bluuebunny/crossref_metadata_2025 huggingface dataset:
Resilience in trade fairs: A study in Brazilian context
Authors: Gerhard Felipe , Peñaloza Verónica
Published: October 2018

This research aims to analyze through the lenses of resilience, the collective construction and social representation of a trade fair by its actors. To this, an exploratory qualitative case study was conducted with vendors of a large trade fair in the city of Fortaleza. The main reasons that provide growth, reduction or stability of these environments are not restricted to purely financial factors; the resilience of trade fairs transcends a marketing perspective, achieving also social and cultural dimensions.
Jovens e juventudes em estudos rurais do Brasil
Authors: Troian Alessandra , Breitenbach Raquel
Published: October 2018

O objetivo deste estudo foi apresentar as perspectivas teóricas e normativas utilizadas para definir jovens e juventude, resgatar pesquisas brasileiras sobre jovens rurais, identificando critérios de definição utilizados e os resultados das investigações. Metodologicamente é uma pesquisa bibliográfica. Os resultados demonstraram existir diversos estudos sobre a temática no Brasil, que utilizam distintas formas de definir juventude rural. O foco das pesquisas brasileiras está na problemática da sucessão rural e elevada migração rural-urbana, além da busca de ações para solucioná-la
MRSA Infection and Mortality Rate in California
Authors: Witwit Haydar
Published: October 2018

Average of 41,900 patients are diagnosed annually with staphylococcus bacterial infection in California, 24,089 patients have Methicillin-resistant Staphylococcus Aureus (MRSA) and 17,810 patients have Methicillin-Sensitive Staphylococcus (MSSA). This paper demonstrates that there is a difference in mortality rate due to staphylococcus infection between males and females (P-value<0.05, CI 95%). Male patient diagnosed with S. aureus has 1.3 chance of mortality incidence than female patient. In addition, MRSA infection rate is 1.4 times MSSA infection (P-value<0.05, CI 95%), but the gap of infection is decreasing; however, mortality of both infections combined are more than threefold greater compared to three decades ago.
Curvature Changes in Biological Dynamics
Authors: Tozzi Arturo
Published: October 2018

Geometry deals both with analogical thinking and physical/biological observables.  Naïve, common-sense descriptions of objects’ shapes and systems’ trajectories in geometric phase spaces may help experimental investigation.  For example, very different biological dynamics, as the developmental growth patterns of the oldest known animal (the extinct Dickinsonia) and the human brain electric oscillations, display a striking analogy: when encompassed in abstract geometric spaces, their paths describe the same changes in curvature: from convex, to flat, to concave and vice versa.  This dynamical behavior, anticipated by Nicholas de Cusa in his analogical account of “coincidentia oppositorum” (1440), helps to describe widespread biological paths in the manageable terms of concave, flat and convex curves on donut-like structures.  Every trajectory taking place on such toroidal manifolds can be located, through a topological technique called Hopf fibration, into a four-dimensional space.  We discuss how the correlation between Hopf fibration and Navier-Stokes equations allows us to treat the above-mentioned biological and neuroscientific curved paths in terms of flows taking place into a viscous fluid medium that can be experimentally assessed and quantified.
INFLUENCIA DEL EJERCICIO FÍSICO SUBACUADO EN PERFIL DE ÁCIDO GRASO DE CADENA MEDIA Y LARGA EN SUERO DE INDIVIDUOS CON SOBREPESO
Authors: Wagmacker Djeyne Silveira , Petto Jefferson , Matias Jackeline Barbosa , Mota Sindy Kerole Andrade , Andrade Luiz Erlon Araújo , Ladeia Ana Marice Teixeira
Published: October 2018

Objetivo: probar la hipótesis de que el ejercicio físico agudo podría cambiar los ácidos grasos en el suero de individuos con un mayor peso corporal. Método: Se incluyeron en la muestra 66 mujeres con exceso de peso, (IMC = 29.6 ± 4.2) sedentarias, y con una edad de 24.4 ± 3.6 años, divididas al azar en grupos control y ejercicio. Después de 12 horas de ayuno, se realizó la recolección de sangre basal. 12 horas después de la primera recolección, el grupo de ejercicio se sometió a una sesión de ejercicio físico con un gasto de energía de 250 Kcal. Los voluntarios se sometieron a una segunda extracción de sangre 24 horas después de la primera y dosificaron los ácidos grasos: pelargónico, azelaico, elaídico y oleico. Resultados: El ejercicio físico no modificó la respuesta del perfil de ácidos grasos tanto para el análisis intragrupal como para el análisis intergrupal: Grupo de ejercicios: Pelargónico (antes = 0,12 ± 0,06% vs después = 0,15 ± 0,14%, p = 0,507); Azelaico (antes = 20,3 \ pm 10,5% vs después = 27,7 \ pm 25,4%, p = 0,295); Elaidic (antes = 0.03 ± 0.01% Vs. after = 0.04 ± 0.01%, p = 0.328); Oleico (antes = 16.1 ± 7.4% vs después = 20.3 ± 14.6%, p = 0.236); Grupo control: Pelargónico (antes = 0.70 ± 0.45% vs después = 0.71 ± 0.51%, p = 0.776); Azelaic (antes = 62.1 ± 26% Vs. después = 57.1 ± 27%, p = 0.197); Elaidic (antes =0.05 ± 0.02% mg / dL vs. después = 0.05 ± 0.03%, p = 0.530); Oleico (antes = 26.8 ± 22.7% mg / dL Vs. después = 29.0 ± 22.4%, p = 0.525). Conclusión: las mujeres con sobrepeso y ejercicio físico de baja intensidad no son capaces de cambiar los ácidos grasos de cadena media en las primeras 12 horas.
Sebaran Populasi dan Klasifikasi Resistensi Eleusine indica terhadap Glifosat pada Perkebunan Kelapa Sawit di Kabupaten Deli Serdang
Authors: Tampubolon Koko , Purba Edison , Hanafiah Diana Sofia , Basyuni Mohammad
Published: October 2018

