bluuebunny/crossref_metadata_2025 huggingface dataset:
The Right Stuff: Mitigating Human Factors — The Application of Crew Resource Management in Banyu Urip Drilling Operations
Authors: Morris W. C. , Wright R. A. , Ehrmann D. J.
Published: October 2016

Recent discussions and publications in the oil and gas industry (OGP 501 2014, OGP 502 2014) identify the significance of human factors in industry incidents (personnel safety, process safety, environmental, procedural discipline, etc.). Human factors are generally regarded as human performance limiting factors that, left unchecked, can lead and have led to high potential/high consequence events. Human factors include, but are not limited to, fatigue, stress, task overload, complacency, distraction, cognitive and physiological limits, as well as attitudes shaped by workplace/societal culture, education, and motivation. ExxonMobil Cepu Limited's Indonesia Drill Team (EMCL-Drilling) recognized that in order to achieve perfect or near perfect operations, including a completely hurt free and spill free environment while significantly improving performance efficiency, there needed to be a step change in the understanding and mitigation of human factors in its Banyu Urip drilling operations. EMCL-Drilling, in conjunction with PT. Ponco Oilfield Supplies & Services and Check-6, Inc. (Check-6), facilitated a 14-month, 2-rig program to assess and improve human factors awareness and modify team behaviors using Check-6's Performance Excellence® curriculum. This included application of Crew Resource Management (CRM), Plan Based Execution® (PBE), and After Action Review (AAR) principles. CRM PBE-AAR is recognized as a component of Performance Excellence and High Reliability Leadership (HRL) and a proven method for High Reliability Organizations (HROs) to improve operational discipline and achieve perfect days in our industry. Ultimately, EMCL-Drilling's application of CRM PBE-AAR produced significant days of perfect HSSE and operational execution.

This paper provides background on initial workforce performance and behaviors, the introduction and continuous coaching and mentoring of CRM PBE-AAR, and the results achieved. EMCL-Drilling concluded over 20-rig months of operations with CRM PBE-AAR, with notable obstacles of language barriers and arduous rig moves in difficult terrain, where rigsite personnel and supervisors were assessed, human behaviors modified, and process controls improved with zero hurts, zero spills, and significant improvement in operational performance efficiency. As a result of workforce improvements and empowerment, new tools and technology were introduced to further ingrain learnings and capabilities. Rigsite teams demonstrated increased professional and personal pride in their work, taking ownership of processes, accepting responsibility and accountability for their actions and the actions of others, and most importantly developed a sense of empowerment knowing their voices and opinions were heard, respected, and acted upon. The culmination of these efforts resulted in EMCL-Drilling completing the final phase of its Banyu Urip drilling campaign completely hurt free, spill free, and with a perfect day efficiency of 95%.
Emerging Numerical Modelling Technique to Evaluate Asphaltene Inhibitor Efficiency During Entire Field Life
Authors: Yonebayashi Hideharu , Zhang Xiaohong
Published: October 2016

This work was motivated for establishing a robust asphaltene flow assurance engineering using asphaltene inhibitor to mitigate the risk of asphaltene precipitation in tubing. For this purpose, the best candidate was selected through asphaltene dispersant test (ADT). Furthermore, its inhibiting efficiency was evaluated by generating a numerical model. The purpose of this evaluation was to predict how it's efficiency varied during entire field life in which production condition changed in early and late life.

Through the two staged ADT, the best inhibitor IB-23 was selected from total nineteen samples. The IB-23 revealed high inhibiting efficiency more than 80 % at 200 ppm concentration and maintained its efficiency more than 70 % even at 10 ppm. Currently, any commercial software is not available for modelling of asphaltene inhibitor due to confidentiality for inhibitor's physical data. This study achieved to model inhibiting efficiency by treating inhibitor as pseudo-resin and/or pseud-component. It could be defined using limited physical data that was available in public accessible material safety data sheet (MSDS).

The numerical model was generated using cubic-plus-association (CPA) EoS together with the conventional fluid characterization to characterize the asphaltene crudes. This paper demonstrated that the numerical model expressed the inhibiting efficiency as size-reduction of asphaltene precipitation envelope (APE) and decrease in the amount of asphaltene precipitated. The model validity was checked by comparing with experimentally measured weight data of asphaltene deposits during the ADT. Assuming natural depletion, the APEs were compared with variation of vertical lifting curves (VLC) in tubing. Two VLCs were assumed to represent early and late field conditions (i.e. high wellhead/reservoir pressures and depleted ones). The no-inhibitor case revealed precipitating risk existed over most of the tubing section. In contrast, the inhibitor-dosed case could significantly reduce the risks in the early stage in particular. Even in the late stage, the risks could be minimized as the interception of VLC on the APE became shorter than that of the no-inhibitor case.

Asphaltene inhibitor is a typical counter measure; however, most of the applications are temporary relief. Through an entire field life, the production condition varies such as pressure decline, GOR increase, etc. Accordingly, efficiency of the inhibitor, once selected as the best, fades away. Then, another screening would be required to select alternative one that can adapt effectiveness to the new operating condition. This paper contributes to estimate its inhibiting efficiency during a whole field life.
Numerical Analysis of Production Impairment by Condensate Banking in Gas Condensate Fields
Authors: Wilkins A. J. , Morrison G. R.
Published: October 2016

Producing gas-condensate reservoirs below the fluid's dew-point pressure will lead to an increased condensate saturation in the near wellbore region, which impacts the relative permeability to gas. This phenomenon is known as condensate banking and is a cause of productivity impairment. During a field's operational phase, failure to predict condensate banking behaviour accurately will cause problems with a well's ability to attain production targets.

