bluuebunny/crossref_metadata_2025 huggingface dataset:
Christian philosophy of education in South Africa: the cultural-historical activity theory to the rescue?
Authors: van der Walt Johannes
Published: November 2016

Parents’ choice of schools for their children has become particularly problematic in the current circumstances because of the fact that most schools have become secular and hence cannot support Christian parents in their task of educating children in line with the former’s baptismal vow. In addition to this, Philosophy of Education has all but disappeared from teacher education curricula. These circumstances have not, however, detracted from Christian parents’, teachers’, caregivers’ and other educators’ need for a Christian Philosophy of Education. This article offers such a Philosophy of Education in the form of Biblical perspectives regarding the main facets of education couched in cultural-historical activity theory. This approach circumvents objections against a mere “grab bag” of Biblical perspectives about education as well as against yet another master theory or grand narrative about Christian education.

Ouers se skoolkeuse het in die huidige omstandighede tot ‘n ernstige probleem ontwikkel aangesien die meeste skole gesekulariseerd geraak het en dus nie die ouers kan ondersteun in hulle taak om die kinders ooreenkomstig die ouers se doopbeloftes op te voed nie. Om die probleem te vererger, het Filosofie van die Opvoeding ook uit die kurrikulums vir onderwysersopleiding verdwyn ten gunste van ‘n blote teoretiese refleksie oor onderwys en opvoeding. Christenouers, -onderwysers, -sorggewers en ander -opvoeders het desondanks nog steeds ‘n behoefte aan ‘n Bybelsgefundeerde Filosofie van die Opvoeding. Hierdie artikel omlyn sodanige Filosofie van die Opvoeding. Dit benut die kultuur-historiese aktiwiteitsteorie as ‘n raamwerk vir ‘n stel Bybelse opvoedingsperspektiewe. Hierdie benadering voorkom enersyds besware teen ‘n blote onsamehangende versameling Bybelse perspektiewe oor opvoeding en onderwys en andersyds besware teen die bou van ‘n nuwe meesterteorie of grootskaalse narratief aangaande Christelike opvoeding.
SCAM Detection in Credit Card Application
Authors:   Student, Department of CSE, Jayam College of Engineering & Technology, DharmapuriTamilnadu, India, kumar M.Sanjeeev , Ms A.Kamakshi ,   Asst. Professor, Department of CSE, Jayam College of Engineering & Technology, Dharmapuri, Tamilnadu, India
Published: November 2016

Identity crime is well known, prevalent, and costly, and credit application scam is a specific case of identity crime. The existing no data mining recognition system of business rules and scorecards and known scam matching have confines. To address these confines and combat identity crime in real time, this paper proposes a new multilayered discovery system complemented with two additional layers: communal detection (CD) and spike detection (SD). CD finds real social relationships to reduce the suspicion score, and is tamper unaffected to synthetic social relationships. It is the whitelist-oriented methodology on a fixed set of attributes. SD finds spikes in false to increase the suspicion score, and is probe-unaffected for elements. It is the attribute-oriented approach on a variable-size set of elements. Together, CD and SD can detect more types of attacks, better account for changing legal activities, and remove the redundant elements. Experiments were carried out on CD and SD with several million real credit applications. Results on the data support the suggestion that successful credit application scam patterns are sudden and exhibit sharp spikes in false. Although this research is specific to credit application scam recognition, the concept of flexibility, together with adaptively and quality data discussed in the paper, are general to the model, implementation, and evaluation of all recognition systems.
Generic Methodology for Field Calibration of Nacelle-Based Wind Lidars
Authors: Borraccino Antoine , Courtney Michael , Wagner Rozenn
Published: November 2016

Nacelle-based Doppler wind lidars have shown promising capabilities to assess power performance, detect yaw misalignment or perform feed-forward control. The power curve application requires uncertainty assessment. Traceable measurements and uncertainties of nacelle-based wind lidars can be obtained through a methodology applicable to any type of existing and upcoming nacelle lidar technology. The generic methodology consists in calibrating all the inputs of the wind field reconstruction algorithms of a lidar. These inputs are the line-of-sight velocity and the beam position, provided by the geometry of the scanning trajectory and the lidar inclination. The line-of-sight velocity is calibrated in atmospheric conditions by comparing it to a reference quantity based on classic instrumentation such as cup anemometers and wind vanes. The generic methodology was tested on two commercially developed lidars, one continuous wave and one pulsed systems, and provides consistent calibration results: linear regressions show a difference of ∼ 0.5 % between the lidar-measured and reference line-of-sight velocities. A comprehensive uncertainty procedure propagates the reference uncertainty to the lidar measurements. At a coverage factor of two, the estimated line-of-sight velocity uncertainty ranges from 3.2 % at 3 m s−1 to 1.9 % at 16 m s−1. Most of the line-of-sight velocity uncertainty originates from the reference: the cup anemometer uncertainty accounts for ∼ 90 % of the total uncertainty. The propagation of uncertainties to lidar-reconstructed wind characteristics can use analytical methods in simple cases, which we demonstrate through the example of a two-beam system. The newly developed calibration methodology allows robust evaluation of a nacelle lidar’s performance and uncertainties to be established in order to further be used for various wind turbines’ applications in confidence.
PENGARUH KONSENTRASI KATALIS ENZIM GLUKOAMILASE (ASPERGILLUS NIGER) TERHADAP KONSENTRASI PRODUK GLUKOSA PADA KINETIKA REAKSI SIMULTAN SAKARIFIKASI DAN FERMENTASI BIOETANOLDARI SORGUM (SORGHUM BICOLOR L.)
Authors: Dyartanti Endah Retno
Published: November 2016

