Inversion tectonics: a brief petroleum industry perspective

Abstract. Inverted structures provide traps for petroleum exploration, typically four-way structural closures. As to the degree of inversion, based on a large number of worldwide examples seen in various basins, the most preferred petroleum exploration targets are mild to moderate inversion structures, defined by the location of the null points. In these instances, the closures have a relatively small vertical amplitude but are simple in a map-view sense and well imaged on seismic reflection data. Also, the closures typically cluster above the extensional depocenters which tend to contain source rocks providing petroleum charge during and after the inversion. Cases for strong or total inversion are generally not that common and typically are not considered as ideal exploration prospects, mostly due to breaching and seismic imaging challenges associated with the trap(s) formed early on in the process of inversion. Also, migration may become tortuous due to the structural complexity or the source rock units may be uplifted above the hydrocarbon generation window, effectively terminating the charge once the inversion has occurred. Cases of inversion tectonics can be grouped into two main modes. A structure develops in Mode I inversion if the syn-rift succession in the preexisting extensional basin unit is thicker than its post-rift cover including the pre- and syn-inversion part of it. In contrast, a structure evolves in Mode II inversion if the opposite syn- versus post-rift sequence thickness ratio can be observed. These two modes have different impacts on the petroleum system elements in any given inversion structure. Mode I inversion tends to develop in failed intracontinental rifts and proximal passive margins, and Mode II structures are associated with back-arc basins and distal parts of passive margins. For any particular structure the evidence for inversion is typically provided by subsurface data sets such as reflection seismic and well data. However, in many cases the deeper segments of the structure are either poorly imaged by the seismic data and/or have not been penetrated by exploration wells. In these cases the interpretation in terms of inversion has to rely on the regional understanding of the basin evolution with evidence for an early phase of crustal extension by normal faulting.

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Inversion tectonics: a brief petroleum industry perspective

10.5194/se-2020-33 ◽

2020 ◽

Author(s):

Gábor Tari ◽

Didier Arbouille ◽

Zsolt Schléder ◽

Tamás Tóth

Keyword(s):

Petroleum Industry ◽

Structural Complexity ◽

Source Rocks ◽

Petroleum Exploration ◽

Data Sets ◽

Hydrocarbon Generation ◽

Seismic Reflection Data ◽

Reflection Seismic ◽

Reflection Data ◽

Well Data

Abstract. The concept of structural inversion was introduced in the early 1980s. By definition, an inversion structure forms when a pre-existing extensional (or transtensional) fault controlling a hangingwall basin containing a syn-rift or passive fill sequence subsequently undergoes compression (or transpression) producing partial (or total) extrusion of the basin fill. Inverted structures provide traps for petroleum exploration, typically four-way structural closures. As to the degree of inversion, based on large number of worldwide examples seen in various basins, the most preferred petroleum exploration targets are mild to moderate inversional structures, defined by the location of the null-points. In these instances, the closures have a relatively small vertical amplitude, but simple in a map-view sense and well imaged on seismic reflection data. Also, the closures typically cluster above the extensional depocentres which tend to contain source rocks providing petroleum charge during and after the inversion. Cases for strong or total inversion are generally not that common and typically are not considered as ideal exploration prospects, mostly due to breaching and seismic imaging challenges associated with the trap(s) formed early on in the process of inversion. Also, migration may become tortuous due to the structural complexity or the source rock units may be uplifted above the hydrocarbon generation window effectively terminating the charge once the inversion occurred. For any particular structure the evidence for inversion is typically provided by subsurface data sets such as reflection seismic and well data. However, in many cases the deeper segments of the structure are either poorly imaged by the seismic data and/or have not been penetrated by exploration wells. In these cases the interpretation of any given structure in terms of inversion has to rely on the regional understanding of the basin evolution with evidence for an early phase of substantial crustal extension by normal faulting.

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Integration of Geophysical Technologies in the Petroleum Industry

10.1017/9781108913256 ◽

2021 ◽

Keyword(s):

Co2 Storage ◽

Petroleum Industry ◽

Petroleum Exploration ◽

Reflection Seismology ◽

Seismic Reflection Data ◽

Reflection Data ◽

Advanced Students ◽

Storage Reservoirs ◽

Magnetic Resistivity ◽

Exploration And Production

The most utilized technique for exploring the Earth's subsurface for petroleum is reflection seismology. However, a sole focus on reflection seismology often misses opportunities to integrate other geophysical techniques such as gravity, magnetic, resistivity, and other seismicity techniques, which have tended to be used in isolation and by specialist teams. There is now growing appreciation that these technologies used in combination with reflection seismology can produce more accurate images of the subsurface. This book describes how these different field techniques can be used individually and in combination with each other and with seismic reflection data. World leading experts present chapters covering different techniques and describe when, where, and how to apply them to improve petroleum exploration and production. It also explores the use of such techniques in monitoring CO2 storage reservoirs. Including case studies throughout, it will be an invaluable resource for petroleum industry professionals, advanced students, and researchers.