This paper explores the effect of both absolute permeability and condensate gas ratio (CGR) in order to quantify production impairment. To achieve this, three sets of PVT data were characterised. The reservoirs Alpha, Bravo and Charlie have an ideal split (C4-/C5+) CGR of 174.1, 44.7 and 13.9 (stb/MMscf) respectively. For each set of PVT data the absolute permeability has been tested within the range 1 to 1000mD. Both porosity and the relative permeability model were adjusted in proportion to absolute permeability. The range of parameters selected provide coverage of most gas-condensate fields. The PVT data from these reservoirs has been tuned and simulated using a Peng-Robinson twenty-two (22) component dynamic compositional model. Primarily, a single well radial model was used, although implementation of a Cartesian model was also explored for full-field modelling. All models discussed represent an ideal reservoir, consisting of homogeneous properties throughout.

Under a steady-state dry gas production rate of 50MMscfpd productivity impairment reached a maximum of 15.4% assuming an absolute permeability of 1mD and an initial CGR of 174.1 stb/MMscf. This low value of 15.4% was assisted by the positive effect of Velocity Dependent Relative Permeability (VDRP) and condensate stripping within the near wellbore region. In contrast, for situations where VDRP does not apply such as low production rates or post shut-down production ramp-up operations, the effects of condensate banking were significant. That is, removing VDRP to simulate these conditions, under the same dry gas production rate of 50MMscfpd a productivity impairment of 93.2% was observed. This result suggests that the most detrimental effect of condensate banking is caused by unsteady-state production operations. It is intended that the findings of this study be applied to wells currently on production to screen for potential condensate banking in later well life.
E-Learning to Action Learning, a Successful Case Study of an Upstream Oil & Gas Company
Authors: Al-Daihani Eisa , Nandi Arun Kumar , Al-Awadhi Sherif , Matar Maqhim Bander , Razaa Syed Mohammad
Published: October 2016

There are many learning tools available to fill competency gaps of an employee. The common learning tools are classroom courses, workshops, internal on job Training, external on job training with international companies, NOCs and Service Companies, e learning and other learning activities like attending conferences, forums, symposiums etc. However, the most cost effective tool is E-learning. This helps to fill the technical knowledge gap of the participant with flexibility and conveniently. Most of the E-Learning topics include multimedia for better deliverability. It is the most popular learning tool among new generation because they are technology oriented.

The present paper focusses on a pilot project where an attempt has been made to strengthen the E-learning tool through Action learning. The pilot project needed involvement of Coaches and Discipline Experts (DEs) besides candidates selected as participants of E-learning. Accordingly, as a case study, 10 employees (batch of same job family) with same topic were chosen to participate in the pilot project. Few discipline experts and coaches were also involved related to the course content of the E-learning session. A half-day session was organized with online access of the E-learning topic to all participants and DEs and coaches. After going through the entire topic, a group discussion was held and followed by question answer (QA) session.

As E-learning is a kind of self-learning; the effectiveness of the learning tool was dependent on the seriousness of an individual employee. Conventional assignment of E-learning topic and its implementation was helpful in filling the competency gap in the order of 60 to 70% of the course contents or even lower. However, after making E-Learning in to Action Learning through pilot project, the competency gap filling has been achieved up to 100%.

The implementation of E-learning through Action Learning has developed an interest, value addition and fulfillment of competency gaps of individual employees. This will result in fast track development of technical competence and thus help to achieve the group's business needs and company's goal.
Well Abandonment Project and Recommendation for Applying Activity Based Cost/Earn Value Management
Authors: Prasetya Afriandi Eka , Herputra Shanni Ardhana
Published: October 2016

Review the Activity Based Costing (ABC) and Earned Value Management (EVM) fundamentals of being applied to the case study. Examine the constraints and its feasibilities in recommending the implementation of ABC combined with EVM to well abandonment projects.

Well abandonment project is one of phase in the oil well's life span that must be done after it is no longer producing and to protect environment. Instead of giving revenue, well abandonment projects are spending money. To fulfill its deliverables with cost-effectively and in timely manner, the project coverage requires good planning, scheduling, and control. This paper is an actual case study which documents the abandonment of 7 oil wells located in Indonesia. ABC assigns resource costs to a cost object based on activities performed for the cost object. EVM coordinates the work scope, schedule, and cost goals of a program or contract, and objectively measures progress toward these goals.

By applying the fundamentals of ABC and EVM, the abandonment project of 7 oil wells was completed in a total of 131 days, a slippage of 12% over the approved plan of 117 days and at a total cost of 1.078 million USD, versus the target cost of 1.074 million dollars.