Abstract: Sorghum(Sorghum bicolor L.) is one of raw materials to make bioethanol containing carbohydrate which can be hydrolysis becomeglucose. Making of bioethanol is started by liquification and continued by simultaneous saccharification and fermentation (SSF) by adding glucoamylase (aspergillus niger) enzyme and dry yeast (Saccharomyces cerevisiae). This research aim to know influence of enzyme catalyst concentration inSSF reaction to make bioethanol from sorghum. Reaction time of SSF 6 hours at 30oC by adding glucoamilase enzyme and 8 grams dry yeast with velocity of shaker at  8 scale, after liquification in 2 hours at80oC by adding 2 ml alpha-amilase enzyme. From this research earned relation between concentration of glucoamylase enzyme with concentration of glucose product. Ever greater concentration of glucoamylase enzyme applied, ever greater also concentration of glucose product. From this research, it can be concluded that reaction of SSF with the range of glucoamylase enzyme are 4 ml, 8 ml, 10 ml, and 12 ml for 12% substrate concentration, earned optimum condition is using concentration of glucoamylase enzyme at 8 ml. Michaelis-Menten constant (Km) from this research for 12% substrate concentration and 8 ml glucoamylase enzyme is 11.6875 g/l.hours and maximum velocity of reaction (Vmax) is 12.5 g/l.hours.

 

Keywords: Bioethanol, Sorghum, SSF Kinetic
M-Commerce: A Necessity for Future India
Authors: Khurana Priyanka
Published: November 2016

Innovation is the change that unlocks new value. With the increased use of mobile internet and innovative smartphones, the business has transformed from direct selling to mobile selling in India. People now-a-day have become ‘mobify’. Use of tablets, smartphones and i-pad has become common for a common man. The next generation e-commerce, m-commerce enables buying and selling of goods and services through wireless handheld devices which not only provides convenience but also speedifies the quality and quantity of transactions. Mutual Funds are the most preferred financial investment in today’s scenario. M-commerce will help the Mutual Fund Industry to reach greater heights with advancements in technology. The purpose of this study is to evaluate the current status of mobile commerce in India with special reference to Mutual Funds and to establish m-commerce as a necessity for Future India. The researcher has used analytical approach to undertake this study. A questionnaire was prepared and data was collected regarding the financial preference of investors and also the mobile internet users in India. The study concluded that technology based smarter ways of doing business will be the natural favourites for doing business in Future India. India’s growth through financial sector and m-commerce will contribute towards shaping India for a better tomorrow. And by 2020, m-commerce will be the most preferred place for marketers, content creators and advertisers to reach out target audience.  
Transition Zone Development in a Complex Carbonate System
Authors: Ahonsi Wilson , Al Muhairi Layla , El Mahdi Ahmed , Al Shabibi Tariq
Published: November 2016

In a volatile market such as the oil and gas industry, the ability to produce effectively and economically reservoir reserves is crucial. One of the most complex areas of a reservoir is the transition zone, especially in carbonates reservoirs. Transition zone refers to a certain height above the free water level (FWL) where both oil and water usually flow together. Reserves within transition zones vary from one reservoir to the other, in our reservoir we estimate that the transition zone contains about 20% of the total reservoir reserve. As such a study was conducted, to characterise and the defined the best development strategy, in order to produce the transition zone effectively.

In characterising the transition zone various core were acquired, for routine core analysis (RCA) and special core analysis (SCAL). Cores collected were acquired to represent both the crest and flank of the reservoir structure. Using the mercury injection capillary pressure (MICP) and the reservoir quality index (RQI) from the RCA and SCAL, 5 reservoir rock types (RRT) were defined. With reservoir rock type 1 (RRT1) representing the best rock type and reservoir rock type 5 (RRT5) representing the worst rock type. Reservoir rock type 3 (RRT3) occurred mostly in the transition zone.

The reservoir contains a very complex fluid, as the pressure volume and temperature (PVT) properties varies both vertically and areally, with a variation of bubble point pressure (Pb) between 1400psi and 4000psi. Flank location showed lower bubble point pressure, while crest location showed higher bubble point pressure. However, there are also certain cases where flanks show higher bubble point pressure, and crest show lower bubble point pressure. In order model this complicated behaviour in the reservoir simulator, one equation of state (EOS) i.e. the Peng Robinson (PR), with two regions were used in dynamic reservoir model.

