scholarly journals A systematic approach to unconventional play analysis: the oil and gas potential of the Kockatea Shale and Carynginia Formation, North Perth Basin, Western Australia

2015 ◽  
Vol 55 (1) ◽  
pp. 193 ◽  
Author(s):  
Gareth Cooper ◽  
Roger Xiang ◽  
Nick Agnew ◽  
Phil Ward ◽  
Mark Fabian ◽  
...  

Key formations throughout the North Perth Basin have been mapped from 3D and 2D seismic data to define depth grid inputs to a 3D basin model calibrated with temperature and maturity data from 45 wells, plus an additional 27 pseudo well models. The Permian Carynginia Formation and Early Triassic Hovea Member of the Kockatea Shale have been defined in this model as unconventional shale reservoir targets. Basin-wide pyrolysis data have been used to construct kinetics curves for both the Carynginia Formation and Kockatea Shale, which define Type D/E and mixed B, and D/E kerogen types, respectively. When combined with thermal history inputs, these source rocks expel and retain significant volumes of hydrocarbons, of which the free hydrocarbons in the retained components reach 22 BCF/km2 for the Carynginia Formation gas and 8 MMBBLS/km2 and 21 BCF/km2 for the Hovea Member liquids and gas, respectively. The defined kinetics relationships allow the estimation of kerogen-specific oil and gas windows, which have been applied across the study area to map unconventional play fairways for both formations, and to calculate the initial total organic carbon (TOC) and hydrogen index (HI) for each unit prior to significant maturation. This study employs a mass balance approach through basin modelling as a means of estimating likely retained hydrocarbon volumes in key unconventional reservoirs in the basin. Sonic and density data from 28 wells in the basin have been used to calculate theoretical porosity to determine likely areas of overpressure. When combined with observed connection gas peaks and modelled maturity, there is a reasonable correlation suggesting that the basin exhibits modest overpressure of 2–6 MPa associated with the main gas window at 1.2 Ro% and this observation is applied to the play fairway mapping process. Play fairways are further constrained through geomechanical and stress considerations from mechanical earth models (MEMs) built from log and image data for wells in the basin. These data define an overall strike-slip stress regime with SHmax consistently oriented east to west with the exception of local perturbations. Dynamic rock strength calculated from the same MEM process shows target zones in the Kockatea Shale and Carynginia Formation ranging from ~60–130 MPa unconfined compressive strength (UCS), calibrated against available static data. The net thickness of rock with a UCS >75 MPa is mapped and overlain on retained in place hydrocarbon maps to restrict the area of likely economically extractable resource. While unconventional play cut-offs in the Perth Basin are notably lower than those commonly used in shale gas plays in the US, successful stimulation of Perth Basin rocks has been demonstrated by substantial flows from wells such as Arrowsmith–2. This study outlines a new workflow for mapping unconventional resources and suggests that Australian rocks are unique in both depositional environment and mechanical properties such that unconventional assessment using US play cut-offs may be misleading.

GeoArabia ◽  
2009 ◽  
Vol 14 (3) ◽  
pp. 199-228 ◽  
Author(s):  
Mohammad Faqira ◽  
Martin Rademakers ◽  
AbdulKader M. Afifi