This paper explores the step-by-step process that is used to create the Baseline Schedule, track the progress against the schedule and report to the appropriate stakeholders. The paper concludes by recommending ABC combined with EVM be applied to other well abandonment projects.
High-Value Data at Zero Cost: Pulse and Interference Testing in a Deepwater Gas Field Under LNG Plant Start-Up Constraints
Authors: Ly K.. , Das S.. , Pudin V.. , Kazanov D.. , Affinito R. J.
Published: October 2016

Commissioning and start-up (CSU) of an all-subsea development of offshore gas reserves feeding into an onshore liquefied natural gas (LNG) plant is complex and challenging – yet project success is driven by a timely and flawless LNG project start-up. To this end, development wells in the Jansz-Io gas field had to be flowed back to the onshore facility to prove up Gorgon LNG Train 1 capacity before the wells could be relied upon for uninterrupted gas supply to Train 1 start-up. Here, a carefully-considered well proving sequence can yield unique, once-in-a-lifetime and zero-cost subsurface data that improves reservoir characterisation and future decision quality. This paper describes:

Design aspects of the well proving sequence that enabled opportunistic pulse and interference tests to be conducted at no expense to Train 1 start-up: Optimality: balancing the well proving objectives of the various functional stakeholders (flow assurance, facilities, operations and subsurface) while honouring all CSU / operational constraints. Flexibility: recognising and planning for CSU uncertainties (subsea gathering system versus onshore plant readiness; onshore gas demand; and pigging schedule for liquids management). Contingencies: planning for sequence execution issues such as well unavailability and gauge failure(s). Execution – how the tests were executed and how the reservoir responded. Analysis and interpretation of pulse and interference test data, whereby: A simple, conceptual analytical model based on the line source solution was constructed and used to guide analyses in more detailed numerical models. A single-layer 2D numerical reservoir model with local grid refinement at the wells was constructed and used to infer inter-well average reservoir storativity (porosity-total compressibility-thickness product, ϕcth) and transmissivity (mobility-thickness product, kh/μ) and across-fault communication. Existing 3D models were calibrated to the pulse and interference testing data for improved reservoir performance predictions in support of future reservoir management decisions.
The Petrophysic Role of Low Resistivity Pay Zone of Talang Akar Formation, South Sumatera Basin, Indonesia
Authors: Holis Z. , Prayogi A. , Purwaman I. , Damayanti S. , Nugroho D. , Kamaluddin M. K.
Published: October 2016

The South Sumatra Basin is one of the most hydrocarbon prolific Indonesian Tertiary back-arc basins today. Identifying, evaluating, and testing Low Resistivity Pay Zone (LRPZ) in South Sumatera Basin, is a challenge for increasing hydrocarbon resources in term of exploration in Indonesia. The objective of this study was to formulate the petrophysical paramater reference of LRPZ of Talang Akar Formation in South Sumatera Basin, validated by well test data.

The methods used in this study included regional well correlation, petrophysical analysis, core and cutting description, petrography analysis, petrophysical cross plot and cut-off analysis, and well test data analysis. Regional well correlation and petrophysical analysis was conducted for 110 well data in all of sub basin in South Sumatera Basin, those are Jambi, Central Palembang, North Palembang, and South Palembang Sub Basin. Core, cutting description, and petrography analysis needed to observe Low Resistivity Pay mineralogy content. Result of petrophysical cross plot and cut-off parameter analysis would be validated by well test data to formulate the role of LRPZ.

Based on well data, LRPZ was controlled by stratigraphy on sequence boundary of SB-T4 till Maximum Flooding Surface of MFS-T5 in Jambi Sub Basin, and on Maximum Flooding Surface of MFS-T4 till sequence boundary of SB-T5 in South Palembang Sub Basin. Core and cutting description indicated presence of pyrite and glauconite mineral in LRPZ of Talang Akar. Furthermore, petrography analysis indicated presence of pyrite and siderite mineral. These mineral were responsible to increase conductivity on formation. Based on cross plot, it was observed that LRPZ of Talang Akar Formation contained dispersed-laminated shale. It indicated that presence of LRPZ in South Sumatera Basin was caused by presence of fine grained reservoir or superficial porosity. Cross plot two parameter, RPD (Relative Porosity Difference) and resistivity log cross plot, defined cut off parameter is 5 Ohmm for LRPZ of Talang Akar Akar. Based on well test data validation, the water saturation (Sw) cut off on LRPZ is 70%. The observation result concluded that Low Resistivity Pay Zone (LRPZ) of Talang Akar Formation, South Sumatera Basin, was characterized by low gamma ray value, presence of neutron-density log crossover, and presence of hydrocarbon evidence on total gas reading and oil show on cutting, but very low resistivity (<5 Ohm.m).

This petrophysic role of Low Resistivity Pay Zone would be useful to help geoscientist to determine well test interval technically for successful hydrocarbon discovery in Low Resistivity Pay Zone of Talang Akar Formation, South Sumatera Basin, Indonesia.
Fast Track Well Planning in Borneo
Authors: Pathy Kuhanesapathy AL , Kumar Premila AP , Kaeng Geovani C. , Mansor Aznizan Bin , Sausan Sarah
Published: October 2016

This paper highlights the phenomenal achievement of a Malaysian operator's first fast track drilling operation in a deepwater well offshore Borneo. The collaborative well planning (CWP) method fundamental to the drilling success is discussed.