Various development strategies were investigated in order to obtain the best development strategy, including but not limited to water alternating gas (WAG), gas injection, water injection, different well spacing, different completion strategy, injection rates, WAG cycles, etc. This paper describes how the transition zone was defined in terms of static and dynamic properties, the various development strategy used and the respective recovery obtained from the most likely development strategy. The best development strategy for this field was found to be water alternating gas (WAG), with wells placed higher up in the transition zone using 6months WAG cycles.
New Approach to Prevent Non Accidental Deaths NAD by Strengthening System Barriers
Authors: Tayab Muhammad R. , Purra Ajaz
Published: November 2016

Non Accidental Deaths (NAD) among contractor workers is a common occurrence within Oil & Gas Industry especially in remote areas. Generally, NAD events involve aggravation of chronic illnesses/conditions and these illness/conditions are, unlike injuries, not always apparent. Historically, NAD events were rarely investigated as no linkage with work relationship or gaps in HSE management system was considered. This paper highlights the extent of NADs, scope of investigation & analysis of data, and identification of opportunities to improve medical emergency response and awareness among workers.
Quantitative Evaluation of the Reservoir Flow Profile of Short String Production with High Precision Temperature HPT Logging and Spectral Noise Logging SNL in the Long String of a Dual Completion Well
Authors: Sarsekov Arlen , Al-Neaimi Ahmed Khalifa , Abed Abdalla , Saif Omar Yousef , Ahmed Fazeel , Skutin Vasiliy , Makhiyanov Ruslan , Vorozhikhin Sergey , Karantharath Radhakrishnan
Published: November 2016

Dual-string completions are cost-effective to independently develop multi-layer reservoirs completed using a single wellbore. However, the upper reservoir that produces through the short tubing string is generally not surveyed across the perforation interval due to safety concerns of tool getting entangled around the long string on exiting below the short-string tubing shoe. Therefore, the upper reservoir producing through the short string can only be surveyed through the long string, which requires logging tools with radii of investigation extending beyond the tubing and not impacted by multiple strings of tubing/casing.

In dual string completions, it is not possible to evaluate the short string production profile with conventional tools. The High Precision Temperature (HPT) and Spectral Noise Logging (SNL) tools have large radii of investigation and can detect reservoir noise and temperature variations caused by fluid flow from the reservoir into the wellbore, through one or several pipe barriers. SNL is effective in identifying the inflow and injection zones of the reservoir and cross-flows/channeling behind casing. The active production/injection zones and the thickness identified using SNL are used as input for temperature modelling to produce quantitative reservoir production or injection profiles. Additionally, temperature modelling requires input of production and injection history, thermophysical properties of the reservoir and surrounding rocks, geothermal profile, hydrodynamic reservoir parameters as well as well trajectory and completion components. Also, in geographical locations where significant variation in injection water temperature is observed during day and night, surface temperature variations are to be accounted for in the modeling software.

In this paper three case studies from a middle eastern field are presented where the HPT-SNL technology was used effectively to evaluate short string flow profile in a dual string completion, water/gas breakthrough and cross-flow behind casing.
Comparison of CO2 and Nitrogen Injection at Low Temperatures in High Temperature Reservoirs for Improving Oil Recovery
Authors: Hamdi Zakaria , Awang Mariyamni , Basyouni Ahmad , Hematpour Hamed , Bataee Mahmood
Published: November 2016

Gas flooding methods have been used as successful tertiary recovery agents for decades. Recent studies suggested the effectiveness of using low temperature CO2 injection in high temperature reservoirs. With respect to current economic limitations, nitrogen and CO2 seems to be one of the most conventional ways to improve the oil recovery. The high temperature reservoirs may not be suitable for isothermal gas injections as they would suffer from gravity override of the gas, while low temperature injection could minimize the effect. The main goal of this study is to compare the low temperature injection of these two fluids in high temperature reservoirs aiming to improve the oil recovery.

To obtain a proper comparison between CO2 and nitrogen, several simulations have been constructed and performed. Thermal compositional runs seem to be the perfect candidate to achieve the goals of this study. The results suggest that with equal injection amount and duration of both fluids, liquid CO2 is a better candidate for improving oil recovery. Ultimate recoveries for CO2 and nitrogen injection at same initial conditions were recorded as 73% and 55%, respectively. The effectiveness of liquid CO2 for oil recovery was recorded as 1.52 barrels of oil for each barrel of injection, whereas a barrel of nitrogen recovered only an average of 0.65 barrel of oil. The viscosity reduction was more severe in liquid CO2, which suggests better mobility for the oil than in nitrogen injection. The CO2 breakthrough happened at an earlier time than nitrogen but due to much higher ultimate recovery, it can be overlooked. The overall conclusion suggests that low temperature CO2 injection can be considered a beneficial and promising method for enhancing oil recovery in high temperature reservoirs.
A Multiple Contaminant Tolerant and Eco-Friendly Water-Based Mud System for Superior Down Hole Performance
Authors: Amanullah Amanullah
Published: November 2016

Millions of barrels of water-based muds are used each year to explore and exploit oil and gas resources both in the onshore and offshore drilling environments. Conventional water-based muds usually have poor contaminant tolerance and hence trigger different borehole problems in down hole conditions. Some of the contaminant induced borehole problems such as induced loss of circulation, poor hole cleaning, stuck pipe, etc may cost thousands of dollars for a single well and thus may increase overall drilling cost dramatically. This highlights the technical and economic significances of a high contaminant tolerant water-based mud for current and future drilling operation.

