wang Feng , Zhang Yingan , Pan Ruosheng , Yin Guojun , Ma Dongmei
Published: October 2013

Daqingzi oil field is of low permeability, which gets a low fluid production. After implementing CO2 flooding, the carrying fluid can increase obviously. Meanwhile, a series of problems, including high CO2 content, casing pressure increase and high gas-oil ratio, arise, which can influence pump efficiency and lift efficiency.

Combined with production performance law and factors to influence lift efficiency in CO2 flooding well, a parameter optimizing design model was established. The CO2 breakthrough and the gas-oil increase were restrained by the methods of fluid pressure control and reasonable lift parameter optimizing. Meanwhile, an anti-gas lifting equip used in the well with high gas-oil ratio was developed, and a gas lift- pump assist- casing control integration technique, which can prevent pump efficiency from influencing by the gas, provide a gas bypass way and utilize gas to pump carrying fluid out, was designed.

The field application showed that this technique can meet the needs of regular production of the oil well whose gas-oil ratio is 300m3/t, effectively control the casing pressure under 2MPa, increase the pump efficiency by 12%, low down the casing pressure, as well as improving the production efficiency of the oil well.
Bracing for Rising Challenges in Well Integrity Management
Authors: Gilbert Rayner , Setiawan Toto , Yaakub M Yuzmanizeil , Hui Nicholas Foo
Published: October 2013

Well Integrity has become a top most concern in oil and gas industry recently following significant incidents happened that were mostly caused by defective asset integrity. New field development should take into account all aspects of well integrity in full well life cycle. Prudent WI management needs careful and continuous effort to review well conditions and eventually performing assessment of the asset. Proper assessment of the risk exposed to the well eventually will benefit us on safety of people and safeguarding the environment. Basic and effective method in appraising well integrity has been critical to give a safety assurance and minimize the risk of flawless well integrity. At the same time an array of recommended mitigation actions need to be in place as a precaution measure for any possible escalated risk. Combined with the enforcement on company policies and guidelines on safe operating the well, the earlier knowledge of well integrity status will definitely reduce operating cost on well failures rectification or workover. The proactive identification and firs line rectification will eliminate unnecessary subsequent failures that, if it is not being anticipated, will worst the failure causing more costly repair job.

The paper provides the readers the ideas on how the field operator is performing the routine monitoring of well integrity related parameters, assessing the associated risk conceivable, capturing a potential well integrity failure with the quick analysis systematically and eventually generating mitigation plan in line.
Minimizing uncertainties in reservoir monitoring and evaluation with combination Oof Cased hole formation resistivity and Pulsed Neutron Logging in Jasmine field, Gulf of Thailand
Authors: Shi ZhanGuo , Platt Chris , Piyatad T. , Theeranun L. , Suttapan V.
Published: October 2013

For a producing field, oil-water contact movement, gas cap expansion/shrinkage and residual oil saturation (thus the sweep efficiency) are key reservoir dynamic properties for resource estimation and proper reservoir management. Jasmine field in the Gulf of Thailand first began oil production in June 2005. Light oil & gas has been produced from multiple high permeability fluvial sandstones of Miocene-Oligocene age. After more than seven years of development and production, reservoir monitoring becomes even more critical in decision making for well recompletion, drilling of new infill wells and overall fluids management.

To understand fluid movement, pulsed neutron logging, including inelastic spectrum (carbon-oxygen ratio, C/O), thermal decay time (Sigma) and cased formation resistivity have been widely employed to evaluate formations through casing. However, each technology has its advantage and limitations. There are three major challenges for formation evaluation through casing in Jasmine field: Formation water is relatively fresh so it is very difficult to distinguish oil from fresh water with pulsed neutron capture (PNC) Sigma.In undertaking hydraulic workover operations, sea water has to be used to kill producing wells before logging, and therefore deep invasion is experienced in perforated zones with high permeability (multi Darcy) sandstone reservoirs. This can result in high uncertainty in oil saturations derived from C/O and partially to cased hole resistivity.In the deeper Oligocene reservoir section, massive shaly sands with low resistivity low contrast (LRLC) pay with high water saturation are present. Fluid typing in such strata is problematic even with open hole resistivity data.

To address these various challenges, a combination of cased hole resistivity and pulsed neutron inelastic spectrum, thermal decay porosity & Sigma data have been employed used to reduce water saturation uncertainty and achieve multiple reservoir monitoring and formation evaluation objectives. Results from several logging campaigns since 2009 demonstrate the advantages of using these technologies in-parallel.

