Exploring and appraising the oldest gas accumulations in Australia

2013 ◽  
Vol 53 (2) ◽  
pp. 470
Author(s):  
Ray Johnson ◽  
Josh Bluett ◽  
Luke Titus ◽  
David Warner
Keyword(s):  
Shale Gas ◽  
Oil And Gas ◽  
Source Rocks ◽  
Petroleum Exploration ◽  
Drill Cuttings ◽  
Exciting Potential ◽  
Air Drilling ◽  
Unconventional Oil And Gas ◽  
Shale Reservoirs ◽  
Middle Proterozoic

In early 2012, Armour Energy set out to evaluate the Middle-Proterozoic formations in the Batten Trough, McArthur Basin, NT. The Batten Trough holds a massive potential shale gas play in the Barney Creek Formation, and recent gas discoveries in the overlying Lynott and Reward formations, and underlying Coxco Dolomite. The Lawn Supersequence, Isa Superbasin, Queensland, is another Middle-Proterozoic shale gas play with overlying and underlying conventional and unconventional oil and gas accumulations. Exploratory drilling between the 1980s and 1990s showed gas and oil shows across the Isa Superbasin, Queensland. Egilabria–1, ATP 1087, exhibited 390 gas units while drilling with mud, highlighting the prospectivity of this area. In both areas, the Barney Creek and Lawn Hill formations are proven source rocks and are significantly older than North American shale reservoirs. In 2012, an innovative exploration program was designed and implemented in the NT to maximise the capture of drilling data while integrating data from previous mineral and petroleum exploration programs. This resulted in gas discoveries at Cow Lagoon–1, EP 176, and in the Glyde–1 and Glyde–1 ST lateral wells in the Glyde Sub-basin in EP171. In both cases, air drilling was instrumental in aiding drilling penetration rates, gauging gas influx while drilling, and allowing geologists to rapidly obtain and assess drill cuttings. The authors first discuss the details of the formation evaluation methods used in Armour’s successful 2012 program and how these methods are extended to Armour’s 2013 program in the Isa Superbasin, northern Queensland. Next, an outline of the strategy for further delineation of the Batten Trough is provided. Finally, the authors summarise the exciting potential of the Lawn Supersequence in Queensland.

An emerging shale gas play in the Northern Territory

2012 ◽  
Vol 52 (2) ◽  
pp. 672
Author(s):  
Ray Johnson ◽  
Geoff Hokin ◽  
David Warner ◽  
Rod Dawney ◽  
Mike Dix ◽  
...  
Keyword(s):  
Shale Gas ◽  
Oil And Gas ◽  
Mineral Exploration ◽  
Northern Territory ◽  
Gas Flows ◽  
Oil And Gas Resources ◽  
Unconventional Oil And Gas ◽  
Shale Reservoirs ◽  
Drill Holes ◽  
Live Oil

As attention to unconventional oil and gas resources increases, historical oil and gas flows in shale reservoirs across the world are being given renewed attention. Such is the case of the shaly and carbonate deposits of the McArthur and Nathan groups in the Northern Territory. The Batten Trough is a Proterozoic depocenter with potential for a shale gas play in the Barney Creek Shale and potential for conventional gas accumulations in the underlying Coxco Dolomite. This Barney Creek Shale gas play is evidenced by a number of mineral exploration drill holes that encountered live oil and gas shows within the McArthur Group. The most prominent was a mineral exploration hole drilled at the Glyde River prospect by Amoco in 1979. This well reportedly flowed gas and condensates at 140 psi for six months before it was sealed at the surface, which certainly shows permeability values greater than micro-darcies reported for many North American shale plays; thus, an exploration program of this prospective area has been planned by Armour Energy in EP 171 on several targets adjacent to the Emu Fault Zone near both Glyde and Caranbirini, along with other anticline related targets adjacent to the Abner Range. This extended abstract details how the targets were identified, the plan for data acquisition (e.g. seismic, drilling, logging and testing), and the proposed completion strategy to test this highly prospective target.

