bluuebunny/crossref_metadata_2025 huggingface dataset:
Three Years CO2 Geological Storage at In Salah
Authors: Wright Iain Washington
Published: February 2016

In Salah Gas is a joint venture of BP, Sonatrach and Statoil, which started in July 2004, producing 900bcf/d gas for sale in Europe. The natural gas contains up to 10% CO2, which has to be reduced to 0.3% before the gas is sold. Hence, 1 million tonnes/year CO2 is produced. Rather than vent that CO2 to the atmosphere (business as usual), this project re-injects it into the Krechba Carboniferous Sandstone reservoir via three horizontal wells at a depth of 1,900 metres. CO2 injection started in August 2004 and over the life of the project, 17million tonnes CO2 will be geologically stored at a cost of $100mm ($6/tonne CO2 avoided). This project is an industrial-scale demonstration of CO2 geological storage and is the first industrial-scale project in the world to store CO2 in the water leg of a gas reservoir.

The In Salah CO2 Storage Project is a five-year, $30mm, Joint Industry Project (JIP) with participation from the EU and USA governments. The storage location is heavily instrumented and data is collected and analysed, to monitor the behaviour of the CO2. Objectives are to:Demonstrate to stakeholders that industrial-scale geological storage of CO2 is a viable GHG mitigation option.Provide assurance that secure geological storage of CO2 can be cost-effectively verified and that long-term assurance can be provided by short-term monitoring.Set precedents for the regulation and verification of the geological storage of CO2.

A key part of the monitoring programme will be the deployment of a novel permanent seismic array, allowing frequent, real-time imaging of CO2 migration through the storage formation. This will provide a benchmark against which, alternative technologies can be evaluated. This paper will share results to date of the ongoing CO2 monitoring project.
Shake and Go - Advances in Vibroseis Technology
Authors: Krohn Christine Elizabeth , Neelamani Ramesh , Johnson Marvin
Published: February 2016

A new patented vibroseis acquisition method, Shake and GoSM, allows operation of multiple vibrators at multiple source points simultaneously and continuously with no waiting for between-sweep listening times or for between-vibrator slip times. This method allows for unsurpassed production rates. Model simulations, field gathers, and processed stacks are used to demonstrate excellent data quality compared to other high productivity methods.

The cost of vibroseis land acquisition is directly related to the time it takes to shake each vibrator point and move to the next point. Shake and Go can be used to record seismic data at lower cost, or it can be used to record more data at the same cost with improved sampling of signal and noise. It is especially efficient for new point source and point receiver (MEM) acquisition without arrays.

Shake and Go, also called C-HFVSSM or Continuous High Fidelity Vibrator SeismicSM, uses long segmented sweeps and HFVS separation. Measurements of the individual vibrator motion are recorded and used to derive a filter that optimally recovers individual seismograms from vibrators operating simultaneously. Cross contamination from strong events, which are simultaneously recorded, are not observable in the individual recovered seismograms. Interference and harmonic noise from the continuous sweeping are limited to the end of a long record and can be removed with a new novel processing method.

Because of the high production rates and high data quality, the new method is expected to dominate land acquisition in the future. We present analysis of the noise and show data comparisons for different vibroseis methods. We also overcome the limitation that there must be as many sweeps as vibrators or time delays to optimally separate records for simultaneous sourcing.

Methodology

Shake and Go or Continuous-HFVSSM (C-HFVSSM) is a combination of ExxonMobil's HFVS (High Fidelity Vibratory Seismic) method and its proprietary Cascaded-Sweep technique. Both acquisition methods, HFVS and its super high efficiency version C-HFVS are licensed to a number of contractors. We have recently developed a proprietary processing method (patent application filed) to further improve the quality of the C-HFVS method so that it matches the high quality of HFVS and allows us to exploit super high efficiency acquisition without any compromise in data quality.
KOC 1% Gas Flaring Target
Authors: Al-Otaibi Faisal , Al Adwani Adnan Eid , Nour Maher Mustafa
Published: February 2016

Gas flaring is increasingly recognized as a major environmental problem, contributing more than 1% to global emissions of CO2 in addition to its valuable resource. At KOC an effective utilization of associated gas in all fields became a serious concern in 1995 and ongoing efforts were put in place for minimizing gas flaring. Detailed exercises were carried out in 1996/1999 for identifying causes, establishing action plans, and setting allowable targets. Current Action Plan covers the following on-going activities:Operating Process & ProceduresTraining & DevelopmentFlaring Awareness ProgramGas Supply TeamIn-hand Projects

All the above-mentioned planned implementations are on schedule and are expected to be completed by 2010/2011 in order to reach the target of 1% gas flaring at KOC.

INTRODUCTION

Crude oil contains associated hydrocarbon gases and when brought to the surface the gases are released and where there is no market for the gas, the industry standard for disposal is flaring (1). Flaring of produced gas is the process of burning-off surplus combustible vapors from a well, either as a means of disposal or as a safety measure to relieve well pressure and it is the most significant source of air emissions from onshore and offshore oil and gas installations. Venting also occurs - releasing un-burnt gases directly into the atmosphere and alternatives include re-injection, on-site power generation, and transport to market (1). The following are the Four Main Causes of Gas Flaring:Culture: gas was once viewed as a waste product, global warming was not an issue.Contracts: flaring permitted and there was no obligation to find a market for the gas.Markets: markets poorly developed and responsibilities for marketing ill-defined.Governance: no incentive to maximize economic use of gas.