Dedicated research conducted by Saudi Aramco lead to the development of a high contaminant tolerant water-based drilling mud system that is immune to mono and divalent salts, drill solids and cement that are usually encountered in any drilling operation. Experimental results at room and elevated temperature indicate excellent contaminant tolerance capacity of the newly developed mud system. The mud is environment friendly, virtually non-toxic, OHS friendly and thus expected to eliminate the scope of any short and long term occupational health and environmental hazards.

Due to high contaminant tolerant and no/negligible environmental impact, the newly developed water-based mud is expected to be an excellent drilling fluid system to be in the forefront of best drilling practices in sensitive environments.
Basin Scale Geomechanical Modeling of Tight Carbonate Reservoir in Abu Dhabi: Implications on Pore Pressure Development
Authors: Fadipe O.A. , Bouhlel A. , Noufal A.
Published: November 2016

The in-situ stress state in a rock mass is widely recognized as being of major importance in unconventional field. The inherent variation of stress distribution associated with geological environments is widely recognized as being a key factor in an unconventional field; hence, the need to understand from the basin-scale phase is critical. The three main ingredients needed to formulate a model for the mechanics of the porous sediments, are the concepts of bulk stress, pore pressure and compaction. Most available rock-stress-based numerical engines uses default laboratory properties for the set of lithology's in their library. However, understanding the mechanical properties of the lithologies and applying such to the model makes the result more representative of the local geology.

This paper is an update on the previously published model (Mohamed et al., 2015), exploring the impact of rock stress and external geomechanical boundary (otherwise known as tectonic stress) on pore pressure development and rock failure. Middle Cretaceous formation (layer of interest ~ 150 m) was sub-divided into seven layers based on mechanical log signatures. Athy's law, formulated with effective stress combined with 3-D rock stress based on poro-elasticity, was used in the forward modeling simulator to improve the pore pressure prediction. Depositional events such as erosion and hiatus periods were also taken into account during simulation. The development of porosity, pore pressure, temperature, stress and related rock failure through time were simulated and calibrated to measured data. The main geomechanical properties, such as Young's Modulus, Poisson ratio, cohesion and friction angle depend on lithology and porosity. Appropriate relationship were established and ultimately used to calibrate the first–pass rock properties prediction from the numerical engine. Model porosity is dependent on burial depth, weight of the overburden sediment columns, and lithology properties. The mean stress was ultimately considered in deriving pore pressure results.

Results reveal a dynamic representation of the three principal effective and total stresses within the studied formations. The maximum stress shows a NE-SW trend in the synclinal area and N-S trend on the anticlinal structures, the medium stress shows N-S trend on the synclinal structure with an E-W and NW-SE trend on Well A and Pseudo-well A wells respectively. The minimum stress reveals a NW-SE direction on the synclinal area and N-S trend on both flanks. The model also shows an improved pore pressure result ranging from 26.97 – 42.50 MPa (with 28.46 MPa average values within layers of interest) revealing ~ 1450 psi (10 MPa) difference when compared to the previous model where rock stress modeling was not performed.
Consequence Assessment for Weapons Impact of Process Plant
Authors: Vickers Matthew , Rettie Colin , McKechnie Douglas
Published: November 2016

Historically, deliberate attack on Oil and Gas process facilities has been excluded from process safety assessments and the consequences of weapons impact are not frequently studied. It is noted however that consequence modelling techniques for weapons attack have been developed independently for buildings and structures protecting personnel. In the modern geopolitical and international security climate, facilities may be subject to attack with little warning. Additionally, larger munitions, previously only associated with national forces, are more commonly held and used by insurgents. Plant operators and designers need to understand the hazards posed by such weapons when deciding on the mitigation required. Responses range from complete shutdown of a threatened facility to continued operation with risk reduction measures including plant and personnel protection, reduced manning, reduced inventory and operational restrictions. Abbott Risk Consulting (ARC) Ltd. has experience of applying munitions assessment to process plant situations and this paper presents the lessons learned in combining the, generally separate, disciplines of process plant hazard analysis and munitions effect analysis.

Munitions cause damage to structures and equipment by a number of mechanisms including: overpressure, fragmentation and kinetic penetration, with or without subsequent explosion. The paper discusses the general characteristics and hazards from commonly-available munition types, from small arms and hand held missiles to artillery shells and larger vehicle-mounted rocket systems.