Development Prospect of Unconventional Oil and Gas Resources

2013 ◽  
Vol 421 ◽  
pp. 917-921
Author(s):  
De Xun Liu ◽  
Shu Heng Tang ◽  
Hong Yan Wang ◽  
Qun Zhao
Keyword(s):  
Shale Gas ◽  
Global Economy ◽  
Large Scale ◽  
Oil And Gas ◽  
Small Scale ◽  
Tight Oil ◽  
Environmental Capacity ◽  
Unconventional Oil ◽  
Oil And Gas Resources ◽  
Unconventional Oil And Gas

Affected by the constant development of global economy and the imbalance in distribution of conventional oil and gas, oil and gas resources can no longer meet the demand in many countries. Development of unconventional oil and gas has begun to take shape. Shale gas and tight oil become the focus of global attention. Unconventional oil and gas resources are relatively abundant in China. Preliminary results have been achieved in the development of shale gas. Tight oil has been developed in small scale, and the main technologies are maturing gradually. Yet we face many challenges. Low in work degree, resources remain uncertain. Environmental capacity is limited, and large scale batch jobs will confront with difficulties.

NEW DIRECTIONS IN GEOSCIENCE TECHNOLOGY FOR PETROLEUM EXPLORATION IN THE NEW AGE

1994 ◽  
Vol 34 (1) ◽  
pp. 189
Author(s):  
T. L. Burnett
Keyword(s):  
Oil And Gas ◽  
Regional Scale ◽  
Seismic Energy ◽  
Oil And Gas Industry ◽  
Transport Processes ◽  
Source Rocks ◽  
P Wave ◽  
Petroleum Exploration ◽  
S Wave ◽  
Seismic Acquisition

As economics of the oil and gas industry become more restrictive, the need for new means of improving exploration risks and reducing expenses is becoming more acute. Partnerships between industry and academia are making significant improvements in four general areas: Seismic acquisition, reservoir characterisation, quantitative structural modelling, and geochemical inversion.In marine seismic acquisition the vertical cable concept utilises hydrophones suspended at fixed locations vertically within the water column by buoys. There are numerous advantages of vertical cable technology over conventional 3-D seismic acquisition. In a related methodology, 'Borehole Seismic', seismic energy is passed between wells and valuable information on reservoir geometry, porosity, lithology, and oil saturation is extracted from the P-wave and S-wave data.In association with seismic methods of determining the external geometry and the internal properties of a reservoir, 3-dimensional sedimentation-simulation models, based on physical, hydrologic, erosional and transport processes, are being utilised for stratigraphic analysis. In addition, powerful, 1-D, coupled reaction-transport models are being used to simulate diagenesis processes in reservoir rocks.At the regional scale, the bridging of quantitative structural concepts with seismic interpretation has led to breakthroughs in structural analysis, particularly in complex terrains. Such analyses are becoming more accurate and cost effective when tied to highly advanced, remote-sensing, multi-spectral data acquisition and image processing technology. Emerging technology in petroleum geochemistry, enables geoscientists to infer the character, age, maturity, identity and location of source rocks from crude oil characteristics ('Geochemical Inversion') and to better estimate hydrocarbon-supply volumetrics. This can be invaluable in understanding petroleum systems and in reducing exploration risks and associated expenses.

PETROLEUM SYSTEMS IN TASMANIA'S FRONTIER ONSHORE BASINS

2000 ◽  
Vol 40 (1) ◽  
pp. 26
Author(s):  
M.R. Bendall C.F. Burrett ◽  
H.J. Askin
Keyword(s):  
Oil And Gas ◽  
Source Rocks ◽  
Petroleum Exploration ◽  
Late Triassic ◽  
Upper Permian ◽  
Lower Permian ◽  
Peak Oil ◽  
Petroleum Systems ◽  
Upper Proterozoic ◽  
Oil Seep

