bluuebunny/crossref_metadata_2025 huggingface dataset:
Agroecological transition and reconfiguration of horticultural work among family farmers in Buenos Aires, Argentina
Authors: Parodi Gabriela
Published: May 2018

In Argentina, family farmers who engage in horticultural production have recently adopted the process of agroecological transition into their work. The process involves organisations, such as the Land Workers’ Union (UTT) cooperative, located in the horticultural belt in the province of Buenos Aires. The case study under analysis shows family farmers’ challenges with the agroecological transition process. These challenges include the reconfiguration of horticultural work, which impacts the skills needed to perform the work; the organisation of work; and the sustainability conditions involved in introducing agroecology as a social-productive model for growing vegetables. We examine start-up and development strategies for the agroecological transition process involving farmers and State agents. Our methodology is qualitative and we rely on semi-structured interviews and observations with family farmers belonging to the UTT cooperative. This paper explores how the process of agroecological transition that family farmers in Buenos Aires implement into their horticultural work affects their production and marketing practices. The primary goal is to explain the unequal evolution of this process. This inequality is particularly evident in the decision-making processes in which farmers engage prior to implementing the agroecological transition. They must consider a host of factors influencing their capacity to innovate and diversify production and sales through short food supply chains. These factors include their land tenure conditions (i.e., be a tenant or owner of the land), their level of economic capital (i.e., their access to greenhouses), and the size of their production. They largely account for the varying speeds at which farmers in this case study implement the process of agroecological transition into their farming.
Stabilizing effect of intra-specific competition on prey-predator dynamics with intraguild predation
Authors: Namba Toshiyuki , Takeuchi Yasuhiro , Banerjee Malay
Published: May 2018

Multi-species population models with various types of interactions are important to understand the stable coexistence of prey and predator species and the role of various factors leading to complex dynamics and extinction of one or more species. Models of two predators sharing one prey population are analyzed by some researchers and the role of nonlinear functional responses and interaction strengths are reported to be responsible for the stable coexistence of three species. However, one-prey-two-predator models with intraguild predation have received relatively less attention from researchers. Recent literature on this topic mainly focused on the study of local and global stability properties of possible equilibria and appearance of various types of bifurcations. Intra-specific competition among predator species is an important factor for coexistence of more than one predator species competing for one shared prey. Hence it is quite essential to understand the role of intra-specific competition on the stability and bifurcation behavior. In this work we wish to demonstrate the stabilizing role of intra-specific competition among intermediate and top predators when the growth rate of prey species is adequate to support both the predator species. With the help of stability and bifurcation analysis we show the stabilizing role of intra-specific competition among predators. Moreover, strong self-regulation in intraguild predator prevents extinction of intraguild prey at high productivity and resolve the contradiction between empirical and previous theoretical results on the fate of intraguild prey at high productivity. To establish our claim we present, apart from analytical results, extensive numerical simulation results and couple of bifurcation diagrams.
Update ESC-Leitlinie 2017 – Akuter Myokardinfarkt (STEMI)
Authors: Jung Christian , Elsässer Albrecht
Published: May 2018

Was ist neu?

Diagnose des ST-Strecken-Hebungsinfarkts Die aktualisierte Leitlinie zum ST-Hebungsinfarkt (STEMI) der Europäischen Gesellschaft für Kardiologie (ESC) definiert den ersten qualifizierten medizinischen Kontakt genauer: Hierunter versteht man die Anwesenheit von medizinischem Personal, welches in der Lage ist, ein EKG zu schreiben und zu interpretieren. Von diesem sollte die Arbeitsdiagnose STEMI gestellt und die definierten Maßnahmen zur schnellstmöglichen Revaskularisation organisiert werden (ideal < 90Minuten). In der EKG-Beurteilung wurde der Nachweis eines neu aufgetretenen kompletten Rechtsschenkelblocks in der Bewertung dem eines entsprechenden Linksschenkelblocks gleichgestellt.

Akutmanagement und Notfallversorgung Die perkutane Koronarintervention (PCI) ohne vorherige Lysetherapie ist als Standardversorgung etabliert. Eine Versorgungszeit von Diagnosestellung bis PCI von unter 90 Minuten ist zu gewährleisten, in einem PCI-Zentrum binnen 60 Minuten. Die medikamentöse Notfallversorgung besteht aus unfraktioniertem Heparin, ASS und ggf. Sedativa und Analgetika. Aufgrund aktueller Studienergebnisse sollte eine Sauerstoffgabe via Nasenbrille nur bei Hypoxämie (Sauerstoffsättigung < 90 %) erfolgen.

Revaskularisationsstrategie Die Versorgungsstrategie der Wahl ist die perkutane Koronarintervention mit der dezidierten Präferenz des radialen Zugangsweges. Der Einsatz von Drug-eluting-Stents sollte uneingeschränkt erfolgen, die Thrombusaspiration spielt in der Routinebehandlung keine Rolle mehr. Bei stabilen Patienten mit STEMI und Mehrgefäßerkrankung sollte eine komplette Revaskularisation angestrebt werden. In der Index-Prozedur steht die Versorgung der „culprit lesion“ im Mittelpunkt, der Interventionszeitpunkt der weiteren relevanten Stenosierungen in den Nicht-Infarkt-Gefäßen ist patienten- und prozedurabhängig.