Eleusine indica populations on oil palm plantations in Deli Serdang Regency have not been reported to be resistant to glyphosate. This study was aimed to report distribution and resistance classification of E. indica population on oil palm plantations in Deli Serdang Regency. The research was conducted on Weed Research Center in Faculty of Agriculture, Universitas Sumatera Utara from October 2016 until August 2017. This research used Randomized Block Design with recommended dose at 720 g a.i.ha-1 of glyphosate and three replications. Population ESU0 (from Politeknik Negeri Medan Ball Field) as a comparison. Data on average survival, mortality, dry weight, resistance classification of E. indica were analyzeds using IBM SPSS Statistics 20 software. The results showed that there were 12 E. indica populations classified as glyphosate-resistant (56.52%), 7 glyphosate-resistant developing (30.43%), and 4 populations classified as glyphosate-susceptible (13.04%) with the recommended dose at 720 g a.i.ha-1 from oil palm plantations in Deli Serdang Regency.
The Effect of Depression on Patient-Reported Outcomes After Total Joint Arthroplasty Is Modulated by Baseline Mental Health
Authors: Halawi Mohamad J. , Cote Mark P. , Singh Hardeep , O’Sullivan Michael B. , Savoy Lawrence , Lieberman Jay R. , Williams Vincent J.
Published: October 2018

Background:

Depression and poor mental health are known to be negative predictors of patient-reported outcomes after total joint arthroplasty. Although previous studies have examined these risk factors in isolation to each other, they are, in reality, closely related, and yet each represents a different aspect of one’s psychological well-being. The objective of this study was to investigate the association between depression and patient-reported outcomes, taking into account patients’ baseline mental health.

Methods:

Our prospective, institutional joint registry was queried for patients who had undergone primary elective total joint arthroplasty and had a minimum follow-up of 1 year. Baseline mental health was measured by the Short Form-12 Mental Component Summary (SF-12 MCS). Four cohorts were analyzed on the basis of the presence or absence of depression and patients’ SF-12 MCS scores at the time of the surgical procedure, which were categorized as either poor or good on the basis of previously defined cutoffs. The primary outcomes were the net changes in SF-12 MCS, SF-12 Physical Component Summary (PCS), and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scores at 4 and 12 months postoperatively. Univariate and mixed-effects model analyses were performed to control for potential confounding factors.

Results:

Patients with depression but good baseline mental health achieved gains in patient-reported outcomes that were comparable with those of normal controls (p > 0.05). Patients with poor baseline mental health achieved significant gains in all patient-reported outcomes, but the changes were largest for those without depression (p < 0.05). Only patients with depression and poor baseline mental health did not cross the threshold for good mental health at the time of the latest follow-up despite achieving similar gains in physical function compared with their counterparts who did not have depression.

Conclusions:

The effect of depression on patient-reported outcomes is more complex but less pessimistic than previously thought. Patients with depression undergoing total joint arthroplasty may have significant improvements in their patient-reported outcomes, but the net gains are modulated by their mental health at the time of the surgical procedure. Preoperative screening of patients with depression using the SF-12 MCS may help to identify those who are at risk for attaining suboptimal patient-reported outcomes and may benefit from counseling or psychiatric referral for optimization before undergoing a surgical procedure.

