Petroleum generation and expulsion characteristics of Lower and Middle Jurassic source rocks on the southern margin of Junggar Basin, northwest China: implications for unconventional gas potential

2014 ◽  
Vol 51 (6) ◽  
pp. 537-557 ◽  
Author(s):  
Jigang Guo ◽  
Xiongqi Pang ◽  
Fengtao Guo ◽  
Xulong Wang ◽  
Caifu Xiang ◽  
...  
Keyword(s):  
Source Rock ◽  
Shale Gas ◽  
Middle Jurassic ◽  
Junggar Basin ◽  
Northwest China ◽  
Source Rocks ◽  
Coal Bed ◽  
Southern Margin ◽  
Petroleum Generation ◽  
Gas Potential

Jurassic strata along the southern margin of Junggar Basin are important petroleum system elements for exploration in northwest China. The Lower and Middle Jurassic source rock effectiveness has been questioned as exploration progresses deeper into the basin. These source rocks are very thick and are distributed widely. They contain a high total organic carbon composed predominantly of Type III kerogen, with some Type II kerogen. Our evaluation of source rock petroleum generation characteristics and expulsion history, including one-dimensional basin modeling, indicates that Jurassic source rocks are gas prone at deeper depths. They reached peak oil generation during the Early Cretaceous and began to generate gas in the Late Cretaceous. Gas generation peaked in the Paleogene–Neogene. Source rock shales and coals reached petroleum expulsion thresholds at thermal maturities of 0.8% and 0.75% vitrinite reflectance, respectively, when the petroleum expulsion efficiency was ∼40%. The petroleum generated and expelled from these source rocks are 3788.75 × 108 and 1507.55 × 108 t, respectively, with a residual 2281.20 × 108 t retained in the source rocks. In these tight reservoirs, a favorable stratigraphic relationship (where tight sandstone reservoirs directly overlie the source rocks) indicates short vertical and horizontal migration distances. This indicates the potential for a large, continuous, tight-sand gas resource in the Lower and Middle Jurassic strata. The in-place natural gas resources in the Jurassic reservoirs are up to 5.68 × 1012 − 15.14 × 1012 m3. Jurassic Badaowan and Xishanyao coals have geological characteristics that are favorable for coal-bed methane resources, which have an in-place resource potential between 3.60 × 1012 and 11.67 × 1012 m3. These Lower and Middle Jurassic strata have good shale gas potential compared with active US shale gas, and the inferred in-place shale gas resources in Junggar Basin are between 20.73 × 1012 and 113.89 × 1012 m3. This rich inferred conventional and unconventional petroleum resource in tight-sand, coal-bed, and shale gas reservoirs makes the deeper Jurassic strata along the southern margin of Junggar Basin a prospective target for future exploration.

scholarly journals Geochemical characteristics and origin of hydrocarbons in the Mesoproterozoic reservoirs in the Liaoxi Depression, NE China

2019 ◽  
Vol 38 (2) ◽  
pp. 333-347 ◽  
Author(s):  
Youjun Tang ◽  
Meijun Li ◽  
Qiuge Zhu ◽  
Daxiang He ◽  
Xingchao Jiang ◽  
...  
Keyword(s):  
Molecular Marker ◽  
Source Rock ◽  
Middle Jurassic ◽  
Distribution Patterns ◽  
Geochemical Characteristics ◽  
Oil Reservoirs ◽  
Source Rocks ◽  
Ne China ◽  
Normal Alkanes ◽  
Petroleum Generation

Oil reservoirs have been discovered in the Mesoproterozoic strata in the Liaoxi Depression, NE China. In order to determine the source of oil shows of the Mesoproterozoic Gaoyuzhuang Formation and their organic geochemical characteristics, eight source rocks and reservoir cores from the Mesoproterozoic Gaoyuzhuang Formation and four source rocks from the overlying Middle Jurassic Haifanggou Formation were geochemically analysed. The distribution patterns of normal alkanes, acyclic isoprenoids, hopanes, steranes and triaromatic steroids of the Mesoproterozoic hydrocarbons from Well N-1 are consistent with those of source rock extracts from the Mesoproterozoic Gaoyuzhuang Formation in the Well L-1. The molecular marker compositions of source rock extracts from the overlying Middle Jurassic Haifanggou Formation are distinctively different from those of the Mesoproterozoic hydrocarbons. The results suggest that the Mesoproterozoic source rocks have significant petroleum generation potential. The Mesoproterozoic paleo-reservoir may be prospecting exploration targets in the Liaoxi Depression, NE China.