Sedimentary successions belonging to three petroleum su persy stems can be recognised in and below the Late Carboniferous to Late Triassic onshore Tasmania Basin. These are the Centralian, Larapintine and Gondwanan. The oldest (Centralian) is poorly known and contains possible mature source rocks in Upper Proterozoic dolomites. The Larapintine 2 system is represented by rocks of the Devonian fold and thrust belt beneath the Tasmania Basin. Potential source rocks are micrites and shales within the 1.8 km-thick tropical Ordovician Gordon Group carbonates. Conodont CAI plots show that the Gordon Group lies in the oil and gas windows over most of central Tasmania and probably under much of the Tasmania Basin. Potential reservoirs are the upper reefal parts of the Gordon Group, paleokarsted surfaces within the Gordon Group and the overlying sandstones of the Siluro-Devonian Tiger Range and Eldon Groups. Seal rocks include shales within the Siluro-Devonian and Upper Carboniferous-Permian tillites and shales.The Gondwanan supersystem is the most promising supersystem for petroleum exploration within the onshore Tasmania Basin. It is divided into two petroleum systems— the Early Permian Gondwanan 1 system, and the Late Permian to Triassic Gondwanan 2 system. Excellent source rocks occur in the marine Tasmanite Oil Shale and other sections within the Lower Permian Woody Island and Quamby Formations of the Gondwanan 1 system and within coals and freshwater oil shales of the Gondwanan 2 system. These sources are within the oil and gas windows across most of the basin and probably reached peak oil generation at about 100 Ma. An oil seep, sourced from a Tasmanites-rich, anoxic shale, is found within Jurassic dolerite 40 km WSW of Hobart. Potential Gondwanan 1 reservoirs are the glaciofluvial Faulkner Group sandstones and sandstones and limestones within the overlying parts of the glaciomarine Permian sequence. The Upper Permian Ferntree Mudstone Formation provides an effective regional seal. Potential Gondwanan 2 reservoirs are the sandstones of the Upper Permian to Norian Upper Parmeener Supergroup. Traps consisting of domes, anticlines and faults were formed probably during the Early Cretaceous. Preliminary interpretation of a short AGSO seismic profile in the Tasmania Basin shows that, contrary to earlier belief, structures can be mapped beneath extensive and thick (300 m) sills of Jurassic dolerite. In addition, the total section of Gondwana to Upper Proterozoic to Triassic sediments appears to be in excess of 8,500 m. These recent studies, analysis of the oil seep and drilling results show that the Tasmanian source rocks have generated both oil and gas. The Tasmania Basin is considered prospective for both petroleum and helium and is comparable in size and stratigraphy to other glaciomarine-terrestrial Gondwanan basins such as the South Oman and Cooper Basins.

Two effective methods for calculating water saturations in shale-gas reservoirs

Geophysics ◽  
2017 ◽  
Vol 82 (3) ◽  
pp. D187-D197 ◽  
Author(s):  
Jingling Xu ◽  
Lei Xu ◽  
Yuxing Qin
Keyword(s):  
Shale Gas ◽  
Water Saturation ◽  
Critical Issue ◽  
Petroleum Exploration ◽  
Gas Content ◽  
Gas Reservoirs ◽  
Gas Saturation ◽  
Shale Gas Reservoirs ◽  
Shale Reservoirs ◽  
Southeastern Sichuan Basin

Water saturation is one of the most important parameters in petroleum exploration and development. However, its calculation has been limited by the insufficient logging data required by a new technique that further influences the calculation of the free gas content. The accuracy of water saturation estimates is also a critical issue because it controls whether or not we can obtain an accurate gas saturation estimate. Organic matter plays an important role in shale-gas reservoirs, and the total organic carbon (TOC) indirectly controls the gas content and gas saturation. Hence, water saturation is influenced by inorganic and organic components. After analyzing the relationship among TOC, core water saturation, and conventional gas saturation, considering the influence of TOC on gas saturation in organic-rich shale reservoirs, we developed two new methods to improve the accuracy of water saturation estimates: the revised water saturation-TOC method and the water saturation separation method, in which Archie water saturation, modified total shale water saturation, and TOC are integrated. According to case studies of Longmaxi-Wufeng shale, southeastern Sichuan Basin, China, the water saturation results from these two methods in shale reservoirs with different lithologies are consistent with those from core analysis. We concluded that these two methods can be evaluated quickly and they effectively evaluate the water saturation of shale reservoirs.

Geology, resource potentials, and properties of emerging and potential China shale gas and shale oil plays

2015 ◽  
Vol 3 (2) ◽  
pp. SJ1-SJ13 ◽  
Author(s):  
Shu Jiang ◽  
Jinchuan Zhang ◽  
Zhiqiang Jiang ◽  
Zhengyu Xu ◽  
Dongsheng Cai ◽  
...  
Keyword(s):  
South China ◽  
Shale Gas ◽  
Oil And Gas ◽  
Northwest China ◽  
Shale Oil ◽  
Yangtze Platform ◽  
Lower Paleozoic ◽  
High Maturity ◽  
Shale Reservoirs ◽  
Gas Potential