Medikamentöse Therapie Die periprozedurale Standardantikoagulation erfolgt mittels Heparin, die Bedeutung von Bivalirudin wurde hier abgewertet. Standard bleibt ebenso weiterhin eine duale Thrombozytenaggregationshemmung (DAPT), bevorzugt mit den Präparaten Ticagrelor oder Prasugrel in Kombination mit ASS. Die Dauer der DAPT sollte im Kontext des Ischämie- und Blutungsrisikos festgelegt werden, grundsätzlich wird eine Dauer von 12 Monaten empfohlen. Ein Fokus in der Nachsorge der Patienten liegt in der Reduktion des LDL-Cholesterins mit einem Zielwert < 70 mg/dl.

Myokardinfarkt mit nicht obstruktiven Koronararterien Neu in den Leilinien aufgenommen ist unter dem Thema unklarer STEMI ein Kapitel zu Myokardinfarkt mit nicht obstruktiven Koronararterien (MINOCA). Hier werden die möglichen Differenzialdiagnosen vorgestellt sowie deren Verifizierung diskutiert.
Systemischer Lupus erythematodes (SLE) – neue Klassifikationskriterien
Authors: Aringer Martin , Dörner Thomas
Published: May 2018

Was ist neu?

Suchtest Anti-nukleäre Antikörper (ANA) Fast alle SLE-Patienten sind ANA-positiv. Anti-DFS70-Antikörper sprechen gegen das Vorliegen einer Kollagenose.

Neue Klassifikationskriterien fast am Ziel EULAR (European League Against Rheumatism) und ACR (American College of Rheumatology) haben ein Projekt zur Überarbeitung der Klassifikation gefördert: ANA-Positivität gilt nun als Eingangskriterium, die Gewichtung der Kriterien hat sich verändert.

Kardiovaskuläres Risiko SLE-Patientinnen haben ein 10-fach erhöhtes kardiovaskuläres Risiko. Neben einer Reduktion klassischer Risikofaktoren sind Eindämmung der Entzündung und Glukokortikoidreduktion entscheidend. ASS und mäßiger Alkoholkonsum wirken sich positiv aus.

Remission und niedrige Krankheitsaktivität Die Definitionen beinhalten fehlende klinische Aktivität und sehr niedrige Glukokortikoiddosen. Niedrige Krankheitsaktivität ist erreichbar und geht mit weniger Schüben einher.

Hydroxychloroquin Hydroxychloroquin gilt heute beim kutanen Lupus erythematodes als Mittel der Wahl. Das Erblindungsrisiko wird als extrem niedrig eingeschätzt.

Belimumab Das einzige zugelassene SLE-Biologikum ist ab sofort als wöchentliche Subkutan-Injektion verfügbar.

Mycophenolat Seit September 2017 sind Mycophenolat-Mofetil (MMF) und Mycophenolensäure (MPA) für die Induktions- und Erhaltungstherapie der schweren Lupus-Nephritis gestattet. Für die Off-label-Therapie des nicht-renalen SLE gibt es eine neue kontrollierte Studie.
Thrombotische Mikroangiopathien
Authors: Schubert Jörg , Dechant Michael
Published: May 2018

Was ist neu?

Pathophysiologische Differenzierung Das Krankheitsbild der thrombotischen Mikroangiopathie (TMA) wird pathophysiologisch in verschiedene Gruppen differenziert: TTP, HUS, aHUS, medikamentös induzierte, Systemerkrankungs-assoziierte und posttherapeutische TMA. Diese Unterscheidung ist auch im klinischen Alltag essenziell zur Auswahl der optimalen Therapiestrategie.

Klinische Manifestation und Diagnosestellung Das kombinierte Auftreten einer Thrombopenie und einer hämolytischen Anämie in Verbindung mit neurologischen oder renalen Organschädigungen sollte an das Vorliegen einer TMA denken lassen. Laborchemisch essenziell zu bestimmen sind ADAMTS-13 bei TTP, bakterieller bzw. Shiga-Toxin-Nachweis beim STEC-HUS sowie spezifische Komplement-Untersuchungen beim aHUS.

Therapie Bis vor wenigen Jahren waren Plasmapheresen und ggf. immunsuppressive Behandlungen die einzigen wirksamen Behandlungsansätze. Inzwischen gibt es weitere Therapiemöglichkeiten: So steht der Antikörper Caplacizumab kurz vor der Zulassung zur supportiven Therapie der TTP. Der Komplement-blockierende Antikörper Eculizumab ist bereits zugelassen und besitzt einen festen Stellenwert in der Behandlung des aHUS. Zudem hat Defibrotide 2016 von der amerikanischen Food and Drug Administration (FDA) eine Zulassung zur Behandlung des SOS/TMA-Syndroms erhalten.
Moderne Asthma-Therapie im Licht der neuen Leitlinien
Authors: Lommatzsch Marek
Published: May 2018

Was ist neu?

5-Stufen-Schema der Asthma-Therapie Die neuen Leitlinien empfehlen ein 5-Stufen-Therapieschema, in welchem je nach Asthma-Kontrolle die Therapie eskaliert oder deeskaliert wird. Basistherapie sind weiterhin inhalative Steroide (ICS), die um langwirksame inhalative Bronchodilatatoren erweitert werden können. Bei unzureichender Asthma-Kontrolle unter maximaler inhalativer Therapie stehen Biologika zur Verfügung, welche Vorrang vor einer Prednisolon-Dauertherapie haben.

Allergen-Immuntherapie Eine Allergen-Immuntherapie (AIT) sollte nicht nur im Sinne einer Asthma-Prävention bei allergischer Rhinitis, sondern auch bei bereits bestehendem (leichtgradigem) allergischem Asthma mit Allergen-induzierten Verschlechterungen der Asthma-Kontrolle erwogen werden. Neue Studien zeigen, dass die AIT auch bei Patienten mit mittelschwerem Asthma und einem perennialen Allergen (Hausstaubmilben) wirksam und sicher sein kann. Für schweres Asthma ist die AIT nicht zugelassen.