scholarly journals Evaluation of the quality, thermal maturity and distribution of potential source rocks in the Danish part of the Norwegian–Danish Basin

2008 ◽  
Vol 16 ◽  
pp. 1-66 ◽  
Author(s):  
Henrik I. Petersen ◽  
Lars H. Nielsen ◽  
Jørgen A. Bojesen-Koefoed ◽  
Anders Mathiesen ◽  
Lars Kristensen ◽  
...  
Keyword(s):  
Source Rock ◽  
Early Cretaceous ◽  
Middle Jurassic ◽  
Upper Cretaceous ◽  
Vitrinite Reflectance ◽  
Lower Jurassic ◽  
Source Rocks ◽  
Thermal Maturity ◽  
Potential Source ◽  
Petroleum Generation

The quality, thermal maturity and distribution of potential source rocks within the Palaeozoic–Mesozoic succession of the Danish part of the Norwegian-Danish Basin have been evaluated on the basis of screening data from over 4000 samples from the pre-Upper Cretaceous succession in 33 wells. The Lower Palaeozoic in the basin is overmature and the Upper Cretaceous – Cenozoic strata have no petroleum generation potential, but the Toarcian marine shales of the Lower Jurassic Fjerritslev Formation (F-III, F-IV members) and the uppermost Jurassic – lowermost Cretaceous shales of the Frederikshavn Formation may qualify as potential source rocks in parts of the basin. Neither of these potential source rocks has a basinwide distribution; the present occurrence of the Lower Jurassic shales was primarily determined by regional early Middle Jurassic uplift and erosion. The generation potential of these source rocks is highly variable. The F-III and F-IV members show significant lateral changes in generation capacity, the best-developed source rocks occurring in the basin centre. The combined F-III and F-IV members in the Haldager-1, Kvols-1 and Rønde-1 wells contain 'net source-rock' thicknesses (cumulative thickness of intervals with Hydrogen Index (HI)> 200 mg HC/g TOC) of 40 m, 83 m, and 92 m, respectively, displaying average HI values of 294, 369 and 404 mg HC/g TOC. The Mors-1 well contains 123 m of 'net source rock' with an average HI of 221 mg HC/g TOC. Parts of the Frederikshavn Formation possess a petroleum generation potential in the Hyllebjerg-1, Skagen-2, Voldum-1 and Terne-1 wells, the latter well containing a c. 160 m thick highly oil-prone interval with an average HI of 478 mg HC/g TOC and maximum HI values> 500 mg HC/g TOC.The source-rock evaluation suggests that a Mesozoic petroleum system is the most likely in the study area. Two primary plays are possible: (1) the Upper Triassic – lowermost Jurassic Gassum play, and (2) the Middle Jurassic Haldager Sand play. Potential trap structures are widely distributed in the basin, most commonly associated with the flanks of salt diapirs. The plays rely on charge from the Lower Jurassic (Toarcian) or uppermost Jurassic – lowermost Cretaceous shales. Both plays have been tested with negative results, however, and failure is typically attributed to insufficient maturation (burial depth) of the source rocks. This maturation question has been investigated by analysis of vitrinite reflectance data from the study area, corrected for post-Early Cretaceous uplift. A likely depth to the top of the oil window (vitrinite reflectance = 0.6%Ro) is c. 3050–3100 m based on regional coalification curves. The Frederikshavn Formation had not been buried to this depth prior to post-Early Cretaceous exhumation, and the potential source rocks of the formation are thermally immature in terms of hydrocarbon generation. The potential source rocks of the Fjerritslev Formation are generally immature to very early mature. Mature source rocks in the Danish part of the Norwegian–Danish Basin are thus dependent on local, deeper burial to reach the required thermal maturity for oil generation. Such potential kitchen areas with mature Fjerritslev Formation source rocks may occur in the central part of the study area (central–northern Jylland), and a few places offshore. These inferred petroleum kitchens are areally restricted, mainly associated with salt structures and local grabens (such as the Fjerritslev Trough and the Himmerland Graben).

