Deep fluids and their role in hydrocarbon migration and oil deposit formation exemplified by supercritical СO2

2021 ◽  
pp. 1-11
Author(s):  
Sara LIFSHITS
Keyword(s):  
Supercritical Fluid ◽  
Oil And Gas ◽  
Gas Permeability ◽  
Sedimentary Rocks ◽  
Source Rocks ◽  
Reservoir Properties ◽  
Hydrocarbon Migration ◽  
Geological Processes ◽  
Before And After ◽  
Oil Source

ABSTRACT Hydrocarbon migration mechanism into a reservoir is one of the most controversial in oil and gas geology. The research aimed to study the effect of supercritical carbon dioxide (СО2) on the permeability of sedimentary rocks (carbonates, argillite, oil shale), which was assessed by the yield of chloroform extracts and gas permeability (carbonate, argillite) before and after the treatment of rocks with supercritical СО2. An increase in the permeability of dense potentially oil-source rocks has been noted, which is explained by the dissolution of carbonates to bicarbonates due to the high chemical activity of supercritical СО2 and water dissolved in it. Similarly, in geological processes, the introduction of deep supercritical fluid into sedimentary rocks can increase the permeability and, possibly, the porosity of rocks, which will facilitate the primary migration of hydrocarbons and improve the reservoir properties of the rocks. The considered mechanism of hydrocarbon migration in the flow of deep supercritical fluid makes it possible to revise the time and duration of the formation of gas–oil deposits decreasingly, as well as to explain features in the formation of various sources of hydrocarbons and observed inflow of oil into operating and exhausted wells.

scholarly journals Indicator signs of carbonate microbialites in black shale formations: isotopic composition and biomarkers

2021 ◽  
Vol 11 ◽  
pp. 55-61
Author(s):  
M. A. Tugarova ◽  
Keyword(s):  
Isotopic Composition ◽  
Black Shale ◽  
Oil And Gas ◽  
Source Rocks ◽  
Unconventional Reservoirs ◽  
Shale Formations ◽  
Geological Processes ◽  
History Of ◽  
Oil Source ◽  
Gas Potential

Carbonate rocks represented by nodules, lenses, layers of different morphology and length are typical for the black shale formations of different ages. They are of the greatest interest in oil source rocks as indicators of complex and not always unambiguously interpreted geological processes. A special place among these sedimentary bodies is occupied by microbialites, which indicate suppression of development of marine organic biocenoses, and often reflect emanation processes in ancient strata. Proof of these phenomena is fundamentally important for predicting and assessing the oil and gas potential of unconventional reservoirs. On the example of carbonate solids of Triassic and Jurassic black shale formations, we present a complex analytical method to determine the microbial biochemical genesis of rocks on the base of the isotopic composition of carbon and oxygen, together with the hydrocarbon molecular markers of organic matter. The geochemical features of the isolated microbialites suggest that they are resulted from a complex history of black shale formations, which reflects both background lithogenetic transformations and superimposed processes, including high-temperature hydrothermal ones.

scholarly journals The Relationship between Fluid Flow, Structures, and Depositional Architecture in Sedimentary Rocks: An Example-Based Overview

Geofluids ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-19 ◽  
Author(s):  
Vilde Dimmen ◽  
Atle Rotevatn ◽  
Casey W. Nixon
Keyword(s):  
Fluid Flow ◽  
Sedimentary Rocks ◽  
Structure Type ◽  
Mineral Dissolution ◽  
Rock Properties ◽  
Hydrocarbon Migration ◽  
Geological Processes ◽  
Wide Range ◽  
Depositional Architecture ◽  
The Relationship