Schweres und schwieriges Asthma Für Patienten mit schwerem Asthma stehen aktuell 4 hochwirksame Biologika zur Verfügung. Der Einsatz von Biologika erfolgt aufgrund individueller Charakteristika der Patienten und verlangt spezifische Erfahrung, daher sollten potenzielle Patienten zumindest einmal in einem spezialisierten Zentrum vorgestellt werden. Abzugrenzen ist das schwere, therapierefraktäre Asthma vom schwierigen Asthma, bei dem die Verbesserung der Adhärenz und Inhalationstechnik bzw. die Beseitigung persistierender Trigger oder Komorbiditäten im Vordergrund steht.
Neue Leitlinien und Daten zu Clostridium difficile – Was ändert sich?
Authors: Lübbert Christoph , Lippmann Norman , von Braun Amrei
Published: May 2018

Was ist neu?

Epidemiologie Clostridium-difficile-Infektionen (CDI) gehen auch in Deutschland mit unverändert hoher Krankheitslast und einem Anstieg der Zahl schwerer bzw. letaler Verläufe einher. Der Anteil ambulant erworbener CDI steigt weltweit weiter an und umfasst selten auch Patienten mit einer Reisediarrhö. Es gibt eine gute Evidenz dafür, dass nosokomiale Fälle durch Implementierung von Antibiotic-Stewardship- (ABS-) Programmen stark verringert werden können.

Diagnostik Nur Patienten mit unklarer, neu aufgetretener Diarrhö sollten getestet werden. Die mikrobiologische Untersuchung auf toxigene C.-difficile-Stämme sollte mehrstufig erfolgen, d. h. mittels Glutamatdehydrogenase- (GDH-) Test plus Toxinnachweis oder Nukleinsäureamplifikationstests (NAAT), oder NAAT plus Toxinnachweis. Von einem alleinigen Toxinnachweis mittels Enzymimmunoassay (EIA) oder einem alleinigen Einsatz von NAAT wird abgeraten.

Neue Therapieleitlinien Nach den 2017/18 aktualisierten US-amerikanischen Leitlinien gilt oral verabreichtes Vancomycin inzwischen als Mittel der ersten Wahl. Fidaxomicin ist ähnlich wirksam wie Vancomycin, sein Vorteil besteht jedoch in der geringeren Rate an Rezidiven.

Weitere Behandlungsoptionen und Impfung Es konnte gezeigt werden, dass die zusätzliche Gabe des monoklonalen Antikörpers Bezlotoxumab die Rezidivrate signifikant senkt. Neue Antibiotika, die die Darmmikrobiota besser schützen, werden derzeit in klinischen Studien getestet. Für die Therapie multipel rezidivierender CDI bestehen gesicherte Behandlungserfolge von ≥ 90 % durch den fäkalen Mikrobiomtransfer (FMT). Da der FMT in Deutschland zurzeit lediglich den Status eines individuellen Heilversuchs hat, ist eine evidenzbasierte generelle Empfehlung für die klinische Praxis nicht möglich. Wahrscheinlich wird sich die Applikation kryokonservierter FMT-Kapseln längerfristig durchsetzen. Es ist zu erwarten, dass Toxoid-Impfstoffe CDI wirksam verhindern können; allerdings wurde bislang noch keine Zulassungsstudie abgeschlossen.
Solitär fibröser Tumor: eine seltene Ursache rezidivierender schwerer Hypoglykämien
Authors: Kühn-Velten Ute , Hohmann Christian , Strauss Tim , Heizmann Oleg , Klöppel Günter
Published: May 2018

Anamnese und klinischer Befund Eine 73-jährige Patientin wurde morgens vom Notarzt bei initial unklarem komatösem Zustand mit einem Blutzucker von 24 mg/dl [70 – 115 mg/dl] in der Notaufnahme vorgestellt. Wesentliche Vorerkrankungen waren bei ihr nicht bekannt. Die Patientin hatte bis dato keinerlei Vormedikation. Bis zum Aufnahmetag hatte Wohlbefinden bestanden.

Untersuchungen Bis auf ein abgeschwächtes Atemgeräusch rechts bestanden keine Auffälligkeiten im körperlichen Aufnahmebefund. Mittels gezielter endokrinologischer Labordiagnostik, Feinnadelpunktion und Bildgebung (Röntgen-Thorax, Abdomen- und Thoraxsonografie, Abdomen- und Thorax-CT) konnte als Ursache der Hypoglykämie ein Nicht-Inselzell-Tumor (NICTH) im Bereich der rechtsseitigen Pleura identifiziert werden.

Therapie und Verlauf Durch die operative Entfernung des Tumors konnten normoglykäme Werte und damit zunächst eine Heilung erreicht werden. Die Histologie ergab einen solitär fibrösen Tumor.

