bluuebunny/crossref_metadata_2025_split huggingface dataset:
Wettability Alteration by Asphaltene Deposition: A Field Example
Authors: Uetani Takaaki 
Published: April 2016

Abstract

Description
Identifying and understanding wettability alteration caused by asphaltene deposition, and its implications for field development optimization is growing in interest. In this paper, we present a field case study on the cause of an unexpected decline in reservoir productivity and simultaneous rapid increase in water production. We concluded that the decline in productivity and water cut increase were caused by asphaltene precipitation in the formation with a subsequent increase in the water relative permeability. This was caused by alteration of rock wettability from water-wet to oil-wet by asphaltene deposition.

Applications
This work's findings can improve understanding of reservoir performance and help optimize reservoir management strategies for oil reservoirs with potential asphaltene precipitation problems.

Results and Conclusions
All possible parameters in the reservoir simulation model was thoroughly examined and discussed. Switching the relative permeability type from water-wet toward oil-wet at the asphaltene onset pressure (AOP) yielded an excellent history match with the observed rapid water production increase. The reservoir had been depleted following primary production; the laboratory PVT data indicated that the AOP was a little below the initial reservoir pressure and hence asphaltene precipitation had been predicted.

Technical Contributions
This work contributes to (1) providing a field case bridging asphaltene deposition and wettability alteration, (2) understanding phenomena such as rapid increase in water production associated with asphaltene deposition, and (3) optimizing reservoir management and field development for oil reservoirs with potential asphaltene precipitation problems.
Sustainability in Re-cycling Drilling Fluids Between Rigs
Authors: Al Maskary Shamsa , Halim Adam Abdul , Dahche Ali , Hammam Mohamad , Abu Ali Ithad 
Published: April 2016

Abstract
ADCO is drilling a highly deviated holes through long section of unstable shale formations which require a drilling fluid system to inhibit such shale and stabilize the wellbore as experienced hole problems such as sloughing, hole packed off and hole collapsed. This will result in rig lost time due to stuck pipe, plugging back and sidetrack.
Water Base Mud system was used to drill such deviated section but due to swelling and hydration of the shale within short period resulted in hole collapsing and excessive non productive time. The directional drilling through the shale could reach to 70 degree at the bottom of the shale formation with high build up rate. The hole cleaning is critical and requires drilling technology such as sing Rotary Steerable system and drilling practices to ensure good hole cleaning.
Oil Base mud are expensive but are worth the cost when drilling through troublesome shales that would otherwise swell and disperse in water base mud. Thus, ADCO is drill these shally sections using the oil base mud on large scale across all ADCO fields successfully due to wellbore stability and resulted in running & cementing liners at bottom without any problems. Once the drilling operations completed, the solids content must be minimized and the mud has to be run through the centrifuge for de-bariting. Thereafter can be loaded into haulage trucks whereby sent to mud plant for treatment and stored in storage tanks for re-use. The oil base mud (1500-2000 bbls) should be transferred to mud plant for treatment.
Accordingly, a re-cyclying and re-conditioning mud plant was built to be used for the storage and treatment of oil base mud and brine services respectively require to be used for drilling and rigless operations.
In addition, the formation pressures of wells are high which require heavy brine to be used in order to have sufficient hydrostatic head to control the well. Non damaging fluid is used to drll all reservoirs which is mainly consists of brine (CaCl2, CaBr2 or NaBR) with the addition of viscosifiers and water loss reducers. After completing the deviated section then the non damaging fluid is centrifuged to get rid off the solids and transferred to other rigs for use otherwise will be sent to mud plant for storage and reuse. Moreover, the inhibited filtered brine is prepared to be used as completion fluid and to be left in the hole as packer fliuid. The excess of fluid has to be collocted and transported by dedicated haulage tankers to othe rigs for re-use. Moreover, ADCO rigless operation requirement is to use brine of different mud weight which varies from 75 pcf up to 106 pcf based on the formation pressures. We are preparing in the plant the required brine and send to these rigless operations for killing purposes to secure the wells and also for production testing packages for displacing the fluid inside the production testing string.
Fast Hydrating Fracturing Fluid for Ultrahigh Temperature Reservoirs
Authors: Lee W. , Makarychev-Mikhailov S. M. , Buelvas M. J. , Abad C. , Christiawan A. B. , Narayan S. , Singh M. , Sengupta S. 
Published: April 2016

