A Quantitative Study of Hydrocarbon Generation & Expulsion of Lower Silurian Longmaxi Shale in the Southern Sichuan Basin

2014 ◽  
Author(s):  
Xiaoming Chen ◽  
Jianzhong Li ◽  
Tao Yang ◽  
Weipeng Yan
Keyword(s):  
Quantitative Study ◽  
Sichuan Basin ◽  
Hydrocarbon Generation ◽  
Lower Silurian ◽  
Longmaxi Shale

Sichuan Basin Shale Gas, China: Exploring the Lower Silurian Longmaxi Shale

2011 ◽  
Author(s):  
Claudia Hackbarth ◽  
Kwong Yin Soo ◽  
Navpreet Singh
Keyword(s):  
Shale Gas ◽  
Sichuan Basin ◽  
Lower Silurian ◽  
Longmaxi Shale

Comparative analysis of shale reservoir characteristics in the Wufeng-Longmaxi (O3w-S1l) and Niutitang (Є1n) Formations: A case study of wells JY1 and TX1 in the southeastern Sichuan Basin and its neighboring areas, southwestern China

2018 ◽  
Vol 6 (4) ◽  
pp. SN31-SN45 ◽  
Author(s):  
Ruyue Wang ◽  
Zongquan Hu ◽  
Chuanxiang Sun ◽  
Zhongbao Liu ◽  
Chenchen Zhang ◽  
...  
Keyword(s):  
Comparative Analysis ◽  
Pore Structure ◽  
Sichuan Basin ◽  
Tectonic Deformation ◽  
Hydrocarbon Generation ◽  
Reservoir Characteristics ◽  
Longmaxi Shale ◽  
Methane Sorption ◽  
Shale Reservoir ◽  
Southeastern Sichuan Basin

A systematic comparative analysis of shale reservoir characteristics of the Wufeng-Longmaxi (O3 w-S1 l) and Niutitang (Є1 n) Formations in southeastern Sichuan Basin and its neighboring areas was conducted with respect to mineralogy, organic geochemistry, pore structure, methane sorption, brittleness, and fractures. Results indicate that (1) organic matter (OM)-hosted pores that are hundreds of nanometers to micrometers in size in the Longmaxi shale are well-developed in migrated OM rather than in the in situ OM, and they are the dominant reservoir spaces. Furthermore, the total organic carbon (TOC), brittleness, organic pores, and bedding fractures have good synergistic development relationships. However, there are fewer OM-hosted pores in the Niutitang shale; they are smaller in size, usually less than 30 nm, and have a more complicated pore structure. The intergranular pores in cataclastic organic-inorganic mineral fragments are the dominant reservoir spaces in the Niutitang shale and are coupled with stronger methane sorption and desorption capacities. (2) The piecewise correlation between TOC and brittleness indicates the significant differences in pore and fracture characteristics. When the TOC [Formula: see text], the TOC, brittleness, organic/inorganic pores, and fractures synergistically develop; when the TOC [Formula: see text], even though the increase in ductility reduces the number of fractures, the lower cohesive strength, internal friction angle, and weaker surfaces of interlayer fractures and cataclastic minerals promote the development of slip fractures, which significantly improves the fracture effectiveness and reservoir spaces for free and absorbed shale gas. (3) The Longmaxi, Wufeng, and Niutitang shales formed and evolved in different evolutionary stages. With the evolution of hydrocarbon generation, diagenesis, tectonic deformation, and pressure, the size and proportion of OM-hosted pores gradually decrease. At the same time, the complexity of the pore-fracture structure, the methane adsorption/desorption capacity, and the proportion of inorganic pores and fractures increase.

scholarly journals Organoporosity Evaluation of Shale: A Case Study of the Lower Silurian Longmaxi Shale in Southeast Chongqing, China

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Fangwen Chen ◽  
Shuangfang Lu ◽  
Xue Ding
Keyword(s):  
Organic Carbon ◽  
Shale Gas ◽  
Material Balance ◽  
Model Parameters ◽  
Correction Coefficient ◽  
Hydrocarbon Generation ◽  
Gas Reservoir ◽  
Lower Silurian ◽  
Shale Gas Reservoir ◽  
Longmaxi Shale