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THE STRUCTURAL DEVELOPMENT AND HYDROCARBON POTENTIAL OF PALAEOZOIC SOURCE ROCKS IN THE ADAVALE BASIN REGION

The APPEA Journal ◽

10.1071/aj83031 ◽

1984 ◽

Vol 24 (1) ◽

pp. 393 ◽

Cited By ~ 2

Author(s):

V. L. Passmore ◽

M. J. Sexton

Keyword(s):

Middle Devonian ◽

Oil And Gas ◽

Structural Features ◽

Source Rocks ◽

Geochemical Data ◽

Mature Stage ◽

Hydrocarbon Generation ◽

Structural Development ◽

Seismic Reflection Data ◽

Basin Region

The Adavale Basin of southwestern Queensland consists of a main depression and several isolated synclinal extensions, traditionally referred to as troughs. The depressions and troughs are erosional remnants of a once more extensive Devonian depositional basin, and are now completely buried by sediments of the overlying Cooper, Galilee and Eromanga Basins. Geophysical and drilling investigations undertaken since 1959 are the only source of information on the Adavale Basin. A single sub-economic discovery of dry gas at Gilmore and a few shows of oil and gas are the only hydrocarbons located in the basin to date.In 1980, the Bureau of Mineral Resources in cooperation with the Geological Survey of Queensland commenced a major, multidisciplinary investigation of the basins in southwestern Queensland. Four long (> 200 km) seismic lines from this study over the Adavale Basin region and geochemical data from 20 wells were used to interpret the Adavale Basin's development and its present hydrocarbon potential.The new seismic reflection data allow the well-explored main depression to be correlated with the detached troughs, some of which have little or no well information. The BMR seismic data show that these troughs were previously part of one large depositional basin in the Devonian, the depocentre of which lay east of a north-trending hingeline. Structural features and Devonian depositional limits and patterns have been modified from earlier interpretations as a result of the new seismic coverage. The maximum sediment thickness is re-interpreted to be 8500 m, considerably thicker than previous interpretation.recognised. The first one, a diachronous Middle Devonian unconformity, is the most extensive, and reflects the mobility of the basement during the basin's early history. The second unconformity within the Late Devonian Buckabie Formation reveals that there were two phases of deformation of the basin sediments.The geochemical results reported in this study show that most of the Adavale Basin sediments have very low concentrations of organic carbon and hydrocarbon fractions. Maturity profiles indicate that the best source rocks of the basin are now in the mature stage for hydrocarbon generation. However, at Gilmore and in the Cooladdi Trough, they have reached the dry gas stage. The maturity data provide additional evidence for the marked break in deposition and significant erosion during the Middle Devonian recognised on the seismic records, and extend the limits of this sedimentary break into the northern part of the main depression.Hydrocarbon potential of the Adavale Basin is fair to poor. In the eastern part of the basin, where most of the data are available, the prospects are better for gas than oil. Oil prospectivity may be improved in any exinite-rich areas that exist farther west, where palaeo-temperatures were lower.

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The transformation effect of source rock-derived acidic fluid on carbonate reservoir from simulation experiments

10.5194/egusphere-egu2020-21098 ◽

2020 ◽

Author(s):

Qian Ding ◽

Zhiliang He ◽

Dongya Zhu

Keyword(s):