The discussed drilling environment is an overpressured deepwater area that has not only forced the earlier A1 and A2 to early total depth (TD) and caused abandonment of geological targets, but also contributes to numerous operational problems. Despite the challenges, operations on A3 ST-1 required significantly less operational time cost than budgeted. The difference between the previous two wells and A3 ST-1 was that, during the planning period, multidisciplinary concerns were addressed more carefully in real-time by employing CWP to unite geoscientists, drilling engineers, and other stakeholders using 3D integrated platform technology.

This CWP helped the operator meet objectives for A3 ST-1, a fast track well that required only two months of drilling time, rather than the typical 12 to 18 months. It resulted in one primary well location and six geological sidetrack scenarios being accomplished in only one day. Upon the end of the operation, Well A3 was drilled with one successful cased hole sidetrack to geological target objectives without significant operational problems. A significant portion of the success can be attributed to the proper accommodation of concerns and best practices of rig usage, engineering insights, tool usage, and geological conditions during the planning process through the common software platform that can seamlessly allow collaboration of both geoscience and engineering data. The process automation only requires key drilling parameters to construct well trajectories, which was also significant in terms of shortening the planning time.

This paper describes the first application of the CWP concept in offshore Borneo, which has become a trendsetter in terms of efficient and safe deepwater drilling planning and operations.
Production Optimization in Waterfloods with a New Approach of Inter-Well Connectivity Modeling
Authors: Zhai Xiang , Wen Tailai , Matringe Sebastien
Published: October 2016

We present a novel methodology to model inter-well connectivity in mature waterfloods and achieve an improved reservoir energy distribution and sweep pattern to maximize production performance by adjusting injection/production strategy on well control level. The method involves a reduced-physics based fast numerical tracer test on each well that yields inter-well connection strength or well allocation factors, and then a data-driven efficiency model on each inter-well connection calibrated automatically from the production/injection history of the reservoir. The latter one identifies the undesired connection suffered from water cycling or aquifer coning. A producer-injector/aquifer communication network is established which enables instantaneous forecast on reservoir response to various hypothetical well control strategies. An optimization algorithm is applied to improve the flux pattern by strengthening efficient connection and weakening inefficient connection. The objective of the optimization can be to maximize oil production or to minimize water cut. A set of physics constraints (lift limits, injection limits, liquid capacity, etc.) and economic constraints (e.g. oil target) can be enforced in the optimization process.

The methodology is tested based on a full-scaled history-matched simulation model of a real carbonate field. The field is a large waterflood with 200+ wells and 5 years history, and the current water cut is above 30% and rapidly increasing. The full field simulation model was regarded as the true reservoir in this study. The network model was trained up to a time point, and then used to optimize the waterflooding strategy for six months. Reservoir response to the optimized strategy was simulated on the full field model, as well as the historical strategy and do-nothing strategy. The results demonstrated that the optimized strategy maintained oil production and reduced water production by 50% without adding new well, while the historical operation satisfied the oil target by drilling tens of new wells and scarifying water-cut.

This new approach models the key physics in waterflooding with a network model, and uses the model to optimize well control strategy effectively. The model reduces the non-critical physics and incorporates data-driven techniques, therefore it is fast to build, calibrate and run. Compared to traditional simulation modeling, this approach can be used by production engineers to guide operations in a daily to weekly manner.
Subsea Separation – an Undervalued Tool for Increased Oil Recovery IOR
Authors: Hendricks R.. , McKenzie L. J. , Jahnsen O. F. , Storvik M.. , Hasan Z..
Published: October 2016

Over the past 10 to 15 years subsea processing has been globally established as a market segment within the subsea development arena, and subsea separation has been a vital part of this development with Troll C, Tordis SSB, Pazflor and others. The track record of these installations have been outstanding, some of them with documented uptime of more than 99%. Still focus in the market seems to turn towards more ‘clean’ pumping or compression solutions at a time where the boosting technology options increases, while separation seems to be linked to more complexity and higher capex and are often not included as an option in evaluating a field.

Still, subsea separation has some distinguished qualities that cannot be matched by other IOR methods. The more obvious scenarios are linked to flow assurance issues such as hydrate or slugging conditions in a field, but in addition some fields with very low production pressure or very long transportation distance to shore. Equally important is the operators need for flexibility in the design to cover for uncertainty in the production over the life of field and to count for future unexpected situations. This could be for a greenfield, redevelopment of a brownfield, or in general uncertainties about future sand or water production. Subsea separation is a simple way of mitigating these uncertainties, while at the same time increasing the operational envelope of the overall system compared to a pump or compressor alone. The paper will present examples of how separation can hugely add value compared to boosting alone by using simple, robust technology, resulting in more predictability an increased Net Present Value (NPV) for the operator.
Monitoring Wellbore Fluid Displacement in the Perforation Interval Using Multiple Downhole Pressure and Temperature Gauges
Authors: Paterson Lincoln , Ennis-King Jonathan , Freifeld Barry
Published: October 2016

