bluuebunny/crossref_metadata_2025_split huggingface dataset:
Well Structure Integrity Threat Due To Near Surface Corrosion of Outer Casing at Offshore Wells
Authors: Pandey Shri Kant , Rana Shahzad Amin , Fakhro Ahmed  Jassim 
Published: March 2015

Abstract
QP Offshore operates in shallow water at Arabian Gulf. The wells are drilled and completed at surface on multi slot wellhead jackets.
We encountered well subsidence with some offshore wells. The well subsidence caused stresses to flowlines, gas lift hook up and jacket members.
As a result, the flowlines and gas lift hook up were under threat with subsided wells. This meant high risk potential of uncontrolled release of hydrocarbon to atmosphere, with significant potential of asset damage and environmental pollution.
The Offshore wellhead jacket structure and conductor casings are protected against corrosion by cathodic protection. These were primarily installed to protect wellhead jacket structure against sea water and its corrosion protection to wells is not known to us.
The well subsidence occurred due to structural failure of outer casing caused by the atmospheric corrosion. The corrosion occurred due to outer casing being in contact with sea water and atmospheric air near splash zone.
We looked at options of isolating the air and seawater contact from outer casing to prevent further corrosion.
It was possible to achieve this by placing bio degradable oil into Conductor. The oil being lighter than water shall stay above the water, thereby isolating air in the oxygen from sea water. We dropped this option as high ambient temperature in summer months shall cause bacterial growth and degrade oil. The degraded oil could result in accelerated corrosion instead of preventing it.
The other option considered was to install sealing type cover at the top and replace trapped air inside annular space with nitrogen. This too could not find favor due to lack of assurance in isolating the air inside the Conductor.
QP selected to top up the conductor with cement. It shall cut off air between conductor and outer casing. The other major advantage was well structure strengthening by joining the conductor with outer casing to support wells with weakened outer casing.
The paper shall illustrate on the findings of corrosion analysis with outer casing recovered during well workover operations for subsided wells.
A Joint Shell / Adco development Of A Shared Earth Model (sem) To Support Further Development Of A Giant Field, onshore UAE
Authors: Meyer B.  D. , Nieuwenhuijs R. A. , Bennett R. , Brint J.  F. , Vizamora A. 
Published: March 2015

Abstract
The field is located onshore Abu Dhabi and has been in production for more than 50 years. It covers an area of approximately 1500 square kilometers and has 20 reservoirs with producible hydrocarbons comprising a series of stacked oil and gas reservoirs with differing drive mechanisms and development maturity, including in-field exploration targets. This paper describes the work undertaken to build a full field Shared Earth Model (SEM) to support future drilling to maximize the field recovery and extend the field lifetime.
The key business deliverable for the SEM was to allow more effective assurance of planned well trajectories in a highly congested surface/subsurface environment, thus increasing the safety of such operations. As a consequence, the SEM had to extend from ground level to the deepest penetrated reservoirs. The reservoir model is constrained by more than 70 seismic horizons and by more than 40,000 well markers of various vintages; this alone represented a significant modeling challenge. Automated QC & QA workflows were used heavily to analyse the input data and the model during each of the model construction iterations.
The reservoir units are faulted but these faults do not extend to the surface. Due to limitations in the representation of such faults in pillar grids and a lack of continuity of fault interpretations from one reservoir to the next, it was decided to represent faults as properties and not as fault planes. This not only allowed adjustment per reservoir, without requiring a rebuild of the whole structural model, but also identified clearly a zone of uncertainty around the predicted faults, assisting well planning efforts.
A major focus of the project was to provide an evergreen model which could be kept up to date with ADCO's substantial drilling program. Therefore considerable effort was made to hand over not just a model, but also training in the key workflow's and work practices which would ensure that ADCO staff have the skills in house to update and maintain the model. This was achieved through extensive use of Petrel workflows, which enabled quick & structured model updates and through several training sessions in Abu Dhabi, run over 3–4 days. This proved to be an effective mechanism to hand over the model and workflows to ADCO staff.
Process Safety Management - a prerequisite for sustainable gas production
Authors: den Bakker Kees 
Published: March 2015

Abstract

1. Introduction
The LNG industry enjoys a commendable track record in reliability and safety. There is however no reason to be complacent, as we can learn from various major hazard accidents across the energy industry (e.g. Piper Alpha, Texas City, Macondo), which regretfully resulted in fatalities, asset damage and had environmental impact. LNG operations may be similarly vulnerable to major incidents if hazards are not properly managed.
Root causes for major accidents are often complex in nature. They are related to a series of interlinked failures in mechanical, human judgment, engineering design, operational implementation and team interfaces.
To avoid such incidents, we must translate learning into effective barriers, aimed at reducing risk to acceptable levels. This article will share some insights on how this is done in Shell.
Core Flood Analysis Of Acid Stimulation In Carbonates: Towards Effective Diversion And Water Production Mitigation.
Authors: Gharbi Oussama , Goedeke Stefan , Al-Sammaraie Mohammed , Al-Shahwani Saqer , Cheneviere Pascal , Al-Mohannadi Nasser , Julien Philippe 
Published: March 2015