Case studies are presented for the impact of munitions on a conceptual Liquefied Natural Gas (LNG) facility including process plant, full containment LNG tanks and manned buildings. The importance of assumptions regarding the damage mechanism, particularly between fragmentation and kinetic penetration, is demonstrated. Methodologies for combining such munitions studies with process safety techniques, including event tree analysis of the hazard frequency, are discussed such that a scenario-based risk assessment can be produced. "Conditional Risk", the risk of undesired consequences given that an attack takes place, is proposed as the most appropriate risk measure for such studies since the greatest unknown is usually the probability of an attack.
Factor Affecting Sustainable Design and Materials Selection for Offshore Topside Facilities Projects
Authors: Alyafei Ezeldine , Ogunlana Stephen
Published: November 2016

Offshore oil and gas operation is growing rapidly with the high demand for energy as oil is still the most important source of energy. Many studies indicate that the discovery of future oil will be more in the offshore area than onshore. However, the huge offshore facilities and activities create negative environmental and social impact as well as consequences ranging from air and water pollution to health and safety. Therefore, sustainability in offshore operation and design is a major challenge in the offshore industry. This paper explores and identifies the factors affecting sustainable design and materials selection for offshore topside facilities.

A qualitative approach has been adopted in order to develop and identify the factors affecting sustainable design and materials selection for topside offshore fixed platforms. The methodology has been conducted in two parts comprising: 1) an exhaustive literature review to determine the criteria considering the sustainability dimensions (environmental, social, economics) as well as the technical and engineering aspects. 2) A semi-structured face-to-face interview, which included both an open-ended and closed-ended questions component. In order to take into account both the views of oil operators and of the consultancy offices, forty experts and practitioners across the engineering disciplines in oil and gas industries were interviewed. Twenty-four experts from an international oil operator company and sixteen experts from an international consultancy office took part in the study. Seventy-seven criteria were identified via the exhaustive literature review and were distributed into seven subgroups. Relative importance index (RII) was utilized to rank the factors and the groups of factors based on the responses from the experts. Moreover, the internal consistency was calculated in order to check data quality and reliability of the scale.

The findings revealed that all 77 factors are highly important with minimum RII value being 0.640. The criterion offshore evacuation plan and clear escape route was considered the most important criterion among the 77 factors, whereas, the group of offshore health and safety was considered the top among the groups.

Since a limited amount of researches have focused on the sustainability for topside facilities of the offshore platforms, this research fills the gap in the existing knowledge of the offshore industry by contributing the following areas: exploring and identifying the factors affecting sustainable design and materials selection for topside facilities of offshore platform. In addition, the future research may take into consideration the determinant factors from this research in developing a decision framework for topside projects in terms of materials selection and sustainable design.
Real Time Dynamic Simulator for a Multi-Phase Pipeline System to Increase Production and Reduce Operational Costs
Authors: Pagliuca G. , Riviere R. la , Clercq M. Le , Lisdonk S. van , Macnair C.
Published: November 2016

Liquids handling is often a challenge for the production of gas-condensate brown fields. The gas flowrate declines for ageing fields while the water-gas ratio increases. To be able to sustain a stable production in which the amounts of liquid arriving at the downstream facilities can be handled, it is of importance to be able to accurately predict the pipeline liquid inventory in the pipeline.

An offshore Shell operated asset in the North Sea was regularly struggling with flooding of the slug catcher, onshore and offshore facilities trips, too high salt concentration in the production water, etc. The limited prediction capabilities of the offshore production network was identified as one of the root causes of these operational issues. As result of this a real time online simulator was built to better predict the liquids arriving at various operation scenarios.

The simulator consists of a UniSim Design® model with Compas (Shell proprietary multiphase transient pipeline simulator) for the pipelines that has been connected to the production database with the help of a dedicated UniSim Design scripting interface. This real time online simulator can follow the production history of the field and it can predict the future production features. Such a model can help with optimising the production by providing a better prediction of the pipeline liquid holdup and of the downstream liquid arrival rates at various operating scenarios. This can also decrease costs by optimising chemical injection rates for e.g. hydrate inhibition. At any moment in time a copy of the simulator can be made available and "what if" scenarios can be simulated to estimate the impact of a specific operation.

The deployment of this technology helps the asset to reduce the field OPEX and to increase the system uptime with a consequent reduction in production deferment.
An Effective Reservoir Pressure Measurement and Fluid Sampling Methodology in Tight Formations
Authors: Sultan Mir Asif , Ali Muhammad , Hegazy Gehad Mahmoud
Published: November 2016

One of the main challenges in exploration / appraisal phase is to measure the reservoir pressures and sample down-hole single phase fluids to identify the fluid types in tight layers (permeability <1md). This challenge escalates when multiple reservoirs are exposed in same open-hole with varying differential pressures across them. A novel wireline formation tester (WFT) technique was applied in an open-hole condition to collect in-situ representative fluid samples faster and cost effectively. It also significantly reduces the risks associated while sampling across multiple reservoirs in comparison to the conventional techniques.