Permanent downhole gauges for measuring pressure and temperature are very useful for reservoir surveillance. Whereas most applications have used a single downhole gauge, here we discuss experience using multiple downhole gauges simultaneously in a single well. At the CO2CRC Otway site four permanent gauges were installed in the CRC-2 well in 2011 with these gauges bracketing the perforation interval. The gauges were used to monitor the injection at various stages of water, pure carbon dioxide, impure carbon dioxide and nitrogen. Observations from these gauges have allowed the position of the gas-water interface to be observed as it moved up and down through the perforation interval. This provides information on the effectiveness of the perforations and the fraction of reservoir zone being accessed. The changing densities of gas mixtures due to temperature and composition were also inferred. These observations assist the development of better wellbore models for use in reservoir simulation of near-wellbore fluid flow, replacing the often-used initial assumption that one single phase contacts the entire injection or production interval. The current installation in CRC-2 at Otway has eight gauges distributed over two completion intervals, one flowing and one isolated from the wellbore. This elaborate configuration allows observations of additional information including the vertical pressure diffusion between the reservoir intervals.
Comparison of Capillary Pressure-Saturation Models for Gas-Water Systems in Shale Gas Reservoirs
Authors: Ren Wenxi , Li Gensheng , Tian Shouceng , Sheng Mao , Yang Ruiyue , Wang Tianyu
Published: October 2016

For two phase flow simulation in shale gas reservoirs, such as carbon sequestration, drilling fluid filtration and fracturing fluid leak off, it is critical to know the relation of capillary pressure versus saturation (P-S relation). Many P-S models were proposed to characterize the P-S relation. The aim of our study is to evaluate the existing models for P-S relation of shale, including van Genuchten model, modified J-function, Li-Horne model, Kosugi model and Brooks-Corey model.

To meet this goal, first, we converted available mercury-injection capillary pressure data (A total of 13 sets of data from different shales) into gas-water data. Then, each model's parameters were estimated by the nonlinear fitting of experimental data. Finally, the root mean square errors (RMSE) and the correlation coefficients (R2) were employed to evaluate the quality of fitting.

The results show that: 1) for the five models, the mean RSME varies between 0.0087 and 0.1375; 2) van Genuchten model and Kosugi model give better fitting than others, while van Genuchten model and Kosugi model are not much different in terms of fitting precision, both of which are recommended for two phase (gas-water) flow simulation in shale gas reservoirs; 3) Brooks-Corey model exhibits largest RMSE values; 4) for Li-Horne model, pore fractal dimension obtained from fitting is out of the range from 2 to 3, which may be physically unreasonable. Furthermore, it should be note that Kosugi model is derived based on log-normal pore size distribution. Each parameter in Kosugi model has clear physical meaning. Therefore, when involves pore size distribution, Kosugi model is preferable than van Genuchten model.
Modelling of Drainage Capillary Pressure: A Comparative Study of Various Analytical Capillary Pressure Formulations in Matching Laboratory Results
Authors: Behrenbruch Peter , Huu Minh Triet , Hoang Tuan Gia , Bui Khang Duy
Published: October 2016

Capillary pressure relationships (drainage) is of importance in both, reservoir engineering and petrophysics. Reservoir engineers use capillary pressure relationships in reservoir engineering calculations and petrophysicists use such relationships in saturation-height modelling. The overall objective of the study presented is to perform a comparative study of various capillary pressure models commonly used by the petroleum industry and to access their ability to match diverse laboratory data.

Over the years many capillary pressure formulations have been proposed to match laboratory data, from the well-known Leverett J-function approach to more recent methods. Generally, formulations may be theoretical, semi-empirical, empirical or statistical basis. The comparative study presented involves the following analytical formulations: modified Leverett J-function, modified Brooks-Corey (MBC), Thomeer, Skelt-Harrison, Lambda (λ) and the more recently established, Modified Carman-Kozeny-Purcell (MCKP) model.

Various types of pore structures may be modelled: homogeneous (narrow), broad (poorer sorting) and bimodal (two distinct distributions) where one of the distributions is often related to pore-fill, or a mixture of distribution types. Results presented in this paper compare application of the above-mentioned methods for homogeneous plugs. It is demonstrated that the MCKP method consistently outperforms the other methods and it is the only method that is able to identify the type of pore throat distribution without any further input data. The advantage of the MCKP method is that it does not contain any fitting parameters. The degree of accuracy of the MCKP model is typically R2 > 0.99. The MCKP model also lends itself very easily to predict capillary pressure relationships from more basic parameters.

Presented are examples with data from two Australian fields, one offshore and one onshore.
Tight TVD Control on Australia’s North West Shelf Through a Cutting Edge Solution High-Definition Surveying
Authors: Naveed Muhammad , Kirthi Singam Chandrasekhar , Viandante Mauro , Ali Malik Kashif , AKhmadeev Vadim , Jury Ben , Belson Will , Wroth Andy
Published: October 2016

It is widely recognized in the industry that 30m survey intervals are too large to capture the true trajectory of the directional borehole and can result in significant True Vertical Depth (TVD) errors. This is particularly true when drilling with motors or geosteering in reservoirs with tight-TVD tolerance. Based on experience with horizontal wells drilled in North West Shelf (Vincent, Wandoo and Coniston drilling campaigns), a new technique of high definition surveying (HDS) was introduced.

The North West Shelf (NWS) in Australia imposes significant challenges for maintaining constant directional control while drilling in sand layers, which can be unconsolidated and include or traverse faulted or fractured zones. In such formations, TVD control in horizontal wells is a challenge. To improve control, extra surveys would be needed to reduce the vertical uncertainty; this process would be very time-consuming iand adds a risk of stuck pipe and hole washout.