Utilizing case studies, this paper summarizes the technical challenges and reservoir monitoring solutions as applied in the Jasmine field, including: Gas cap dynamics & OWC movementUnproduced perforated zones in commingled completionsUnswept portions of perforated zonesLow resistivity, low contrast shaly sand evaluation through casingReducing uncertainty in saturation estimation on sands killed by sea waterInputs to resource estimation, reservoir simulation and production optimization
A Discussion of the HSE Aspects of Carbon Dioxide Sequestration
Authors: Pawde Chaitanya , Parekh Rathin
Published: October 2013

Amidst increasing global warming concerns, carbon dioxide, being a major Greenhouse Gas (GHG), poses a threat to the environment if its amount in the atmosphere increases substantially. In this context, carbon dioxide sequestration has emerged as a key technology pathway to reducing GHG emissions. Sequestration is the long term isolation of carbon dioxide from the atmosphere through physical, chemical, biological, or engineered processes. The very nature of the sequestration process involves dealingwith a gas as hazardous as CO2, capable of polluting air, water and land. Hence, health, safety and environment considerations need to be carefully examined at every stage of the sequestration project; right from design to implementation.

Major risks involved with a sequestration project are the chance of leakage of sequestered CO2 as well as the risk of fracturing subsurface formations wherein CO2 might be injected. These risks should therefore be strictly maintained in the As Low As Reasonably Practicable (ALARP) region. Safe gas storage, transport, compression, injection and monitoring facilities need to be designed and reviewed regularly.

The aim of this paper is to review all the current Health Safety & Environment (HSE) practices, risk analyses as well as HAZOP/HAZID studies being conducted and followed for the implementationof sequestration projects worldwide. The binding laws and policies aimed at safe implementation of sequestration projects are also presented. New methodologies that are being employed for the monitoringof sequestered CO2 gas are also discussed along with possible reasons for their success. Also, previous actual CO2 leakages are presented, along with the damages they caused to the ecosphere of the concerned region.

This, being a review paper, the safe practices needed to be implemented for sequestration projectsare highlighted and the state of the art for the same is presented in a consolidated manner.
Developing Information Management Competency for Oil and Gas Operations
Authors: Kozman J. B.
Published: October 2013

Mubadala Petroleum has a robust and growing exploration and production (E&P) and development program in Southeast Asia, with business unit operations in Indonesia, Malaysia, Thailand and Vietnam. The Information Management (IM) and Human Resource (HR) teams for the region are located in the logistical hub in Singapore, where they have the ability to collaborate on companywide initiatives for the region. With an aggressive five-year growth strategy in place, the organisation is evolving from a set of locally managed country offices to a mature international organisation, requiring standardised and robust HR processes, but at a level that will provide sufficient rigor whilst neither stifling innovation nor introducing delay (Wood Mackenzie, 2013). Mubadala executive management describes this as "learning in the right place and extending" and "moving from an evolved to an engineered process". The goal is to prioritize the establishment of process based on business risk and exposure, and put in place just enough process to efficient. As one of the corporate strategies involves the development of local talent in the countries where the company operates, several recent initiatives have been put in place to insure a career ladder for young professionals in various technical disciplines. The current exploration program relies heavily on large volumes of quality and validated data delivered to petrotechnical end users in a timeframe and format that supports mission critical decisions. Thus the role of IM has been identified as a key pillar of the exploration process, an area of critical risk, and an area where Mubadala can gain a competitive advantage by building on organisational knowledge and decades of exploration experience.
On the Economic Optimization of the Fracturing of Coal Seam Reservoirs
Authors: Marongiu-Porcu Matteo , Ajao Omobola , Dalamarinis Panagiotis , Economides Michael J.
Published: October 2013

The production of natural gas from coal seam reservoirs follows a succession of stages that are well established and understood. Salient components are the execution of hydraulic fractures, dewatering of both native and introduced water, and the subsequent production of what it is almost entirely methane. Most coal seams are of relatively small net pay thickness and in many cases also of low permeability, i.e. 2 md or less. Produced gas comes from a combination of both free gas in the coal porosity and, especially, desorbing gas. Because of large heterogeneities and major differences among coal seam reservoirs, the hydraulic fracturing is rarely uneventful with a large number of issues to be resolved, such as fluid selection or the mass of proppant. Most of these decisions are local and often conclusion cannot be drawn from elsewhere. Frequently, a well is subjected to multiple stages of hydraulic fracture treatments.

Production performance characteristics also vary considerably. The interaction between permeability, natural cleat networks and natural and artificial fractures is often complicated and difficult to predict. This results in different periods of post-treatment de-watering, the volume of water that is produced and the onset of predominant natural gas production.

We have constructed a realistic physical and economic model where the NPV criterion is used to identify successful or potentially uneconomic candidates. We forecast fractured well performance using the Unified Fracture Design (UFD) approach and we account for time of de-watering and the cost of water management. Charged against the net present value of the revenue are the costs of fracturing and well completion.