According to the Alberta Energy and Utilities Board (AEUB), there are four main reasons for flaring:As a part of the completion and testing of natural gas wells.During routine maintenance at gas compressing facilities.When oil wells produce very small amounts of solution gas.In emergency situations when there is an uncontrolled release of gas from a well or pipeline.

AMOUNTS AND EFFECTS OF GAS FLARING

World Bank estimates that over 150 bcm of gas is flared annually (2) and this is equivalent to the combined annual gas consumption of Germany and France. This amount of gas flared is also equivalent to 25% of US consumption. Reference to the figure below, the 40 bcm of gas flared in Africa is equivalent to half of the continent's power consumption.
Pattern Balancing and Waterflood Optimization of a Super Giant: Sabiriyah Field, North Kuwait, a Case Study
Authors: Clark Robert Alfred , Karami Hossein , Al-Ajmi Moudi Fahad , Lantz James R.
Published: February 2016

This paper outlines the successful integration of subsurface, water handling, well surveillance and production operations teams across the North Kuwait asset to significantly improve the operating procedure for waterflooding the Sabiriyah Mauddud field. This effort required a new way of managing this reservoir in NK: a multifaceted approach of balancing voidage with injection, conducting extensive surveillance/analysis within the reservoir to assess the efficacy of various courses of action and, most significantly, adjusting various teams' "key performance indicators" (KPIs) to align injection and production allowables with sound reservoir management principles.

An innovative, unified information management system was used to monitor voidage replacement ratio (VRR) to provide a basis for pattern balancing. Extensive surveillance operations provides the data necessary to monitor individual pattern balance, watercut performance, optimize areal sweep efficiency by adjusting injection and production allowables, assist in planning water shutoff operations, and design new completions.

Waterflooding the Cretaceous Mauddud reservoir is in an early stage of operations. Water injection commenced in 12 of 17 predrilled waterflood patterns in 2000. These wells were drilled on an inverted nine-spot pattern with spacing of 250 acres per well to quickly provide coverage over the major portion of the reservoir. Surveillance data indicates the reservoir is relatively well connected. Pattern VRR, pressures, and watercuts were somewhat out of balance prior to engaging in this effort. Now, individual waterflood pattern balance is significantly improved and the field-wide VRR is ~1.

Sound reservoir surveillance and waterflood management procedures implemented within a diverse group of teams that have performance goals aligned with "best practice" has resulted in effectively re-balancing this major waterflood. This effective integration of teams retains the flexibility to adjust for an ongoing development of this super giant field.

The Sabiriyah Field

The Sabiriyah field was discovered in the 1950's with the drilling of the SA-001 well. Production commenced in 1958. Located in North Kuwait (Figure 1), Sabiriyah Field consists of several stacked pay intervals, trapped in a North-South elongated faulted anticline with approximately 500 ft. of present-day four-way closure (Figure 2). Present-day closure has been modified slightly by a recent structural tilt, which occurred after the trap was filled with oil. To date, the major oil pay intervals in the Sabiriyah field occur between 7,100–8,300 ft. drilling depth and include various high-productivity Burgan sandstones overlain by a more moderate-permeability shallow-water ramp-carbonate, the Mauddud. These reservoirs were normally- pressured at the time of discovery.
The Role of Seismic Coherence Attributes in Mapping the Fracture Network and Improving the Productivity From Thick, Tight and Fractured Deep Gas Reservoir
Authors: Qassim Naji A. , Al-Anaisi Abdulla Jaffar , Al-Muftah Ali Ebrahim
Published: February 2016

This reference is for an abstract only. A full paper was not submitted for this conference.

This paper describes an integrated study of utilizing 3D seismic, open hole logs with simulation, pressure transient analysis and production data to define and map fracture network patterns to aid enhance the productivity from thick, tight and fractured deep gas-bearing carbonate reservoir in the Bahrain field. The Lower Permian K3 zone is a thick, tight, highly faulted and irregularly fractured Carbonate reservoir. The massive 800 ft thick reservoir with very low average permeability of the order of 1 md, poses challenge in efficient recovery of hydrocarbons. The present production from this thick reservoir accounts for less than 10 % of the total gas production from the Khuff Formation of the field. This has prompted a detailed integrated study to help enhance the well productivity. It is well known that seismic coherence data plays a pivotal role in defining and mapping fracture network and similarly well testing to understand the reservoir dynamics and connectivity. The approach involves identification of fracture network from seismic data and validating them with transient well testing & production data at and around well-bore. The study is applied to derive and input fracture network and related data of the K3 zone into the simulation model to define and map the reservoir fracture patterns to aid in increasing productivity and also recovery.
Optimized EOR Design for the EWE area, Greater Prudhoe Bay
Authors: Panda Manmath Nath , McGuire Patrick Lee , Ambrose James Gilbert , Beuhler Gilbert G.
Published: February 2016

The Prudhoe Bay field, located on the north coast of Alaska, is the largest oil field in North America. Discovered in 1968, the Prudhoe Bay field is a massive sandstone reservoir complex covering over 200 square miles.