Conventional approach of using dual packer module requires longer set-unset time as well as pumping out the trapped volume between the packers before receiving fluid from the formation. On the other hand, the probe module is more effective for sampling in high permeability layers. In tight reservoirs, the fluid sampling is very challenging due to low formation withdrawal rates, high drawdown and elongated station times. These challenges were overcome with a radically designed WFT that utilizes a 3D elliptical probe module with an optimum reservoir contact area. These probes enable circumferential flow from the formation with a faster cleanup process and hydrocarbon breakthrough.

The new sampling technique showed an improvement, over the conventional methods in several aspects: (1) Tight zone pressures are obtained faster with lower supercharging effects. (2) In-Situ representative fluid samples are acquired in tight reservoirs above saturation pressure enabling proper fluid characterization PVT studies. (3) Stationary times during sampling are reduced due to negligible trapped volume. (4) Set and retract timing is shorter so that a new sampling method of retract-move-reset is developed to minimize the mud invasion between multiple settings. (5) Reduces the differential sticking risk in longer operations with multiple reservoirs exposed in the same open-hole. (6) Minimizes the sampling runs resulting in significant cost saving. Logging operation proved to be successful with the new sampling method by acquiring representative fluid samples in tight formations, which was not possible earlier.

This paper describes a case history and recent achievements made in acquiring representative single phase fluid samples in tight reservoirs, overcoming the challenges and risks associated with conventional sampling techniques.
A Novel Approach to Maximize Hydrocarbon Liquids Recovery in Gas Compression Systems
Authors: Al-Zahrani Talal , Soliman Mohamed , Salu Samusideen , Ansari Nisar
Published: November 2016

This paper evaluates a technical new approach to establish the optimum operating conditions of associated gas multistage compression systems. The target is to maximize the total steady-state hydrocarbon (HC) liquids recovery of the surface producing facilities utilizing available resources and without any the need for plant modification. Maximizing liquids removal from associated gas has several benefits to gas-oil separation plants (GOSPs) such as increasing crude oil throughput, exporting leaner gas through pipelines in addition to other advantages that will be highlighted through two implemented case studies:

Abu Ali Plant (Arab Extra Light crude oil producing facility). Manifa Central Processing facility (Arab Heavy crude oil producing facility).

The concept is basically to raise the after-cooler's operating temperature (minimize cooling) of the lower pressure compression stages, to enable shifting rich/heavier gas to the optimum side where it is more favorable for the HC heavy ends to coalesce and condense. At that point, the after-cooling is maximized to collect the liquids from the discharge knockout (KO) drum of the highest pressure compression stage. This setup, when compared to conventional setup, which is maximizing the cooling across all stages, yields higher overall HC liquid recovery from the associated gas.

In case study #1, where condensate removed from the gas compression plant is normally spiked in the crude production, this approach was evaluated and field tested, resulting in gain of 2,000 barrels per day in export crude for the same GOSP feed rate. In addition, 50% drop in export gas water load and 25% drop in the HC's dew point was achieved, which helps mitigating pipeline corrosion and slugging issues in export gas transport, given the unavailability of a gas conditioning system in the facility.

In case study #2, where condensate removed from the gas compression plant is segregated and shipped to downstream facilities, this approach was evaluated, field tested and resulted in a gain of approximately 5,000 barrels per day in export condensates for the same GOSP feed rate. This gain resolved a chronic low velocity issue in the export condensate pipeline and helped mitigate water, solids settling and associated corrosion problems in the pipeline as well as downstream facilities upsets.
Application of Nitrate Based Fluid as a Completion Fluid
Authors: Sangka Nataniel B. , Budiman Hendra
Published: November 2016

Objectives/Scope

This paper is expected to be a lesson Learns of using nitrate-based fluid as an alternative solution to improve drilling performance and production optimization old wells.

Methods, Procedures, Process

This Lesson Learns begins from literature studied, laboratory test, field trials and continuous improvements.

Results, Observations, Conclusions

Nitrate Completion Fluids have good solubility for wide range of contaminants. Furthermore, it may have some well stimulation effects. Return permeability testing of sandstone coring samples after immersion fluid completion Nitrate, in some conditions, showed some increase in the value of return oil permeability (Ko) from 25.55 to 36.25 mD.

In the field of applications, it has been tested as an additive and drilling mud on one of the deepest wells in Indonesia (5850 m) in Seram. As the additive, used in NaCl polymer mud system in order to reduce levels of solids and chloride, without changing the other mud properties significantly. With decreased levels of chloride, the corrosion rates of drilling and production equipments are also decreased. As a completion fluid, Nitrate CF have been used in the workover wells in South Sumatra and Riau. As a washer on perforation wash job, it is capable of delivering up to 20x increase in oil production and gas production compared to the previous 3x. Operationally, it has not been recorded for any Non Productive Time related this fluid.