Abstract
An increase in the number of explorations of deeper and hotter formations has prompted the need for an ultrahigh- temperature fracturing fluid. Conventional fracturing fluids are typically based on polysaccharides or their derivatives, which can provide enough viscosity to carry proppant deep into the formation at temperatures only up to 177 °C (350 °F). Beyond this temperature, these biopolymers hydrolyze too rapidly to be an effective and cost-efficient carry fluid; therefore, a new fluid was needed. We developed a new fluid system that can deliver the required rheological properties for successful fracturing operations up to bottom hole static temperature of 232 °C (450 °F) without the need for cool-down. This fluid is composed of a fast-hydrating synthetic copolymer and a metal crosslinker. This system has been engineered to provide a controllable crosslink mechanism and viscosity reduction profile to accommodate varying well conditions and job designs. Numerous proppant-pack conductivity tests have shown that this resilient fluid system can be broken and easily cleaned up at temperatures above 149 °C (300 °F). The rheological performance of the fluid, along with its high proppant pack regained permeability, makes the new fluid ideal in ultrahigh-temperature explorations. The fluid has already been successfully applied in the field. Preliminary lab and field implementation results are discussed.
New Developed Acid Soluble Cement and Sodium Silicate Gel to Cure Lost Circulation Zones
Authors: Al-Yami Abdullah S. , Al-Ateeq Abdullah , Vikrant B , AlAbdullatif Ziad , Al-Qahtani Mohammad 
Published: April 2016

Abstract
Moderate to severe loss of circulation problem encountered while drilling in Aramco field is a major economic burden that increases the total well construction cost dramatically in some cases. Complete or even partial control of the moderate to massive loss circulation problem may save thousands of dollars/per well and thus can make the drilling economics more economical.
Saudi ARAMCO has developed a LCM formulation that can be used to cure lost circulation in the Middle East. The formulation consists of acid soluble cement and a sodium silicate gel that has a high potential to control moderate to severe loss circulation problem.
Experimental data indicate that the control of loss of circulation using the silicate gel and soluble cement can be achieved as follows: 1) injection of the gel first into the fracture to penetrate the near fracture rock matrix, 2) pumping a small volume of spacer after the gel to delay the contact between the sodium silicate gel and the soluble cement, and finally 3) injection of soluble cement into the fracture to plug the fracture zone.
Silicates have been used with cement to cure lost circulation and for water shut off treatment over the past 50 years. The major limitation of such technicue is rapid reaction and acid insoubility, Bauer et al. (2005). The objective of this paper is to introduce the use of acid soluble cement and sodium silicate gel as a possible solution to cure lost circulation zones in Saudi Arabia fields.
Implementation of a Lightning Protection System on LNG Facility - Risks and Challenges
Authors: Devkaran Naveen 
Published: April 2016