Physical Properties ◽

Source Rock ◽

Carbonate Reservoir ◽

Carbonate Reservoirs ◽

Source Rocks ◽

Petroleum Exploration ◽

Hydrocarbon Generation ◽

High Quality ◽

Simulation Experiments ◽

Deep Layers

<p>Deep and ultra-deep carbonate reservoir is an important area of petroleum exploration. However, the prerequisite for predicting high quality deep ultra-deep carbonate reservoirs lays on the mechanism of carbonate dissolution/precipitation. It is optimal to perform hydrocarbon generation-dissolution simulation experiments to clarify if burial dissolution could improve the physical properties of carbonate reservoirs, while quantitatively and qualitatively describe the co-evolution process of source rock and carbonate reservoirs in deep layers. In this study, a series of experiments were conducted with the limestone from the Ordovician Yingshan Formation in the Tarim Basin, and the low maturity source rock from Yunnan Luquan, with a self-designed hydrocarbon generation-dissolution simulation equipment. The controlling factors accounted for the alteration of carbonate reservoirs and dissolution modification process by hydrocarbon cracking fluid under deep burial environments were investigated by petrographic and geochemical analytical methods. In the meantime, the transformation mechanism of surrounding rocks in carbonate reservoirs during hydrocarbon generation process of source rock was explored. The results showed that: in the burial stage, organic acid, CO<sub>2</sub> and other acidic fluids associated with thermal evolution of deep source rocks could dissolve carbonate reservoirs, expand pore space, and improve porosity. Dissolution would decrease with the increasing burial depth. Whether the fluid could improve reservoir physical properties largely depends on calcium carbonate saturation, fluid velocity, water/rock ratio, original pore structure etc. This study could further contribute to the prediction of high-quality carbonate reservoirs in deep and ultra-deep layers.</p>

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Late Accumulation of Kunbei Area in Qaidam Basin

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.690-693.3549 ◽

2013 ◽

Vol 690-693 ◽

pp. 3549-3552

Author(s):

Hui Shi ◽

Hui Li

Keyword(s):

Seismic Data ◽

Qaidam Basin ◽

Scientific Evidence ◽

Source Rocks ◽

Petroleum Exploration ◽

Tibet Plateau ◽

Hydrocarbon Generation ◽

Long Distance ◽

Hydrocarbon Charging ◽

The Tibet Plateau

This paper is aimed to find out the main reason of late accumulation of Kunbei area in Qaidam Basin using geochemistry and seismic data and to provide scientific evidence to the potential petroleum exploration in this area. Reservoirs in Kunbei fault terrace zone originate from petreoleum generated by source rocks of E32 in Zhahaquan depression after N23(about 5.2Ma), which means a charcteristic of hysteretic hydrocarbon generation. Brine inclusions shows two hydrocarbon charging periods.The first charging most likely happens at N1 and the second begins at N21,continuing to Q.Two deformaton stages exist in the study area due to the Tibet Plateau uplifting. The accumulations of first stage have been damaged after Middle N1. The reservoirs of Kunbei zone at present are almost orignated from E32 in depression. Above all,the primary cause of late accumulation is due to long-distance effects of the Tibet Plateau uplifting.

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Maturity Evolution of the Cambrian Source Rocks in the Tarim Basin

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.622-623.1642 ◽

2012 ◽

Vol 622-623 ◽

pp. 1642-1645

Author(s):

Zong Lin Xiao ◽

Qing Qing Hao ◽

Zhong Min Shen

Keyword(s):

Source Rock ◽

Tarim Basin ◽

Source Rocks ◽

Petroleum Exploration ◽

Mature Stage ◽

Hydrocarbon Generation ◽

Foreland Basins ◽

Structural History ◽

Depositional Age ◽

Petroleum Basin

The Tarim basin is an important petroleum basin in China, and the Cambrian strata are the major source rock successions in the basin. Integrated the source rock depositional and structural history with its geochemical and thermal parameters, this paper simulates the evolution of the Cambrian source rocks with the software Basinview. The simulation result shows that the main hydrocarbon-generation centers of the Manjiaer sag in the Tabei depression and the Tangguzibasi sag in the Southwest depression are characterized by their early hydrocarbon generation, and in the late Ordovician depositional age, they reached dry gas stage. The Kuqa and Southwest depressions developed in the Cenozoic foreland basins made the Cambrian source rocks mature rapidly in the Cenozoic period. The source rock maturity in the Tarim basin now is characterized by high in the east and west and low in the middle, and most of the area is in the over-mature stage in the present. This study can provide available maturity data for the next petroleum exploration work.

