Evaluation on Shale Gas Potential in the Sheling Group Yitong Basin

2014 ◽  
Vol 941-944 ◽  
pp. 2584-2587
Author(s):  
Han Yue Xu ◽  
Hai Tao Xue ◽  
Shuang Fang Lu ◽  
Wen Biao Huang ◽  
Lei Shi
Keyword(s):  
Organic Matter ◽  
Adsorption Isotherm ◽  
Chemical Kinetics ◽  
Shale Gas ◽  
Jilin Province ◽  
Resource Potential ◽  
Geochemical Parameters ◽  
High Maturity ◽  
Gas Potential

Yitong Basin is a Tertiary depression bas in Jilin Province , and from north to south were Chaluhe , Luxiang and Moliqing depression. As the depth is larger , high maturity of organic matter , more than 1% , mainly shale gas. Based on the geochemical parameters of sheling group , using chemical kinetics method study the birth hydrocarbon volume, using the sum of the largest shale gas tolerance capabilities , based on the adsorption isotherm experiments, combined hydrocarbon volume , calculated the shale gas resources in the region , the results showed that the total amount of resources sheling group Yitong Basin shale gas level was 238.215 billion square . Indicates that the area has huge shale gas resource potential

Lithofacies, Depositional Environment and Diagenetic Evolution of the Paleocene Patala Formation, Potwar Basin, Pakistan: Implication for Shale Gas Potential

2021 ◽  
Author(s):  
Nasar Khan ◽  
Rudy Swennen ◽  
Gert Jan Weltje ◽  
Irfan Ullah Jan
Keyword(s):  
Organic Matter ◽  
Shale Gas ◽  
Gas Reservoirs ◽  
Shallow Marine ◽  
Anoxic Conditions ◽  
Fine Grained ◽  
Potwar Basin ◽  
Diagenetic Evolution ◽  
Reservoir Assessment ◽  
Gas Potential

<p><span><strong>Abstract:</strong> Reservoir assessment of unconventional reservoirs poses numerous exploration challenges. These challenges relate to their fine-grained and heterogeneous nature, which are ultimately controlled by depositional and diagenetic processes. To illustrate such constraints on shale gas reservoirs, this study focuses on lithofacies analysis, paleo-depositional and diagenetic evolution of the Paleocene Patala Formation at Potwar Basin of Pakistan. Integrated sedimentologic, petrographic, X-ray diffraction and TOC (total organic carbon) analyses showed that the formation contained mostly fine-grained carbonaceous, siliceous, calcareous and argilaceous siliciclastic-lithofacies, whereas carbonate microfacies included mudstone, wackestone and packstone. The silicious and carbonaceous lithofacies are considered a potential shale-gas system. The clastic lithofacies are dominated by detrital and calcareous assemblage including quartz, feldspar, calcite, organic matter and clay minerals with auxiliary pyrites and siderites. Fluctuations in depositional and diagenetic conditions caused  lateral and vertical variability in lithofacies. Superimposed on the depositional heterogeneity are spatially variable diagenetic modifications such as dissolution, compaction, cementation and stylolitization. The δ</span><sup>13</sup><span>C and δ</span><sup>15</sup><span>N stable isotopes elucidated that the formation has been deposited under anoxic conditions, which relatively enhanced the preservation of mixed marine and terrigenous organic matter. Overall, the Patala Formation exemplifies deposition in a shallow marine (shelfal) environment with episodic anoxic conditions.</span></p><p><strong>Keywords</strong><strong>:</strong> Lithofacies, Organic Matter, Paleocene, Potwar Basin, Shale Gas, Shallow Marine.</p>

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.

scholarly journals Geochemistry and shale gas potential of the lower Permian marine-continental transitional shales in the Eastern Ordos Basin

2020 ◽  
pp. 014459872097924
Author(s):  
Jingyi Wei ◽  
Yongli Wang ◽  
Gen Wang ◽  
Zhifu Wei ◽  
Wei He
Keyword(s):  
Organic Matter ◽  
Organic Carbon ◽  
Total Organic Carbon ◽  
Shale Gas ◽  
Higher Plants ◽  
Ordos Basin ◽  
Organic Matter Content ◽  
Lower Permian ◽  
Gas Desorption ◽  
Geochemical Parameters