Novel/Additive Information

Nitrate based fluid is an alternative completion fluid products that have been developed as an additive, mud drilling and stimulation fluids. Nitrate based fluid is sold in powder or liquid forms. Nitrates are also the basic ingredient of fertilizer. Nitrate Completion fluids have a density specification up to 1.75, the corrosion rate is lower than 10 MPY @350 deg F with standard carbon steel corrosion coupon, 5 NTU turbidity and pH 6-9, with pH buffering capacity, so it has a resistance to contamination of sour gas, having properties endotermic and environmentally friendly reaction.
Multiple Water Zones Isolation Techniques in Horizontal Open Hole Case Study
Authors: Arif Naveed , Mahmoud Gehad , Buzdar Mudasar , Ali Andaleed , Ali M. , Sanchez Isidro
Published: November 2016

Designing and drilling of an optimized horizontal well has always been challenging due to limited subsurface data available to the petroleum geoscientists. The situation becomes more complex where water bearing zone is encountered at both heel and toe of the horizontal section facing abrupt structural changes primarily due to faults. In order to avoid excessive water production and in some cases even abandoning the well, an innovative technique was proposed and implemented to isolate the undesired water bearing zones.

This paper describes the procedures followed when selective zonal isolation was applied successfully in an onshore well. The well was planned to be drilled horizontally in a thin layer reservoir with limited structural control. While Geo-steering, LWD data revealed the abrupt change in structure along with faults; deeper than prognosis. Consequently the first ~500 ft of horizontal section had to be drilled in water zone. Decision was made to continue drilling up-dip into an oil bearing zone. A major vertical fault was encountered in later part of horizontal hole also. Further investigation in subsurface data revealed that this fault is crossing multiple formations and have high chances of connecting the current horizontal hole to the bottom water bearing zones.

In order to resolve these problems, a forward-looking approach was adapted to isolate the water bearing zones at both the heel (near 7" liner shoe) and the toe. Two different isolation assemblies were run and set in horizontal open hole one by one, instead of using conventional cement plugs before running the completion.

The isolations of these sections were done before running the final 3-1/2" single oil completion which secured the well from abandoning, early water breakthrough and excessive water production.
Optimize Pump Discharge, Save Steam
Authors: Breiki Hana Ali , Pitsas Athanasios , Ameiry Ahmed Al , Abdulla Haitham Salmeen
Published: November 2016

Energy efficient use constitutes the main focus and ultimate goal in oil and gas industry nowadays with low oil prices era. A meticulous planning and a corporate strategy of energy use can improve significantly the company's profitability and reduce its environmental impact in corporate level while can improve the resources management and macro-economics in national level. Towards to this direction, ADGAS has implemented an Energy Management System (EnMS) which covers plant facilities as well as it considers all organization's aspects. Equipped with policy, manuals, procedures, and daily monitoring of its Significant Energy Uses (SEUs) within the plants, this system contributes towards the organization's continuous improvement in energy usage of the assets through regulating and monitoring energy use. Defining SEU can help the organization to focus on areas where significant saving can be made. Boiler Feed Water (BFW) pumps of LNG train 3 are one of the 2015's significant energy uses due to their high steam consumption and its potential for improvement. With a purpose of saving energy, steam reduction is considered as a main target for improving BFW pumps performance. The implementation of this action was completed in two stages. At the first stage, the differential pressure was reduced from 15 bar to 13 bar. This reduction led to a decrease in the steam consumption by 0.61 Ton steam/hr while the level indications of Boiler 5 and 6 steam drums did not experience any change or disturbance. During the second stage, the differential pressure set point was further decreased to 12 Bar, which led to saving of up to 0.26 Ton steam/hr. In conclusion, combining the results of the two trails (reducing the differential pressure from 15 Bar to 12 Bar), the total achieved steam savings was 6,559 GJ.
Fracture Patterns and Controlling Factors using LIDAR: An Outcrop Case Study of Kuqa Depression, Tarim Basin, NW China
Authors: Qinglu Zeng , Huiliang Zhang , Wenzhong Lu
Published: November 2016

Fracture is of primary importance to gas producibility from many tight sandstone reservoirs in the Kuqa depression, Tarim Basin, NW China, but the orientation, size and plane porosity of fractures in the subsurface is difficult to measure directly. Terrestrial light detection and ranging (LIDAR) surveys can offer factual information of outcrop-based research efforts to characterize fracture development laws and control factors. In this paper, we obtain the three-dimensional (3-D) point cloud data by the LIDAR survey from a typical outcrop. Matching with high-resolution digital photos and artificial measured information, the 3-D positions of natural fractures are extracted strictly in the data volume section. Furthermore, the fracture patterns and controlling factors are revealed accurately with the fracture and reservoir model founded by computer simulation technology based on the systematic sampling and laboratory analysis. It is founded that three groups of shear fractures are mainly developed with large inclination, short trace length and small spacing of normal distribution. The fracture aperture is related to the orientation with bimodal distribution of 0.2~0.4mm and 0.8~1mm. The fracture patterns provide the literal distribution of grid-like fracture zone and reticular fracture zone with a single and a double set of advantage orientation respectively. The fractures in the former zone have greater trace length, spacing and smaller surface density and run through the adjacent shale mostly while the latter is just the opposite. The plane porosity of fractures in 11 single sandbodies of different microfacies has been calculated quantitatively with a range of 0.026~0.081% and an average of 0.05%. It is in the sandbodies of underwater distributary channel is better than mouth bar and distal bar. It turned out that the size of fracture is controlled by lithology, bed thickness, maximum paleostress and rock composition with a good exponential relationship. The fractures are more developed relatively with the coarser particle size of the rock, the thinner thickness, the greater paleostress, the lower content of feldspar and the higher content of cement.
Ultra-Deep Directional Resistivity Measurements and The Way of Revealing Formation Tops Ahead of Time
Authors: Bazara Magdi , Abdelwahid Dia Khalil , Popov Timofey
Published: November 2016