Level of Evidence:

Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.
Morphological Similarity Analysis of Elite Rice Varieties Released in 1980–2011
Authors: Sitaresmi Trias , Yunani Nani , Nafisah Nafisah , Satoto Satoto , Daradjat Aan A.
Published: October 2018

High acceptance of farmer to variety with have similar to IR64 type has led to almost all new varieties always be assessed based on their degree of similarity with IR64. Closely relations between elite upland varieties may contribute to the stagnation of yield potential and also give the impact un-durable of the resistance to pest and diseases. The aim of this study was to elucidate the morphology similarity kinship characters of elite rice varieties which were released from 1980 to 2011. The study was conducted in September–January 2012 in Indonesian Center for Rice Research field experiment. The material consisted of 46 rice varieties representing the released varieties from 1980–2011. The material was grown in 2 m × 5 m of plot size with 3 replications. Observations were conducted on qualitative and quantitative characters based on UPOV descriptors. Data were analyzed by Principal Component Analysis and Cluster Analysis. Principal component analysis revealed 40 components with 79,86% of cumulative variation that was used to determine the genetic relationship by cluster analysis. Based on the principal component analysis and cluster analysis, irrigated rice varieties released before and in 2000 and after 2008 (Inpari group) tend to be one big group and have a high phenotypic similarity. While the upland rice varieties tend to spread or were grouped in small groups. This high similarity suggested that the irrigated rice varieties have a close genetic relationship, which is derived from Ciherang or IR64.
Dynamic Error Analysis of Measurement While Drilling Using Variable Geomagnetic In-Field Referencing
Authors: Kabirzadeh Hojjat , Rangelova Elena , Lee Gyoo Ho , Jeong Jaehoon , Woo Ik , Zhang Yu , Kim Jeong Woo
Published: October 2018

The safe and economical determination of a wellbore trajectory in directional drilling is traditionally achieved by measurement-while-drilling (MWD) methods, which implement magnetic north-seeking sensor packages. Inaccuracies in the determination of well path arise because of random and systematic errors in the measurements of the sensors. Multistation analysis (MSA) and magnetic in-field referencing (IFR) have already demonstrated the potential to decrease the effects of errors because of magnetization of drillstring components along with variable errors caused by irregularities in the magnetization of crustal rocks in the vicinity of wells. Advanced MSA methodologies divide a borehole into several sections and use the average reference values of the total magnetic field, declination, and dip angle for analysis of errors in each section. Our investigations indicate that the variable-reference MSA (VR-MSA) can lead to a better determination of errors, specifically in areas of high magnetization. In this methodology, magnetic reference values are estimated at each station using forward and inverse modeling of surface-magnetic observations from IFR surveys. The fixed errors in magnetometer components are then calculated by minimizing the variance of the difference between the measured and unique estimated reference values at each station. A Levenberg-Marquardt algorithm (LMA) is adopted to solve the nonlinear optimization problem. Examination of this methodology using MWD data confirms more than 20% improvement in well-path-determination accuracy by comparing the results with the corrected path from the conventional MSA method and gyro surveys.
Synthesis and Evaluation of Novel Gas-Wetting Reversal Agent for Shale Gas Reservoir
Authors: Li Yongfei , Wang Yanling , Tang Longhao , Yuan Lin , Zhang Chuanbao , Jia Wenfeng , Guo Baoyu , Wang Xudong
Published: October 2018

Shale gas usually distributes in dense porous media reservoirs, which is not easy to develop without external force. Hydraulic fracturing has been an effective technology utilized to improve the yield of shale gas. However, the performance of this method depends on large displacement and liquid volume, resulting in the blockage of the flowing channels in the reservoir and huge waste of water resources. Thus, it is particularly important to increase the rate of fracturing fluid return.

The contact angle test, owens two-liquids method and spontaneous imbibition were conducted to investigate the effect of gas-wetting alteration on the shale wettability and liquid flow. Moreover, the energy dispersive spectroscopy was used to analyze elemental changes on the shale surface.

The results showed that the contact angles of water and n-decane on the shale surface increased from 36o and 0o to 128o and 115o, respectively. The surface free energy rapidly reduced from primeval 71 mN/m to 5.6 mN/m after treated by 0.4 wt.% gas-wetting reversal agent. The results were further verified by spontaneous imbibition. The analysis of energy dispersive spectroscopy (EDS) indicated that the gas-wetting reversal agent could product adsorption layer on shale surface, which played an important role in super gas-wetting.

The wettability of shale surface could be reversed from liquid-wetting to super gas-wetting by the novel gas-wetting reversal agent with double-chain hydrophobic and olephobic structure, which could significantly enhance the flowback rate of the fracturing fluid due to super gas-wetting alteration.
A Multiscale Study on The Onset of Sand Production
Authors: Lv Adelina , Ramandi Hamed Lamei , Roshan Hamid
Published: October 2018

Despite decades of numerical, analytical and experimental researches, sand production remains a significant operational challenge in petroleum industry. Amongst all techniques, analytical solutions have gained more popularity in industry applications because the numerical analysis is time consuming; computationally demanding and solutions are unstable in many instances. Analytical solutions on the other hand are yet to evolve to represent the rock behaviour more accurately.