Eileen West End (EWE) is a western extension of Prudhoe Bay field, connected only through the aquifer. It consists of two tilted fault blocks, each with a gas cap and an oil leg having a combined OOIP over 750 MMSTB. Production began at EWE in June, 1988, approximately 11 years after Prudhoe field startup.

Initially, EWE was considered an analogue to the gravity drainage area of Prudhoe Bay. The reservoir management strategy employed at EWE was gas cap expansion and gravity drainage of oil with injection of Prudhoe Bay produced gas into the EWE gas caps. A review of surveillance data, material balance studies, fluid mapping, simulation and other analogue data, changed the perception that gravity drainage was an efficient recovery process at EWE. The work also showed that aquifer influx was stronger than anticipated. As a result, gas injection was stopped in 2001 and water injection into the gas caps was started for pressure maintenance and to prevent oil from resaturating the gas cap.

A pattern water alternating miscible gas (WAG) flood was initiated in 2003. The initial WAG patterns targeted areas with large gas cap expansion and gas underruns to capture oil trapped in these gas invaded intervals. The WAG flooding is being expanded to areas of low gas cap expansion and peripheral regions.

This paper describes the technical process used to select the major design parameters of the pattern WAG flood to optimize EWE recovery. The key parameters evaluated were slug size, injection rate, WAG ratio, and WAG sequencing. A fine grid fully compositional numerical simulator was used to determine the optimal design parameters. The modeling indicated that optimal design consists of multiple WAG cycles with high voidage replacement ratio (VRR) during the gas cycle with an overall WAG ratio of 1. Timing of the first gas slug within the first year after start of waterflood in addition to realignment of the injection and production wells also optimizes recovery. Surveillance of the secondary and tertiary recovery through well performance monitoring and surface and down hole data acquisition combined with classical reservoir engineering is ongoing to ensure that the EWE enhanced oil recovery (EOR) project remains optimized.
Application of Six Sigma Statistical Methodology to Reduce ESP Failures in Central Arabia Fields
Authors: Al-Hamdan Mohammed Radhi
Published: February 2016

This reference is for an abstract only. A full paper was not submitted for this conference.

This paper presents the application of Six Sigma statistical methodologies to diagnose, measure, improve, and control the root causes of electrical submersible pump (ESP) failures in Central Arabian (CA) fields. The word six sigma is a statistical term that measures how far a given process deviates from perfection. The main objective of this study is to increase the run life of ESPs in six Central Arabian fields of Saudi Arabia to at least three years or more using Six Sigma tool. In the last ten years 241 ESPs have experienced downhole equipment failure and were subsequently replaced at Central Arabia fields. This has a huge impact on over all fields' performance and economic resources which would be utilized elsewhere otherwise. This study was initiated and focused to diagnose the major causes of 23 ESP failures occurred in the year 2005 only. However, the scope of work will be extended to the previous failures as well. It was found that 22% of the total failures were caused by sand accumulation inside the pump stages. Scale, downthrust, and seal problems caused 51% failures with 17% each. Underestimated water cut forecasts in successive years and poor installation practices were responsible for 18% failures with 9% each. Lastly, upthrust and cable problems together caused 8% ESP failures with 4% each. This paper is divided into four sections: Effective data collection methodologies are outlined,ESP run life analysis is discussed in detail,findings and root causes of ESP failures are listed,finally, based on the findings, solutions and quality control procedures are recommended.

Some of these solutions and procedures have been implemented since March 2006 and have resulted in significant reduction in the number of premature ESP failures as compared to the previous year.
Modeling Uncertainties of a Gas-Delivery Project
Authors: Frizzell Dominique F. , Sibley Michael , Cotner Bryan Clayton , McCartney Simon Peter , Schmidt George Russell , Burkes Robert , Phelps James , Tosdevin Michael Andrew , Mazloom Jalal
Published: February 2016

A primary objective of any project evaluation is to understand the fundamental economic value and the uncertainty in that value. The uncertainty in value is a function of numerous variables in both the surface and subsurface parts of a project which are often evaluated separately. In fact, the surface and subsurface are tightly linked and should be studied together to fully quantify the effects of one on the other and on the economic value.

An evaluation was performed of more than 21 undeveloped fields with multiple reservoirs each to predict the economics of delivering gas at a nearly constant rate to a specific downstream project, and the associated oil and condensate to a country's export system. The fields are spread across a 6000 km2 area. The data comes from nearly 70 wells drilled mostly in the early 60's to a few today. The uncertainties associated with the reservoirs: gas in place, drive mechanism, inflow performance, fluid properties; were linked to the wells: well architecture, tubing flow performance, well head pressure; and linked to the pipelines: distance, diameter, liquid holdup, and elevation changes. All uncertainties were studied over their probable range of values.

This paper describes the application of mature technologies across the broad spectrum of disciplines required in most projects. The significance is the integration of the contributions from many experts into a model which gives a quantitative result of the impact uncertainties have in a linked surface / subsurface system, and their importance to the value of the project. The models used to describe the linked systems are commercially available software; the value of this paper is the description of the methodology used to evaluate and integrate many surface and subsurface uncertainties. Table 1 summarizes the uncertainties to be discussed.