Petroleum Development of Oman (PDO) operates most of the fields of the Sultanate. In one of the developed fields, the formation has many internal subdivisions and discontinuous sublayers separated by dense argillaceous zones that make it difficult to land the well. Challenges to landing include depth, thickness, and dip uncertainties. Additionally, there are the errors that are inherent to correlating between the reservoir scale and the seismic scale. Finally, it is difficult to discern boundaries in this low-resistivity environment characterized by very low resistivity contrast. Resistivity contrast, in particular, is of major importance as it plays the main role in determining the operability of common distance-to-boundary tools.

A reservoir mapping-while-drilling tool with a large depth of investigation was used to reveal details of subsurface bedding and fluid contacts at the reservoir scale. The data provided were integrated with seismic surveys to refine the reservoir structure and geometry interpretation. The improved understanding made it possible to optimize recovery and production through optimum landing of the well and to map the overlying and underlying reservoir parameters.

By selecting the right tool configurations in the bottom hole assembly (BHA), formation tops were detected from a distance of up to 27-m true vertical depth (TVT), well before the drilling bit reached the formation. Resistivity contrast was as low as 1 ohm.m versus the more typical 1.4 ohm.m when detecting the limestone marker in the shale unit. In two wells, a formation petrophysical evaluation tool deployed in the BHA was used to calculate and confirm the reservoir formation tops while drilling to serve as a conventional means of confirming the tops that had been detected in advance of the bit by the new technology.
Surface Flow Selective Carbon Molecular Sieve Membrane for NG Separation
Authors: Khan Shaihroz , Wang Kean
Published: November 2016

Carbon molecular sieve membranes (CMSM) were derived from the pyrolysis of polymeric precursors at 3 different pyrolytic temperatures (600, 700, and 800°C), respectively. The CMSM samples were characterized and tested for the permeation of 4 pure gases (CH4, CO2, N2 and He) in a time-lag rig at different operation temperatures (20 and 0°C). For N2/CH4 gas pair at ambient temperature, CMSM700 showed a good perm-selectivity of ~ 40 with a N2 permeability of ~5.8 Barrer and a CH4 permeability of 0.145 Barrer. Analysis showed that the membrane is working more on sieving mechanism rather than surface diffusion mechanism on this membrane. For CO2/CH4 pair, CMSM700 demonstrated a good selectivity of ~1,000, with a CO2 permeability of ~180 Barrer and CH4 permeability of ~0.1 Barrer. The permeation by surface flow (or surface diffusion) is more significant for strongly adsorptive species CH4 on CMSM800, which revise the trend from N2 selective to CH4 selective. In summary, although the permeation flux is still a bit low for N2/CH4, CMSMs demonstrated superior separation performance for the purification of impurities such as N2 and CO2 in natural gas.
Real-Time Azimuthal Acoustic Data Acquisition Advances and Applications in Carbonate Reservoirs - Offshore Abu-Dhabi - Case Study
Authors: El Wazeer Fathy , Al Hosani Habeeba , El Farouk Omar , Mostafa Hassan , Awad Huda , El Kholy Mohamed
Published: November 2016

LWD acoustic data has been available in real-time for nearly 20 years, but the data quality has not always been acceptable. Recent developments in data acquisition, including the transmission of semblance quality control (QC) logs, have greatly improved the quality and reliability of LWD acoustic data for applications such as real-time inter-granular porosity measurements, synthetic seismic creation, cement quality indications, and geo-mechanics applications.

This new development in LWD azimuthal acoustic logging enablesd expansion of these advanced applications into the while-drilling environment and presents the oil industry a robust geosteering and formation evaluation tool.

This paper presents a case study in a giant oil reservoir onshore Abu Dhabi, where back-to-back conventional logging was used to evaluate the new data acquisition advances. The data collected with an azimuthal unipolar sonic LWD tool provides 16-bin compressional and shear slowness images in memory and quadrant images in real time.

New algorithms have been implemented to enhance the quality of transmitted data. Several Middle East case studies comparing the real-time sonic images to the memory data, in terms of resolution and data quality, have clearly showed improved data acquisition quality, which is crucial tor real-time formation evaluation and decision making.

Examples presented in this paper prove that these advances in acoustic data acquisition are very helpful in the following applications:Onshore horizontal wells in formations whose resistivity contrast is too low for conventional geosteering tools.Sourceless porosity tool in horizontal extended-reach wells, where the risk of sticking and losing nuclear sources is higherReal-time geomechanical modeling to determine the safe mud weight window, uniaxial rock strength, and mechanical rock properties