Marine–continental transitional strata were widely developed in the Ordos Basin in Upper Carboniferous - Lower Permian. The Taiyuan - Shanxi Formation possesses promising shale gas exploration layers. Shale samples from two drilling wells of Shanxi-Taiyuan Formation in Shilou and Xixian, Ordos Basin, were investigated to study their carbon–sulfur contents and distribution characteristics of organic components using carbon/sulfur analyzer and gas chromatography–mass spectroscopy. Using results of total organic carbon analyses, Rock-Eval pyrolysis, X-ray diffraction analysis, shale gas desorption experiments, and other relevant experimental data, the shale samples were comprehensively analyzed. The exploitability of the shale in the study area was evaluated. The Shanxi-Taiyuan Shale in the Shilou and Xixian areas was characterized by high total organic carbon contents of 7.1% and 2.1% and high Tmax values of 499 and 505 °C, respectively. The organic matter of the shale is types II2 and III. Moreover, biomarker parameters including n-alkanes, Paq, Pwax, average carbon chain length, and the ternary diagram of C27-C28-C29 steranes show the organic matter constituted terrestrial higher plants and aquatic low biological algae. Multiple n-alkane parameters show the organic matter input in the Shilou area is mainly derived from terrestrial higher plants. The Pr/Ph value and trace element indicators show the deposition environment is dominated by weak oxidation–reduction conditions. A shale gas desorption experiment shows the average desorbed gas contents of the shale samples in the Shilou and Xixian areas were 1.79 and 0.37 m3/t, respectively. The organic matter content determined the differences in shale gas properties between the two areas in Ordos Basin. The composition and content of inorganic minerals affect the reservoir physical properties. According to the analyses, the shale in the Shilou area has good shale gas reservoir characteristics in terms of desorbed gas content and the above-mentioned geochemical parameters. Furthermore, the Shanxi shale has good potential for shale gas industrial exploitation.

Upper Carboniferous Shale Gas Potential Analysis in Eastern Qaidam Basin, Northwestern China

2014 ◽  
Vol 1010-1012 ◽  
pp. 1425-1429
Author(s):  
Hai Yan Cheng ◽  
Yin Sheng Ma ◽  
Cheng Ming Yin ◽  
Yuan Yuan Yang
Keyword(s):  
Organic Matter ◽  
Shale Gas ◽  
Oil And Gas ◽  
Qaidam Basin ◽  
Source Rocks ◽  
Carbonaceous Shale ◽  
Silty Mudstone ◽  
Upper Carboniferous ◽  
Carboniferous Shale ◽  
Gas Potential

Shale of rich organic matter presents in Upper Carboniferous in Qaidam Basin, Northwest of China. Carboniferous shale thickness is between 100 ~ 300m in the Qaidam Basin, the shale includes silty mudstone shale, calcareous mudstone, shale and carbonaceous shale, and it is very favorable lithology type for shale gas. According to the shale organic geochemical analysis, the abundance of organic matter reaching the middle - good degree of hydrocarbon source rocks; the type of organic matter is mainly II2 and III type. The maturity of organic matter is mainly between 1 % -1.3 %. The Upper Carboniferous shale thermal evolution is in mature oil and gas stage. The Upper Carboniferous hydrocarbon-rich shale distribute stability, with great thickness. Shale gas potential in Upper Carboniferous is quite large.

scholarly journals Jurassic Terrestrial Shale Gas Potential of the Northern Kashi Sag in the Tarim Basin, Northwestern China

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-16
Author(s):  
Wei Wu ◽  
Zhiwei Liao ◽  
Honghan Chen ◽  
Shaohu Li ◽  
Ao Su ◽  
...  
Keyword(s):  
Organic Matter ◽  
Surface Area ◽  
Tarim Basin ◽  
Shale Gas ◽  
Pore Volume ◽  
Middle Jurassic ◽  
Vitrinite Reflectance ◽  
Mature Stage ◽  
Average Pore ◽  
Gas Potential

