scholarly journals Depositional environment and pore structure of mixed lithofacies shale of the Longmaxi Formation in the DM Block, the Southern Sichuan Basin, China

2019 ◽  
Vol 38 (3) ◽  
pp. 629-653 ◽  
Author(s):  
Jijun Tian ◽  
Chuanzheng Xu ◽  
Xin Li ◽  
Wenfeng Wang ◽  
Wen Lin
Keyword(s):  
Organic Carbon ◽  
Total Organic Carbon ◽  
Sichuan Basin ◽  
Depositional Environment ◽  
Sedimentary Environment ◽  
Nitrogen Adsorption ◽  
X Ray Diffraction ◽  
Low Field ◽  
Water Wetting ◽  
Longmaxi Shale

Distinguishing the differences of pore characters between different mixed lithofacies shales is helpful for improving shale gas development efficiencies. In this study, the targeted Longmaxi shale ( L1) of the Southern Sichuan Basin was selected as the research object. Two kinds of mixed lithofacies shale were identified by analyzing total organic carbon and X-ray diffraction results. The forming depositional environment of mixed lithofacies shale was researched by elements analyses. Pores in different mixed lithofacies shale were observed using field emission scanning electronic microscope. Low-field nuclear magnetic resonance and low-temperature nitrogen adsorption were conducted to analyze pore characters of different mixed lithofacies shale. The results showed that L1 were mainly composed of organic rich clay–siliceous mixed shales (OR-M-1) and organic extreme rich calcareous–siliceous mixed shales (OER-M-3). OR-M-1 and OER-M-3 were formed in high paleo-producing dysoxic–oxic seawater and anoxic waterbody, respectively. Micro-pore and meso-pore volumes of OER-M-3 were greater than those of OR-M-1 while macro-pore volume of OER-M-3 was lower than that of OR-M-1. Meso-pore surficial and structural complexities of OER-M-3 were greater than those of OR-M-1. OER-M-3 were greater in oil-wetting micro-pore structural complexities while lower in water-wetting micro-pore structural complexities, compared with OR-M-1. The inherent relationships between lithofacies type and sedimentary environment, total organic carbon, as well as pore characters, respectively, were quite close.

Lithology and sedimentary heterogeneity of the Longmaxi Shale in the southern Sichuan Basin, China

2021 ◽  
pp. 1-49
Author(s):  
Boling Pu ◽  
Dazhong Dong ◽  
Ning Xin-jun ◽  
Shufang Wang ◽  
Yuman Wang ◽  
...  
Keyword(s):  
Continental Shelf ◽  
Deep Water ◽  
Shale Gas ◽  
Sichuan Basin ◽  
Sedimentary Environment ◽  
Gas Production ◽  
Carbonaceous Shale ◽  
Gas Wells ◽  
Longmaxi Shale ◽  
Siliceous Shale

Producers have always been eager to know the reasons for the difference in the production of different shale gas wells. The Southern Sichuan Basin in China is one of the main production zones of Longmaxi shale gas, while the shale gas production is quite different in different shale gas wells. The Longmaxi formation was deposited in a deep water shelf that had poor circulation with the open ocean, and is composed of a variety of facies that are dominated by fine-grained (clay- to silt-size) particles with a varied organic matter distribution, causing heterogeneity of the shale gas concentration. According to the different mother debris and sedimentary environment, we recognized three general sedimentary subfacies and seven lithofacies on the basis of mineralogy, sedimentary texture and structures, biota and the logging response: (1) there are graptolite-rich shale facies, siliceous shale facies, calcareous shale facies, and a small amount of argillaceous limestone facies in the deep - water shelf in the Weiyuan area and graptolite-rich shale facies and carbonaceous shale facies in the Changning area; (2) there are argillaceous shale facies and argillaceous limestone facies in the semi - deep - water continental shelf of the Weiyuan area and silty shale facies in the Changning area; (3) argillaceous shale facies are mainly developed in the shallow muddy continental shelf in the Weiyuan area, while silty shale facies mainly developed in the shallow shelf in the Changning area. Judging from the biostratigraphy of graptolite, the sedimentary environment was different in different stages.