Folgerung Ein solitär fibröser Tumor ist eine relativ häufige Ursache der insgesamt sehr seltenen Nicht-Inselzell-Tumor-Hypoglykämien (NICTH). Sie zeigt im Vergleich mit anderen Ursachen rezidivierender Hypoglykämien eine typische Konstellation hinsichtlich endokrinologischer Laborparameter. Daher sollte bereits initial unter Hypoglykämiebedingungen neben der Bestimmung des Blutzuckers eine sinnvolle endokrinologische Labordiagnostik erfolgen, um dieses Syndrom, das durch eine erhöhte Produktion von IGF-2 bzw. Big-IGF-2 durch die Tumorzellen gekennzeichnet ist, diagnostizieren zu können.
A Highly Efficient Copper(II)-Catalyzed Cross-Dehydrogenative-Coupling Reaction of N-Arylglycine Esters with 2-Arylimidazo[1,2-a]pyridines
Authors: Zhu Zhi-Qiang , Le Zhang-Gao , Xiao Li-Jin , Chen Ying , Xie Zong-Bo , Zhu Hai-Bo
Published: May 2018

A rapid and highly efficient copper(II)-catalyzed cross-dehydrogenative coupling (CDC) reaction of N-arylglycine esters with imidazo[1,2-a]pyridines has been described. A broad range of N-arylglycine esters underwent the CDC reaction smoothly with 2-arylimidazo[1,2-a]pyridines to give α-substituted α-amino acid esters in excellent yields. This synthetic method has the advantages of high yields, good functional groups compatibility, simple operation, and mild reaction conditions. A possible mechanism for the CDC reaction is also proposed. The use of a copper salt as the catalyst and air as the terminal oxidant makes this transformation sustainable and practical.
Total Synthesis of Astellatol: A Three-Decade Synthetic Puzzle
Authors: Xu Jing , Zhao Nan , Xie Shengling , Huang Hengjun
Published: May 2018

Here we briefly discuss and review our journey to achieve the first, enantiospecific total synthesis of a rare, complex sesterterpenoid, astellatol.

1 Introduction

2 Model Study of Reductive Radical Cyclization

3 Total Synthesis of Astellatol

4 Conclusion
Typ-2-Diabetes: Nach Metformin – Verändern neue Studien die Therapie?
Authors: Elbelt Ulf
Published: May 2018

Was ist neu?

Kardiovaskuläre Endpunktstudien Seit 2013 wurden mehrere auf Nicht-Unterlegenheit angelegte, Placebo-kontrollierte Endpunktstudien zur kardiovaskulären Sicherheit einzelner Substanzen neuer antidiabetischer Wirkstoffklassen publiziert. Während für die Therapie mit den GLP-1-Rezeptoragonisten Liraglutid und Semaglutid sowie für die mit den SGLT-2-Inhibitoren Empagliflozin und Canagliflozin eine Reduktion kardiovaskulärer Endpunkte demonstriert werden konnte, zeigten die bisher abgeschlossenen Studien mit DPP-4-Inhibitoren keine Reduktion kardiovaskulärer Ereignisse.

Therapieeskalation nach Metformin Für die notwendige Therapieeskalation bei unzureichender Blutzuckerkontrolle unter Metformin wird bei Patienten mit Diabetes mellitus Typ 2 und hohem Risiko für kardiovaskuläre Erkrankungen vorrangig die Erweiterung der Therapie mit GLP-1-Rezeptoragonisten und SGLT-2-Inhibitoren empfohlen. Auch der Einsatz von DPP-4-Inhibitoren ist für Patienten sinnvoll, bei denen einfache Therapiedurchführung, gute Verträglichkeit und Therapiesicherheit im Vordergrund stehen.
Hepatozelluläres Karzinom: neue multimodale Therapiekonzepte
Authors: Schultheiß Michael , Bettinger Dominik , Fichtner-Feigl Stefan , Thimme Robert
Published: May 2018

Was ist neu?

Aktueller Stand und Allgemeines Die Leitlinien für das hepatozelluläre Karzinom (HCC) sind derzeit unter Revision, Neuauflagen werden 2018 erwartet. Patienten mit chronischen Lebererkrankungen oder Leberzirrhose müssen mittels Ultraschall alle 6 Monate in Bezug auf die Entwicklung eines HCC gescreent werden. Die chirurgische Resektion oder die Lebertransplantation sind kurative Optionen im frühen Stadium.

Lokoregionäre Therapien Die selektive interne Radiotherapie (SIRT) wird zunehmend häufiger als lokoregionäre Therapie eingesetzt. Die Studiendaten sprechen für eine gute Verträglichkeit, aber keine überlegene Wirksamkeit gegenüber transarterieller Chemoembolisation (TACE) oder Systemtherapie mit Sorafenib.

Neue zielgerichtete Therapien Regorafenib stellt bei Patienten mit Progress unter Sorafenib eine neu zugelassene Alternative in der Zweitlinientherapie dar. Positive Phase-III-Studien wurden für Lenvatinib in der Erst- und Cabozantinib in der Zweitlinientherapie publiziert.

Immuntherapie Der Checkpoint-Inhibitor Nivolumab ist in den USA in der Zweitlinientherapie aufgrund guter Phase-I/II-Daten zugelassen worden. Daten zu einer Phase-III-Studie in der Erstlinientherapie vs. Sorafenib werden 2018 erwartet.
Australia's premier shale basin: five plays, 1 000 000 000 years in the making
Authors: Côté Alexander , Richards Brenton , Altmann Carl , Baruch Elizabeth , Close David
Published: May 2018

The successful fracture stimulation and production test of the Amungee NW-1H well placed the Velkerri Shale play and the Beetaloo Sub-basin on Australia’s energy radar. The Velkerri Shale dry gas play is currently Australia’s most promising shale gas prospect; however, it is not the only prospect in the Beetaloo Sub-basin. Four additional potential plays have been identified, each with their own specific risk profile and relative benefits. These are the Velkerri Shale liquids rich gas play, the Kyalla Shale and hybrid liquids rich gas plays, and the Hayfield Sandstone oil/condensate play. Appraising each of these opportunities requires special attention to ensure efficient and appropriate deployment of capital. A framework approach allows for the high-level assessment and comparison of each of the discussed opportunities within the Beetaloo Sub-basin portfolio.
Impact of injected water salinity on CO2 storage efficiency in homogenous reservoirs
Authors: Al-Khdheeawi Emad A. , Vialle Stephanie , Barifcani Ahmed , Sarmadivaleh Mohammad , Iglauer Stefan
Published: May 2018