Table 1: Summary of Uncertainties

Introduction

Understanding and quantifying uncertainty in major projects in the oil industry is not a new problem. Linking surface demands and performance to subsurface performance is a recognized need as well. References 1 to 4 at the end of this paper provide some more discussion and alternate approaches to the issues to be discussed here. The Influence Diagram below illustrates the interrelationships among surface and subsurface unknowns and begins to show why the two cannot be evaluated separately. The circles indicate inputs to calculations of performance; the boxes are decisions to be made. The inputs have some degree of uncertainty which is captured by a range of values for each.
Prevent system hydrate formation during sudden depressurization
Authors: Zeydabadi Babak Asadi , Haghshenas Mehri , Roshani Shahram , Moshfeghian Mahmood
Published: February 2016

A concise and accurate methodology has been developed using well known software packages to predict the type and amount of inhibitor required during sudden depressurization of a system to prevent hydrate formation. The outlined procedure exhibits the P-T history of the system and hence the hydrate formation temperature profile. A practical example of using such procedure clearly indicates the ease and accuracy of designing a hydrate inhibition package for any units in the oil, gas and petrochemical industries.

1. Introduction

A hydrate is a physical combination of water (H2O) and other small molecules producing a solid, which has an "ice-like" appearance but possesses a different molecular structure. Formation in gas and/or natural gas liquid (NGL) systems can plug pipelines, equipment, and instruments, and restrict or interrupt flows. There are three crystalline structures for such hydrates. In each, H2O molecules - host molecules - build the lattice, and hydrocarbons, nitrogen (N2), xenon (Xe), argon (Ar), carbon dioxide (CO2) and hydrogen sulfide (H2S) - guest molecules - occupy the cavities. Smaller molecules such as methane (CH4), ethane (C2H6), CO2, and H2S stabilize a body-centered cubic called Structure I. Larger molecules propane (C3H8), isobutene (iso-C4H10) and n-butane (n-C4H10) form a diamond-lattice called Structure II. Molecules larger than n-C4H10 do not form hydrates as they are too large to stabilize the lattice.1

Gas composition determines structure type and mixed gases will typically form Structure II lattices. Limiting hydrate numbers (the ratio of H2O molecules to molecules of included gaseous component) are calculated using gas molecule sizes and cavity sizes in a H2O lattice. The structure type does not affect appearance, properties or problems caused by the hydrate; it does, however, have a significant effect on the pressure and temperature at which hydrates form. Also Structure II hydrates are more stable than Structure I. Structure H hydrates are a double hydrate that requires two kinds of molecules to be stabilized: a small molecule like Xe, Ar or H2S and a larger molecule like methylcyclohexane.2,3

Natural gas mixtures that have H2S present result in a substantially warmer hydrate formation temperature at a given pressure. CO2, in general, has a much smaller impact and often reduces the hydrate formation temperature at fixed pressure for a hydrocarbon gas mixture.4,5
Using Down-Hole Control Valves to Sustain Oil Production from the First Maximum Reservoir Contact, Multilateral and Smart Well in Ghawar Field: Case Study
Authors: Al-Mubarak Saeed Mohammed , Pham Tony Reuben , Shamrani Sultan S. , Shafiq Muhammad
Published: February 2016

This paper describes a case-study detailing planning, completion, testing, and production of the first Maximum Reservoir Contact (MRC), Multilateral (ML) and Smart Completion (SC) deployment in Ghawar Field.

The well was drilled and completed as a proof of concept. It was completed as a trilateral and was equipped with a SC that encompasses surface remotely controlled hydraulic tubing retrievable advanced system coupled with pressure and temperature monitoring system.

The SC provides isolation and down hole control of commingled production from the laterals. Using the variable positions flow control valve, the well was managed to improve and sustain oil production by eliminating water production. Monitoring the rate and the flowing pressure in real time allowed producing the well optimally.

The appraisal and acceptance loop of the completion has been closed by having this well completed, put on production and tested. Approval of the concept was achieved when the anticipated benefits were realized by monitoring the actual performance of the well.

Leveraged knowledge from this pilot has provided an insight into SC capabilities and implementation. Moreover, it has set the stage for other developments within Saudi Aramco.

Background

Haradh forms the southwest part of the Ghawar oil field located about 80 kms onshore from the Arabian Gulf, in the Eastern Province of Saudi Arabia (Figure-1). Haradh field consists of three increments where the initial production started in May, 1996 from Increment-1 followed by Increment-2 and 3 in April, 2003 and January, 2006, respectively.

Increment-1 was initially developed using mainly vertical wells while Increment-2 was developed with horizontal wells. The subsequent MRC, ML wells and Smart Completion installations in Increment-2 were part of a proof of concept project to test and evaluate the impact of these technologies on reservoir, well performance and overall reservoir management strategies. As a result of the proof of concept project, Increment-3 was developed with MRC, ML wells with SCs.
Contaminated Feed To LNG Plants - Consequences For Midstream Design
Authors: Bras Ed , Klinkenbijl Jeanine , Clinton Paul , Van der Zwet Gerard
Published: February 2016

Growing demand for Liquefied Natural Gas (LNG) is leading to increased production of natural gas from less attractive reservoirs. These are generally contaminated with sulphur components and located in inhospitable environments such as deep offshore waters. Conventional upstream processing in such locations is either infeasible or excessively expensive, so more and more production is by full wellstream transfer, thereby reducing the upstream facilities to the bare minimum. The consequences are that the midstream facilities need to be much more complex and require very special design attention.