Abstract
ADGAS Plant facilities at Das Island were not provided with lightning protection system with a view that UAE experiences very few rainy days every year. Traditionally, lightning strikes were not a major concern for LNG facilities on Das Island. With the ageing plant and the changing environmental conditions, the LNG Plant has been experiencing fire situations near Boilers, fuel gas, lube oil and other process vent points during thunderstorm days.
A study was conducted to identify the potential risk areas and propose the most appropriate solution based on the latest IEC standard and industry practices.
A risk assessment process was carried out for all the existing plant facilities to identify which specific structures/equipment were at risk and hence were required to be provided with lightning protection system, the steps taken to mitigate and eliminate these risks identified, and the challenges in completing and implementing these installations in a running LNG plant evaluated.
A novel technology was implemented for the Paraffinic Naphtha Tanks to eliminate the risk of fire from lightning, where an RGA protection system was implemented in place of the more traditionally used catenary lightning protection system.
For most of the structures use of existing structures as down conductors for lightning protection was explored and implemented which lowered the implementation cost and significantly reduced the installation time.
Stochastic Optimization of Gas Cycling in Gas Condensate Reservoirs
Authors: Siddiqui Mohammed A. , Al-Nuaim Sami , Khan Rizwan Ahmed 
Published: April 2016

Abstract
A major challenge in gas condensate reservoirs is to minimize the condensate drop-out which is mostly heavier fractions representing the rich part of the gas accounting for most of its heat capacity and consequently its price. Most widely used technique to improve gas condensate reservoir performance is gas cycling. In this study, gas cycling in the form of produced lean gas re-injection was considered. Parameters which impact the effectiveness of gas cycling processes are often evaluated by performing limited sensitivity studies on all or some parameters.
A more efficient technique that uses a stochastic optimization algorithm to automatically optimize the parameters governing the gas cycling process is proposed in this paper. Stochastic optimization of well placement and gas cycling operational parameters has not been reported previously in the literature. Global optimization techniques such as Covariance Matrix Adaptation Evolution Strategy (CMA-ES) and Differential Evolution (DE), both of which are evolutionary algorithms, were used to optimize the producer and injector well locations, fraction of produced gas to be re-injected, and production and injection rates. A modified reservoir model from the Third SPE Comparative Solution Project was used in this study. The optimization was done on several realizations and utilizing a numerical compositional simulator. Net Present Value (NPV) of the gas cycling project and field average oil saturation (FOSAT) were used as the objective functions separately. The optimum parameters and well placement would maximize NPV and minimize FOSAT.
The results show that NPV can be significantly increased if the parameters are optimized simultaneously rather than sequentially suggesting the importance of optimizing well placement alongside the operational parameters. The results also show that optimization of well placement, sales volume and production rates remarkably reduces the condensate saturation in the reservoir. Furthermore, DE was seen to be more robust and performed better than CMA-ES. The presented technique provides a base for oil companies to consider stochastic optimization in designing field development plans for gas condensate reservoirs.
Redox and Temperature Dependent Attenuation of Twenty Organic Micropollutants – A Systematic Column Study
Authors: Burke Victoria , Greskowiak Janek , Grünenbaum Nele , Massmann Gudrun 
Published: April 2016

ABSTRACT: Owing to advanced analytical procedures an increasing number of organic micropollutants have been identified within the aquatic environment. Results from field investigations evidenced the attenuation of various organic micropollutants to be impacted by the predominant hydrochemical conditions. In the course of this study, column experiments were performed to examine the influence of redox conditions and temperature on the attenuation of 20 wastewater derived organic micropollutants. For this purpose, the degradation behavior of these compounds were investigated under oxic, nitrate reducing, iron/manganese reducing and sulfidic conditions at 21 °C in sandy aquifer sediments. Redox dependent degradation was observed for the pharmaceutically active compounds atenolol, metoprolol, sotalol, iopromide, phenazone, propyphenazone, acesulfame and trimethoprim as well as for two phenazone type metabolites. In order to identify temperature dependencies, oxic columns were in addition operated at 6 °C, indicating the removal of several compounds to be influenced by the prevalent temperature.
Treatment of Tannery Effluent Using a Rotating Disc Electrochemical Reactor
Authors: Palani R. , AbdulGani A. , Balasubramanian N. 
Published: April 2016