Evaluation of terrestrial shale gas resource potential is a hot issue in unconventional oil and gas exploration. Organic-rich shales are widely developed in the Jurassic strata of Tarim Basin, but their shale gas potential has not been described well. In the study, the Lower-Middle Jurassic fine-grained sedimentary rocks (Kangsu and Yangye Formations) in northern Kashi Sag, northwestern Tarim Basin, were taken as the study object. The comprehensive studies include petrology, mineralogy, organic geochemistry, and physical properties, which were used to characterize the organic matter and reservoir characteristics. Results show that the Jurassic terrestrial shale in the northern Kashi Sag was mainly deposited in lakes, rivers, and deltas. The thickness of black lacustrine shale developed in the Early-Middle Jurassic in the study area is generally over 100 m. The total organic carbon (TOC) content is rich, averaging 2.77%. The vitrinite reflectance ( R o ) values indicate that the Lower Jurassic shale organic matter is in the early mature–mature stage, while the Middle Jurassic is in the mature stage. Besides, organic matter is primarily II and III in kerogen types. The whole shale contains a large number of clay minerals, especially illite. The average brittle minerals such as quartz and feldspar are 28.67%, and the average brittleness index is 38.63%. Nanoscale pores containing intergranular pores, dissolution pores, and organic pores, coupled with microcracks, are well developed in Jurassic shale. The sample’s average pore volume is 0.017 cm3/g, and the specific surface area is 9.36 m2/g. Mesoporous contribute the most to pore volume, while the number of microporous is the largest. Both of them provide most of the surface area for the shale. Combined with regional geologic settings, we propose that the Jurassic terrestrial shale has good-excellent shale gas exploration potential and development prospects.

Characteristics of Chang 7 shale gas in the Triassic Yanchang Formation, Ordos Basin, China

2017 ◽  
Vol 5 (2) ◽  
pp. SF31-SF39 ◽  
Author(s):  
Xiangzeng Wang
Keyword(s):  
Organic Matter ◽  
Clay Mineral ◽  
Shale Gas ◽  
Mineral Content ◽  
Ordos Basin ◽  
Central China ◽  
Late Triassic ◽  
Yanchang Formation ◽  
Geochemical Parameters ◽  
Porosity And Permeability

The Yanchang Formation in the Ordos Basin in North Central China represents a large, long-lived lacustrine system of the late Triassic Period. The extensive shales within this system provide hydrocarbons (HCs) for conventional and unconventional oil and gas reservoirs. In the formation, the Chang 7 shale is the thickest shale with the best geochemical parameters, and it is the main source rock in this area. In recent years, the discovery of shale gas in the Chang 7 shale has promoted the exploration and development of lacustrine shale gas in China. We have estimated the shale gas resource potential based on the analysis of the geologic conditions of the Chang 7 shale. The average thickness of the Chang 7 shale reaches 42.6 m, and the main organic matter types are types [Formula: see text] and [Formula: see text]. The average content of organic carbon is more than 3%, and the average HC potential is [Formula: see text]. However, the thermal maturity of the Chang 7 shale is low with a vitrinite reflectance [Formula: see text] ranging from 0.83% to 1.10%. The Chang 7 shale lithology consists of shale and sandy laminations or thin sandstones. The shale is characterized by high clay mineral content and poor porosity and permeability, with an average porosity of 1.8% and an average permeability of [Formula: see text]. The sandy laminations or thin sandstones are characterized by relatively higher brittle mineral content, relatively lower clay mineral content, and higher porosity and permeability. The pores of the Chang 7 shale include primary intergranular and intragranular pores, secondary intragranular and intragranular dissolved pores, fracture pores, and organic-matter-hosted pores. The proportion of adsorbed gas, free gas, and dissolved gas is approximately 52%, 37%, and 11%, respectively, and the shale gas resources of the Chang 7 shale are [Formula: see text].

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