Fluid flow in the subsurface is fundamental in a variety of geological processes including volcanism, metamorphism, and mineral dissolution and precipitation. It is also of economic and societal significance given its relevance, for example, within groundwater and contaminant transport, hydrocarbon migration, and precipitation of ore-forming minerals. In this example-based overview, we use the distribution of iron oxide precipitates as a proxy for palaeofluid flow to investigate the relationship between fluid flow, geological structures, and depositional architecture in sedimentary rocks. We analyse and discuss a number of outcrop examples from sandstones and carbonate rocks in New Zealand, Malta, and Utah (USA), showing controls on fluid flow ranging from simple geological heterogeneities to more complex networks of structures. Based on our observations and review of a wide range of the published literature, we conclude that flow within structures and networks is primarily controlled by structure type (e.g., joint and deformation band), geometry (e.g., length and orientation), connectivity (i.e., number of connections in a network), kinematics (e.g., dilation and compaction), and interactions (e.g., relays and intersections) within the network. Additionally, host rock properties and depositional architecture represent important controls on flow and may interfere to create hybrid networks, which are networks of combined structural and stratal conduits for flow.

scholarly journals Application of Machine Learning Algorithms in Predicting Pyrolytic Analysis Result

2021 ◽  
Vol 931 (1) ◽  
pp. 012013
Author(s):  
Le Thi Nhut Suong ◽  
A V Bondarev ◽  
E V Kozlova
Keyword(s):  
Machine Learning ◽  
Random Forest ◽  
Linear Regression ◽  
Decision Tree ◽  
Multiple Linear Regression ◽  
Oil And Gas ◽  
Polynomial Regression ◽  
Source Rocks ◽  
Regression Algorithms ◽  
Before And After

Abstract Geochemical studies of organic matter in source rocks play an important role in predicting the oil and gas accumulation of any territory, especially in oil and gas shale. For deep understanding, pyrolytic analyses are often carried out on samples before and after extraction of hydrocarbon with chloroform. However, extraction is a laborious and time-consuming process and the workload of laboratory equipment and time doubles. In this work, machine learning regression algorithms is applied for forecasting S2ex based on the pyrolytic analytic result of non-extracted samples. This study is carried out using more than 300 samples from 3 different wells in Bazhenov formation, Western Siberia. For developing a prediction model, 5 different machine learning regression algorithms including Multiple Linear Regression, Polynomial Regression, Support vector regression, Decision tree and Random forest have been tested and compared. The performance of these algorithms is examined by R-squared coefficient. The data of the X2 well was used for building a model. Simultaneously, this data is divided into 2 parts – 80% for training and 20% for checking. The model also was used for prediction of wells X1 and X3. Then, these predictive results were compared with the real results, which had been obtained from standard experiments. Despite limited amount of data, the result exceeded all expectations. The result of prediction also showcases that the relationship between before and after extraction parameters are complex and non-linear. The proof is R2 value of Multiple Linear Regression and Polynomial Regression is negative, which means the model is broken. However, Random forest and Decision tree give us a good performance. With the same algorithms, we can apply for prediction all geochemical parameters by depth or utilize them for well-logging data.

Investigation of the geological, technical and economical obstacles for large-scale utilization of geothermal energy from Danish sandstone reservoirs

2020 ◽  
Author(s):  
Mette Olivarius ◽  
Niels Balling ◽  
Jesper P. M. Baunsgaard ◽  
Esben Dalgaard ◽  
Hanne Dahl Holmslykke ◽  
...  
Keyword(s):  
Large Scale ◽  
Oil And Gas ◽  
Gas Permeability ◽  
Business Case ◽  
Depositional Environments ◽  
Heat Extraction ◽  
Geothermal Resource ◽  
Burial History ◽  
Reservoir Properties ◽  
Sandstone Reservoirs