Five wells with different Langmuir isotherm parameters were considered for the NPV parametric studies. The parametric studies include a range of reservoir permeabilities, porosities, proppant masses, and fracture heights. The results show the window of attractive prospects and delineate the unattractive prospects which can be considerable.
Creation of a National Database from Multiple Legacy Data Sources
Authors: Bougherara Nazim E. , Morsli Sid Ahmed , Sali Said , Khelili Farid , Badache Reda
Published: October 2013

One of the largest oil and gas producers in North Africa has decided to create a national E&P data bank that will hold the country’s entire E&P activity data, including legacy digital and physical heritage. This national data bank is expected to not only archive data, but also provide a wide range of services to internal and external stakeholders, enabling the country to attract potential investors willing to bid based on the shared data. It will also improve the knowledge of the country’s subsurface potential.

Since 1950, the country’s E&P legacy data has been traditionally stored by different operators, applying their own processes and technologies. Data therefore resides on different sources—even within the same operator—including databases, interpretation platforms, file systems, magnetic storage, legacy formats, and media (paper, films, etc.). Most of the bulk data (seismic and well logs) were acquired in industry-recognized formats such as SEG-Y and LAS, but many are only available in a physical format not electronically. Transferring legacy data to the newly created structure is obviously challenging, especially when strict standardization (naming conventions, references, and units of measurement) are not common among operating companies. Furthermore, databases have, by nature, proprietary data structures, raising the difficulty of a database-to-database transfer. Digitalization and transcription would also be required for old media types.

This paper discusses tailored strategies to overcome these challenges and the lessons learned while moving the data from disparate sources. The presented strategies include scenarios such as transferring data from digital data sources and physical assets, while monitoring time and budget. Processes for quality filters and aligning data to standards before and after the transfer, recommendations on prioritization criteria to target the most valuable data source, and future plans are also discussed.
Field Testing Experience of Wet Gas and Multiphase Flow Meters Conducted in Wet Gas Condensate Producers
Authors: Rodriguez Ruben Villegas , Al-Asiri Mohammed , Asiri Khalid S.
Published: October 2013

The paper describes the challenges and uncertainties associated with the accurate flow measurement of gas, oil and water and also the results of a trial test conducted using four multiphase flow meters in wet gas-condensate producers at a wide range of flowing conditions. The measurement of these three phases is very critical for the reservoir monitoring and production diagnostics and obtaining the accurate three-phase data poses a significant challenge for the majority of conventional multiphase flow meters, because of the high-gas volume fraction (95 % and above) nature of the wells.

Multiphase flow meter technology has been successfully used around the world for over 15 years in oil and gas fields with a very low cost comparing with three-phase test separator use. This success encourages all the manufacturers to continue developing meters; to satisfy and meet the production test requirements and the acceptance criteria established by the operator companies.

At the end of 2010, Saudi Aramco conducted a second pilot test to evaluate the four wet gas and multiphase flow meters (WGMPFMs) from various leading manufacturers. The objective of this test was to confirm the accuracy and reliability of these meters for measuring gas, condensate and water flow rates in the wet gas stream. A high pressure test separator was the reference measurement and the test was repeated at several selected gas wells. After almost 4 months, the testing concluded that only a particular type of meter performed better than others and met the minimum Saudi Aramco acceptance criteria in measuring the three-phase flow with acceptable accuracy.

This paper also describes the Saudi Aramco’s experience of field testing the latest WGMPFM’s meters in real production condition, field test methodology, equipment setup and result analysis.
China Shale Gas and Shale Oil Resource Evaluation and Technical Challenges
Authors: Stevens Scott H. , Moodhe Keith D. , Kuuskraa Vello A.
Published: October 2013

China has abundant organic-rich source rock shales which are prospective for commercial shale gas/oil development but still in the early phase of evaluation and testing. We analyzed petroleum source rock data published in nearly 400 Chinese language papers to construct a unique GIS data base of shale geologic and reservoir properties throughout the country. We then conducted a comprehensive assessment of the country’s shale gas and shale oil resource potential. China’s risked technically recoverable resources within high-graded prospective areas are estimated at 1,115 Tcf of shale gas and 32 BBO of shale oil resources (Table 1). Of the dozen onshore sedimentary basins that were assessed, the most prospective are Sichuan, Tarim, Junggar, and Songliao. One of the most intriguing prospects is liquids-rich Permian shale on the structurally simple northwest flank of the Junggar Basin. The Pingdiquan/Lucaogou lacustrine shale is about 250 m thick and 3,500 m deep here. TOC averages 5% and the shale is oil- prone (Ro 0.85%). The area is close to infrastructure. Table 1Estimated Shale Gas and Shale Oil Resources in China

The Sichuan Basin, industry’s primary focus for shale gas, has multiple shale targets but also significant geologic challenges, such as numerous faults (some active), often steep dips, high tectonic stress, slow drilling in hard formations, and high H2S and CO2 in places. Tarim Basin shale targets are mostly too deep (>5 km) apart from uplifts where they may be thin with low TOC. The Songliao Basin has liquids-rich potential in over-pressured and naturally fractured Cretaceous lacustrine shales. However, China’s shale oil deposits tend to be waxy and stored mainly in lacustrine-deposited shales, which may be clay-rich and less "frackable" than the low-clay brittle marine shales productive in North America.