ABSTRACT During the past decade, considerable improvements in the seismic imaging of the deeper Paleozoic section, along with data from new well penetrations, have significantly improved our understanding of the mid-Carboniferous deformational event. Because it occurred at the same time as the Hercynian Orogeny in Europe, North Africa and North America it has been commonly referred to by the same name in the Middle East. This was the main tectonic event during the late Paleozoic, which initiated or reactivated many of the N-trending block uplifts that underlie the major hydrocarbon accumulations in eastern Arabia. The nature of the Hercynian deformation away from these structural features was poorly understood due to inadequate seismic imaging and insufficient well control, along with the tectonic overprint of subsequent deformation events. Three Hercynian NE-trending arches are recognized in the Arabian Plate (1) the Levant Arch, which extended from Egypt to Turkey along the coast of the Mediterranean Sea, (2) the Al-Batin Arch, which extended from the Arabian Shield through Kuwait to Iran, and (3) the Oman-Hadhramaut Arch, which extended along the southeast coast of Oman and Yemen. These arches were initiated during the mid-Carboniferous Hercynian Orogeny, and persisted until they were covered unconformably by the Khuff Formation during the Late Permian. Two Hercynian basins separate these arches: the Nafud-Ma’aniya Basin in the north and Faydah-Jafurah Basin in the south. The pre-Hercynian Paleozoic section was extensively eroded over the arches, resulting in a major angular unconformity, but generally preserved within the basins. Our interpretation suggests that most of the Arabian Shield, except the western highlands along the Red Sea, is the exhumed part of the Al-Batin Arch. The Hercynian structural fabric of regional arches and basins continue in northern Africa, and in general appear to be oriented orthogonal to the old margin of the Gondwana continent. The Hercynian structure of arches and basins was partly obliterated by subsequent Mesozoic and Cenozoic tectonic events. In eastern Saudi Arabia, Qatar, and Kuwait, regional extension during the Triassic formed N-trending horsts and graben that cut across the NE-trending Hercynian mega-structures, which locally inverted them. Subsequent reactivation during the Cretaceous and Neogene resulted in additional growth of the N-trending structures. The Hercynian Arches had major impact on the Paleozoic hydrocarbon accumulations. The Silurian source rocks are generally preserved in the basins and eroded over the arches, which generally confined Silurian-sourced hydrocarbons either within the basins or along their flanks. Furthermore, the relict Hercynian paleo-topography generally confined the post-Hercynian continental clastics of the Unayzah Formation and equivalents to the Hercynian basins. These clastics contain the main Paleozoic oil and gas reservoirs, particularly along the basin margins where they overlie the sub-crop of the Silurian section with angular unconformity, thus juxtaposing reservoir and source rock.


Minerals ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 510 ◽  
Author(s):  
Valery Vernikovsky ◽  
Georgy Shemin ◽  
Evgeny Deev ◽  
Dmitry Metelkin ◽  
Nikolay Matushkin ◽  
...  

The geodynamic development of the north–western (Arctic) margin of the Siberian craton is comprehensively analyzed for the first time based on our database as well as on the analysis of published material, from Precambrian-Paleozoic and Mesozoic folded structures to the formation of the Mesozoic-Cenozoic Yenisei-Khatanga sedimentary basin. We identify the main stages of the region’s tectonic evolution related to collision and accretion processes, mainly subduction and rifting. It is demonstrated that the prototype of the Yenisei-Khatanga basin was a wide late Paleozoic foreland basin that extended from Southern Taimyr to the Tunguska syneclise and deepened towards Taimyr. The formation of the Yenisei-Khatanga basin, as well as of the West-Siberian basin, was due to continental rifting in the Permian-Triassic. The study describes the main oil and gas generating deposits of the basin, which are mainly Jurassic and Lower Cretaceous mudstones. It is shown that the Lower Cretaceous deposits contain 90% of known hydrocarbon reserves. These are mostly stacked reservoirs with gas, gas condensate and condensate with rims. The study also presents data on oil and gas reservoirs, plays and seals in the Triassic, Jurassic and Cretaceous complexes.