We therefore developed a new set of closed-form solutions for poro-elastoplasticity with strain softening behaviour to predict stress-strain distributions around the borehole. A set of hollow cylinder experiments was then conducted under different compression scenarios and 3D X-Ray Computed Tomography was performed to analyse the internal structural damage. The results of the proposed analytical solutions were compared with the experimental results and good agreement between the model prediction and experimental data was observed. The model performance was then tested by analysing the onset of sand production in a well drilled in Bohai Bay in Northeast of China. Acoustic and density log along with core data were used to provide the input parameters for the proposed analytical model in order to predict the potential sanding in this well. The proposed solution predicted the development of a significant plastic zone thus confirming sand production observed by today sanding issue in this well.
Operationalising MHF Safety Assessments
Authors: Jefferies Lillie , Ooi Pamela
Published: October 2018

A novel extended bowtie risk assessment methodology was used to develop the safety assessments for three Major Hazard Facilities (MHFs). Combined with an innovative risk management tool for operationalizing risk management processes, it provides a clear overview of each facility's current operational risk profile and the health of the safety critical barriers. This paper describes the bowtie methodology, its application in the development of the MHF safety assessments and the operationalization of the safety assessments through the risk management tool.
The Numerical Simulation of Hydraulic Fracture Propagation with Competing Perforations at the Defining Plane
Authors: Shi Xian , Li Dongjie , Cheng Yuanfang , Han Zhongying , Fu Weiqi
Published: October 2018

Fixed plane perforation technology is regarded as a good mean to address near wellbore tortuosity and reduce breakdown pressure in low permeability reservoirs. To better understand of the fracture behavior in wellbore perforations at the defining plane, a 2D finite element model has been implemented in ABAQUS to investigate the effects of mechanical, perforation and treatment parameters on hydraulic fracture propagation path. The global zero thickness cohesive elements have been inserted into numerical model, thus the existence of natural fractures on patterns of fracture propagation can be considered in this model. It shows that there is a great impact of natural fracture on the fracture propagation path. Moreover, the fracturing fluid viscosity, pumping rate, in-situ stress and perforation parameters also play critical roles on fracture propagation. Comparisons of numerical simulations show that the effects of the stress anisotropy, pumping rate, fluid viscosity, Young's modulus, Poisson's ratio and perforation intersection angle on the hydraulic fracture geometry of exterior fractures and interior fracture at the defining plane are different. It found that the width of interior fracture is almost zero at the near wellbore zone at the end of pumping which induced by the stress interference of neighboring fractures in some cases, thus perforations design at the defining plane must be carefully considered. Additionally, in most cases, hydraulic fractures from exterior perforations tend to propagate upward and downward simultaneously. Although hydraulic fractures initiated from a perforation that misaligned with the direction along the maximum in-situ stress initially at short distance, hydraulic fractures would finally reorient itself to the maximum in-situ stress direction, thus increase chances of creating one simple transverse fracture along maximum in-situ stress orientation. Because the strong stress interference of competing fractures, the possible breakdown of casing and perforation tunnels should be considered before well completion. The simulation results from this study offer some insights to enhance fixed plane perforation design for hydraulic fracturing treatments.
Australia's World Scale Gas Resources, Its Markets and Why New Approaches Are Required
Authors: Towler Brian , Firouzi Mahshid , Wilkinson Rick
Published: October 2018

Australia is uniquely positioned globally as a major energy provider, but this comes with multiple challenges that must be overcome to realize its full potential. LNG developments that are nearing fruition are set to make Australia the largest supplier of LNG in the world. The Asian LNG market continues to be the growth market. The development of the world's first coal bed methane (coal seam gas) to LNG projects on the east coast has created a robust east coast LNG export market, which in the near future is expected to coincide with domestic energy shortages arising from low exploration activity, maturing fields, higher costs, the interaction of government policy, commercial decisions and activism. As a result, unique approaches to project management and community relations have been developed that are complementary to the Australian consumer's needs for reliable, affordable and cleaner energy. The east coast demand for gas is likely to trigger new development of onshore Northern Territory gas in the short term, if political opposition can be managed. In Western Australia, new approaches leverage technologies such as floating LNG, and more utilization of existing infrastructure and plant capacity to achieve lower costs. This paper outlines Australia's natural gas supply & demand and the challenges to be faced in the coming years.
Controls on CH4 Adsorption on Shales: Characterisation of Beetaloo Sub-Basin Gas Shales and Comparison to Global Shales
Authors: Sander Regina , Pan Zhejun , Connell Luke D , Camilleri Michael , Grigore Mihaela
Published: October 2018

The Beetaloo Sub-basin in the Northern Territory is one of Australia's most prospective basins for shale gas production. The Beetaloo gas shales are unique in that they could become some of the oldest producing source rocks in the world, if commercialized successfully. In this work we characterise gas shales from two target reservoirs in the Beetaloo Sub-basin and compare them to other shales from around the globe to improve the current understanding of what controls gas adsorption on shales.

We characterise the methane adsorption capacity of two sets of Beetaloo shale samples: middle Velkerri B shale (8 samples, ~2450 m depth) and lower Kyalla shale (10 samples, ~1300 m depth). Measurements are performed at reservoir conditions, i.e. up to 110°C and 30 MPa, using CSIRO's gravimetric isotherm rig. The samples’ mineralogy is analysed using X-ray powder diffraction (XRD) and the total organic carbon (TOC) is determined using a LECO machine.