<p>The Triassic–Jurassic sandstone reservoirs in the Danish subsurface at c. 1–3 km depth contain an enormous geothermal resource that is currently utilized in only three geothermal plants due to a number of geological, technical and commercial barriers. These barriers have been addressed in the GEOTHERM project funded by Innovation Fund Denmark and recommendations for overcoming the obstacles have been made. Some of the methods that are used in the oil and gas sector have successfully been introduced in the geothermal reservoir evaluations to reduce the risk associated with new exploration wells. Quantitative seismic interpretation proved capable of giving a reliable reservoir characterization with regards to estimation of porosity and sand/clay distribution. Diagenesis modelling gave good estimates of reservoir quality by utilizing the knowledge obtained about depositional environments, petrography, reservoir properties and burial history. Relationships between fluid and gas permeability have been established such that the regularly measured gas permeability can be recalculated to fluid permeability giving a better representation of the reservoir. The composition of the formation water in the three geothermal plants has been measured and used for geochemical modelling to evaluate the risk of scaling, where especially barite showed a tendency to precipitate upon cooling of the brine. Simulations of the thermal development of the reservoirs during long-term geothermal exploitation demonstrate significant heat extraction from the layers present above and below each reservoir, which ensures that only a small decrease in production temperature occurs over several decades. The regional geothermal resource estimation has been updated based on a new comprehensive 3D temperature model of the subsurface, confirming the presence of a huge geothermal resource with wide geographical extend covering most of the country. The causes of injection problems have been investigated including corrosion and scaling processes, showing that careful choice of well-lining and tubing materials besides cautious operation of plants are of utmost importance to prevent problems. A geothermal business case has been developed to give a lifetime assessment of geothermal plants including feasibility, design, drilling, construction, production and abandonment, showing that the operational costs are closely linked to the existing infrastructure and to the choices made when designing the geothermal plant. In conclusion, the new scientific results and best-practice manuals provide a significantly higher chance of success of new geothermal projects when including the recommended measures to minimize the geological uncertainties and prevent problems during drilling and production.</p>

Main Factors Controlling Oil-Gas Enrichment Regularities and Accumulation Modes of Putaohua Oil Layer in Chaochang Region

2013 ◽  
Vol 295-298 ◽  
pp. 2732-2735
Author(s):  
Yan Yun Zhang ◽  
Zi Nan Li ◽  
Lu Lu Zhou
Keyword(s):  
Oil And Gas ◽  
Source Rocks ◽  
Gas Distribution ◽  
Accumulation Mode ◽  
Sedimentary Characteristics ◽  
Geological Conditions ◽  
Main Factors ◽  
Facies Types ◽  
Oil Source ◽  
Oil Gas

In order to clarify some kinds of geological conditions on the hydrocarbon accumulation process, this paper analyses the main factors controlling oil-gas enrichment regularities of Putaohua oil layer in Chaochang region of Daqing city, which conclude tectonics, sedimentary characteristics, oil source condition and the mutual relationship between of them. The results show that the organic abundance of hydrocarbon source rocks of Qing1 section control oil and gas distribution range. The configuring relationships of oil-source fault and reservoir sand body control oil and gas migration. The configuring relationship of sedimentary micro-facies types and structures controls oil and gas distribution. On the basis of these studies, oil and gas accumulation mode in Putaohua reservoir are summarized in Chaochang region. There are two accumulation models: nearby accumulation mode in northwest and updip accumulation mode in southeast.

scholarly journals Hydrocarbon generation from Carboniferous-Permian coaly source rocks in the Huanghua depression under different geological processes

2020 ◽  
Vol 17 (6) ◽  
pp. 1540-1555
Author(s):  
Jin-Jun Xu ◽  
Qiang Jin
Keyword(s):  
Oil And Gas ◽  
Vitrinite Reflectance ◽  
Source Rocks ◽  
Bohai Bay ◽  
Hydrocarbon Generation ◽  
Oil And Gas Exploration ◽  
Geological Processes ◽  
Light Oil ◽  
Huanghua Depression ◽  
Higher Temperature

AbstractNatural gas and condensate derived from Carboniferous-Permian (C-P) coaly source rocks discovered in the Dagang Oilfield in the Bohai Bay Basin (east China) have important implications for the potential exploration of C-P coaly source rocks. This study analyzed the secondary, tertiary, and dynamic characteristics of hydrocarbon generation in order to predict the hydrocarbon potentials of different exploration areas in the Dagang Oilfield. The results indicated that C-P oil and gas were generated from coaly source rocks by secondary or tertiary hydrocarbon generation and characterized by notably different hydrocarbon products and generation dynamics. Secondary hydrocarbon generation was completed when the maturity reached vitrinite reflectance (Ro) of 0.7%–0.9% before uplift prior to the Eocene. Tertiary hydrocarbon generation from the source rocks was limited in deep buried sags in the Oligocene, where the products consisted of light oil and gas. The activation energies for secondary and tertiary hydrocarbon generation were 260–280 kJ/mol and 300–330 kJ/mol, respectively, indicating that each instance of hydrocarbon generation required higher temperature or deeper burial than the previous instance. Locations with secondary or tertiary hydrocarbon generation from C-P coaly source rocks were interpreted as potential oil and gas exploration regions.