Additionally, as the field become more congested through infill drilling, the risk of collision with nearby wells would increase because of poor TVD control.

The HDS gives a more accurate reconstruction of the wellbore position while drilling with respect to the pre-drilled geological model all the way out to target depth.

Reservoir mapping while drilling (RMWD) and Bed boundary mapping (BBM) services both measure the distance to nearby boundaries. These services map the form and position of reservoir boundary structure with respect to the associated well path. Therefore, the position of the reservoir structure in space is directly related to the directional wellbore survey. An inaccurate survey leads to errors in reservoir geometries and structural tie-in to the adjacent exploration and development wells. Because the wellbore is more accurately defined using HDS, so is the reservoir structure when coupled with RMWD services. This greater definition has enabled better well planning to drive maximum value extraction from reservoirs. With these features in place HDS has become an integral part for RMWD and BBM Services.

This paper illustrates the potential benefits of using HDS as a further service quality improvement component applicable to drilling horizontal wellbores and gives examples of practical implementation such as borehole tortuosity, torque and drag modelling, well placement and drilling and completion optimization.
A new GIS landscape classification method for rain/snow temperature thresholds in surface based models
Authors: Feiccabrino James M. , Grigg Laurie D.
Published: October 2016

Landscape air temperature thresholds (TA) and percent misclassified precipitation (error) for 12 years of meteorological observations from 40 stations across the Scandinavian Peninsula were derived and compared using both manual and geographic information system (GIS) landscape classification methods. Dew-point, wet-bulb, and wet bulb 0.5 were also tested. Both classification methods used the following west to east landscape categories: windward (WW) ocean, coast, fjord, hill, and mountain in Norway; and leeward (LW) mountain, hill, rolling terrain, and coast in Sweden. GIS landscape classification has the advantages of automating the classification process and increasing objectivity. The GIS classification was based on station location (LW or WW) relative to the Scandinavian mountain range, and the % water or range of elevation change within 15 km. The GIS and manual method had the same TA for 20 stations, and similar total reduction in error (2.29 to 2.17% respectively) when compared to country TA. Therefore, automated GIS landscape classification can be used to decrease error from common country or global scale TA. Wet-bulb temperature thresholds for GIS landscapes resulted in a greater reduction in error (8.26%) compared to air (2.29%), and dew-point (−16.67%) thresholds. However, finding stations reporting relative humidity or wet-bulb temperature may limit its widespread use.
Magnetite nanoparticles influence the ammonium-oxidizing bacteria activity during nitritation process
Authors: Perazzoli Simone , Michels Camila , Soares Hugo M.
Published: October 2016

With nanotechnology dissemination, nanomaterials' (NMs) release into the environment is inevitable and may adversely affect the wastewater treatment processes. Among the NMs, the iron oxide nanoparticles have a considerable commercial potential, mainly because their magnetic properties, high catalytic ability and antimicrobial activity. However, few studies have examined their potential effect on the biological wastewater treatment. In this process, ammonium-oxidizing bacteria (AOB) are sensitive to the presence of inhibitory compounds and are useful as biosensors to assess contaminant toxicity information. Thus, this work aimed to assess the effect of commercial magnetite nanoparticles (Fe3O4-NPs) on AOB activity. Kinetic experiments were carried out where AOB were exposed in a short-term period (14 h) to different concentrations (from 0.2 to 1.0 g L−1) of Fe3O4-NPs. A decrease of the 61.33% in the NO2−-N production rate was observed to the highest concentration of Fe3O4-NPs studied, compared with the control sample. The Fe3O4-NPs concentration that reduces 50% of NO2−-N production rate (IC-50) was estimated 0.483 g Fe3O4-NP L−1. Scanning electron microscopy images revealed that NPs remained incorporated in the biomass (sludge). These results suggest that NPs can reach the environment through sludge disposal, mainly in cases of the reuse as soil fertilizer.
Application of coupled zero-valent iron/biochar system for degradation of chlorobenzene-contaminated groundwater
Authors: Zhang Xu , Wu Yanqing
Published: October 2016

A novel iron-carbon micro-electrolysis system, bamboo-derived biochar coupled with zero-valent iron (ZVI), was investigated for chlorobenzene (CB)-contaminated groundwater removal. Influences of initial pH value, mass ratio of the ZVI/Biochar, initial CB concentration and ionic strength of the ZVI/Biochar micro-electrolysis were studied. The results indicated that the increase of initial pH led to the decrease of the CB removal efficiency. While the optimum mass ratio of ZVI to biochar was 2:1, the improved initial concentration and reaction time were 33.68 mg/L and 4 h, respectively. When pH of 2, mass ratio of 2:1 and reaction time of 4 h were applied, the CB removal efficiency was 99.92%. Enhanced degradation of CB was observed with increased Cl− concentration. When the Cl− concentration of 1,000 mg/L and reaction time of 1 h were applied, the CB removal efficiency arrived at 98.2%. Additionally, considering that biochar is cost-effective and readily produced, the coupled ZVI/Biochar micro-electrolysis could represent an effective approach for the treatment of groundwater containing chlorinated organic compounds in the future.
Photochemical Elimination of Endocrine Disrupting Chemical (EDC) by ZnO Nanoparticles, Synthesized by Gel Combustion
Authors: Rajesha J. B. , Ramasami Alamelu. K. , Nagaraju G. , Balakrishna Geetha. R.
Published: October 2016

