Study on Hydrocarbon Source Rocks with Accumulation Characteristics Research of Camck-Aral Sea

2013 ◽  
Vol 703 ◽  
pp. 139-142
Author(s):  
Hui Ting Hu ◽  
Hai Tao Xue ◽  
Xiang Qi Kong ◽  
Hong Peng Yao

Camck-Aral sea is one of the important China's developing overseas oil and gas exploration blocks. But conditioned by the degree of exploration, the hydrocarbon source rocks quality and resource potential of this block are not clear. Therefore, in this study, we analyzed the regional geological survey, hydrocarbon source rock condition and reservoir conditions. The results indicated that: The middle Jurassic formation in Camck-Aral sea block has a texture of interbeded sandstones and mudstones. Middle Jurassic hydrocarbon source rocks in Camck-Aral sea block is high in the abundance of organic matter,of which the matrix belongs to the type II2, and it has reached the maturity stage. This may mean that the study area should be based primarily on natural gas exploration.

2013 ◽  
Vol 868 ◽  
pp. 107-112
Author(s):  
Dan Ning Wei ◽  
Gui Lei Wang

The distribution of high quality hydrocarbon source rocks plays an important role in the accumulation of oil and gas. As a result, the identification of geochemical characteristics of high quality source rocks is the key to discriminate the distribution of high quality source rocks accurately. By core observation and sample analysis, taking Wuerxun-Beier depression in Hailaer Basin as the target regions, we make accurate discrimination of high quality hydrocarbon source rock developmental characteristics and comparison with common source rocks. The research shows that: (1) the hydrocarbon expulsion efficiency in study zone is high due to the alternating deposits of high quality hydrocarbon source rocks and sandstones. The high quality hydrocarbon source rocks deposited in the reducing environment to strong reducing ones, whereas common rocks deposited in oxidizing environment to weak oxidizing ones. (2) the occurrence of organic matter of high quality hydrocarbon source rocks is mainly in stratified enrichment type. The organic matter develops parallel bedding or basic parallel bedding. However, the distribution of organic matter of common source rocks is porphyritic and heterogeneous, or interrupted lamellar. (3) the hydrocarbon potential of high quality hydrocarbon source rocks is more than ten times that of common source rocks. (4) the content of organic carbon in high quality source rocks is high and the content of chloroform asphalt A is relatively low, which reflects that the hydrocarbon expulsion efficiency of high quality source rocks in the sand-shale interbeds of study zone is high.


2012 ◽  
Vol 63 (4) ◽  
pp. 319-333 ◽  
Author(s):  
Paweł Kosakowski ◽  
Dariusz Więcław ◽  
Adam Kowalski ◽  
Yuriy Koltun

Assessment of hydrocarbon potential of Jurassic and Cretaceous source rocks in the Tarnogród-Stryi area (SE Poland and W Ukraine) The Jurassic/Cretaceous stratigraphic complex forming a part of the sedimentary cover of both the eastern Małopolska Block and the adjacent Łysogóry-Radom Block in the Polish part as well as the Rava Rus'ka and the Kokhanivka Zones in the Ukrainian part of the basement of the Carpathian Foredeep were studied with geochemical methods in order to evaluate the possibility of hydrocarbon generation. In the Polish part of the study area, the Mesozoic strata were characterized on the basis of the analytical results of 121 core samples derived from 11 wells. The samples originated mostly from the Middle Jurassic and partly from the Lower/Upper Cretaceous strata. In the Ukrainian part of the study area the Mesozoic sequence was characterized by 348 core samples collected from 26 wells. The obtained geochemical results indicate that in both the south-eastern part of Poland and the western part of Ukraine the studied Jurassic/Cretaceous sedimentary complex reveals generally low hydrocarbon source-rock potential. The most favourable geochemical parameters: TOC up to 26 wt. % and genetic potential up to 39 mg/g of rock, were found in the Middle Jurassic strata. However, these high values are contradicted by the low hydrocarbon index (HI), usually below 100 mg HC/g TOC. Organic matter from the Middle Jurassic strata is of mixed type, dominated by gas-prone, Type III kerogen. In the Polish part of the study area, organic matter dispersed in these strata is generally immature (Tmax below 435 °C) whereas in the Ukrainian part maturity is sufficient for hydrocarbon generation.