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The role of deep seismic reflection data in understanding the architecture and petroleum potential of Australia's onshore sedimentary basins

The APPEA Journal ◽

10.1071/aj09090 ◽

2010 ◽

Vol 50 (2) ◽

pp. 726 ◽

Cited By ~ 1

Author(s):

Lidena Carr ◽

Russell Korsch ◽

Leonie Jones ◽

Josef Holzschuh

Keyword(s):

Seismic Reflection ◽

Sedimentary Basins ◽

Source Rocks ◽

Petroleum Exploration ◽

Seismic Line ◽

Seismic Reflection Data ◽

Petroleum Potential ◽

Deep Seismic Reflection ◽

Reflection Data ◽

Stratigraphic Sequences

The onshore energy security program, funded by the Australian Government and conducted by Geoscience Australia, has acquired deep seismic reflection data across several frontier sedimentary basins to stimulate petroleum exploration in onshore Australia. Detailed interpretation of deep seismic reflection profiles from four onshore basins, focussing on overall basin geometry and internal sequence stratigraphy, will be presented here, with the aim of assessing the petroleum potential of the basins. At the southern end of the exposed part of the Mt Isa Province, northwest Queensland, a deep seismic line (06GA–M6) crosses the Burke River structural zone of the Georgina Basin. The basin here is >50 km wide, with a half graben geometry, and bounded in the west by a rift border fault. Given the overall architecture, this basin will be of interest for petroleum exploration. The Millungera Basin in northwest Queensland is completely covered by the thin Eromanga Basin and was unknown prior to being detected on two seismic lines (06GA–M4 and 06GA–M5) acquired in 2006. Following this, seismic line 07GA–IG1 imaged a 65 km wide section of the basin. The geometry of internal stratigraphic sequences and a post-depositional thrust margin indicate that the original succession was much thicker than preserved today and may have potential for a petroleum system. The Yathong Trough, in the southeast part of the Darling Basin in NSW, has been imaged in seismic line 08GA–RS2 and interpreted in detail using sequence stratigraphic principles, with several sequences being mapped. Previous studies indicate that the upper part of this basin consists of Devonian sedimentary rocks, with potential source rocks at depth. In eastern South Australia, seismic line 08GA–A1 crossed the Cambrian Arrowie Basin, which is underlain by a Neoproterozoic succession of the Adelaide Rift System. Stratigraphic sequences have been mapped and can be tied to recent drilling for mineral and geothermal exploration. Shallow drill holes from past petroleum exploration have aided the assessment of the petroleum potential of the Cambrian Hawker Group, which contains bitumen in the core, indicating the presence of source rocks in the basin system.

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Geology and petroleum prospectivity of the Sea of Hebrides Basin and Minch Basin, offshore northwest Scotland

Petroleum Geoscience ◽

10.1144/petgeo2021-003 ◽

2021 ◽

pp. petgeo2021-003

Author(s):

Laura-Jane C. Fyfe ◽

Nick Schofield ◽

Simon Holford ◽

Adrian Hartley ◽

Adrian Heafford ◽

...

Keyword(s):

Poor Quality ◽

Lower Jurassic ◽

Source Rocks ◽

Petroleum Exploration ◽

Small Scale ◽

Organic Carbon Content ◽

Seismic Reflection Data ◽

Reflection Data ◽

Porosity And Permeability ◽

Atlantic Margin

The Sea of Hebrides Basin and Minch Basin are late Palaeozoic-Mesozoic rift basins located to the northwest of the Scottish mainland. The basins were the target of small-scale petroleum exploration from the late 1960s to the early 1990s, with a total of three wells drilled within the two basins between 1989 and 1991. Although no commercially viable petroleum discoveries were made, numerous petroleum shows were identified within both basins, including a gas show within the Upper Glen 1 well in Lower Jurassic limestones. Organic rich shales have been identified throughout the Jurassic succession within the Sea of Hebrides Basin, with one Middle Jurassic (Bajocian-Bathonian) shale exhibiting a Total Organic Carbon content of up to 15 wt%. The focus of this study is to review the historic petroleum exploration within these basins, and to evaluate whether the conclusions drawn in the early 1990s of a lack of prospectivity remains the case. This was undertaken by analysis of seismic reflection data, gravity and aeromagnetic data and sedimentological data, from both onshore and offshore wells, boreholes and previously published studies. The key findings from our study suggest that there is a low probability of commercially sized petroleum accumulations within either the Sea of Hebrides Basin or the Minch Basin. Ineffective source rocks, likely due to low maturities (due to lack of burial) and the fact that the encountered Jurassic and Permian-Triassic reservoirs are of poor quality (low porosity and permeability) has led to our interpretation of future exploration being high risk, with any potential accumulations being small in size. While petroleum accumulations are unlikely within the basin, applying the knowledge obtained from the study could provide additional datasets and insight into petroleum exploration on other northeast Atlantic margin basins, such as the Rockall Trough and the Faroe-Shetland Basin.