2018 ◽  
Vol 36 (5) ◽  
pp. 1229-1244
Author(s):  
Xiao-Rong Qu ◽  
Yan-Ming Zhu ◽  
Wu Li ◽  
Xin Tang ◽  
Han Zhang

The Huanghua Depression is located in the north-centre of Bohai Bay Basin, which is a rift basin developed in the Mesozoic over the basement of the Huabei Platform, China. Permo-Carboniferous source rocks were formed in the Huanghua Depression, which has experienced multiple complicated tectonic alterations with inhomogeneous uplift, deformation, buried depth and magma effect. As a result, the hydrocarbon generation evolution of Permo-Carboniferous source rocks was characterized by discontinuity and grading. On the basis of a detailed study on tectonic-burial history, the paper worked on the burial history, heating history and hydrocarbon generation history of Permo-Carboniferous source rocks in the Huanghua Depression combined with apatite fission track testing and fluid inclusion analyses using the EASY% Ro numerical simulation. The results revealed that their maturity evolved in stages with multiple hydrocarbon generations. In this paper, we clarified the tectonic episode, the strength of hydrocarbon generation and the time–spatial distribution of hydrocarbon regeneration. Finally, an important conclusion was made that the hydrocarbon regeneration of Permo-Carboniferous source rocks occurred in the Late Cenozoic and the subordinate depressions were brought forward as advantage zones for the depth exploration of Permo-Carboniferous oil and gas in the middle-northern part of the Huanghua Depression, Bohai Bay Basin, China.


2008 ◽  
Vol 48 (1) ◽  
pp. 53 ◽  
Author(s):  
Chris Uruski ◽  
Callum Kennedy ◽  
Rupert Sutherland ◽  
Vaughan Stagpoole ◽  
Stuart Henrys

The East Coast of North Island, New Zealand, is the site of subduction of the Pacific below the Australian plate, and, consequently, much of the basin is highly deformed. An exception is the Raukumara Sub-basin, which forms the northern end of the East Coast Basin and is relatively undeformed. It occupies a marine plain that extends to the north-northeast from the northern coast of the Raukumara Peninsula, reaching water depths of about 3,000 m, although much of the sub-basin lies within the 2,000 m isobath. The sub-basin is about 100 km across and has a roughly triangular plan, bounded by an east-west fault system in the south. It extends about 300 km to the northeast and is bounded to the east by the East Cape subduction ridge and to the west by the volcanic Kermadec Ridge. The northern seismic lines reveal a thickness of around 8 km increasing to 12–13 km in the south. Its stratigraphy consists of a fairly uniformly bedded basal section and an upper, more variable unit separated by a wedge of chaotically bedded material. In the absence of direct evidence from wells and samples, analogies are drawn with onshore geology, where older marine Cretaceous and Paleogene units are separated from a Neogene succession by an allochthonous series of thrust slices emplaced around the time of initiation of the modern plate boundary. The Raukumara Sub-basin is not easily classified. Its location is apparently that of a fore-arc basin along an ocean-to-ocean collision zone, although its sedimentary fill must have been derived chiefly from erosion of the New Zealand land mass. Its relative lack of deformation introduces questions about basin formation and petroleum potential. Although no commercial discoveries have been made in the East Coast Basin, known source rocks are of marine origin and are commonly oil prone, so there is good potential for oil as well as gas in the basin. New seismic data confirm the extent of the sub-basin and its considerable sedimentary thickness. The presence of potential trapping structures and direct hydrocarbon indicators suggest that the Raukumara Sub-basin may contain large volumes of oil and gas.


2018 ◽  
Vol 58 (2) ◽  
pp. 871 ◽  
Author(s):  
Melissa Thompson ◽  
Fred Wehr ◽  
Jack Woodward ◽  
Jon Minken ◽  
Gino D'Orazio ◽  
...  