This paper describes the geology of organic-rich shales in China, their resource potentials, and properties of emerging and potential China shale gas and shale oil plays. Marine, lacustrine, and coastal swamp transitional shales were estimated to have the largest technically recoverable shale gas resource (25.08 trillion cubic meters or 886 trillion cubic feet) and 25 to 50 billion barrels of technically recoverable shale oil resource. The Precambrian Sinian Doushantuo Formation to Silurian Longmaxi black marine shales mainly accumulated in the intrashelf low to slope environments in the Yangtze Platform in South China and in the Tarim Platform in northwest China. The marine shales in the Yangtze Platform have high maturity (Ro of 1.3%–5%), high total organic carbon (mainly [Formula: see text]), high brittle-mineral content, and have been identified as emerging shale gas plays. The Lower Paleozoic marine shales in the Upper Yangtze area have the largest shale gas potential and currently top the list as exploration targets. The Carboniferous to Permian shales associated with coal and sandstones were mainly formed in transitional depositional settings in north China, northwest China, and the Yangtze Platform in south China. These transitional shales are generally rich in clay with a medium level of shale gas potential. The Middle Permian to Cenozoic organic-rich lacustrine shales interbedded with thin sandstone and carbonate beds are sporadically distributed in rifted basins across China. Their main potentials are as hybrid plays (tight and shale oil). China shales are heterogeneous across time and space, and high-quality shale reservoirs are usually positioned within transgressive systems tract to early highstand systems tract intervals that were deposited in an anoxic depositional setting. For China’s shale plays, tectonic movements have affected and disrupted the early oil and gas accumulation, making tectonically stable areas more favorable prospects for the exploration and development of shale plays.

Using the pair-correlation function as a tool to identify the location for shale gas/oil reservoir based on well-log data

Geophysics ◽  
2016 ◽  
Vol 81 (2) ◽  
pp. D91-D109 ◽  
Author(s):  
Aslan Gassiyev ◽  
Feifei Huang ◽  
Evgeni M. Chesnokov
Keyword(s):  
Correlation Function ◽  
Shale Gas ◽  
Pair Correlation Function ◽  
Oil And Gas ◽  
Pair Correlation ◽  
Potential Applications ◽  
Shale Reservoirs ◽  
Highly Correlated ◽  
Unconventional Resource ◽  
Production Target

Shale reservoirs, as an unconventional resource, are becoming an increasingly important exploration, development, and production target in the oil industry. One of the main problems in these reservoirs is the answer to the question of where to drill (the “sweet-spot” location). In other words, one desires to detect the productive portion of the reservoir. This involves finding data criteria that can be used to distinguish between productive and nonproductive portions of a reservoir. As one of these criteria, we have investigated the amplitude of the pair correlation function (PCF) for sonic data, which reflected the contrast in elastic properties between inclusions (oil and gas) and background media. Based on various data from eight different wells, we calculated the amplitudes of the PCF. The obtained results showed that the productive layers were highly correlated, and nonproductive layers had low values of the PCF amplitude. Hence, the results of these calculations showed the potential applications of the PCF of seismic data and its amplitude in the detection of the productive layers. Therefore, we could use this PCF and its amplitude as a tool to predict the location of shale gas or oil reservoirs and to estimate the thickness of productive zones in the well.

scholarly journals Study on the Upper Paleozoic Source Rocks in Southwestern Henan, China

2021 ◽  
Vol 257 ◽  
pp. 03010
Author(s):  
Fengyu Sun ◽  
Gaoshe Cao ◽  
Zhou Xing
Keyword(s):  
Carbonate Rock ◽  
Oil And Gas ◽  
Lower Layer ◽  
Sedimentary Environment ◽  
Source Rocks ◽  
Oil And Gas Exploration ◽  
Potential Source ◽  
Upper Paleozoic ◽  
Unconventional Oil And Gas ◽  
Coal Rock

The Upper Paleozoic strata in Southwestern Henan have good prospects for unconventional oil and gas exploration. This paper takes the Upper Paleozoic source rocks in the Yuzhou area and the Pingdingshan area in Southwestern Henan as the research object, and tests 107 samples from the Upper Paleozoic coal rock, mudstone and carbonate rock. Combined with the sedimentary environment background, the Upper Paleozoic source rocks in Southwestern Henan are comprehensively evaluated. The results show that the Upper Paleozoic source rocks in Southwestern Henan, including coal rocks, mudstone and carbonate rocks, can be used as potential source rocks. Vertically, the source rocks are continuously distributed in the lower layer below the sandstone of Shanxi Formation. The Dazhan sandstone is only locally developed; the distribution of Upper Paleozoic source rocks in Southwestern Henan is mainly related to the Late Paleozoic transgression.