Our experiments demonstrate that the gravimetric rig is capable of obtaining fast and reliable measurements on low adsorbing shales at high pressures and high temperatures for sample quantities of around 90 g. The results highlight that the adsorption capacity of middle Velkerri B shale is significantly higher than of lower Kyalla shale (average Langmuir volume 3.23 m3/t compared to 2.27 m3/t) and that the isotherms can be represented using a Langmuir relationship. In spite of their age, the Beetaloo shales exhibit adsorption behaviour comparable to that of other shales with similar TOC.

Two global shale data sets, which include the Beetaloo samples, demonstrate that there is a strong relationship between TOC and a shale's adsorption capacity. However, the TOC alone cannot account for the differences in adsorbed amount observed within the two sets of Beetaloo shale samples.

Bulk clay content appears to control the adsorption capacity of shales with low TOC (< 2%), such as the lower Kyalla shale. Analysis assessing the contribution of individual clay minerals to the CH4 adsorption capacity indicates that it is the high illite/muscovite content (30-40%) that controls adsorption on the lower Kyalla shale samples. For the high TOC/low clay middle Velkerri B samples (3.7-6.3% TOC, 20-23% clay) clay content cannot account for the differences observed in adsorbed gas between the samples, even as a secondary control. Further investigation is required to understand what controls gas adsorption on this shale.
A Case Study: The First Hydraulically Fractured Well in Carbonate Reservoirs in Iraq
Authors: Cui Mingyue , Ding Yunhong , Zhu Dawei , Chen Yandong , Cai Wenxin , Liang Chong , Hu Zihui , Yan Jun , Wang Dayong , Zhang Tianwen
Published: October 2018

The reserves of tight carbonate S formation amounts to 25% of the total of X field in Iraq, but the production contributed only 0.3% to the total output. Accordingly, hydraulic fracturing was implemented in well V5X in Dec. 2016, the first pilot test in Iraq. In this paper, the fractured well was taken for a case study to illustrate the holistic optimization to guarantee the treatment success, a world-wide difficulty with high engineering risk.

There are uncertainties concerning the breakdown pressure, in-situ stress and the development of natural fissures in the region, posting challenges in figuring out a reasonable treatment design.

For this purpose, comprehensive lab experiments and numerical simulation were conducted to analyze and benchmark the reservoir characteristics, rock mechanics and geological model. Systematic study on fracture parameters optimization, treatment fluid formulation, proppant screening and operation program were carried out. Based on the treatment parameter optimization, the main-frac scheme was perfected in combination with mini-frac and temperature logging interpretation.

S formation is a limestone reservoir with unique petrophysics, i.e., medium to high porosity (15-20%) but low permeability (0.05-1.3 mD), poor connectivity between pore throats, and hence resulting in inadequate liquid supply. Lab experiments revealed the "low Young's modulus and high Poisson's ratio" rock mechanics features, which is contrary to common understanding. In this case, large-scale treatment was required to ensure the high fracture conductivity. Moreover, there is no significant contrast in the in-situ stress profile or lithology barrier. Consequently, the development plan which requires fractures to be constricted within S formation would be hardly realized. Therefore, proppant sizing was prudently conducted to achieve the rational sand placement and treatment fluid performance was optimized to control the vertical fractures extension. For the fracturing job, totally 443.1 m3 treatment fluid and 39.6 m3 proppant were pumped. The operation parameters were in reasonable agreement with the design. The initial test production was 10 times higher than before. Currently the "production under controlled pressure" mode has been executed. The wellhead pressure has been stable, and the boosted production has been maintained for over one year. Comprehensive analysis of reservoir characteristics and suitable fracturing design are crucial to the success of stimulation treatment.

The experience gained in this case study has some guiding significance for improving the success rate of hydraulic fracturing treatments and for effectively developing such low permeability carbonate reservoirs, both theoretically and practically.
Mitigating the Failure of Downhole Pumps Due to Gas Interference in Coal Seam Gas Wells
Authors: Wu Benjamin , Firouzi Mahshid , Rufford Thomas E. , Towler Brian
Published: October 2018

Coal seam gas (CSG) well operators typically follow an industry rule of thumb 0.5 ft/s liquid velocity to prevent the onset of gas carryover during CSG dewatering operations. However, there is very little experimental data to validate this rule of thumb with only a publication by Sutton, Christiansen, Skinner and Wilson [1] available in the open literature. A review of more general studies on two-phase gas-water flows in vertical pipes and annuli revealed that experimental conditions, especially pipe and annuli diameters, can have a significant impact on development of two-phase flow phenomena. As such, the limited available data may not be applicable due to differences in experimental conditions. This study experimentally investigates the onset of gas carryover using an experimental setup intended specifically for the study of CSG wells.