scholarly journals THE USE OF X-RAY MICROTOMOGRAPHY TO ASSESS CHANGES IN THE VOIDS STRUCTURE OF ROCKS

2017 ◽  
Vol 26 (26) ◽  
pp. 12-16
Author(s):  
Andrei Aleksandrovich PONOMAREV ◽  
Aleksandra Vladimirovna BUBNOVA ◽  
Marcos Antônio KLUNK
Keyword(s):  
Oil And Gas ◽  
Oil And Gas Industry ◽  
High Tech ◽  
Cylindrical Shape ◽  
Void Space ◽  
Gas Generation ◽  
Gas Industry ◽  
X Ray ◽  
Before And After ◽  
Oil Source

The oil and gas industry is developing rapidly. Based on this, it is necessary to determine new methods of productive prospecting of mineral deposits. One of the most high-tech and perspective methods is computer X-ray microtomography. For this stage, this method is widely used for the different fields of geology and geophysics. The main advantage is the ability to study the sample without destruction, which is especially important in the process of working with the kern material. In this paper, the method of computerized X-ray microtomography is highlighted. A comparative analysis of the voids structure of an oil source rock before and after exposure to microwave fields using the standard DataViewer software is clarified. As a result of this analysis, an increase in the diameter of a sample of a cylindrical shape after treatment with microwave fields was established, and the formation of microcracks was also established. Based on the results obtained, assumptions were made about the formation of hydrocarbon deposits. In other words, the paper discusses in detail the method that allows fixing changes in the structure of the void space of rocks as a result of oil and gas generation flowing under the influence of wave fields.

scholarly journals Petroleum Potential of the Deep Ordovician- Lower Devonian Oil and Gas Complex in the South-East of the Timan-Pechora Petroleum Province

2021 ◽  
Vol 20 (3) ◽  
pp. 274-283
Author(s):  
E.A. Kuznetsovа ◽  
Keyword(s):  
Lower Devonian ◽  
Oil And Gas ◽  
Source Rocks ◽  
Hydrocarbon Generation ◽  
The South ◽  
Reservoir Properties ◽  
Lower Paleozoic ◽  
Petroleum Potential ◽  
Middle Paleozoic ◽  
Gas Potential

The article is devoted to the assessment of the oil and gas potential of the deep Ordovician-Lower Devonian oil and gas complex in the south-east of the Timan-Pechora oil and gas province. Within the Upper Pechora Basin of the Pre-Ural trough and in the south of the Pechora-Kolva aulacogen, several wells were drilled with a depth of more than 5 km, some of which entered the Lower Paleozoic deposits. These strata are difficult to access and poorly studied, and the prospects for their oil and gas potential are unclear. The article describes the composition of the complex, gives geochemical characteristics, describes reservoir properties, and presents the results of 1D and 2D basin modeling. Models of the zoning of catagenesis are presented. The oil and gas complex includes a variety of oil and gas source rocks. It is possible to allocate collectors, as well as the seals. In the Lower Paleozoic sediments, the processes of oil, gas and gas condensate generation took place, which could ensure the formation of deposits both in the deep strata of the Lower and Middle Paleozoic, and in the overlying horizons. The generation and accumulation of hydrocarbons in deep-buried sediments occurred at a favorable time for the formation of deposits. However, it is considered that the scale of hydrocarbon generation for the Lower Paleozoic deposits is not high.