ABSTRACT: A novel rotating disc electrochemical (RDE) reactor has been developed to treat tannery effluent. Experiments were carried out in batch, batch recirculation, and once—through modes in the reactor covering wide range of operating conditions. The effect of current density (i), cathode rotation speed (R), electrolysis time (t), influent pH, and electrolyte flow rate (Q) on the pollutant removal efficiency and specific energy consumption was critically evaluated. The response of the process parameters were measured in terms of percentage total organic carbon (TOC) removal. The reaction mechanism of electro‐oxidation was modeled using first‐order kinetics. GC‐MS and FT‐IR analysis of the raw and treated effluent show that the tannery effluent can be effectively treated using the RDE reactor.
Quantification of Groundwater ‐ Saline Surface Water Interaction in a Small Coastal Plain in North‐East Tunisia using Multivariate Statistical Analysis and Geophysical Method
Authors: Chekirbane Anis , Tsujimura Maki , Lachaal Fethi , Khadhar Samia , Mlayah Ammar , Kawachi Atsushi , Isoda Hiroko , Tarhouni Jamila , Benalaya Abdallah 
Published: April 2016

ABSTRACT: Amultivariate statistical analysis used with geophysical investigation enabled the assessment of interaction between saline surface water and groundwater in the coastal plain of Wadi Al Ayn and Daroufa in CapBon peninsula, north‐east Tunisia. The application of the Principal Component Analysis (PCA) identified the end members which contribute to groundwater recharge: the wastewater infiltrated from Wadi Al Ayn, the oilfield brine infiltrated to the aquifer through the sandy bed of Wadi Al Ayn, the intruded seawater near Wadi Daroufa in the downstream region and the fresh groundwater flowing from the upstream region. The contribution of wastewater in groundwater recharge varies from 1.4% in the upstream region of Wadi Al Ayn to 77% near its downstream part. The fraction of oilfield brine mixed with groundwater in the alluvial aquifer under Wadi Al Ayn varies from 1% to 13%; whereas the fraction of intruded seawater into the coastal part of the aquifer near Daroufa region varies from 2% to 21%.
KIT multi-physics tools for the analysis of design and beyond design basis accidents of light water reactors
Authors: Sanchez V. , Miassoedov A. , Steinbrück M. , Tromm W. 
Published: April 2016

Abstract
This paper describes the KIT numerical simulation tools under extension and validation for the analysis of design and beyond design basis accidents (DBA) of Light Water Reactors (LWR). The description of the complex thermal hydraulic, neutron kinetics and chemo-physical phenomena going on during off-normal conditions requires the development of multi-physics and multi-scale simulations tools which are fostered by the rapid increase in computer power nowadays. The KIT numerical tools for DBA and beyond DBA are validated using experimental data of KIT or from abroad. The developments, extensions, coupling approaches and validation work performed at KIT are shortly outlined and discussed in this paper.
Safety and security aspects in design of digital safety I&C in nuclear power plants
Authors: Ding Y. , Waedt K. 
Published: April 2016

Abstract
The paper describes a safety objective oriented systematic design approach of digital (computerized) safety I&C in modern nuclear power plants which considers the plant safety requirements as well as cybersecurity needs. The defence in depth philosophy is applied by using different defence lines in the I&C architecture and protection zones in the plant IT environment.
The reactor dynamics code DYN3D
Authors: Kliem S. , Bilodid Y. , Fridman E. , Baier S. , Grahn A. , Gommlich A. , Nikitin E. , Rohde U. 
Published: April 2016

Abstract
The article provides an overview on the code DYN3D which is a three-dimensional core model for steady-state, dynamic and depletion calculations in reactor cores with quadratic or hexagonal fuel assembly geometry being developed by the Helmholtz-Zentrum Dresden-Rossendorf for more than 20 years. The current paper gives an overview on the basic DYN3D models and the available code couplings. The verification and validation status is shortly outlined. The paper concludes with the current developments of the DYN3D code. For more detailed information the reader is referred to the publications cited in the corresponding chapters.
Scientific codes developed and used at GRS – Nuclear simulation chain
Authors: Schaffrath A. , Sonnenkalb M. , Sievers J. , Luther W. , Velkov K. 
Published: April 2016