Extended Abstract

Introduction:
It is well established that acid stimulation in carbonates can enhance the productivity of oil and gas wells. As carbonate porous media are highly reactive in contact with acidic solutions, when acid is injected into carbonate reservoirs, the near wellbore region is subject to chemical dissolution. This is a reactive transport phenomenon, as acid is flowing and transported through a porous media. Coupled changes of the fluid and rock properties are taking place. Changes in chemical concentrations of the in situ fluids, the surface area, the permeability and porosity are also occurring. In this context, many studies have experimentally and numerically investigated carbonate acidizing. It has been shown that different dissolution regimes can be observed based on two main parameters, basically, the injection flow rate and the acid content. Wormholing i.e. a non uniform dissolution which is characterized by the creation of a conductive pathway along the porous media, is therefore observed for relatively high flow rates and low pH (high acid content). It also has been shown that for a certain pore structure, optimum injection rates, where the minimum acid volume leads to the highest permeability increase, (optimum wormholing) exist. Therefore, in field applications during acid stimulation jobs, the acid is injected at relatively high pumping rates in order to achieve an efficient zonal coverage and sweeping efficiency. Today, acid stimulation is widely used for newly drilled wells or wells that are experienced in production decline.

Context:
It has been observed that acid stimulation of carbonate oil and gas wells, especially in mature carbonate fields, can be inefficient and might sometimes lead to negative outcomes. Targeted low permeability regions can be kept untreated and water production might arise after the acid injection. These negative results are often explained by the presence of a high permeability matrix contrast or the presence of active fracture networks in the reservoir. In such configurations, the acid enters the highest permeability matrix regions or flows through the fracture networks and might connect to a new water pathway. A large number of investigations have considered chemical or mechanical diversion techniques that allow the acid to stimulate a low permeability zone in the presence of a permeability contrast. In addition, a series of studies have considered reducing water production through water shutoff chemical products. Although efforts have been made towards fluid formulations, only a few studies have considered the experimental validation of diversion and water mitigation in heteregenous carbonates. In this paper, we experimentally revisit improved acid stimulation techniques in the presence of watered and permeability-contrasted carbonates.
Technological Evolution In Natural Gas Plant Automation
Authors: Dey Nilangshu 
Published: March 2015

Abstract
Natural Gas Liquid (NGL) Plants in Qatar have undergone major operational transformation during the last decade. The large step change in operational strategy, efficiency and maintenance optimization has occurred due to automation evolution taken place in monitoring & control, protection and asset management of all NGL Plants of Qatar Petroleum at Mesaieed.
The paper will focus how such technological evolution has made flexibility in gas plant's operation and in deriving key business decisions for operation and maintenance optimization using foundation field bus technology, integration of the plant controls to the business enterprise etc. The paper presents following three major areas of technical transformation contributed significantly towards NGL Plants upgrade indicating the problem faced, application of new technology, the challenges faced while implementation and benefits achieved in terms of operability and maintainability.Utilization of Foundation Fieldbus technology for control and monitoring application in NGL storage & loading plantsIntegration of all NGL plant control systems with business enterprise using Real Time Process Information Management system for achieving Alarm management, Control system performance, On line reporting and calculation of KPIs relating to Production and Maintenance for deriving on line various business decisionsIntroducing integrated hardware and software platform for large gas turbine and compressor controls of propane refrigeration and lean gas booster compressors in various NGL plants
The paper provides the multifold benefits achieved in above three major areas of automation transformation in various NGL Plants along with its cost benefits analysis.

Introduction
NGL-1 & 2 plants receives raw NGL feed (4100 T/D capacity of each plant) from Dukhan oil field and produce C1, C2, C3, C4 and C5 + hydrocarbons. NGL-2 plant also receives Rich Associated Gas (RAG) from offshore wells and in turn it produces raw NGL which are being processed either in NGL-1 or 2 plant to produce various hydrocarbons.
NGL-3 plant receives raw gas feed (1024 MMSCFD capacity) from offshore (North field alpha) and produce raw NGL, fuel gas C1, stabilized condensate and acid gas. This raw NGL from NGL-3 are processed in NGL-4 plant having capacity of 12000 T/D and produce C2, C3, C4 and C5 + hydrocarbons. Propane (C3) and Butane (C4) are stored in refrigerated storage tanks (4 nos. of propane storage tanks of total capacity 356,000 m3 and 4 nos. of butane storage tanks of total capacity 192,000 m3) and Gasoline (C5+) are stored in floating roof tank (2 nos. of tank capacity 120,000 m3). C1 (fuel gas) and C2 (ethane) are supplied to the various power stations and other neighboring companies thru gas distribution stations.
Achieving Maintenance Excellence in Maersk Oil Qatar
Authors: Smart Kenny , Blakey Kevin 
Published: March 2015