This paper describes how the contaminants (e.g. hydrogen sulphide, mercaptans, carbon dioxide, water, salts, organic acids) and the necessary additives (e.g. corrosion inhibitor, hydrate inhibitor) are dealt with in the upstream and midstream designs whilst complying with ever more stringent environmental requirements (e.g. sea water quality, sulphur dioxide emissions, hydrocarbon losses). It also describes how the various contaminants and additives can interact, (e.g. forming emulsions, solids) and can cause additional problems such as foaming, fouling or corrosion.

The paper concludes that a functioning and cost-effective line-up can only be achieved by using an integrated approach, in which all the processing steps such as pipelining, separation, stabilisation, treating and NGL extraction are considered together.

Conventional & Historical Developments

Given a choice of which fields to develop, companies have always chosen the easiest and hence cheapest and most profitable ones. The consequence is that historically LNG plants have been supplied from sweet reservoirs in accessible locations.

When the undesirable constituents of the LNG plants feed gas are only carbon dioxide (CO2) and traces of sulphur components, the acid gas is called sweet. If sulphur components are present in higher concentrations, specifically hydrogen sulphide (H2S), carbonyl sulfide (COS) and organic sulphur components such as mercaptans, the gas is called sour.

When the upstream gas supply to an LNG plant is sweet and comes from an easily accessible field, it is convenient and cheap to dry the gas in the upstream facilities before pipelining the gas to an LNG plant. Consequently, the receiving facilities for such uncontaminated streams are simple. This is illustrated in figure 1, which shows a typical offshore development with a sweet reservoir in shallow water.
Exploration & Exploitation of Gas Hydrates and Its Related Environmental Hazards
Authors: Nautiyal Siddhartha , Upadhyay Vaibhav
Published: February 2016

This reference is for an abstract only. A full paper was not submitted for this conference.

Gas hydrates, also known as clathrates are naturally occurring icelike solids in which guest molecules like methane, chlorine, carbon dioxide, nitrogen etc. are entrapped inside host (Water) molecule. It is estimated that 1 m3 of natural gas hydrate can accommodate around 164.3 m3 of methane gas. Volume of carbon contained in methane hydrates worldwide is estimated to be twice the amount contained in all fossil fuels on earth including coal. Also combustion of methane adds significantly less carbon dioxide to the atmosphere than combustion of either coal or oil. The NGHP is being monitored by a Steering Committee headed by Secretary, MOP & NG with Oil Industry Development Board (OIDB), ONGC, GAIL etc. as members. The D.G. of Hydrocarbons has drawn up an ambitious plan and prepared Road Map to tap these gas hydrate resources. Minister of Petroleum & Natural Gas, Government of India flagged off the drill ship on April 30 from Mumbai for undertaking drilling, coring and logging activities. The importance of gas hydrates as future source of natural gas is very evident from the above mentioned details and a lot of research work on the techno-commercial aspects of gas hydrates is still in progress across the world. In this paper focus is on the various exploration and exploitation techniques of gas hydrates and its related environmental hazards. Factors affecting the formation of gas hydrates, origin of In-situ gas hydrates and Hydrates stability zones (HSZ) will be discussed. Properties of gas hydrates like acoustic permittivity and various exploration techniques used for the identification of gas hydrates will be analyzed. Application of high frequency electromagnetic field & Gas lifting technique will be discussed and their relative merits and demerits of these techniques will be compared with the help of a case study.
Natural Gas Networks between Iran and Europe, Asia, and Russia
Authors: Paknejad Hamidreza , Mahdavian Zahra
Published: February 2016

Iran is endowed with the second largest natural gas reserves of the world and will be one of the main exporters of natural gas to the global markets in the near furture. Iran is located strategically in the vicinity of Persian Gulf and Hormuz Strait and has the potential to export large quantities of natural gas both to European markets in the West, and growing energy markets of Southeast Asia and beyond. Potential customers for Iranian natural gas exports include: Ukraine, Armenia, Azerbaijan, Georgia, Austria, Italy, Kuwait, Pakistan, India, Taiwan, South Korea, and China. European countries as well as India and China will become even more dependent on natural gas in the coming decades, and Iran will be the next natural gas provider after Russia.

Iran is planning to develop its natural gas pipeline network by extending it to its eastern and western borders, becoming a major hub for natural gas trade. Further extensions of this network to East could supply Pakistan, India, and China, and in the west through Turkey to Europe, which would complete the link between Iran, Asia and Europe. Viable swap agreements can be reached between Iran and its gas-rich neighbor countries to benefit all the exporting countries as well as demanding markets in Europe and South East Asia. In addition, subsea pipelines could connect Arabian states to Iran for delivering natural gas from Iranian gas fields to the energy intensive industries in the Gulf states.

The next wave of foreign partnerships in the Iranian energy sector could focus on expanding natural gas network for exporting gas to Europe and other world markets.