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Observing Maturing Source Rocks on Seismic Reflection Data

Geophysics ◽

10.1190/geo2020-0205.1 ◽

2020 ◽

pp. 1-56

Author(s):

T. Matava ◽

R. G. Keys ◽

S. E. Ohm ◽

S. Volterrrani

Keyword(s):

Source Rock ◽

Seismic Data ◽

Pore Space ◽

Regional Scale ◽

Source Rocks ◽

Hydrocarbon Generation ◽

Maturity Model ◽

Eastern Canada ◽

Amplitude Response ◽

Seismic Reflection Data

Hydrocarbon generation in a source rock is a complex, irreversible phase change that occurs when a source rock is heated during burial to change phase to a fluid. The fluid density is less than the kerogen density so in a closed or partially closed system the volume of the pore space occupied by fluids increases. Burial also increases the effective stress which leads to compaction and a significant reduction in porosity. The challenge of identifying source rocks on seismic data then becomes differentiating the smaller porosity increase due to hydrocarbon formation from the larger porosity decrease associated with burial. We use a calibrated rock physics model to show that Vshale and porosity data can be used to predict the compressional and shear wave velocities and the density in wells over large sedimentary sections, including a source rock of variable maturity. These well data and models show that the difference between an immature and mature source rock is an increase porosity (lower density) relative to compacting, non-source rock sediments. We use these results to identify a potential source interval in the Orphan Basin in Eastern Canada on 2D regional seismic data. We show that the full stack amplitude response of a maturing source rock is significant during the main phase of generation (0.2<transformation ratio<0.8) relative to surrounding sediments. Regional scale consistency of the amplitude response with the kerogen maturity model from an integrated basin simulator reduces exploration risk because the independence of the thermal model from the seismic amplitude response. Finally, combining the seismic response with the source rock maturity model provides insight into the likely kerogen kinetics. Most applications require regional data sets to capture the maturity window, however, applications are also possible around allochthonous salt where geometries can lead to local changes in heat flow.

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Source rocks evaluation of the Paleogene Shahejie 3 Formation in the Dongpu Depression, Bohai Bay Basin

Energy Exploration & Exploitation ◽

10.1177/0144598718802447 ◽

2018 ◽

Vol 37 (1) ◽

pp. 394-411 ◽

Cited By ~ 2

Author(s):

Zi-Ran Jiang ◽

Yin-Hui Zuo ◽

Mei-Hua Yang ◽

Yun-Xian Zhang ◽

Yong-Shui Zhou

Keyword(s):

Thermal History ◽

Source Rocks ◽

Petroleum Exploration ◽

Geochemical Data ◽

Bohai Bay ◽

Type I ◽

Hydrocarbon Generation ◽

Thermal Maturity ◽

Dongpu Depression ◽

Two Stages

Present simulation results based on two-dimensional basin cannot obtain accurate evaluations of petroleum resources because of not combining the thermal history in the Dongpu Depression. In this paper, Shahejie 3 Formation source rocks are evaluated using the geochemical data, and based on the thermal history, the thermal maturity evolution of typical wells and the top and bottom of the Shahejie 3 Formation source rocks are modeled using BasinMod software. Results show that source rocks are mainly distributed in the Haitongji-Liutun and Qianliyuan areas, and dominated by medium to high maturity source rocks. Organic matter types are primarily types II and III kerogen with a small amount of type I. The Shahejie 3 Formation source rocks in the Menggangji area experienced two stages of hydrocarbon generation: (1) during the Dongying Formation depositional period (33–17 Ma) and (2) from the Minghuazhen Formation depositional period to present (5.1–0 Ma). The source rocks are generally underdeveloped with low potential for hydrocarbon generation due to nonpoor and thin source rocks in this area. The two stages of hydrocarbon generation are not obvious for other areas. When the bottom of the source rocks reached overmature stage, the mid-lower Shahejie 3 Formation experienced the peak of hydrocarbon generation during the Dongying Formation depositional period. The thermal maturity evolution of the Shahejie 3 Formation source rocks revealed that the main hydrocarbon generation period was during the Dongying Formation depositional period. Therefore, petroleum exploration is suggested to be performed at the Shahejie 3 Formation source rocks in the Qianliyuan and Haitongji-Liutun areas to study the lithology and discover complex petroleum reservoirs in the Dongpu Depression.

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