Commencing in 2014, Quadrant Energy and partners have undertaken an active exploration program in the Bedout Sub-basin with a 100% success rate, discovering four hydrocarbon accumulations with four wells. The primary exploration target in the basin, the Middle Triassic Lower Keraudren Formation, encompasses the reservoirs, source rocks and seals that have trapped hydrocarbons in a self-contained petroleum system. This petroleum system is older than the traditional plays on the North-West Shelf and before recent activity was very poorly understood and easily overlooked. Key reservoirs occur at burial depths of 3500–5500 m, deeper than many of the traditional plays on the North-West Shelf and exhibit variable reservoir quality. Oil and gas-condensate discovered in the first two wells, Phoenix South-1 and Roc-1, raised key questions on the preservation of effective porosity and productivity sufficient to support a commercial development. With the acquisition and detailed interpretation of 119 m of core over the Caley Member reservoir in Roc-2 and a successful drill stem test that was surface equipment constrained to 55 MMscf/d, the productive potential of this reservoir interval has been confirmed. The results of the exploration program to date, combined with acquisition of new 3D/2D seismic data, have enabled a deeper understanding of the potential of the Bedout Sub-basin. A detailed basin model has been developed and a large suite of prospects and leads are recognised across a family of hydrocarbon plays. Two key wells currently scheduled for 2018 (Phoenix South-3 and Dorado-1) will provide critical information about the scale of this opportunity.


2021 ◽  
Vol 43 (1) ◽  
pp. 93-128
Author(s):  
V.I. Isaev ◽  
A.O. Aleeva ◽  
G.A. Lobova ◽  
O.S. Isaeva ◽  
V.I. Starostenko

Commercial significance of the majority of Western Siberian oil fields is concerned with the Senomanian, Neocomian and, above all, Upper Jurassic horizons. For now, oil fields are at the late development stage and resource potential of the Jurassic horizon is strongly expired. Commercial potential of the pre-Jurassic (Paleozoic) rocks has been brought out throughout all territory of oil and gas province. Extensive work on estimation of the pre-Jurassic rocks oil and gas potential is performed in southeast, in the territory of Tomsk Region, within which 13 hydrocarbon deposits have been discovered in the Paleozoic. Original hypothesis of anomalousness of geophysical and petrophysical characteristics of the Jurassic layers — uniqueness of «indication» the Paleozoic deposits in geophysical parameters of overlaying Mezozoic-Cenozoic section was stated as a foundation of new prospecting criterion for the Paleozoic deposits. The Paleozoic formations are accepted as a complex with its own oil generating potential, which results in upward migration of hydrocarbon fluids. Additionally, downward direction of vertical interstratal hydrocarbon migration from the Jurassic source rocks into the pre-Jurassic complex is brought out. It was accepted as a conception that as in case of upward, so in case of downward fluid migration, processes of superposed epigenesis perform and lead to secondary epigenetic transformations of rocks of transit Jurassic layers, which result in their anomalous geophysical and petrophysical characteristics. This paper analyzes and compares geophysical and petrophysical characteristics of the Jurassic layers of different field types in Tomsk Region: without oil and gas potential in pre-Jurassic section, with commercial inflows from the pre-Jurassic complex and unknown type. Results of exploration electrical resistivity and carbonatization in the Jurassic layers of 200 wells and also spontaneous potential variation, electrical resistivity and natural radioactivity in Bazhenov suite confirm anomalousness of geophysical and petrophysical parameters of Jurassic rocks in case of pre-Jurassic deposits. This paper determines 6 geophysical and petrophysical characteristics of the Jurassic layers as predictive indicators for oil and gas potential estimation in pre-Jurassic section. Efficiency analysis of using predictive indicators for bringing out fields with and without deposits in the pre-Jurassic complex was performed for different prospecting cases in the research territory with account taken of possible complexing of indicators, their rank and actual availability. This paper states preference of indicators complexing. Application of a new prospecting criterion will improve efficiency of searching in new prioritized stratigraphic horizon — the Paleozoic, which contains unconventional oil.


Author(s):  
К.В. Емельянов ◽  
П.С. Гребнев ◽  
В.Р. Яппаров ◽  
А.М-Э. Абумуслимов

В статье рассмотрены перспективы изучения Доюрского комплекса на Севере Западной Сибири, а также результаты испытаний ДЮК в регионе деятельности «Мегионнефтегаза». The article considers the prospects of studying the pre-jurrasic complex in the North of Western Siberia, as well as the results of the tests of DUK in the region of activity called the «Me- gionneftegaz».


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