Application of integrated formationevaluation and three-dimensional modeling in shale gas prospect identification

2020 ◽  
Vol 1 (3) ◽  
Author(s):  
Jin Gao ◽  
Guangdi Liu ◽  
Zhe Cao ◽  
Lijun Du ◽  
Yuhua Kong
Keyword(s):  
Sorption Capacity ◽  
Shale Gas ◽  
Vitrinite Reflectance ◽  
Three Dimensional ◽  
Junggar Basin ◽  
Northwest China ◽  
Wide Distribution ◽  
Methane Sorption ◽  
Northwestern Margin ◽  
Gas Potential

Identifying the shale gas prospect is crucial for gas extraction from such reservoirs. Junggar Basin (in Northwest China) is widely considered to have high potential as a shale gas resource, and the Jurassic, the most significant gas source strata, is considered as prospective for shale gas exploration and development. This study evaluated the Lower Jurassic Badaowan Formation shale gas potential combined with geochemical, geological, and well logging data, and built a three-dimensional (3D) model to exhibit favorable shale gas prospects. In addition, methane sorption capacity was tested for verifying the prospects. The Badaowan shale had an average total organic carbon (TOC) content of 1.30 wt. % and vitrinite reflectance (Ro) ranging from 0.47% to 0.81% with dominated type III organic matter (OM). X-ray diffraction (XRD) analyses showed that mineral composition of Badaowan shale was fairly homogeneous and dominated by clay and brittle minerals. 67 wells were used to identify prospective shale intervals and to delineate the area of prospects. Consequently, three Badaowan shale gas prospects in Junggar Basin were identified: the northwestern margin prospect, eastern Central Depression prospect and Wulungu Depression prospect. The middle interval of the northwestern margin prospect was considered to be the most favorable exploration target benefitted by wide distribution and high lateral continuity. Generally, methane sorption capacity of the Badaowan shale was comparable to that of the typical gas shales with similar TOC content, showing a feasible gas potential.

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.

Petroleum generation kinetics for Permian lacustrine source rocks in the Junggar Basin, NW China

2016 ◽  
Vol 98 ◽  
pp. 1-17 ◽  
Author(s):  
Baoli Xiang ◽  
Erting Li ◽  
Xiuwei Gao ◽  
Ming Wang ◽  
Yi Wang ◽  
...  
Keyword(s):  
Junggar Basin ◽  
Source Rocks ◽  
Nw China ◽  
Petroleum Generation

scholarly journals Geochemical Characteristics of Gas and Flowback Water in Lake Facies Shale: A Case Study From the Junggar Basin, China

2021 ◽  
Vol 9 ◽  
Author(s):  
Lin Zhang ◽  
Dan Liu ◽  
Yongjin Gao ◽  
Min Zhang
Keyword(s):  
Carbon Isotope ◽  
Shale Gas ◽  
Isotope Composition ◽  
Ordos Basin ◽  
Junggar Basin ◽  
Source Rocks ◽  
Flowback Water ◽  
Lucaogou Formation ◽  
The Difference

The chemical and isotopic compositions of the natural gas and the co-produced flowback water from the XJC 1 well in Junggar Basin, China, were analyzed to determine the origin of gases in the Permian Lucaogou Formation (P2l) and the Triassic Karamay Formation (T2k) in the Bogda Mountain periphery area of the Southern Junggar Basin. The value of carbon isotope composition of the P2l lacustrine shale gas in the Junggar Basin was between the shale gas in Chang 7 Formation of Triassic (T1y7) in the Ordos Basin and that in the Xu 5 Formation of Triassic (T3x5) in the Sichuan Basin. The difference in gas carbon isotope is primarily because the parent materials were different. A comparison between compositions in the flowback water reveals that the P2l water is of NaHCO3 type while the T2k water is of NaCl type, and the salinity of the latter is higher than the former, indicating a connection between P2l source rock and the T2k reservoir. In combination with the structural setting in the study area, the gas filling mode was proposed as follows: the gas generated from the lacustrine source rocks of the Permian Lucaogou Formation is stored in nearby lithological reservoirs from the Permian. Petroleum was also transported along the faults to the shallow layer of the Karamay Formation over long distances before it entered the Triassic reservoir.

Sign in / Sign up

Export Citation Format

Share Document