Zinc Oxide (ZnO) nanoparticles prepared by gel combustion synthesis using cassava pearl starch have been characterized by various microscopy and spectroscopy techniques. The particle size averaged around 45 nm, revealed zincite structure, hexagonal, agglomerated morphology and possessed an excellent photocatalytic activity in sunlight. Contrary to the existing literature survey, this photocatalyst possessed a band gap of 2.7 eV, causing an extended absorption towards broader range of the solar spectrum, thus making it an excellent visible light‐activated photocatalyst. Photocatalytic activity was investigated on one of the highly resistant, most‐focused endocrine disrupting chemical (EDC) benzophenone‐3 (BP‐3), which is used in personnel care products. The observations reveal a near complete photooxidative degradation of BP‐3. A reaction mechanism for the photooxidative pathway was proposed based on the isolated intermediates.
In-vitro Studies of Plant Extracts against Alternaria brassicae (berk.) Sacc. of Indian Mustard (Brassica juncea (L.) Czern. and coss)
Authors: SINGH MAHESH , SINGH H. K.
Published: October 2016

Six plant extract viz., Datura (Daturastramonium), Eucalyptus (Eucalyptus globulous), Karang
(Pongamiaglabra),Neem (Azadirachtaindica), Madar (Calotropis gigantean) and Wild sage (Lantana
camara) were evaluated in-vitro by poison food technique @ 3, 6, 9 and 12% concentrations against
Alternariabrassicaecausing blight of mustard. The results revealed that all the plant extracts
inhibited the percent growth inhibition against test fungus as compared to control. However
A.indica was found most efficacious with growth inhibition of (38.7%) followed by E. globulus
(36.7%). Some extract such as P. glabra and D. stramonium showed moderate inhibition over control
(30.9 and 21.6 respectively). Among all plant extract, C. gigantean showed least (15.3%) inhibition
over control against A. brassicae. These plant extracts can possibly be used as management of seedborne
pathogenic fungi in an eco-friendly way.
Physio-Chemical and Biological Analysis of Radaur-Ladwa
Stretch (Western Yamuna Canal)
Authors: DENIS ANJELO F , RACHNA SUSHRI , ALI EHSAN , DESWAL SURINDER , SATYA PRANJAL
Published: October 2016

This paper deals with the suitability of Surface and Ground water quality of Western Yamuna Canal
in Haryana, India for irrigation and other use. The major water use of this canal is for irrigation
purpose (94%), domestic water use (4%) and industrial and other uses (2%).The rapid increase
inurbanization and industrialization is leading towards deterioration of water quality. In this
study, analysis is performed to identify the groundwater and surface water quality in the vicinity of
Radaur-Ladwa stretch. Direct disposal of domestic and industrial wasteobstructs the flow of
Western Yamuna Canal thus water is stagnant at most places and self-purification mechanism of
water is occurring no more. This study reveals that the surface water of the Western Yamuna Canal
comes under E class of water, which is unfit for domestic use, propagation of wildlife and fisheries.
However it is found suitable for irrigational and industrial cooling purpose only. Most Probable
Number (MPN) values are high in the ground water, which indicates microbial contamination of
water and require immediate action for up-grading existing treatment facilities.The result indicates
alarming signs and suggests immediate response for policy along with adaptation and mitigation
to bring at full stop to contaminating activities. If water contamination is continued likewisea time
will come soon that the water qualityof Radaur-Ladwa stretch (Western Yamuna Canal) will be
unfit for irrigational purpose too.
Awareness, Access and Use of Internet Self-Help Websites for Depression by University Students
Authors: Culjak Gordana , Kowalenko Nick , Tennant Christopher
Published: October 2016

Background

University students have a higher prevalence rate of depression than the average 18 to 24 year old. Internet self-help has been demonstrated to be effective in decreasing self-rated measures of depression in this population, so it is important to explore the awareness, access and use of such self-help resources in this population.

Objective

The objective of this study is to explore university students’ awareness, access and use of Internet self-help websites for depression and related problems.

Methods

A total of 2691 university students were surveyed at 3 time points.

Results

When asked about browsing behavior, 69.6% (1494/2146) of students reported using the Internet for entertainment. Most students were not familiar with self-help websites for emotional health, although this awareness increased as they completed further assessments. Most students considered user-friendliness, content and interactivity as very important in the design of a self-help website. After being exposed to a self-help website, more students reported visiting websites for emotional health than those who had not been exposed.