Introduction

Natural gas is going to turn into one of the world's main energy sources in the near future, and will play a significant role in the future economy of the world. Consumption of natural gas worldwide will increase from 100 trillion cubic feet in 2004 to 163 trillion cubic feet in 2030 according to International Energy Outlook 2007 (IEO2007). Although natural gas trade in the form of LNG has increased about 2% from 2005 to 2006, almost 72% of trade movement is still via pipelines. (BP 2007)

Middle East, and Caspian Sea littoral countries with huge hydrocarbon reserves, and considerable increase in natural gas production, would be the leading players in the future of energy demand-supply scenarios.

Natural gas is also expected to be the fastest growing fuel source in Europe, with a sharp increase in import from 39% in 2004 to 51% in 2015, and to 62% in 2030 (IEO2007).
The Sovereign Translation: Mediation and Hölderlin’s “Das Höchste”
Authors: Pierre Richard
Published: February 2016

This article uncovers the distinctive relationship between sovereignty and translation that is embedded in Hölderlin’s “Das Höchste” (a translation of and commentary to Pindar’s fragment “Nomos Basileus”). “Das Höchste” asserts that sovereign power is always a mediation of the foundational principles of justice, which it can access only indirectly when enacting law. Translation corresponds to this figuration of sovereignty to the extent that it always mediation rather than a direct conveyance of language, text, and context. As this article demonstrates by juxtaposing “Das Höchste,” Hölderlin’s letter to Casimir Böhlendorff on modernity’s relationship to Greek antiquity, and his sketch “Urtheil und Seyn,” Hölderlin understands both sovereignty and translation in terms of problems of knowledge. The concept of discipline (Zucht) as raised in “Das Höchste” indicates how the sovereign/translation might proceed in strict awareness of the fundamental divide between antiquity and the present, text and translation, and justice and law.
Zwischen Befreiung und Einschränkung: Die Poetik der Verwandlung in Das nackte Auge von Yoko Tawada
Authors: Ubieto Miriam Llamas
Published: February 2016

Yoko Tawada’s novel Das nackte Auge (2004) has a number of features that fall somewhere between the modern and postmodern aesthetic in her expression of intercultural and neocolonial transition, which gives the work a prominent place in contemporary literature. The text has important metaliterary and metacultural elements and it explores various forms of aesthetic configurations that play with linguistic and cultural restrictions. In particular the semantic field of the eye and visibility are linked to the linguistic dimension to self-referentially explain a poetology of the intervals of uncertainty caused by cultural friction. Using the concepts o limitation and liberation, the analysis of the novel allows us to combine the formulas found into a poetics of mutation.
Polite Hauntings: Same-Sex Eroticism in Sophie Albrecht’sDas höfliche Gespenst
Authors: Luly Sara
Published: February 2016

This article analyzes Sophie Albrecht’s Das höfliche Gespenst (1797) as a text that employs Gothic motifs to explore queer identity and female same-sex eroticism. The article first identifies the queer nature of the female protagonists and their relationship. It then examines how queer desire is thematized through communicative difficulties, including the excessively polite language referenced in the title. It concludes by exploring the role of the embedded narrative in vilifying queer desire from the perspective of heteronormative society. In doing so, this Gothic text allows moments of female same-sex desire but ultimately reinstates a patriarchal viewpoint that silences queer possibilities.
Investigation of texture, microstructure, and mechanical properties of a magnesium–lanthanum alloy after thermo-mechanical processing
Authors: Elfiad Djazia , Bourezg Yousf Islem , Azzeddine Hiba , Bradai Djamel
Published: February 2016

The texture, microstructure, and mechanical properties of Mg-1.33La (wt.%) alloy after hot rolling and cold plane strain compression were investigated by using X-ray diffraction, optical microscopy, and micro-hardness measurements. This thermo-mechanical processing resulted in a relative weakening of the texture that was mainly a basal type. The microstructures after hot rolling and cold plane strain compression revealed the presence of a second phase (Mg17La2), mostly at grain boundaries. Twins were profuse, and their morphologies were quite different after hot rolling and cold plane strain compression. The Mg-1.33La (wt.%) alloy exhibited good room temperature formability and an increase in strength. The alloy's hardness increased with increasing deformation strain. Such properties were explained by the effect of both the Mg17La2 phase precipitation and the sample's texture.
Dependency of structure, mechanical and electrical properties on rotating magnetic field in the Bi–Sn–Ag ternary eutectic alloy
Authors: Kaya Hasan , Çadırlı Emin , Gündüz Mehmet , Räbiger Dirk , Eckert Sven
Published: February 2016

In the present study, cylindrical samples of the Bi – Sn – Ag ternary eutectic alloy were exposed to a rotating magnetic field (RMF) during upward solidification. The dependence of the eutectic spacing (λ), microhardness (HV), tensile stress (σ) and electrical resistivity (ρ) of the Bi – Sn – Ag eutectic alloy on the RMF-driven flow was investigated in this study. With the increase in the RMF, the eutectic grains are fragmented and gradually refined until a transition from coarser plate-like structure to a fine fibrous eutectic structure for the alloy. It was found that with the increasing of RMF, λ decreases but HV, σ and ρ increase. The enthalpy of fusion (ΔH) and specific heat (C

p
) for the same alloy was determined by means of differential scanning calorimetry from the heating trace during the transformation from the eutectic liquid to eutectic solid. The results obtained in the present work were compared with published data available in the literature.
Phage-assisted assembly of organic–inorganic hybrid bilayers
Authors: Moghimian Pouya , Kilper Stefan , Srot Vesna , Rothenstein Dirk , Facey Sandra J. , Hauer Bernhard , Bill Joachim , van Aken Peter A.
Published: February 2016

