• UNDERSTAND
    Oil Reservoirs
  • UNDERSTAND
    Gas Maturity

Exploration

Die Stabilisotopenanalyse ist eine wichtige Technik in der Exploration von Rohstoffvorkommen. Das Verständnis der Herkunft von Öl und Gas in jedem neuen Reservoir ist eine wesentliche Voraussetzung für die Bestimmung der Machbarkeit und Wirtschaftlichkeit der Ausbeutung. Neben der Herstellung von Öl-Öl-Korrelationen für die Reservoir-Kartierung ist die Stabilisotopenanalyse ein zentraler Bestandteil jedes petrochemischen Servicelabors. Jenseits der Erforschung von konventionellen Rohstoffvorkommen, spielen in jüngster Zeit unkonventionelle Ressourcen wie Schiefergas und Coal Bed Methane (CBM) eine wachsende Rolle, für die ebenfalls Stabilisotopenanalytik benötigt wird. Die Bewertung der Kohlenstoff- und Wasserstoff-Fingerabdrücke ermöglicht den Erdölgeochemikern einen tiefergehenden Einblick in die kontinuierliche Weiterentwicklung dieser neuen Möglichkeiten.

Ölfraktionen & natürliche Gase

Die komponentenspezifische Stabilisotopenanalyse ermöglicht ein hochpräzises Isotopenprofiling von Ölreservoirs und damit eine Bewertung der Ölquelle. Die Kenntnis des Ursprungs des Öls und des Ausmaßes seiner Reife ermöglicht es, die Realisierbarkeit von Bohrstellen zu bestätigen. Kombiniert mit der Kohlenstoff- und Wasserstoff-Isotopenanalyse von Naturgasen kann unser außergewöhnliches GC-IRMS-System in Kombination mit unserer IonOS-Software diese zeitaufwendige Analyse schnell und effizient durchführen und auswerten.

Rohöl und Sedimente

Die komponentenspezifische Stabilisotopenanalyse von Ölfraktionen zusammen mit der Bulk-Stabilisotopenanalyse ist sehr komplementär zum Verständnis des Ölursprungs, aber erlaubt auch die Stickstoff-, Schwefel- und Sauerstoffisotopenanalyse von NSO-Fraktionen. Unsere Elementaranalysatoren bieten auch eine hervorragende Leistung für refraktäre Proben wie Sedimente, die einen besseren Einblick in die Geochemie des Ölreservoirs ermöglichen.

Carbonate und DICs

Durch die Analyse von sedimentären Carbonaten aus einem Becken ergibt sich ein besseres Verständnis der Diagenese, welches auch das Ölreservoir ausgesetzt war. Unser iso FLOW-System ist in der Lage, sedimentäre Carbonate, gelöstes anorganisches Carbonat sowie Bohrlochwasser mit hoher Präzision zu analysieren. Dieses flexible System kann auch gelöste Nitrate analysieren, um eine vollständige Hydrogeologie des Beckens zu ermöglichen.

Publikationen zur Exploration von Öl und Gas mit unseren Geräten

Unsere Kunden nutzen unsere Geräte für erstaunliche Forschungsprojekte im Bereich der Exploration von Öl- und Gaslagerstätten. Um Ihnen zu zeigen, wie unsere Kunden ihre Forschung durchführen und wie unsere IRMS-Geräte eingesetzt werden, haben wir eine Reihe von Fachpublikationen gesammelt, die unsere Produkte namentlich nennen. Die Informationen zu diesen Fachartikeln finden Sie unten. Durch Klicken auf den Link werden Sie zur Website des jeweiligen Zeitschriftenverlags weitergeleitet, wo Sie die Publikation herunterladen können.

Wenn Sie unsere Publikationsdatenbank durchsuchen möchten oder die Liste der Ergebnisse an sich selbst oder an Ihre Kollegen mailen möchten, dann werfen Sie einen Blick auf unsere gesamte Publikationsdatenbank.

43 Ergebnisse:

The effect of source and maturity on the stable isotopic compositions of individual hydrocarbons in sediments and crude oils from the Vulcan Sub-basin, Timor Sea, Northern Australia
Organic Geochemistry (2007)
Daniel Dawson, Kliti Grice, Robert Alexander, Dianne Edwards

Recent work has demonstrated the effect of maturation on the stable hydrogen isotopic compositions (δD) of individual sedimentary hydrocarbons (n-alkanes, pristane and phytane) in a series of marine source rocks from the Perth Basin (Western Australia). There was an enrichment in deuterium (D) in the hydrocarbons with increasing maturity, attributed to isotopic exchange associated with thermal maturation. An initial, large (≈115‰) biologically derived difference between the δD values of n-alkanes and isoprenoids gradually decreased as pristane and phytane became enriched in D, while the n-alkanes generally remained at constant isotopic composition. This work has now been extended to include a series of Late Jurassic sediments from the lower Vulcan Formation of the Vulcan Sub-basin (Timor Sea, Northern Australia), where the δD values of n-alkanes and isoprenoids show similar trends to those observed for the Perth Basin. The enrichment in D in isoprenoids correlates strongly with traditional maturity parameters and is shown to be related to the epimerisation of pristane and phytane. Pristane and phytane extracted from a post-mature Paqualin-1 sediment are significantly enriched in D relative to the n-alkanes, indicating that D enrichment persists at very high maturity, more so for regular isoprenoids than n-alkanes. This supports the notion that hydrogen (H/D) exchange causes the observed shift in δD values, and not free radical hydrogen transfer. A mechanism is proposed which can account for both H/D exchange and epimerisation of pristane and phytane in the sedimentary environment. Pristane is enriched in D relative to phytane throughout the Vulcan Sub-basin sequences, attributed to a lower relative algal input to the isoprenoids, and indicating that they exchange hydrogen at similar rates during maturation. Crude oils and condensates from the sub-basin were also analysed to evaluate their source and thermal maturity and the results complement previous molecular and stable carbon isotopic analysis. The δD values of n-alkanes and regular isoprenoids largely support the previous classification of Vulcan Sub–basin crude oils and condensates into two groups: Group A, having a marine source affinity and Group B, a terrigenous source affinity. Some oils and condensates are suggested to be a mixture of sources A and B, or A and other as yet unknown sources. Tenacious-1 crude oil (formerly a Group A oil) contains n-alkanes with more positive δD values than other Group A oils and is suggested to have been mixed with another source of more mature hydrocarbons. The Group A crude oils and condensates show an upward inflection in the n-alkane δD profile from n-C11 to n-C15, which is suggested to represent an addition of D-enriched lower molecular weight n-alkanes from a more mature wet gas/condensate to an initial oil charge. The small differences between the δD values of the n-alkanes and regular isoprenoids in the crude oils and condensates indicate that significant H/D exchange has taken place, implying that the samples were generated from mature source rocks.
Schlagworte: carbon , hydrogen , geol , oilg , gaschrom