Water alternating gas (WAG) injection significantly improves enhanced oil recovery efficiency by improving the sweep efficiency. However, the impact of injected water salinity during WAG injection on CO2 storage efficiency has not been previously demonstrated. Thus, a 3D reservoir model has been developed for simulating CO2 injection and storage processes in homogeneous reservoirs with different water injection scenarios (i.e. low salinity water injection (1000 ppm NaCl), high salinity water injection (250 000 ppm NaCl) and no water injection), and the associated reservoir-scale CO2 plume dynamics and CO2 dissolution have been predicted. Furthermore, in this work, we have investigated the efficiency of dissolution trapping with and without WAG injection. For all water injection scenarios, 5000 kton of CO2 were injected during a 10-year CO2 injection period. For high and low salinity water injection scenarios, 5 cycles of CO2 injection (each cycle is one year) at a rate of 1000 kton/year were carried out, and each CO2 cycle was followed by a one year water injection at a rate of 0.015 pore volume per year. This injection period was followed by a 500-year post injection (storage) period. Our results clearly indicate that injected water salinity has a significant impact on the quantity of dissolved CO2 and on the CO2 plume dynamics. The low salinity water injection resulted in the maximum CO2 dissolution and minimum vertical migration of CO2. Also, our results show that WAG injection enhances dissolution trapping and reduces CO2 leakage risk for both injected water salinities. Thus, we conclude that the low salinity water injection improves CO2 storage efficiency.
Significant reliability improvements in reciprocating gas compressor packages at Arrow Energy
Authors: Parulekar Prashant S. , Hudson Richard , Boyd Harrison
Published: May 2018

Arrow Energy operates a fleet of four-stage reciprocating compressors in the Surat Basin, boosting low-pressure coal-seam gas (at 60 kPag) to transmission pipeline pressure (in excess of 9000 kPag). Historically, the compressors and the gas engine drivers exhibited persistent problems associated with high vibrations, inadequate engine and process gas cooling, poor compressor valve reliability and premature engine component failures. Hot Queensland summer conditions further exacerbated these problems, which resulted in frequent unit trips during hot periods when gas and electricity prices demanded consistent gas production at nameplate capacity.
Since 2014, Arrow Energy has carried out systematic analytical studies to establish the compressor package component limitations and develop technical solutions to address these. Stub shaft-driven air coolers, compressor valves, gas engine heads and valves, compressor frame and crosshead mounting arrangements were some of the key components studied in detail. Utilising systematically designed field tests with laboratory calibrated test instruments, scale model laboratory tests, advanced computer simulations, data analytics and new technology trials, several key design modifications were implemented. The outcome of these design changes has enabled Arrow Energy to achieve a step-change in reliability for the better, with each reciprocating compression package (including gas engine driver) operating in excess of 98% reliability. The implemented changes were executed at minimal cost and resulted in significant reduction in maintenance costs. The increased reliability and consistent production during the peak summer hours easily justified the modifications made to the packages. This paper describes the technical work undertaken, changes implemented and their outcomes.
Helium in the Australian liquefied natural gas economy
Authors: Boreham Christopher J. , Edwards Dianne S. , Poreda Robert J. , Darrah Thomas H. , Zhu Ron , Grosjean Emmanuelle , Main Philip , Waltenberg Kathryn , Henson Paul A.
Published: May 2018

Australia is about to become the premier global exporter of liquefied natural gas (LNG), bringing increased opportunities for helium extraction. Processing of natural gas to LNG necessitates the exclusion and disposal of non-hydrocarbon components, principally carbon dioxide and nitrogen. Minor to trace hydrogen, helium and higher noble gases in the LNG feed-in gas become concentrated with nitrogen in the non-condensable LNG tail gas. Helium is commercially extracted worldwide from this LNG tail gas. Australia has one helium plant in Darwin where gas (containing 0.1% He) from the Bayu-Undan accumulation in the Bonaparte Basin is processed for LNG and the tail gas, enriched in helium (3%), is the feedstock for helium extraction. With current and proposed LNG facilities across Australia, it is timely to determine whether the development of other accumulations offers similar potential. Geoscience Australia has obtained helium contents in ~800 Australian natural gases covering all hydrocarbon-producing sedimentary basins. Additionally, the origin of helium has been investigated using the integration of helium, neon and argon isotopes, as well as the stable carbon (13C/12C) isotopes of carbon dioxide and hydrocarbon gases and isotopes (15N/14N) of nitrogen. With no apparent loss of helium and nitrogen throughout the LNG industrial process, together with the estimated remaining resources of gas accumulations, a helium volumetric seriatim results in the Greater Sunrise (Bonaparte Basin) > Ichthys (Browse Basin) > Goodwyn–North Rankin (Northern Carnarvon Basin) accumulations having considerably more untapped economic value in helium extraction than the commercial Bayu-Undan LNG development.
Fully integrated dynamic reservoir and well simulation model: Blacktip gas field case study
Authors: Yokote Ryosuke , Albarzanji Mohammad , Suhardiman Yohan , Tran Andrew , Putra Erni Dharma , Gonzalez Nelson Jose Rodriguez
Published: May 2018