Protein-based bottom-up synthesis of functional nanomaterials and devices is one of the most promising areas in bio-nanotechnology. Here, we demonstrate that organic assemblies can serve as biologically controllable scaffolds for the deposition of inorganic nanoparticles. In this work, wild-type M13 phages were employed for controlled mineralization of zinc oxide particles. Our aim was to construct layered structures of organic and inorganic materials which contain alternating layers on a smooth substrate. The structure, elemental composition, and also the integrity of the organic and the biologically-templated inorganic layers were studied. A uniform nano-hybrid structure without significant thickness fluctuations was fabricated by using a high concentration of M13 phages and a carbon-coated substrate. The current study gives insight into the combination of organic–inorganic materials to form a multilayered structure, which in turn sets the stage for the fabrication of electronic devices, e. g. actuators or capacitors.
Microstructural evolution and creep of Fe–Al–Ta alloys
Authors: Prokopčáková Petra , Švec Martin , Palm Martin
Published: February 2016

The microstructural evolution in Fe – Al – Ta alloys containing 23 – 31 at.% Al and 1.5 – 2.2 at.% Ta has been studied in the temperature range 650 – 750 °C by annealing for 1, 10, 100 and 1 000 h. The experiments confirm that in this temperature range the precipitation of the stable hexagonal C14 Laves phase is preceded by formation of coherent, metastable L21 Heusler phase precipitates within the Fe – Al matrix. However, precipitates of C14 are observed after much shorter annealing times than previously assumed. Creep strength increases substantially with increasing Al content of the alloys because the solid solubility for Ta in the Fe – Al matrix increases with increasing Al content and solid-solution hardening contributes substantially to the observed high creep strength. It may therefore be that the microstructural changes during creep have no noticeable effect on creep strength.
Technical considerations in transforaminal endoscopic spine surgery at the thoracolumbar junction: report of 3 cases
Authors: Telfeian Albert E. , Jasper Gabriele P. , Oyelese Adetokunbo A. , Gokaslan Ziya L.
Published: February 2016

OBJECTIVE

In this study the authors describe the technical considerations and feasibility of transforaminal discectomy and foraminoplasty for the treatment of lumbar radiculopathy in patients who have herniated discs at the thoracolumbar junction.

METHODS

After institutional review board approval, charts from 3 consecutive patients with lumbar radiculopathy and T12–L1 herniated discs who underwent endoscopic procedures between 2006 and 2014 were reviewed.

RESULTS

Consecutive cases (n = 1316) were reviewed to determine the incidence and success of surgery performed at the T12–L1 level. Only 3 patients (0.23%) treated with endoscopic surgery for their herniated discs had T12–L1 herniated discs; the rest were lumbar or lumbosacral herniations. For patients with T12–L1 disc herniations, the average preoperative visual analog scale score was 8.3 (indicated in the questionnaire as describing severe and constant pain). The average 1-year postoperative visual analog scale score was 1.7 (indicated in the questionnaire as mild and intermittent pain).

CONCLUSIONS

Transforaminal endoscopic discectomy and foraminotomy can be used as a safe yet minimally invasive technique for the treatment of lumbar radiculopathy in the setting of a thoracolumbar disc herniation.
Does the microendoscopic technique reduce mortality and major complications in patients undergoing lumbar discectomy? A propensity score–matched analysis using a nationwide administrative database
Authors: Ohya Junichi , Oshima Yasushi , Chikuda Hirotaka , Oichi Takeshi , Matsui Hiroki , Fushimi Kiyohide , Tanaka Sakae , Yasunaga Hideo
Published: February 2016

OBJECTIVE

Although minimally invasive spinal surgery has recently gained popularity, few nationwide studies have compared the adverse events that occur during endoscopic versus open spinal surgery. The purpose of this study was to compare perioperative complications associated with microendoscopic discectomy (MED) and open discectomy for patients with lumbar disc herniation.

METHODS

The authors retrospectively extracted from the Diagnosis Procedure Combination database, a national inpatient database in Japan, data for patients admitted between July 2010 and March 2013. Patients who underwent lumbar discectomy without fusion surgery were included in the analysis, and those with an urgent admission were excluded. The authors examined patient age, sex, Charlson Comorbidity Index, body mass index, smoking status, blood transfusion, duration of anesthesia, type of hospital, and hospital volume (number of patients undergoing discectomy at each hospital). One-to-one propensity score matching between the MED and open discectomy groups was performed to compare the proportions of in-hospital deaths, surgical site infections (SSIs), and major complications, including stroke, acute coronary events, pulmonary embolism, respiratory complications, urinary tract infection, and sepsis. The authors also compared the hospital length of stay between the 2 groups.