Abstract
Maintenance Excellence for Maersk Oil Qatar is about a development and a change journey aimed at positively influencing behaviours including system and process transparency and scalability.
This journey questions ways of working and current practices through review of maintenance strategies, policies, CMMS (SAP) functionality and people. In collaboration with our knowledge base, off and onshore personnel and systems, MOQ is seeking to improve why, how and when we maintain our assets, to achieve Maintenance Excellence.
Maintenance Excellence is simply a framework for working more efficiently and effectively. Ensuring that we maintain 'In-service integrity' at all times by "fixing forever, instead of forever fixing". This is achieved by treating the root cause of a problem and not just the symptom.
Understanding the current position and why change is required. It is essential to make a step change from Reactive to Proactive maintenance, thus achieving compliance within the framework of MOQ policies, standards and strategies.
Through developing the Strategy; Populating the Plan; Scheduling Activities; Executing Work; Analysing the Data; Managing Performance - making perfection the goal, Maintenance Excellence will follow.
MOQ Policy; Defines the aspirations to achieve Maintenance Excellence. Drive the development of safe systems of work and the overall assurance of integrity and reliability for plant, systems and equipment. Based on the Standard PAS55 or ISO055000; this clearly states the approach and principal methods for managing assets and asset systems.
Maintenance Strategies; These are developed through a risk based approach whereby high criticality equipment and packages are subject to detailed analysis e.g. FMECA. Followed on by the Structure of how we manage work; introducing commonality across our assets connecting our people to our technology, sharing best practice and removing waste.
The introduction of new Technologies also includes; the CMMS (SAP), Dashboards, (BO) and Document control (EDMS) enabling people to gauge process effectiveness and business performance. Ensuring the right people possess the correct competencies, behaviours, attitude and experience to deliver excellence in their role. Through development and communication, preparing, training and coaching our people, enabling competence and empowerment. This collaboration and adherence to the plan will deliver a seamless implementation.
Through continuous assessment we will remain on track, not losing focus of the end goal; only through The 3 P's - Patience, Perseverance and Persistence will our efforts deliver a successful journey. A journey that is continuous, achieving Maintenance excellence is a living entity, constantly evolving to the many demands made by the business, giving more flexibility in how we espouse continuous improvement. Delivering vision to why, where, when and what we maintain and at what cost. Maintenance Excellence is a lifecycle approach for Continuous Improvement.
Safe Execution of a World Class EGR Facility in Abu Dhabi - The Elixier Mirfa Project
Authors: Al Attas Salem 
Published: March 2015

Abstract
Abu Dhabi is experiencing a clear increase in the demand profile for gas needed for pressure maintenance in oil reservoirs as well as for gas cycling in condensate reservoirs. On top of the requirements from the oil and gas fields, the Emirate is also witnessing a significant increase in the natural gas demand for power. Pressure on gas fields is usually maintained through water and hydrocarbon gas injection. Habshan is one of the first sites using an alternative through the injection of 600mmscfd of Nitrogen into the Thamama F reservoir. Nitrogen injection improves gas recovery from the reservoir with only a very limited reduction on condensate recovery as opposed to the pure Hydrocarbon gas injection case. After two years of successful operations, the paper presents the benefits achieved, the execution performance as well as quality and HSE track record. By bringing these Nitrogen production, distribution and injection facilities into the country, the project is also supporting an intensive local knowledge development of cutting edge cryogenic technologies and its uses. For this plant built in Mirfa, a staff of about 50 people has been trained to the highest technical, operational and SHEQ standards available on the market. From an HSE perspective it is worth to mention that the project execution closed without any reportable LTI (Lost Time Injuries) notwithstanding the over 15 Million man-hours cumulated until start-up.
Microporosity: Characterization, Distribution, and Influence on Oil Recovery
Authors: Fullmer Shawn M , Guidry Sean A , Gournay Jonas , Bowlin Emily , Ottinger Gary , Al Neyadi Abdulla Mohammed , Gupta Gaurav , Gao Bo , Edwards Ewart 
Published: March 2015