This paper describes an experience of integrating a dynamic reservoir simulation model with a dynamic well simulation model, resulting in an integrated dynamic model from the reservoir to the surface that enhances reservoir and well surveillance capability for the Blacktip gas field.
Multiphase transient flow simulation is used to support daily well and pipeline operations for the project. The limitation of the standalone well model using a multiphase transient simulation software was its inability to reproduce pressure build up response during shut-ins, and pressure drawdown during start-ups. The fluid inflow from the reservoir to the well bore is modelled using the Inflow Performance Relationship (IPR) and accordingly the transient pressure behaviour near the well bore is not captured. This makes it difficult to estimate an accurate static reservoir pressure during shut-ins, as the predicted pressure instantaneously builds up to reservoir pressure specified in the IPR. The integrated dynamic model overcomes this limitation. The history matching of production intervals including shut-ins and start-ups using the integrated dynamic model along with high frequency data demonstrates that this integrated modelling approach can be used as a reliable surveillance tool to understand dynamic flow conditions from the reservoir to the surface, including liquid loading and unloading scenarios.
The evolution of the history match and subsequent outcomes are discussed in the paper, along with the lessons learnt. Results of a liquid loading and unloading scenario for a gas well are also discussed in the paper.
Laboratory measurement of Biot's coefficient and pore pressure influence on poroelastic rock behaviour
Authors: Salemi Hossein , Iglauer Stefan , Rezagholilou Ali , Sarmadivaleh Mohammad
Published: May 2018

Understanding rock behaviour as a function of pore pressure and confining pressure is crucial for petroleum and geomechanical analysis. Indeed, deformation and local stress variations within hydrocarbon reservoirs and their surroundings occur due to pore pressure changes. Theoretically, pore pressure changes coupled with stress variations in hydrocarbon reservoirs are a function of the Biot’s coefficient, the elastic properties of the rock and the reservoir shape. Thus, in this study, the Biot’s coefficient was measured as a function of porosity, permeability, and volumetric strain for five Gosford sandstone samples. A triaxial loading system was used to measure rock volumetric strain while pore pressure and confining pressure were varied. The constant deformation technique was employed for these experiments; i.e. the variation of pore pressure created a volumetric strain, and the confining pressure required to restore the original volumetric strain was measured to calculate Biot’s coefficient. For the investigated samples, measured liquid permeabilities were in the range of 7–10 mD and Biot’s coefficients were 0.84–0.91. This is consistent with similar investigations by other researchers in which measured Biot’s coefficients were in the range of 0.65–0.90. This study thus illustrates how liquid permeability and the Biot’s coefficient decrease as a function of confining pressure.
Numerical investigation of dynamic and static properties of reservoir rocks
Authors: Abdolghafurian Mohsen , Joodi Bahman , Iglauer Stefan , Sarmadivaleh Mohammad
Published: May 2018

A 3D geomechanical model describes the elastic and mechanical properties of rock as well as underground stresses. The static elastic parameters of rock are required to build a model. However, the elastic properties resulting from wireline logs, dynamic experiments and seismic inversion are dynamic and must be converted. Implementing an accurate conversion is an essential part of any 3D geomechanical model. The static and dynamic moduli can be obtained by numerical and experimental methods. Laboratory experiments are known to provide more realistic outcomes, but this method has its constraints such as availability of samples, time constraints and limitation of experimental resources. Other approaches such as numerical modelling can be used supplementarily to compute the mechanical behaviour and elastic parameters of sandstone.
This paper provides a literature review on past numerical modelling efforts to examine dynamic and static parameters of rocks. This is followed by an explanation of grain and core scale model and research methodology. A discrete element model-based numerical simulation is then carried out using Itasca’s particle flow code in 3D. The digital plug scale specimen was calibrated to replicate the experimental findings and was then used to establish a broad sensitivity analysis on the important parameters. The simulation results were in good agreement with experiments on sandstone specimens. The present study forms a foundation for building a more reliable 3D geomechanical model and consequently better field development, reducing risks and lowering costs.
Using autonomous underwater gliders for geochemical exploration surveys
Authors: Russell-Cargill Louise M. , Craddock Bradley S. , Dinsdale Ross B. , Doran Jacqueline G. , Hunt Ben N. , Hollings Ben
Published: May 2018

Offshore exploration commonly uses geochemical sniffer technologies to detect hydrocarbon seepage. Advancements in sniffer technology have seen the development of submersible in-situ methane sensors. By integrating a Franatech laser methane sensor onto an autonomous underwater glider platform, geochemical survey durations can be increased, and associated exploration costs reduced. This paper analyses the effectiveness of methane detection using the integrated system and assesses its practical application to offshore hydrocarbon seep detection methods. Blue Ocean Monitoring surveyed the Yampi Shelf, an area with known oil and gas accumulations, and observed hydrocarbon seeps on the North West Shelf of Australia. Results from the survey showed a background dissolved methane concentration of 3 to 4 volumes per million (vpm). A distinct plume of methane between 30 to 84 vpm measured over 24 km2 was detected early in the survey. Three smaller plumes were also identified. Within a small plume, the highest concentration of methane was detected at 160 vpm. Methane above background levels was observed within 8 km of previously identified seeps; however, these seeps were unable to be pinpointed. Comparisons with data from previous surveys suggest similar oceanographic influences on the behaviour of the seeps, including tidal variations and the position of the thermocline. The results demonstrated that the integrated system may be used to effectively ground truth remote sensing interpretations and survey areas of interest over long durations, providing methane presence or absence results. To this effect, the integrated system may be implemented as a supporting technology for assessing the risks of further funding hydrocarbon detection surveys and focusing the area of interest before the deployment of vessel-based surveys.
Working together to reduce land transport safety risk in the CSG sector: can we ever do enough?
Authors: Zaunbrecher Michelle , King Jason , Yeong Brandon
Published: May 2018