Logging Evaluation Method and its Application for Measuring the Total Organic Carbon Content in Shale

2014 ◽  
Vol 962-965 ◽  
pp. 51-54
Author(s):  
Zhi Feng Wang ◽  
Yuan Fu Zhang ◽  
Hai Bo Zhang ◽  
Qing Zhai Meng
Keyword(s):  
Organic Carbon ◽  
Total Organic Carbon ◽  
Shale Gas ◽  
Sichuan Basin ◽  
Evaluation Method ◽  
Organic Carbon Content ◽  
Geochemical Analysis ◽  
Data Logging ◽  
Longmaxi Formation ◽  
Sedimentary Structures

The acquisition of the total organic carbon (TOC) content mainly relies on the geochemical analysis and logging data. Due to geochemical analysis is restricted by coring and experimental analysis, so it is difficult to get the continuous TOC data. Logging evaluation method for measuring TOC is very important for shale gas exploration. This paper presents a logging evaluation method that the shale is segmented according to sedimentary structures. Sedimentary structures were recognized by core, thin section and scanning electron microscope. Taking Wufeng-Longmaxi Formation, Silurian, Muai Syncline Belt, south of Sichuan Basin as research object, the shale is divided into three kinds: massive mudstone, unobvious laminated mudstone, and laminated mudstone. TOC within each mudstone are calculated using GR, resistivity and AC logging data, and an ideal result is achieved. This method is more efficient, faster and the vertical resolution is higher than △logR method.

scholarly journals The Lithofacies of Pandua Formation Shale in the Andowia Area, North Konawe, Southeast Sulawesi and Its potential as Petroleum source rock

2021 ◽  
Vol 325 ◽  
pp. 08013
Author(s):  
Mawar Towan Lestari Ramli ◽  
Hendra Amijaya ◽  
Akmaluddin
Keyword(s):  
Organic Carbon ◽  
Total Organic Carbon ◽  
Source Rock ◽  
Depositional Environment ◽  
Petrographic Analysis ◽  
Hydrocarbon Accumulation ◽  
High Concentration ◽  
Area North ◽  
Excellent Source ◽  
Petroleum Source Rock

Research on the Late Miocene of Pandua Formation shale in Andowia area, Southeast Sulawesi is fundamental because it is considered to have the potential as a source rock in Manui Basin. This study aimed to determine the lithofacies and its potential as petroleum source rock using megascopic, petrographic, and total organic carbon analyses in Pandua Formation shale. Based on the megascopic and petrographic analysis of outcrops, the shale can be subdivided into 11 lithofacies consists of clayey shale, massive claystone, clastic detritus-rich claystone, massive mudstone, mica-rich mudstone, iron oxide-rich mudstone, low-angle laminated mudstone, massive siltstone, carbon-rich massive siltstone, laminated siltstone, and carbon-rich laminated siltstone. The results of the analysis of 19 samples of shale showed that the total organic carbon (TOC) content was classified as poor to excellent (<0.5%- >4%). The lithofacies with a high concentration of TOC are carbon-rich massive siltstone and carbon-rich laminated siltstone. Both lithofacies were categorized as potentially excellent source rock which the TOC value content is 5.78% and 5.74%.The result implies the better understanding of the depositional environment and hydrocarbon accumulation potential of the Manui basin for future exploration.

Carbone organique: indicateur potentiel de paléoenvironnements; deux exemples

1981 ◽  
Vol 18 (12) ◽  
pp. 1838-1849 ◽  
Author(s):  
R. Bertrand ◽  
Y. Héroux
Keyword(s):  
Organic Matter ◽  
Organic Carbon ◽  
Total Organic Carbon ◽  
Sedimentary Rock ◽  
Depositional Environment ◽  
Statistical Processing ◽  
Depositional Environments ◽  
The Other ◽  
Early Paleozoic

The paleoenvironment of deposition and the total organic carbon (TOC) content of two sedimentary rock sequences are studied. One has a Cenozoic age and is located on the Labrador shelf; the other is early Paleozoic and is found in the St. Lawrence Lowlands. In both sequences, variations in the paleoenvironments correspond to changes in the TOC content, despite important differences between them (age, tectonic and general paleogeographic contexts, lithologies, nature of the organic matter).A statistical processing of the data is used in order to show this parallelism between the paleoenvironment and the TOC content. In both cases, the higher the TOC content, the greater is the distance of the depositional environment from the shore. This result is in agreement with the conclusions of many other authors. This method may be very useful for detecting bathymetric variations in depositional environments, especially in monotonous sequences.