Geochemical and isotopic approach to maturitysourcemixing estimations for natural gas and associated condensates in the Thrace Basin, NW Turkey.pdf
Applied Geochemistry (2005)
Kadir Gurgey, R. Paul Philp, Chris Clayton, Hasan Emiroglu, Muzaffer Siyako

The Tertiary Thrace Basin located in NW Turkey comprises 9 km of clastic-sedimentary column ranging in age from Early Eocene to Recent in age. Fifteen natural gas and 10 associated condensate samples collected from the 11 different gas fields along the NW–SE extending zone of the northern portion of the basin were evaluated on the basis of their chemical and individual C isotopic compositions. For the purpose of the study, the genesis of CH4, thermogenic C2+ gases, and associated condensates were evaluated separately. Methane appears to have 3 origins: Group-1 CH4 is bacteriogenic (Calculated d13CC1–C = ?61.48&; Silivri Field) and found in Oligocene reservoirs and mixed with the thermogenic Group-2 CH4. They probably formed in the Upper Oligo- cene coal and shales deposited in a marshy-swamp environment of fluvio-deltaic settings. Group-2 (d13CC1–C = ?35.80&; Hamitabat Field) and Group-3 (d13C1–C = ?49.10&; Deg ˘irmenko ¨y Field) methanes are thermogenic and share the same origin with the Group-2 and Group-3 C2+ gases. The Group-2 C2+ gases include 63% of the gas fields. They are produced from both Eocene (overwhelmingly) and Oligocene reservoirs. These gases were almost certainly generated from isotopi- cally heavy terrestrial kerogen (d13C=?21&) present in the Eocene deltaic Hamitabat shales. The Group-3 C2+ gases, produced from one field, were generated from isotopically light marine kerogen (d13C=?29&). Lower Oligoce ne Mezar- dere shales deposited in pro-deltaic settings are believed to be the source of these gases. The bulk and individual n-alkane isotopic relationships between the rock extracts, gases, condensates and oils from the basin differentiated two Groups of condensates, which can be genetically linked to the Group-2 and -3 thermogenic C2+ gases. However, it is crucial to note that condensates do not necessarily correlate to their associated gases. Maturity assessments on the Group-1 and -2 thermogenic gases based on their estimated initial kerogen isotope values (d13C=?21&; ?29&) and on the biomarkers present in the associated condensates reveal that all the hydrocarbons including gases, condensates and oils are the products of primary cracking at the early mature st age (Req = 0.55–0.81%). It is demonstrated that the open-system source conditions required for such an early-mature hydrocarbon expulsion exist and are supported by fault systems of the basin.

Stable hydrogen isotopic composition of hydrocarbons in torbanites (Late Carboniferous to Late Permian) deposited under various climatic conditions
Organic Geochemistry (2004)
Daniel Dawson, Kliti Grice, Sue X Wang, Robert Alexander, Jens Radke

We measured the stable hydrogen isotopic composition ( D) of selected aliphatic compounds in torbanites from Scotland and Australia, covering the Late Carboniferous to the Late Permian. The torbanites contain organic matter predominantly from a single algal source, Botryococcus braunii, and are of similar thermal maturity. The D values of n-alkanes in the extracts appear to reflect the depositional palaeoclimate of each torbanite, in response to the typical D values of meteoric waters. The D values of n-alkanes in torbanites deposited at high latitude under glacial conditions are depleted in deuterium by up to 70% relative to n-alkanes in a torbanite deposited at low latitude under a tropical climate regime. Torbanites deposited in mid-latitude regions under cool-temperature conditions contain n-alkanes with D values between those of n-alkanes in tropical and glacial sediments. A saw-toothed profile of D values obtained for the n-alkanes in the Australian torbanites is attributed to a dual-source system, perhaps a predominant B. braunii input with a second minor contribution from land plants. Pristane and phytane from two Australian torbanites are significantly depleted in deuterium relative to n-alkanes in the same samples and a significant difference between the D values of pristane and phytane is suggested to be caused by different sources for the two isoprenoids, or isotope effects associated with their derivation from a common phytol precursor. The offset between the D of values of n-alkanes and isoprenoids is similar to that found in modern biological samples, indicating that their indigenous D signatures may have been preserved for at least 260–280 million years.
Schlagworte: hydrogen , oilg , gaschrom