scholarly journals PROSPECTS OF UNCONVENTIONAL OIL AND GAS POTENTIAL OF THE SOUTHERN ZONE OF DNIEPER-DONETSK DEPRESSION

2020 ◽  
pp. 53-60
Author(s):  
V. Mykhailov ◽  
O. Karpenko
Keyword(s):  
Shale Gas ◽  
Thermal Processing ◽  
Oil And Gas ◽  
Thermal Maturity ◽  
Gas Generation ◽  
Southern Zone ◽  
Unconventional Oil ◽  
Unconventional Oil And Gas ◽  
Gas Potential ◽  
Tight Rocks

Based on the analysis of numerous works and publications, the studying of core samples, the interpretation of well-logging data, the studying of geochemical features and the degree of thermal processing of oil and gas strata, the prospects for unconventional oil and gas potential of geological structures and formations of the Zachepiliv-Liventsivsk shaft of the southern zone of the Dnieper-Donetsk Depression (DDD) are determined, which corresponds to the Rudenkivsko-Proletarsky oil and gas region. Based on the studies, it is proved that the thermal maturity of the rocks of the southern zone within the Zachepiliv-Liventsivsk shaft is extremely uneven both in area and in section and only in certain areas (Bagatoyska-25, Kernosivska-2 wells), or at depths greater than 1500 m (well Zachepilsvska-100) or even 2700 m (well Ulyanivska-18), reaches favorable values sufficient for gas generation. Therefore, despite the rather high content of TOC, which, as a rule, significantly exceeds 1–2 %, the prospects of this section of the southern zone of the DDD with respect to the discovery of shale gas or gas of tight rocks are very problematic. According to the set of indicators characterizing potentially gas-containing shale rocks, the most promising section of this part of the southern zone is the well area. Bagatoyska-25 and Kernosivska-2. Predicted shale gas resources of this section can be preliminary estimated at 40–50 billion m3. This should be taken into account when planning further exploration for shale gas. From the data analysis, one can distinguish depth intervals at which rocks enriched with organic matter can generate oil – from 900 to 3100 m, fatty gas with condensate – from 2100 to 4000 m and dry gas – from 2300 to deeper than 4000 m.

THE SUBSURFACE GEOLOGY OF THE WESTERN OFFICER BASIN — RESULTS OF SHELL'S 1980-1984 PETROLEUM EXPLORATION CAMPAIGN

1985 ◽  
Vol 25 (1) ◽  
pp. 34 ◽  
Author(s):  
W.G. Townson
Keyword(s):  
Lower Cambrian ◽  
Oil And Gas ◽  
Source Rocks ◽  
Petroleum Exploration ◽  
Gas Generation ◽  
Upper Proterozoic ◽  
Magnetic Basement ◽  
Complex Structural ◽  
Proterozoic Basement ◽  
The 1960S

The Officer Basin described in this paper includes four Proterozoic to Lower Palaeozoic sub-basins (Gibson, Yowalga, Lennis, Waigen) which extend in a northwest to southeast belt across 200 000 sq. km of central Western Australia. These sub-basins are bounded by Archaean to Proterozoic basement blocks and are almost entirely concealed by a veneer of Permian and Cretaceous sediments. Depth to magnetic basement locally exceeds eight kilometres.Until recently, information on the sub-surface geology was limited to shallow levels, based on the results of a petroleum exploration campaign in the 1960s and the work of State and Federal Geological Surveys. In 1980, the Shell Company of Australia was awarded three permits (46 200 sq. km) covering the Yowalga and Lennis Sub-basins. The results of 4700 km of seismic data and three deep wildcat wells, combined with gravity, aeromagnetic, Landsat, outcrop and corehole information, has led to a better understanding of the regional subsurface geology.The Lennis Sub-basin appears to contain Lower to Middle Proterozoic sediments, whereas the Yowalga Sub- basin is primarily an Upper Proterozoic to Lower Cambrian sequence which comprises a basal clastic section, a middle carbonate and evaporite sequence and an upper clastic section. Widespread Middle Cambrian basalts cap the Upper Proterozoic to Lower Cambrian prospective sequence. Late Proterozoic uplift resulted in salt- assisted gravity tectonics leading to complex structural styles, especially in the basin axis.Despite oil shows, organic matter in the oil and gas generation windows and reservoir-quality sandstones with interbedded shales, no convincing source rocks or hydrocarbon accumulations have yet been located. The area remains, however, one of the least explored basins in Australia.

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