Conclusions

More students reported visiting self-help websites after becoming aware of such resources. Increased awareness of depression and related treatment resources may increase use of such resources. It is important to increase public awareness with the aim of increasing access to targeted strategies for young people.
Особливости лікування пацієнтів, інфікованих 1 и 4 генотипами вірусу гепатиту С, противірусними препаратами прямої дії
Authors: Shypulin V.P. , Kuzminets A.A.
Published: October 2016

Лікування ВГС 1 і 4 генотипів є актуальною проблемою на сьогодні через високу стійкість до традиційної терапії. Вирішенням цієї проблеми, вочевидь, є застосування відносно нової групи противірусних препаратів прямої дії (ПППД). У даній статті розглядаються різні схеми лікування цими препаратами, механізм їх дії та ефективність, а також порівнюються два найбільш ефективні й перспективні із наявних сьогодні на світовому ринку ПППД — Harvoni (софосбувір/ледіпасвір) та Viekira Pak (омбітасвір/паритапревір/ритонавір + дасабувір). Порівнюються також наявні на сьогодні рекомендації Європейської асоціації з дослідження печінки (EASL), Американської асоціації з вивчення захворювань печінки (AASLD) та Канадської асоціації з дослідження печінки (CASL) щодо лікування пацієнтів із ВГС 1 та 4 генотипів.
Albuminuria Changes and Cardiovascular and Renal Outcomes in Type 1 Diabetes: The DCCT/EDIC Study
Authors: de Boer Ian H. , Gao Xiaoyu , Cleary Patricia A. , Bebu Ionut , Lachin John M. , Molitch Mark E. , Orchard Trevor , Paterson Andrew D. , Perkins Bruce A. , Steffes Michael W. , Zinman Bernard ,   for the Diabetes Control and Complications Trial/Epidemiology of Diabetes Interventions and Complications (DCCT/EDIC) Research Group
Published: October 2016

Background and objectives

In trials of people with type 2 diabetes, albuminuria reduction with renin-angiotensin system inhibitors is associated with lower risks of cardiovascular events and CKD progression. We tested whether progression or remission of microalbuminuria is associated with cardiovascular and renal risk in a well characterized cohort of type 1 diabetes.

Design, setting, participants, & measurements

We studied 1441 participants in the Diabetes Control and Complications Trial/Epidemiology of Diabetes Interventions and Complications study. Albumin excretion rate (AER) was quantified annually or biennially for up to 30 years. For each participant, albuminuria status was defined over time as normoalbuminuria (AER continuously <30 mg/d), sustained microalbuminuria (AER, 30–299 mg/d on two consecutive visits), macroalbuminuria (AER≥300 mg/d), or remitted microalbuminuria (transition from sustained microalbuminuria to AER<30 mg/d on two consecutive visits). We tested associations of time-updated albuminuria status with adjudicated clinical cardiovascular events, the development of reduced GFR (<60 ml/min per 1.73 m2 on two consecutive visits), and subclinical cardiovascular disease.

Results

At least one cardiovascular event occurred in 184 participants, and 98 participants developed reduced eGFR. Compared with normoalbuminuria, sustained microalbuminuria, remitted microalbuminuria, and macroalbuminuria were each associated with higher risk of cardiovascular events (adjusted hazard ratios [HRs] and 95% confidence intervals [95% CIs]: 1.79 [1.13 to 2.85], 2.62 [1.68 to 4.07], and 2.65 [1.68 to 4.19], respectively) and reduced eGFR (adjusted HRs [95% CIs], 5.26 [2.43 to 11.41], 4.36 [1.80 to 10.57], and 54.35 [30.79 to 95.94], respectively). Compared with sustained microalbuminuria, remission to normoalbuminuria was not associated with reduced risk of cardiovascular events (adjusted HR, 1.33; 95% CI, 0.68 to 2.59) or reduced eGFR (adjusted HR, 1.75; 95% CI, 0.56 to 5.49). Compared with normoalbuminuria, sustained microalbuminuria, remitted microalbuminuria, and macroalbuminuria were associated with greater carotid intima-media thickness, and macroalbuminuria was associated with a greater degree of coronary artery calcification.

Conclusions

In type 1 diabetes, microalbuminuria and macroalbuminuria are associated with higher risks of cardiovascular disease and reduced eGFR, but achieving a remission of established microalbuminuria to normoalbuminuria does not appear to improve outcomes.
Comportamento de compra de insumos agrícolas dos fornecedores de cana-de-açúcar no estado de São Paulo
Authors: D'Aragone Ruan Richard , Bigaton Aline , Silva Haroldo José Torres da , Marques Pedro Valentim
Published: October 2016

Esta publicação apresenta análises sobre o comportamento de compra de insumos agrícolas pelos fornecedores de cana-de-açúcar do estado de São Paulo. Os dados foram coletados a partir da aplicação de questionários em encontros presenciais denominados “painéis”. Notou-se uma visão estratégica por parte dos fornecedores nos quesitos que abrangem o processo de compra. Para escolha dos produtos, o foco é claro em preço e qualidade, enquanto que para escolha dos locais de compra, o cerne é difundido em diversos atributos diferenciados, mostrando que neste aspecto os interesses de cada fornecedor não são tendenciais.
Nota a dos investigadores sobre la "Epístola Moral"
Authors: Rojas Garcidueñas José
Published: October 2016

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Otra vez Tresguerras
Authors: De la Maza Francisco
Published: October 2016

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México en la Exposición Universal de 1889
Authors: Díaz y de Ovando Clementina
Published: October 2016

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Gramáticas y lenguaje de orden y el caos
Authors: Espinosa Elia
Published: October 2016

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Manuel Ituarte y El Dibujo de Arquitectura
Authors: Anónimo Anónimo
Published: October 2016

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