Esterification of chitosan with L-alanine and a study on their effect in removing the heavy metals and total organic carbon (TOC) from wastewater

2016 ◽  
Vol 88 (6) ◽  
pp. 595-604 ◽  
Author(s):  
Hassan H. H. Hefni ◽  
Mohammed Nagy ◽  
Mohammed M. Azab ◽  
Mohammed H. M. Hussein
Keyword(s):  
Heavy Metals ◽  
Organic Carbon ◽  
Total Organic Carbon ◽  
Adsorption Capacity ◽  
Elemental Analysis ◽  
Maximum Adsorption Capacity ◽  
X Ray Diffraction ◽  
Batch Mode ◽  
Ionic Bonds ◽  
Total Maximum

AbstractIn this work, chitosan was modified by the esterification with L-alanine in the presence of H2SO4 as a catalyst to increase the number of amino groups with the aim of increasing the adsorption efficiency. Chitosan (CS) and chitosan-O-alanine (CS-Aln) were characterized and investigated by elemental analysis, Fourier transform infrared (FTIR) spectroscopy and X-ray diffraction (XRD). The results obtained from elemental analysis and IR indicated the presence of sulfuric acid after neutralization as a crosslinker between CS-Aln chains. Also CS-Aln is more amorphous than CS due to the ionic bonds of crosslinker. The removal of three heavy metals (Mn2+, Pb2+ and Al3+) and total organic carbon (TOC) from wastewater by CS and CS-Aln in the batch mode has been studied at different adsorbent dosages, temperatures and contact times. The maximum metal ions removal efficiency using CS achieved 99.6%, 99.1% and 98.9%, respectively, while by using CS-Aln 95.3%, 99.3% and 98.9% were achieved. However, the maximum adsorption capacity of TOC by CS achieved 50 mg/g and 89 mg/g by CS-Aln. The total maximum adsorption capacity of CS-Aln is higher than CS.

Effect of total organic carbon and aquatic humic substances on the occurrence of lead at the tap

2015 ◽  
Vol 52 (1) ◽  
pp. 2-10 ◽  
Author(s):  
Lisa D. Winning ◽  
Beata Gorczyca ◽  
Kenneth Brezinski
Keyword(s):  
Organic Carbon ◽  
Total Organic Carbon ◽  
Humic Substances ◽  
Free Chlorine ◽  
X Ray Diffraction ◽  
X Ray ◽  
Treated Water ◽  
Aquatic Humic Substances ◽  
Lead Release ◽  
The City

Homes with lead service lines (LSLs) in the City of Brandon, Manitoba, Canada, were found to exceed the provincial standard of 10 μg/L for lead in drinking water. Solids identified by X-ray diffraction of LSL scale were Pb5O8 and PbO2, indicating that lead(II) solids in the LSL scale have been oxidized to lead(IV) solids by free chlorine residuals. Natural organic matter (NOM) can reduce PbO2 within a few hours, and Brandon treated water has high levels of NOM at approximately 5–7.6 mg/L as total organic carbon (TOC). As water stagnates in the LSL during periods of no water use the free chlorine residual is depleted, permitting PbO2 to oxidize NOM and be reduced to more soluble lead(II) species, resulting in an increase in dissolved lead concentrations. Although it is generally believed that aquatic humic substances (AHS) are primarily responsible for the reductant capacity of NOM, removal of AHS from the treated water resulted in a 6% decrease in lead release from PbO2, while removal of 50% of total NOM resulted in a 75% decrease in lead release. AHS and TOC were not found to play a significant role in the reduction of PbO2 in this water.

scholarly journals Using BiVO4/CuO-Based Photoelectrocatalyzer for 4-Nitrophenol Degradation

Materials ◽  
2020 ◽  
Vol 13 (6) ◽  
pp. 1322 ◽  
Author(s):  
Thiago Martimiano do Prado ◽  
Fernando Lindo Silva ◽  
Guilherme Grosseli ◽  
Pedro Sergio Fadini ◽  
Orlando Fatibello-Filho ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Total Organic Carbon ◽  
Hybrid Material ◽  
High Performance ◽  
X Ray Diffraction ◽  
Secondary Products ◽  
X Ray ◽  
Additional Information ◽  
Munk Function ◽  
Nitrophenol Degradation