Queensland coal seam gas (CSG) company, Arrow Energy (Arrow), has been implementing a strategy to improve land transport safety across its business. The present paper examines the strategy Arrow has taken to better understand and mitigate the risks associated with land transport. It looks at current transport risk, specific examples of existing good practice adopted by Arrow and future opportunities.
Land transport-related incidents have historically been the main cause of fatalities in this sector. To address this risk, Arrow has developed a seven-pillar strategy, comprising safe vehicles, safe drivers, safe speeds, safe roads, Arrow assurance program, industry collaboration and contracting strategy. The strategy applies equally to light and heavy vehicles and both professional and non-professional drivers. The unique approach focuses on changing driver behaviours, having a robust assurance and controls program, appointing a third party logistics (3PL) specialist transport provider and developing key relationships with contractors and internal stakeholders.
A continuous improvement approach to safety culture, positive driving behaviours, transport safety education, industry focus group participation (Safer Together), better vehicle technical standards, and having supplier relationships to drive outcomes will further ensure that land transport safety is a key priority across the business. Arrow believes this integrated approach yields the best results, but that it is an ongoing journey, as long as the industry has vehicles and is driving.
LNG as marine fuel – where technology meets logistics
Authors: Raitt Douglas
Published: May 2018

Following the establishment of the ‘LNG Marine Fuel Institute’ in Australia and research projects on alternative fuelling of ore carriers operating out of Australia, the focus of the marine and oil and gas industry is turning increasingly towards the adoption of liquefied natural gas (LNG) as a fuel oil. The development of LNG bunkering facilities on Australian soil followed. For LNG to be a viable option for deep sea shipping, it is all about infrastructure, technology and the human element. Thus far, LNG as fuel oil was only applied on LNG carriers; outside of that, LNG has mainly been used for short sea applications, which are tightly controlled from a technical and human element perspective mainly through shore-to-ship custody transfer. For deep sea shipping however, the infrastructure needs to be in place to allow regular refuelling options on various global shipping trade routes. It is anticipated that for deep sea shipping, the main mode of LNG fuelling will be through ship-to-ship custody transfers with required risk management. LNG bunkering technology standards and procedures are largely maturing, and efforts are underway to harmonise these standards globally to allow for flexible fuelling locations for ships traversing large distances. The remaining challenge will be to enhance a ship’s crew competence. The level of sophistication required of a crew for LNG bunkering is not something attained thus far in conventional oil bunkering and needs to be addressed. Continuous Competence Management Systems taking LNG cargo trading vessel experience into account, together with the ‘Standards of Training Certification and Watchkeeping for Seafarers’ requirements, is vital for the safe development of gas bunkering for deep sea shipping.
Australian exploration review 2017
Authors: Quinn Matthew , Hulbert Frances
Published: May 2018

Seventy acreage grants were awarded in Australia during 2017, with net acreage increasing in the Canning, Bonaparte and Perth basins. More broadly, the area under licence within Australia has been reducing since 2014 and this trend continued with a reduction of just over 100 000 km2.
Both 2D and 3D seismic acquisition levels decreased within Australia during 2017, on an absolute and on a percentage of worldwide basis.
An uptick in exploratory drilling occurred in 2017 with the highest levels since 2014 being reached. Exploratory drilling levels in Australia also increased, in percentage terms, compared with those globally.
Discovered volumes exhibited a sharp decrease with a total of 22 MMboe recoverable reserves added across 14 fields.
In 2018, exploration activity is expected to increase with key wells planned in the North Carnarvon and Roebuck basins.
A new window through which to look at safety culture surveys: a case study at Arrow Energy
Authors: Zaunbrecher Michelle , Mealiff Lisa
Published: May 2018

This paper provides a case study of applying a different approach to executing a safety culture survey. Arrow Energy (Arrow) completed the Safer Together Safety Culture Survey, with an excellent participation rate of 90% of total employees. There were indications from other Safer Together member companies that the typical response rate when the survey was emailed out was 30%. Arrow took the approach to undertake the survey ‘live’, where each team manager or supervisor facilitated the team session; this approach was fundamental to achieving a high response rate. A total of 33 separate team sessions were undertaken, which enabled team-specific results. The survey technique and application was provided by Safer Together, a not-for-profit industry group representing the Queensland coal seam gas industry. The intent is to have all Safer Together member companies undertake the survey so that industry-wide benchmarking can be carried out. The survey was completed by each team all together in one room, and the consolidated results for the team were available as soon as all participants had completed all survey questions, which took ~30 min. The benefits of the Safer Together tool, and live participation compared with online, included:
▪ Visible safety leadership demonstrated by the team manager/supervisor
▪ Team-specific results generated allowing meaningful immediate discussion and follow-up actions
▪ Three layers of organisation results available including everyone, supervisors and managers
▪ Visibility of ‘Most impactful behaviours’ that need improvement
▪ Generation of comments by the participating teams, visible during session as free text.
Overall it was a very meaningful exercise shining a light on key areas the employees believe need to be addressed including:
▪ Planning
▪ More effective learning from incidents
▪ Making the Arrow HSE Management System more accessible and available in relevant bite-sized pieces.
The consolidated results indicate that Arrow has a maturing safety culture.
The effective use of data analytics in an advanced compressor performance and degradation monitoring system
Authors: Lucas Radika , Jones Andy , Ford Wesley , Doyle Matt
Published: May 2018