2020 ◽  
Vol 17 (6) ◽  
pp. 1540-1555
Author(s):  
Jin-Jun Xu ◽  
Qiang Jin

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.


2006 ◽  
Vol 85 (3) ◽  
pp. 221-238 ◽  
Author(s):  
O.A. Abbink ◽  
H.F. Mijnlieff ◽  
D.K. Munsterman ◽  
R.M.C.H. Verreussel

AbstractMiddle Jurassic - Early Cretaceous strata are a target for oil and gas exploration in the Dutch offshore. During the initial stages of the ‘Late Jurassic’ offshore exploration, various oil fields and a few gas fields were discovered of which only one, the F3-FB field, proved to be economically viable. In the Northern Offshore of the Netherlands, latest Middle Jurassic (Callovian) - earliest Cretaceous (Ryazanian) strata are mostly limited to the Dutch Central Graben and Terschelling basins. Outside the Dutch Central Graben and the Terschelling Basin only thin veneers of these strata occur on the fringing highs such as the Schill Grund High and the Step Graben. The geology of this non-marine to shallow marine succession is complex. The combination of lateral facies changes, repetitive log and facies characteristics in time, sea-level and climate changes, salt tectonics and structural compartmentalisation hamper straightforward seismic interpretation and log correlation. The large number of lithostratigraphic units defined in the Stratigraphic Nomenclature of the Netherlands illustrates the complexity of this time-interval.In recent years, new biostratigraphic techniques and newly acquired stratigraphic data led to the identification of a series of events which can be related to the tectonic, climatic, environmental and stratigraphic development of the ‘Late Jurassic’ in the Dutch Central Graben and Terschelling basins. Based on these data, three stratigraphic sequences can be recognized. Sequence 1 (Callovian - earliest Kimmeridgian) records the initiation of the Dutch Central Graben, Sequence 2 (early Kimmeridgian - early Portlandian) that of the initiation of the Terschelling Basin. During sequence 3 (late Portlandian - Ryazanian) the Dutch offshore was draped by a regional transgression. These insights have directly impact on the exploration potential, which is discussed in two play concepts. The first is a strat-trap play in the fluvial/paralic sediments of Sequence 1 in the lows between the graben boundary and salt domes. The second example is the Spiculite play, which comprises a bioclastic sandstone reservoir at the top of a dome with a 4-way dip closure. These two examples highlight the necessity of understanding the paleoenvironment and geography for assessing the future exploration potential.


2021 ◽  
Vol 257 ◽  
pp. 03010
Author(s):  
Fengyu Sun ◽  
Gaoshe Cao ◽  
Zhou Xing

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.


2018 ◽  
Vol 1 (T5) ◽  
pp. 234-250
Author(s):  
Chuc Dinh Nguyen ◽  
Hiep Quoc Cao ◽  
Huy Nhu Tran ◽  
Xuan Van Tran

Up to recent years, major targets of oil and gas exploration in Cuu Long basin have been carried ort at structural traps in anticlines or basement highs in PreTertiary basement, Oligocene / Miocene clastics. As petroleum resources from reservoirs of traditional types become exhausted after many years of production (the remaining unexplored potential targets do not have sufficient reserves for development and production), exploration activities in Cuu Long basin have being focused in Oligocene stratigraphic/combination traps that have been discovered in recent years. Since the 1980s, petroleum explorers have identified oil in pinchouts trap in the Southeastern Cuu Long basin. However, these prospects have been evaluated to be of low potential due to be concerned of poor reservoir quality or incomplete petroleum system (lacking of source rocks or seals). Recent exploration activities in the region have identified several stratigraphic/ combination traps not only as pinch-outs but also as traps formed by appropriate facies changes. This article discusses types of stratigraphic traps that have been recently discovered in the studied area as well as exploration methods for predicting the distribution of these traps.