Abstract
Over 60 technical experts of the reactor safety research division of the Gesellschaft für Anlagen- und Reaktorsicherheit (GRS) gGmbH are developing and validating reliable methods and computer codes – summarized under the term nuclear simulation chain – for the safety-related assessment for all types of nuclear power plants (NPP) and other nuclear facilities considering the current state of science and technology. This nuclear simulation chain has to be able to simulate and assess all relevant physical processes and phenomena for all operating states and (severe) accidents. In the present contribution, the nuclear simulation chain developed and applied by GRS as well as selected examples of its application are presented. The latter demonstrate impressively the width of its scope and its performance. The GRS codes can be passed on request to other (national as well as international) organizations. This contributes to a worldwide increase of the nuclear safety standards. The code transfer is especially important for developing and emerging countries lacking the financial means and/or the necessary know-how for this purpose. At the end of this contribution, the respective course of action is described.
THAI experimental programme for containment safety assessment under severe accident conditions
Authors: Gupta S. , Freitag M. , Poss G. 
Published: April 2016

Abstract
The THAI (THAI = Thermal hydraulics, Hydrogen, Aerosols, Iodine) experimental programme aims to address open questions concerning the behavior of hydrogen, iodine and aerosols in the containment of water cooled reactors. Since its construction in 2000, THAI programme is being performed in the frame of various national projects (sponsored by German Federal Ministry for Economic Affairs and Energy, BMWi) and two international joint projects (under auspices of OECD/NEA). THAI experimental data have been widely used for the validation and further development of Lumped Parameter (LP) and Computational Fluid Dynamics (CFD) codes with 3D capabilities. Selected examples of code benchmark exercises performed based on the THAI data include; hydrogen distribution experiment (ISP-47 and OECD/NEA THAI code benchmark), hydrogen combustion behaviour (ISP-49), hydrogen mitigation by PARs (OECD/NEA THAI-2 code benchmark), iodine/surface interactions, iodine mass transfer, and iodine transport and multi-compartment behaviour (EU-SARNET and EU-SARNET2), thermal-hydraulic tests (German CFD-network). In the present paper, a brief overview on the THAI experiments and their role in the containment safety assessment is discussed.
Progress of Experimental Research on Nuclear Safety in NPIC
Authors: Gong H. , Zan Y. , Peng C. , Xi Z. , Zhang Z. , Wang Y. , He Y. , Huang Y. 
Published: April 2016

Abstract
Two kinds of Generation III commercial nuclear power plants have been developed in CNNC (China National Nuclear Corporation), one is a small modular reactor ACP100 having an equivalent electric power 100 MW, and the other is HPR1000 (once named ACP1000) having an equivalent electric power 1 000 MW. Both NPPs widely adopted the design philosophy of advanced passive safety systems and considered the lessons from Fukushima Daichi nuclear accident. As the backbone of the R&D of ACP100 and HPR1000, NPIC (Nuclear power Institute of China) has finished the engineering verification test of main safety systems, including passive residual heat removal experiments, reactor cavity injection experiments, hydrogen combustion experiments, and passive autocatalytic recombiner experiments. Above experimental work conducted in NPIC and further research plan of nuclear safety are introduced in this paper.
Challenges on innovations of newly-developed safety analysis codes
Authors: Yang Y. , Zhang H. 
Published: April 2016

Abstract
With the development of safety analysis method, the safety analysis codes meet more challenges. Three challenges are presented in this paper, which are mathematic model, code design and user interface. Combined with the self-reliance safety analysis code named COSINE, the ways of meeting these requirements are suggested, that is to develop multi-phases, multi-fields and multi-dimension models, to adopt object-oriented code design ideal and to improve the way of modeling, calculation control and data post-processing in the user interface.