RESULTS

A total of 26,612 patients were identified in the database. The mean age was 49.6 years (SD 17.7 years). Among all patients, 17,406 (65.4%) were male and 6422 (24.1%) underwent MED. A propensity score–matched analysis with 6040 pairs of patients showed significant decreases in the occurrence of major complications (0.8% vs 1.3%, p = 0.01) and SSI (0.1% vs 0.2%, p = 0.02) in patients treated with MED compared with those who underwent open discectomy. Overall, MED was associated with significantly lower risks of major complications (OR 0.62, 95% CI 0.43–0.89, p = 0.01) and SSI (OR 0.29, 95% CI 0.09–0.87, p = 0.03) than open discectomy. There was a significant difference in length of hospital stay (11 vs 15 days, p < 0.001) between the groups. There was no significant difference in in-hospital mortality between MED and open discectomy.

CONCLUSIONS

The microendoscopic technique was associated with lower risks for SSI and major complications following discectomy in patients with lumbar disc herniation.
A brief history of endoscopic spine surgery
Authors: Telfeian Albert E. , Veeravagu Anand , Oyelese Adetokunbo A. , Gokaslan Ziya L.
Published: February 2016

Few neurosurgeons practicing today have had training in the field of endoscopic spine surgery during residency or fellowship. Nevertheless, over the past 40 years individual spine surgeons from around the world have worked to create a subfield of minimally invasive spine surgery that takes the point of visualization away from the surgeon's eye or the lens of a microscope and puts it directly at the point of spine pathology. What follows is an attempt to describe the story of how endoscopic spine surgery developed and to credit some of those who have been the biggest contributors to its development.
Endoscopic minimally invasive transforaminal interbody fusion without general anesthesia: initial clinical experience with 1-year follow-up
Authors: Wang Michael Y. , Grossman Jay
Published: February 2016

OBJECTIVE

One of the principal goals of minimally invasive surgery has been to speed postoperative recovery. In this case series, the authors used an endoscopic technique for interbody fusion combined with percutaneous screw fixation to obviate the need for general anesthesia.

METHODS

The first 10 consecutive patients treated with a minimum of 1 year's follow-up were included in this series. The patients were all treated using endoscopic access through Kambin's triangle to allow for neural decompression, discectomy, endplate preparation, and interbody fusion. This was followed by percutaneous pedicle screw and connecting rod placement using liposomal bupivacaine for long-acting analgesia. No narcotics or regional anesthetics were used during surgery.

RESULTS

All patients underwent the procedure successfully without conversion to open surgery. The patients' average age was 62.2 ± 9.0 years (range 52–78 years). All patients had severe disc height collapse, and 60% had a Grade I spondylolisthesis. The mean operative time was 113.5 ± 6.3 minutes (range 105–120 minutes), and blood loss was 65 ± 38 ml (range 30–190 ml). The mean length of hospital stay was 1.4 ± 1.3 nights. There were no intraoperative or postoperative complications. Comparison of preoperative and final clinical metrics demonstrated that the Oswestry Disability Index improved from 42 ± 11.8 to 13.3 ± 15.1; the 36-Item Short Form Health Survey (SF-36) Physical Component Summary improved from 47.6 ± 3.8 to 49.7 ± 5.4; the SF-36 Mental Component Summary decreased from 47 ± 3.9 to 46.7 ± 3.4; and the EQ-5D improved from 10.7 ± 9.5 to 14.2 ± 1.6. There were no cases of nonunion identified radiographically on follow-up imaging.

CONCLUSIONS

Endoscopic fusion under conscious sedation may represent a feasible alternative to traditional lumbar spine fusion in select patients. Larger clinical series are necessary to validate that clinical improvements are sustained and that arthrodesis rates are successful when compared with open surgery. This initial experience demonstrates the possible utility of this procedure.
Heterocyclisation of 2,5-diacetyl-3,4-disubstituted-thieno[2,3-b]Thiophene Bis-Thiosemicarbazones Leading to Bis-Thiazoles and Bis-1,3,4-thiadiazoles as Anti-breast Cancer Agents
Authors: Gomha Sobhi M. , Badrey Mohamed G. , Edrees Mastoura M.
Published: February 2016

In this paper, the synthesis of bis-thiazoles and bis-1,3,4-thiadiazoles linked to a thienothiophene nucleus is described. The synthesis was achieved through interaction between 2,5-diacetylthieno[2,3-b]thiophene bis-thiosemicarbazones with a variety of hydrazonyl halides in a basic medium. All the synthesised compounds were characterised by IR, 1H NMR, 13C NMR and mass spectroscopic analyses. The newly synthesised compounds represent a variety of novel polyheteroatomic moieties containing nitrogen and sulfur. Most of the synthesised compounds were evaluated for their antitumour activity against the breast cancer MCF-7 cell line. The results revealed that four compounds are equipotent to tamoxifen (IC50 = 8.04 μg mL−1) with IC50 = 8.23, 8.26, 8.68 and 9.12 μg mL−1 respectively.
Two Efficient Derivative-Free Iterative Methods for Solving Nonlinear Systems
Authors: Wang Xiaofeng , Fan Xiaodong
Published: February 2016

In this work, two multi-step derivative-free iterative methods are presented for solving system of nonlinear equations. The new methods have high computational efficiency and low computational cost. The order of convergence of the new methods is proved by a development of an inverse first-order divided difference operator. The computational efficiency is compared with the existing methods. Numerical experiments support the theoretical results. Experimental results show that the new methods remarkably reduce the computing time in the process of high-precision computing.