THE GEOLOGY AND EVOLUTION OF THE SOUTH PEPPER HYDROCARBON ACCUMULATION

1985 ◽  
Vol 25 (1) ◽  
pp. 235 ◽  
Author(s):  
A.F. Williams ◽  
D.J. Poynton
Keyword(s):  
Middle Miocene ◽  
Oil And Gas ◽  
Upper Jurassic ◽  
Lower Jurassic ◽  
Source Rocks ◽  
The South ◽  
Hydrocarbon Migration ◽  
Tectonic Event ◽  
The North ◽  
Migration History

The South Pepper field, discovered in 1982, is located 30 km southwest of Barrow Island in the offshore portion of the Barrow Sub-basin, Western Australia. The oil and gas accumulation occurs in the uppermost sands of the Lower Cretaceous Barrow Group and the overlying low permeability Mardie Greensand Member of the Muderong Shale.The hydrocarbons are trapped in one of several fault closed anticlines which lie on a high trend that includes the North Herald, Pepper and Barrow Island structures. This trend is postulated to have formed during the late Valanginian as the result of differential compaction and drape over a buried submarine fan sequence. During the Turonian the trend acted as a locus for folding induced by right-lateral wrenching along the sub-basin edge. Concurrent normal faulting dissected the fold into a number of smaller anticlines. This essentially compressional tectonic phase contrasted with the earlier extensional regime which was associated with rift development during the Callovian. A compressional tectonic event in the Middle Miocene produced apparent reverse movement on the South Pepper Fault but only minor changes to the structural closure.Geochemical and structural evidence indicates at least two periods of hydrocarbon migration into the top Barrow Group - Mardie Greensand reservoir. The earlier occurred in the Turonian subsequent to the period of wrench tectonics and involved the migration of oil from Lower Jurassic Dingo Claystone source rocks up the South Pepper Fault. This oil was biodegraded before the second episode of migration occurred after the Middle Miocene tectonism. The later oil is believed to have been sourced by the Middle to Upper Jurassic Dingo Claystone. Biodegradation at this stage ceased or became insignificant due to temperature increase and reduction of meteoric water flow. Gas-condensate, sourced from Triassic or Lower Jurassic sediments may have migrated into the structure with this second oil although a more recent migration cannot be ruled out.The proposed structural and hydrocarbon migration history fits regional as well as local geological observations for the Barrow Sub-basin. Further data particularly from older sections of the stratigraphic column within the area are needed to refine the interpretation.

HYDROCARBON GENERATION IN THE AMADEUS BASIN, CENTRAL AUSTRALIA

1984 ◽  
Vol 24 (1) ◽  
pp. 42
Author(s):  
K. S. Jackson D. M. McKirdy ◽  
J. A. Deckelman
Keyword(s):  
Oil And Gas ◽  
Source Rocks ◽  
Hydrocarbon Generation ◽  
Liquid Hydrocarbons ◽  
Gas Source ◽  
Organic Facies ◽  
Hydrocarbon Fields ◽  
Central Australia ◽  
Oil Source ◽  
To Receive

The Proterozoic to Devonian Amadeus Basin of central Australia contains two hydrocarbon fields — oil and gas at Mereenie and gas at Palm Valley, both within Ordovician sandstone reservoirs. Significant gas and oil shows have also been recorded from Cambrian sandstones and carbonates in the eastern part of the basin. The hydrocarbon generation histories of documented source rocks, determined by Lopatin modelling, largely explain the distribution of the hydrocarbons. The best oil and gas source rocks occur in the Ordovician Horn Valley Siltstone. Source potential is also developed within the Late Proterozoic sequence, particularly the Gillen Member of the Bitter Springs Formation, and the Cambrian.Consideration of organic maturity, relative timing of hydrocarbon generation and trap formation, and oil/source typing leads to the conclusion that the Horn Valley Siltstone charged the Mereenie structure with gas and oil. At Palm Valley, only gas and minor condensate occur because the trap was formed too late to receive an oil charge. Differences in organic facies may also, in part, account for the dry gas and lack of substantial liquid hydrocarbons at Palm Valley. In the eastern Amadeus Basin, the Ordovician is largely absent but Proterozoic sources are well placed to provide the gas discovered by Ooraminna 1 and Dingo 1. Any oil charge here would have preceded trap development.

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