The present work reports the degradation of 4-nitrophenol using BiVO4/CuO hybrid material synthesized by the precipitation of BiVO4 in the presence of CuO. Morphological and structural characterizations were performed using X-ray diffraction and scanning electronic microscopy coupled to energy dispersive X-ray spectroscopy. Through the calculation of the Kubelka–Munk function applied to diffuse reflectance spectrophotometry data, the hybrid material presented absorption edge of 1.85 eV. The formation of p-n heterojunction between BiVO4 and CuO renders the hybrid material suitable for the construction of a photoanode employed in hydroxyl radical generation. UV–vis spectrophotometry and high-performance liquid chromatography experiments were performed in order to monitor the degradation of 4-nitrophenol and the formation of secondary products. Additional information regarding the hybrid material was obtained through ion chromatography and total organic carbon analyses. The application of BiVO4/CuO-based photocatalyzer led to a 50.2% decrease in total organic carbon after the degradation of 4-nitrophenol. Based on the results obtained in the study, BiVO4/CuO has proved to be a promising material suitable for the removal of recalcitrant compounds in water treatment plants.

scholarly journals Development Characteristics of Shale Lithofacies in the Longmaxi Formation and their Main Controlling Factors in the Changning Area, South Sichuan Basin, SW China

2021 ◽  
Vol 9 ◽  
Author(s):  
Qingsong Tang ◽  
Lu Zhou ◽  
Lei Chen ◽  
Xiucheng Tan ◽  
Gaoxiang Wang
Keyword(s):  
Seismic Data ◽  
Sichuan Basin ◽  
Spatial Variations ◽  
X Ray Diffraction ◽  
Thin Sections ◽  
Longmaxi Formation ◽  
X Ray ◽  
Lower Silurian ◽  
Longmaxi Shale ◽  
Siliceous Shale

Based on core observations, thin sections, X-ray diffraction (XRD), and seismic data, the lithofacies types in the organic-rich Longmaxi shale (Lower Silurian) in the Changning area of the southern Sichuan Basin were identified. The factors controlling the spatial variations in the shale lithofacies and the influences of the shale lithofacies on shale gas development were also analyzed. Results indicate that there are seven main types of shale lithofacies in the Long11 sub-member of the Longmaxi Formation, including siliceous shale (S-1), mixed siliceous shale (S-2), carbonate-rich siliceous shale (S-3), clay-rich siliceous shale (S-4), carbonate/siliceous shale (M-1), mixed shale (M-2), and argillaceous/siliceous shale (M-4). A vertical transition from the carbonate shale association + mixed shale association at the bottom of the sub-member to a siliceous shale association and mixed shale association + siliceous shale at the top generally appears in the Long11 sub-member. The shale lithofacies of the Long11 sub-member also laterally change from the central depression (low-lying area) to the geomorphic highland in the east and west parts of the Changning area. The spatial variations in shale lithofacies in the Long11 sub-member of the Changning area were mainly controlled by palaeogeomorphology and relative sea level. The geomorphic highland area is dominated by carbonate-rich siliceous shale and mixed siliceous shale, but the depression (low-lying area) is mainly dominated by mixed siliceous shale and argillaceous/carbonate shale.

scholarly journals Reservoir Characteristics of the Lower Silurian Longmaxi Shale in Zhaotong Region, Southern China

Geofluids ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Chao Luo ◽  
Nanxin Yin ◽  
Hun Lin ◽  
Xuanbo Gao ◽  
Junlei Wang ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Total Organic Carbon ◽  
Shale Gas ◽  
Southern China ◽  
Gas Content ◽  
High Quality ◽  
Longmaxi Formation ◽  
Lower Silurian ◽  
Longmaxi Shale ◽  
Scanning Electron

The lower Silurian Longmaxi Formation hosts a highly productive shale gas play in the Zhaotong region of southern China. According to core observation, X-ray diffraction analyses, and scanning electron microscopy (SEM) observations, the shale comprises primarily quartz, carbonate minerals, and clay minerals, with minor amounts of plagioclase, K-feldspar, and pyrite. The clay mineral content ranges from 15.0% to 46.1%, with an average of 29.3% in the Zhaotong region. Organic geochemical analyses show that the Longmaxi Formation has good potential for shale gas resources by calculating total organic carbon, vitrinite reflectance, and gas content. Scanning electron microscope images demonstrate that reservoir pore types in the Longmaxi shale include organic pores, interparticle pores, intercrystalline pores, intraparticle pores, and fractures. Reservoir distribution is controlled by lithofacies, mineral composition, and geochemical factors. In addition, we investigated the relationships between reservoir parameters and production from 15 individual wells in the Zhaotong region by correlation coefficients. As a result, the brittleness index, total organic carbon (TOC), porosity, and gas content were used to define high-quality reservoirs in the Longmaxi shale. Based on these criteria, we mapped the thickness and distribution of high-quality reservoirs in the Longmaxi Formation and selected highlighted several key sites for future exploration and development.

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