The University of Queensland Well Simulation Flow Facilities were designed to replicate as closely as possible the production zone of a typical vertical CSG well in Queensland, Australia in transparent acrylic pipes to observe two-phase flow behavior in simulated downhole conditions. The annular test section in the rig was constructed of a 7-in casing and 2¾-in tubing. Modification of the experimental setup to include a vertical separator allowed for the detection of gas carryover. Conceptual demonstrations of gas carryover were captured and have been illustrated. The experiments in this study validate the industry rule of thumb of 0.5 ft/s liquid velocity as an appropriate guideline for onset of gas carryover in a casing-tubing annulus dimension similar to a typical CSG well in Queensland.
Mechanisms Investigation of Super-Heated Steam Assisted Gravity Drainage
Authors: Liu Xueqi , Liu Shangqi
Published: October 2018

The heat efficiency of steam during SAGD process is vital for the SAGD economic performance. In deposits with buried depth more than 400 meters, the in-situ steam quality is basically less than 85% by injecting the saturated steam on the wellhead. Less steam quality means less specific heat enthalpy and less effect of oil viscosity reduction by steam and lower oil drainage rate. The super-heated steam injection was proposed in this paper in which the key mechanisms of oil drainage rate enhancement were investigated for a typical SAGD project in Athabasca oil sands.

The experimental and numerical simulation approaches were chosen to integrally study the key mechanisms. A serial of two dimensional scaled physical modeling were performed to simulate the characteristics of steam chamber evolution, to compare the dynamics of SAGD production by different steam temperatures, and to determine the potential of SAGD by super-heated steam. In addition, the field scale numerical simulation model was built based on the geologic modeling, and the relationship between steam temperature and steam chamber growth behaviors were studied.

The two dimensional scaled physical modeling results indicated that the steam needed was reduced by elevating the steam temperature, and less time was required to reach the plateau oil production rate. Super-heated steam with higher temperature speeded up the steam chamber growth rate more evidently, while when the super-heated value was more than 300°C, further enhancing the temperature would result in less incremental oil drainage rate and higher risk of caprock failure. The numerical simulation of typical SAGD wellpair required that the overall temperature of super-heated steam should be not above 300°C considering the lifting requirements and hydrothermal reaction. 7.67% of less steam injection for the whole life cycle of SAGD, 13.5% of reduced SCOR would be achieved by steam with super-heated degree of 40°C.

The results from this paper have been used to guide the field operation, and the encouraging performance was expected.
Malaysia's Experience in Integrated Coordination of Offshore Supply Vessels through Integrated Logistics Control Tower ILCT
Authors: Mohammad Nurul Azni , Mohd Azani Muhammad Faiz
Published: October 2018

1. Objectives/Scope

The Integrated Logistics Control Tower (ILCT) aims to enable vessel sharing across 15 Malaysia producing Petroleum Arrangement Contractors (PACs) to lower the logistics cost across upstream operations in Malaysia. Prior to this, each PAC operated their own vessels. Opportunities for synergy and sharing between PACs were rarely tapped resulting in fragmented demand and specification, which in overall leads to higher cost.

2. Methods Procedures, Process

ILCT was triggered from a heuristic study in June 2016 and the study showed the potential of RM100 millions yearly cost saving from reduction of 10-20 vessels through fleet sharing across the producing PACs. A joint project management team was formed comprised of key logistics personnel from PETRONAS and PACs to execute ILCT. Operation simulations were conducted involving stakeholders from operations, Health, Safety and Environment (HSE), legal, finance, and procurements to identify current limitations, and the short, medium and long term solution in order to ensure such sharing will not compromise HSE and production performance.

3. Results, Observations, Conclusions

The joint project management team has encountered multiple obstacles towards ILCT implementation such as vessel priority, marine HSE standardization, vessels technical specifications, joint coordination agreement, liabilities, cost allocation, accumulative contract value re-distribution, and governance matters. In overcoming the obstacles, the team has established ILCT Committee and ILCT Manual. The ILCT Committee comprises of PETRONAS and PACs members with the key roles to control the overall allocation of vessels, mediate any conflict, and improve ILCT performance. The ILCT Manual was jointly developed by PETRONAS and PACs to govern the implementation of ILCT and is regularly referred by PACs as guiding principle in operating vessels.

This national synergy resulted in 12 vessels reductions from 142 to 130 vessels that equivalent to RM100 millions of cost savings yearly. PETRONAS and PACs benefit from this synergy mainly through optimized traveling route, which results in lower Daily Charter Rate and fuel cost. It also supports PETRONAS’ agenda to nurture capabilities of local vessel owners to become regional vessel operators. The key success of ILCT lies on PETRONAS’ role as the regulator for Malaysia upstream industry, by orchestrating the cooperation across PACs in syncing the common alignment towards achieving the desired outcome of ILCT.