Abstract
Microporosity is very common in limestone reservoirs globally and is especially significant in many large Mesozoic reservoirs in the Middle East. Despite its common occurrence there is:Wide variation in its definition,Uncertainty around characterization, genetic controls, and distributionA rudimentary understanding of its influence on reservoir performance and hydrocarbon recovery.
The results of this study, based on a global survey of microporosity and specific Middle Eastern case studies, provide clarity on each of these topics.
One volumetrically significant type of microporosity occurs between micron size subhedral crystals of low magnesium calcite in matrix and within grains. This micro-pore system is very homogenous in terms of pore size distribution with 90% of pores between 1 and 3 microns in diameter. Pore throat radii range between 0.1 and 1.5 microns. Porosity, permeability, and capillarity relationships reflect this homogeneity for rocks dominated by microporosity. Rocks with less than approximately 80% microporosity exhibit a marked increase in pore system heterogeneity.
A pore geometry characterization approach incorporating digital image analyses of petrographic thin-sections was developed and provides a very effective means of rapidly characterizing and quantifying the total pore system, including microporosity.
The lateral and stratigraphic distribution of microporosity is systematically related to the distribution of depositional facies and the regional extent of burial diagenetic processes. Factors that inhibit burial diagenesis, such as hydrocarbon charge, also have a strong influence on the nature and distribution of microporosity.
Remaining oil saturation in microporous limestone, as measured from centrifuge capillary pressure and steady state (SS) core flood experiments, is negatively correlated with the percent fraction of microporosity. Due to the homogenous nature of the micro-pore system, rocks dominated by microporosity have more favorable oil recovery than rocks with mixed pore systems. In the specific cases studied here, water provides more favorable recovery than gas. These results have implications for resource assessment, field development planning and optimization of ultimate recovery in limestone reservoirs with significant microporosity.
Dilute Surfactant Flooding Studies in a Low-Permeability Oil-Wet Middle East Carbonate
Authors: Bennetzen Martin V. , Mogensen Kristian , Frank Soren , Mohanty Kishore 
Published: March 2015

Abstract
The majority of alkali-surfactant-polymer (ASP) applications to date have targeted medium-to-high permeability sandstone reservoirs containing reservoir brine with moderate salinity and hardness. Surfactant flooding experiments have been reported in carbonates, but applications targeting oil-wet, low-permeability limestone rock are still uncommon.
This paper contains results from laboratory core flood tests performed on an oil-wet limestone rock from the Al Shaheen field, offshore Qatar. The rock samples investigated had approximately 30% porosity and 5 mD permeability, whereas the reservoir brine had a salinity of about 120,000 ppm of which about 10,000 ppm were divalent cations.
The first screening step involved testing combinations of several commercial surfactants, co-surfactant and alkalis. Two cost-effective surfactant systems were identified. The first system, denoted ITR, was capable of reducing the interfacial tension below 0.001 mN/m over the required range of salinities. The second system, referred to as WA, effectively altered the wettability from strongly oil-wet to intermediate-wet. Static adsorption was measured to be low for both systems. No polymer was used because the permeability was very low. Both surfactant systems yielded significant incremental oil, when injected in tertiary as well as in secondary mode. The ITR system recovered almost 95% of OIIP but required many pore volumes since the cores remained oil-wet. The WA system, on the other hand, recovered some 85% of OIIP in secondary mode but achieved this with much fewer pore volumes.
The WA system was subjected to extensive analysis. Relative permeability curves from unsteady-state core flooding data were derived and experiments were simulated with UTCHEM.
The main conclusion from the extensive laboratory work is that surfactant systems can be tailored to recover a significant amount of oil from a low-permeability carbonate reservoir. Wettability alteration may assist in unlocking significant volumes of additional oil from this complex, offshore field.
Fuelling the Future with Gas Hydrates as a Perpetual Energy Source
Authors: Steffones K. , Chaturvedi Krishna R. , Sihag Priya 
Published: March 2015

Introduction
Gas hydrates are crystalline compounds that form when water (or ice) contacts small molecules (called hydrate guests) under certain pressure and temperature conditions. The correct chemical name should be gas clathrate hydrates, with a clathrate being a compound formed by the inclusion of molecules of one kind in the crystal lattice of another (water in this case). In practice, these compounds are commonly referred to as gas hydrates, clathrate hydrates, or just hydrates. While specific to the particular hydrate guest, gas hydrates are stable typically at high pressures and low temperatures. A wide range of molecules have been shown to form gas hydrates. Those of the most practical interest are light hydrocarbons such as methane, ethane, and propane. Carbon dioxide and hydrogen sulfide also form hydrates and are of particular interest. When hydrates form, water crystallizes to create a lattice of molecular-sized cages that trap guest molecules without chemical bonding between the host water and the guest molecules.
Alarming Pandrug Resistance (PDR), Extensive Drug Resistance (XDR), and Multidrug Resistance (MDR) Gram-Negative Bacilli
Authors: Hossain Moazzem 
Published: March 2015

No Abstract AvailableJournal of Current and Advance Medical Research 2015;2(1):1-2DOI:http://dx.doi.org/10.3329/jcamr.v2i1.22578