Origin is the upstream operator and joint venture partner in Australia Pacific LNG. Origin’s integrated gas operations require reliable, sustainable delivery of gas to the downstream LNG facility on Curtis Island. This scale of operation requires establishing a ‘single source of truth’ regarding compressor condition and performance while achieving maximum and reliable compression capacities. Therefore, capability of monitoring performance of centrifugal compressors across the fleet is considered an essential component of production surveillance.
Xodus leveraged Origin’s OSIsoft PI AF (PI Historian Asset Framework) tool. This system was used to build a compressor performance and degradation monitoring tool to accurately identify early indications of degradation in a multi-stage centrifugal compression train. The tool utilises live data from the PI historian to calculate key performance indicators which define compressor and driver operation.
Dimensionless parameter analysis allows Origin to accurately quantify performance degradation regardless of variations in plant inlet conditions at each gas processing facility. Deviation from baseline performance in dimensionless parameters such as polytropic efficiency, work input number and polytropic head coefficient is used to quantify capacity losses, additional power consumption and increase in suction pressure.
The tool provided the ability to use performance indicators to confidently determine the mode and extent of compressor degradation and prevent accelerated fouling which can lead to premature bundle changes. Also, this information helps streamline and has led to a major step change for the decision-making process concerning maximum production from rotating equipment. Additionally, this allowed operations to be confident on the condition of the compressor bundle, continue operation with higher capacities during high demand periods and ensure compressor bundle changeout is optimised for availability and economic aspects.
Big oil in 2030: thriving (and driving) in a carbon constrained future
Authors: Cullinane Bernadette , McGill Steve
Published: May 2018

What if you knew that, 12 years from now, demand for your product would dramatically fall? What would you do?
The transportation sector is responsible for more than 60% of worldwide demand for petroleum products. However, several countries have recently introduced policies banning the internal combustion engine (ICE) and/or supporting electric vehicles (EVs), which could have a major impact on this demand. Norway, India, The Netherlands, Germany, China and the UK have all made such announcements. Furthermore, the increasing affordability and reliability of EVs combined with their excellent maintenance and automation capabilities have driven EVs to become among the best-selling luxury cars available today.
There is no way to be certain what the new normal of 2030 may bring for petroleum transportation fuels and the automotive industry. Forecasts range from a world dominated by EVs and substantially reduced demand for oil, to scenarios where the impact to petroleum demand is less than 10%. Whatever the future may bring, renewable energy paired with flexible and intelligent EVs is emerging as a threat, to which the petroleum and automotive industries are responding with a myriad of strategies.
Throughout history, even small disruptions in supply or demand have resulted in major impacts on industry profitability. Based on case studies from around the world and work with large petroleum companies in Australia, this paper discusses how leading companies are preparing for a post-ICE world and considers what steps petroleum and automotive industry executives should be taking today to ensure that they remain vibrant and viable in the new normal of 2030 and beyond.
Pluto 4D—Australia's first 4D over a gas field is an outstanding success
Authors: Tilbury Larry , Gerhardt Andre
Published: May 2018

The Pluto 4D seismic survey is Australia’s first 4D survey acquired over a gas field and has been an outstanding success despite the prior high technical risk of not being able to detect 4D differences above the background noise. At the time of the Pluto 4D monitor survey, the Pluto field had been on production for three years and nine months and produced approximately 1 Tcf of gas.
The first monitor survey was acquired by PGS between November 2015 and February 2016 using dual sources and 12 streamers of 7050 m (geostreamer configuration). Also of note was the use of steerable sources to assist with repeatability, and towing the streamers at 20 m to minimise noise. Data was processed by CGG to pre-stack depth migration (PreSDM), took 12 months to deliver and required significant interaction between Woodside geoscientists and CGG to ensure an excellent 4D product.
4D feasibility studies carried out before acquisition showed that saturation changes (related to water ingress) were expected to show strong 4D responses near the gas water contact (GWC) and would be interpretable if the monitor survey was run after approximately three to four years of production. If the monitor survey was delayed, it showed that the pressure response became too large, swamped the 4D differences and made interpretation difficult or impossible.
Strong ‘hardening’ responses on the 4D difference volumes are interpreted as water ingress into the field. Hardening responses are seen in all reservoir sequences in the Triassic from the TR27 to the TR32 units and range from strong (obvious) to weak (possible). Several examples are shown – the strongest response is seen in the large Triassic (TR27.3) valley within an essentially shale prone unit, which shows water ingress into the valley and moving upwards from the GWC towards the producing well.
The results/insights from the 4D data have provided excellent control points for the history matching of the Pluto Field.
Optimising energy sourcing and consumption in the oil and gas sector
Authors: Danilovich Dmitry
Published: May 2018

Oil and gas companies are fairly large users of electricity, and the rising cost of electricity has become a major issue for the sector. Oil and gas producers often develop their own gas-fired generation plants and consume their own gas as generation fuel. An increasing price of gas in the domestic market has resulted in a corresponding increase in the opportunity cost of utilising gas for power generation.
Declining costs of renewable energy and battery storage open opportunities for oil and gas companies to reduce the consumption of their own gas and source electricity at a lower cost, as well as achieve their sustainability objectives. Gas-fired generation is expected to continue to play a key role in ensuring the reliability of electricity supply. However, the percentage of renewable energy in the supply mix can be increased significantly without compromising the reliability.
This paper will focus on the opportunities that exist for oil and gas companies to reduce their overall energy supply costs through a differentiated approach considering renewable energy sources and batteries, competitive tendering of energy supply requirements, and attracting capital from independent power producers and institutional investors. The paper will draw on lessons learnt from other energy intensive businesses in Australia.