SPE Journal ◽  
2019 ◽  
Vol 24 (03) ◽  
pp. 1395-1414 ◽  
Author(s):  
Seunghwan Baek ◽  
I.. Yucel Akkutlu

Summary Source rocks, such as organic-rich shale, consist of a multiscale pore structure that includes pores with sizes down to the nanoscale, contributing to the storage of hydrocarbons. In this study, we observed hydrocarbons in the source rock partition into fluids with significantly varying physical properties across the nanopore-size distribution of the organic matter. This partitioning is a consequence of the multicomponent hydrocarbon mixture stored in the nanopores, exhibiting a significant compositional variation by pore size—the smaller the pore size, the heavier and more viscous the hydrocarbon mixture becomes. The concept of composition redistribution of the produced fluids uses an equilibrium molecular simulation that considers organic matter to be a graphite membrane in contact with a microcrack that holds bulk-phase produced fluid. A new equation of state (EOS) was proposed to predict the density of the redistributed fluid mixtures in nanopores under the initial reservoir conditions. A new volumetric method was presented to ensure the density variability across the measured pore-size distribution to improve the accuracy of predicting hydrocarbons in place. The approach allowed us to account for the bulk hydrocarbon fluids and the fluids under confinement. Multicomponent fluids with redistributed compositions are capillary condensed in nanopores at the lower end of the pore-size distribution of the matrix (<10 nm). The nanoconfinement effects are responsible for the condensation. During production and pressure depletion, the remaining hydrocarbons become progressively heavier. Hence, hydrocarbon vaporization and desorption develop at extremely low pressures. Consequently, hydrocarbon recovery from these small pores is characteristically low.


2015 ◽  
Vol 733 ◽  
pp. 39-42
Author(s):  
Zi Li Fan

To understand the oil and gas accumulation rules and main controlling factors of H Basin at different phases, approaches such as reservoir dissection and analysis on the spatial allocation of reservoir accumulation conditions are adopted to divide the reservoir of the main fault depression zones of central H Basin into early and late phases. The widely-spread oil and gas at early phase are obviously more than that of the late phase. The main controlling factors of reservoir accumulation at early phase include source rocks area, antithetic faults - tilted upheavals and sand body of fan delta front subfacies while that of the late phase include sources rocks area, inverted structure and long-term developed fractures. The achievement of the study expounded in this paper is significantly important to correctly understand the oil and gas accumulation rules of complicated faulted-block fields and guide the oil and gas exploration activities.


2021 ◽  
Vol 13 (1) ◽  
pp. 294-309
Author(s):  
Fengyu Sun ◽  
Gaoshe Cao ◽  
Zhou Xing ◽  
Shuangjie Yu ◽  
Bangbang Fang

Abstract The Upper Paleozoic coal measure strata in the Southern North China Basin have good potential for unconventional oil and gas exploration. However, there has been no systematic evaluation of potential source rock in this area; this affects the estimation of potential resources and the choice of exploratory target layers. In this study, full core holes ZK0901 and ZK0401, which perfectly reveal Upper Paleozoic strata in the study area, systematically collected and analyzed the samples for total organic carbon, rock pyrolysis, chloroform bitumen “A,” organic maceral, vitrinite reflectance, and kerogen carbon isotopes. The results showed that in addition to coal rocks, mudstones and carbonate rocks are also potential source rocks in the Upper Paleozoic strata. Vertically, the source rocks are continuous in Taiyuan Formation, the lower part of Shanxi Formation, and Lower Shihezi Formation. The organic matter type in the Upper Paleozoic coal rocks and mudstone source rock belong to type III or II. This phenomenon is mainly attributed to the special transgressive–regressive sedimentary environment of the carbonate rocks. The higher degree of thermal evolution in the Upper Paleozoic source rocks may be related to the structure or a higher paleogeothermal gradient in this area. The coal layer and its upper and lower mudstone of the Shanxi Formation and Lower Shihezi Formation are the main target layers of unconventional oil and gas exploration. The results from this study can be used as a reference for the study on potential source rock for unconventional oil and gas exploration in the Southern North China Basin.


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