The organopores play an important role in determining total volume of hydrocarbons in shale gas reservoir. The Lower Silurian Longmaxi Shale in southeast Chongqing was selected as a case to confirm the contribution of organopores (microscale and nanoscale pores within organic matters in shale) formed by hydrocarbon generation to total volume of hydrocarbons in shale gas reservoir. Using the material balance principle combined with chemical kinetics methods, an evaluation model of organoporosity for shale gas reservoirs was established. The results indicate that there are four important model parameters to consider when evaluating organoporosity in shale: the original organic carbon (w(TOC0)), the original hydrogen index (IH0), the transformation ratio of generated hydrocarbon (F(Ro)), and the organopore correction coefficient (C). The organoporosity of the Lower Silurian Longmaxi Shale in the Py1 well is from 0.20 to 2.76%, and the average value is 1.25%. The organoporosity variation trends and the residual organic carbon of Longmaxi Shale are consistent in section. The residual organic carbon is indicative of the relative levels of organoporosity, while the samples are in the same shale reservoirs with similar buried depths.

The shale characteristics and shale gas exploration prospects of the Lower Silurian Longmaxi shale, Sichuan Basin, South China

2014 ◽  
Vol 21 ◽  
pp. 636-648 ◽  
Author(s):  
Chao Liang ◽  
Zaixing Jiang ◽  
Chunming Zhang ◽  
Ling Guo ◽  
Yiting Yang ◽  
...  
Keyword(s):  
South China ◽  
Shale Gas ◽  
Sichuan Basin ◽  
Lower Silurian ◽  
Longmaxi Shale

scholarly journals Coevolutionary Dynamics of Organic-Inorganic Interactions, Hydrocarbon Generation, and Shale Gas Reservoir Preservation: A Case Study from the Upper Ordovician Wufeng and Lower Silurian Longmaxi Formations, Fuling Shale Gas Field, Eastern Sichuan Basin

Geofluids ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-21
Author(s):  
Zhijun Jin ◽  
Haikuan Nie ◽  
Quanyou Liu ◽  
Jianhua Zhao ◽  
Ruyue Wang ◽  
...  
Keyword(s):  
Shale Gas ◽  
Sichuan Basin ◽  
Hydrocarbon Generation ◽  
Upper Ordovician ◽  
Gas Field ◽  
Pressure System ◽  
Lower Silurian ◽  
Eastern Sichuan Basin ◽  
Eastern Sichuan

Shale gas deposits are self-sourced, self-accumulating, and self-preserving in the Upper Ordovician Wufeng Formation and Lower Silurian Longmaxi Formation of the Fuling Shale Gas Field in the eastern Sichuan Basin. They were both seemingly mixed by secondary oil cracking and kerogen cracking gases during the high maturation window. The reservoir space primarily consists of mineral pores and organic matter (OM) pores, and the shale gas was mainly trapped by a high-pressure system. In this study, the Fuling O3w-S1l Shale Gas Field in the eastern Sichuan Basin was used as a case study to discuss the coevolutionary process and organic-inorganic interactions of hydrocarbon generation, accumulation, and preservation. The results indicate that the processes and mechanisms of organic-inorganic interactions and coevolution of hydrocarbon generation and reservoir preservation are quite different among the shale graptolite zones (GZ) with respect to hydrocarbon generation, types and characteristics of shale gas reservoirs, seal characteristics, and their spatiotemporal relations. In the WF2-LM4 GZ, the favorable OM, biogenic authigenic quartz and organic-inorganic interactions are highly coupled, leading to the high level of coevolution demonstrated within the field, as well as to the favorable conditions for shale gas accumulation. Conversely, the overlying LM5-LM8 GZ seemingly exhibits early densification and late charge and has a reverse mode of reservoir development (i.e., low degree of coevolution). These two coevolutionary processes were conducive to the development of a high degree of spatiotemporal matching between the reservoir (i.e., WF2-LM4 GZ) and the seal (i.e., LM5-LM8 GZ). This is due to underlying differences in their coevolutionary histories. The synthetic work presented here on the coevolutionary processes and mechanisms of formation for organic-inorganic interactions and hydrocarbon generation and reservoir preservation reveals insights into the driving mechanisms of shale gas enrichment, providing a basis for effectively predicting favorable enrichment intervals for shale gas worldwide.

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