4. Novel/Additive Information

Malaysia's ILCT is the biggest integrated offshore marine transportation arrangement in the world, with 120 vessels involved in serving offshore transportation needs to 198 producing fields in East & West Malaysia.
From Preservation to Execution: Value Creation through Successful FDP Optimisation for an Offshore Green Field Gas in Peninsular Malaysia
Authors: Sabzabadi Ali , Binti Daeng Aida , Binti Hamza Norashikin
Published: October 2018

Value Creation can be achieved through FDP optimisation initiative for offshore fields that have been impacted by recent slump in activities and investments in the Oil and Gas industry. Each stage of the FDP process can be reviewed and respective value and cost target be revised. It is to ensure that process for the opportunity still carry business value, and aligned with business objectives at current industry outlook. Alongside the opportunity maturation process, there should also be emphasis on value assurance to maximise value and chance of success.

Offshore development of a green field gas development in Peninsular Malaysia was a successful story of Integration and engagement of various functions and disciplines throughout the FDP optimisation efforts, by keeping the FDP stages as "live" cycles. It let the optimisation process to encompass all activity spectrum from subsurface to surface, and warranted the project to be fully assessed from uncertainties and risk management to optimising the value of the project.

Early determination and understanding of the objectives and area of focus for maximum impact on value creation initiatives were chosen to be the road map. Moreover, collaboration between the teams to revise drilling, completion and the depletion strategies with capital cost phasing were identified to be key areas for a successful development and cost optimisation of the project. Drilling and completion strategies for the wells selected in a manner that they focused on most productive zones at the beginning, with development of the shallower reservoirs by workover and intervention activities upon depletion and pressure equalisation with the lower zones. The strategy also led the capital cost to be classified as operational as future expense without compromising the reserve to be developed.

The result of the work led to a significant cost saving which in turn allowed execution of the project from preservation to drilling stage in almost 6 months.

This paper will highlight the initiatives and activities that made the project to be successfully move from preservation to execution mode.
Using a Business Intelligence Tool for Drilling Data Analysis in the Permian Basin
Authors: Chen Zhenyu , Lo Allen , Neves Carrasquilla Maria , Zhao Zhiguo , Shahid Tanveer
Published: October 2018

Oil and gas companies are increasingly using data analytics to improve drilling performance. This paper provides an example of using a business intelligence (BI) tool to analyze drilling data in the Permian Basin. The BI tool helped to improve operation decisions through the use of a visual report. A database, consisting of massive amounts of historical drilling data, is analyzed using the BI tool to better understand drilling performance and predict average operations performance in the area.

A historical drilling database is created based on the bottomhole assembly (BHA) run data and analyzed by the BI tool to review the well performance, in addition to identifying any hazards and summarizing the optimum drilling system during the planning phase. With the help of the BI tool, the drilling database can be displayed in an interactive way to further understand the drilling performance in the area; e.g., the top performing drill bit, drilling system, downhole mud motor configuration, and estimated drilling time for the section of interest. As a result, engineers will find it easier to identify the potentially top performing wells along with drilling hazards in offset wells. The engineers can evaluate the well details and identify the best drilling practices to optimize drilling performance and eliminate downhole incidents.

Using the BI tool helps reduce the data mining time and offers a fast, improved method for gaining technical insights into the drilling operation. These descriptive analytics help to simplify the complex data sets, which are valuable for uncovering patterns that offer data set understanding. With the visualization results, experts can focus on data diagnostics analytics to make suggestions for drilling operation improvements and corrections. Furthermore, these analytical data can be used as inputs for more advanced predictive (forecast drilling performance) or prescriptive analytics (drilling optimization) that deliver real-time insights for making improved business decisions.
Performance of Ceramic Sand Screen for High Rate Gas Application - Gas Sand Screen Erosion Testing
Authors: Manning Nickolas , Cadogan Paul , Barth Peter , Hoskin Ben , Read Trent , Manning David , Jackson Richard , Gundemoni Bhargava
Published: October 2018

Sand production is a common problem throughout the oil and gas industry, particularly in ‘high rate’ gas reservoirs coupled with low rock compressive strength. Conventional downhole sand control techniques such as gravel packing can act to limit both well geometry and/or productivity. Furthermore, problems with gravel pack installations can lead to preferential inflow, leading to ‘hot spotting’ and ultimately loss of sand control. To evaluate the erosion resistance of sand control equipment under the highly erosive environment of high rate gas wells, innovative testing equipment is needed. This paper will discuss the development of a Gas Sand Screen Erosion Test (GSET) rig and its application to evaluate the erosion resistance of ceramic sand screens.

GSET is designed to simulate ‘accelerated’ erosive down-hole conditions. The GSET cell can accommodate but not limited to a screen stub section, screen coupons and variety of downhole equipment. A combination of high flow rate gas and volume controlled particle reservoir matched sand is coalesced into an acceleration tube. The high velocity sand particles (>80m·s-1) impact the ceramic sand screen, causing erosion within the target area. In this paper, the GSET rig was operated for 48 hours at maximum velocity (>80m·s-1) and with a sand concentration of 750 ppmw. Take into consideration that the velocities seen throughout this paper are significantly greater than what a conventional reservoir/completion system would have to tolerate.

Initial and final sand screen analysis was conducted to evaluate the performance of erosion resistance. An array of analysis techniques was applied with focus on gap aperture size and surface topography. Gap aperture measurements were a focal point, as it is directly proportional to its ability to maintain sand retention capabilities.

This paper highlights the potential of the new GSET rig, enabling laboratory testing of erosion resistance of sand control equipment for high rate gas wells under accelerated conditions. Test results obtained with the ceramic sand screen section underpin the inherent high erosion resistance of ceramic sand screen technology ensuring longevity in highly erosive environments. Thus, providing opportunities to complete both new reservoirs and intervene in existing fields with remedial sand control solutions; through extension of the viability of stand-alone screens, simplification of well construction or intervention and increase in productivity.

The observations made by the authors are supported by extensive laboratory testing. The resources provided in this paper will allow petroleum engineers to appropriately evaluate the potential benefits of utilizing ceramic sand screen technology in their completions.
The Hybrid Completion and Stimulation Technology Combining Sleeves with Bridge Plugs: A Case History in Ordos Basin, China
Authors: Tong Zheng , Ma Bing , Wei Ran , Liao Chenglong , Liu Shun , Huang Peng , Wang Xinzhong
Published: October 2018

Operator planned to develop the new low-permeable sandstone gas reservoir below the mature gas layer in Ordos basin. In terms of cost reduction the wellbore was designed to pass through the undeveloped resource locating in the upper mature reservoir to obtain dual-zone commingled production. According to the well logging, there was the indication of hole collapse, enlargement and an unforseen water bearing zone found in the deviated section locating in upper zone. Packers could fail in the irregular deviated wellbore.

Upon the modification of completion solution, the 4 1/2in open-hole packer-sleeve (OHPS) completion and fracturing system was deployed to treat the lower target zone. Top cementing operation using novel stage collar with swellable elements was performed to isolate the upper mature zone. "Plug and Perf" (PnP) via compact bridge plugs was carried out to enable efficient fracturing in deviated wellbore. The single-trip OHPS system employed water-swellable packers (WSPs) with corrugated packing element.

The WSP and compact bridge plug were successfully evaluated by bench test. In one gas well, the operator performed cementing job and the stage collar was opened by wiper plug once the tripping of the OHPS completion with five packers was made successfully. Three bridge plugs were pumped down to the target depth. Hydraulic fracturing operation was sequentially made with all packers and bridge plugs effectively set. It is shown from the field operation that the hybrid completion is able to meet the requirements of completion and stimulation in irregular wellbore with abnormal conditions for tight reservoirs.
Unconventional Techniques Overcome Narrow-Margin Cementing: Case Studies from Malikai Deepwater Project, Malaysia
Authors: Hoe Yijing , Duong Anh , Heu Tieng Soon , Md Radzi Mohd Razif
Published: October 2018

As Malaysia’s first tension leg platform, the Shell Malikai project, represents an unconventional approach towards deepwater operation in this region. In a field embedded characterized by reservoir drawdown from adjacent production wells, the lowest cementing margin is 0.65 ppg. Annular gaps between casings of as tight as 0.53 in each side further elevates the equivalent circulating density (ECD). Cementing software simulation predicts risk of heavy losses during cement placement and subsequently lack of isolation between multiple hydrocarbon-bearing zones. The loss of zonal isolation would mean crossflow between the reservoir. At worst case, some of the water injector wells may be abandoned due to inability to inject into the target reservoir and uncertainties of injection efficiency. This represents a significant loss of capital investment. A two-pronged solution has been developed to secure the long-term well integrity of the deepwater project. Implementation involved front-end design, modelling, planning, and execution.

Two-stage cementing is a technique by which selected intervals along the casing can be cemented in separate stages. It reduces the risk of losses due to long column of cement slurry exerting high hydrostatic head towards the weak formation. In 11 3/4in liner with tight annular gap, the risk of taking losses is high. Therefore, two-stage cementing was employed, combined with specialized blended lightweight 11.5-ppg cement. First-stage cement will provide good liner shoe strength for drilling ahead, and second-stage cement will provide zonal isolation for two hydrocarbon zones near the top of the liner. For 9 5/8in liner, due to the presence of a pressure ramp at the top of the section and weak formation at the bottom, managed pressure cementing (MPC) was the chosen approach to mitigate the risk of losses. MPC is a technique that enables cementation to be conducted in a hydrostatically underbalanced condition where surface backpressure (SBP) is applied to maintain the bottomhole pressure between the highest pore pressure and the lowest fracture pressure of the well.

The combination of MPC and two-stage cementing, together with other existing best practices, formed an integrated solution in narrow margin cementing. This has resulted in flawless cementation for two water injector wells. No losses were observed during cement displacement, there was no gas migration, and the liner top packer was successfully set, and pressure tested in MPC mode. A subsequent cement log confirmed the top of cement requirement was fulfilled. The paper will further explain on how this unconventional technique were planned and executed.