Shale gas enrichment conditions in the frontal margin of Dabashan orogenic belt, south China

Kang, Jin‐Kyu; Sun, Yu; Men, Yupeng; Tian, Jingchun; Qian, Yu; Yan, Jiayong; Jia-shan, Lin; Liu, Jun

doi:10.1016/j.jngse.2018.03.010

Cited by 4 publications

(6 citation statements)

References 26 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Shale gas in these deformed rocks is well-preserved and exploration activity has revealed a high gas content [7,8]. [6], Ma et al [7], Kang et al [10]). 1-1: Xuefengshan fold subzone; 1-2: Western Hubei-Eastern Chongqing-Northern Guizhou fold subzone; 1-3: Qiyueshan-Jinfoushan-Daloushan fold subzone; 2-1: Eastern Sichuan fold belt; 2-2: Central Sichuan fold belt; 2-3: Western Sichuan fold belt; 2-4: Southern Sichuan fold belt; 3: Longmenshan fold belt; 4: Michangshan fold belt; 5: Dabashan fold belt; 6: Emeishan-Daliangshan block-fault belt; 7: Xichang basin; 8: Kangdian tectonic belt.…”

Section: Geological Background and Sample Characterizationmentioning

confidence: 98%

“…The basin is bounded by the Longmenshan fault in the west, the Micangshan uplift in the north, the Dabashan intracontinental orogen in the northeast, the Daloushan in the southeast, and the Emei-Daliangshan fold belt in the southwest [29] (Figure 1a). The Dabashan thrust-fold belt is separated into the South Dabashan and the North Dabashan by the NW-striking Chengkou fault in the transitional zone of the northeast edge of the upper Yangtze block; thus forming a thrusting nappe, ductile shear zone in the front edge of the orogen [6,7,10] (Figure 1b). Shale gas in these deformed rocks is well-preserved and exploration activity has revealed a high gas content [7,8].…”

Section: Geological Background and Sample Characterizationmentioning

confidence: 99%

“…Organic-rich shale currently produces commercial unconventional hydrocarbons and exhibits a wide variation in nano-and microscale geological attributes and geochemical properties [1][2][3][4][5]. The lower Cambrian Lujiaping Formation marine, organic-rich shales in the Dabashan Thrust-fold Belt of South China are being studied for their potential as shale gas reservoirs [6][7][8][9][10]. Several studies have discussed structural style and conditions of shale gas enrichment [6,10], while other studies have characterized microstructures and associated reservoir quality [7][8][9].…”

Section: Introductionmentioning

confidence: 99%

“…The lower Cambrian Lujiaping Formation marine, organic-rich shales in the Dabashan Thrust-fold Belt of South China are being studied for their potential as shale gas reservoirs [6][7][8][9][10]. Several studies have discussed structural style and conditions of shale gas enrichment [6,10], while other studies have characterized microstructures and associated reservoir quality [7][8][9]. Such investigations concentrate on nano-to microscale pore systems in the Lujiaping Shale using high-pressure methane sorption analysis, mercury injection capillary pressure (MICP), low-pressure nitrogen adsorption (LPNA), low-field nuclear magnetic resonance (NMR), and focused ion beam-scanning electron microscope imaging (FIB-SEM).…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Tectonic and Thermal Controls on the Nano-Micro Structural Characteristic in a Cambrian Organic-Rich Shale

Zhu

Huang

et al. 2019

Minerals

View full text Add to dashboard Cite

Until recently, the characteristics of nano-microscale structures in the naturally deformed, overmature, marine shales were poorly known. Thermally overmature Lujiaping shales in the complex tectonic area of the northeast part of the upper Yangtze area, China have experienced strong tectonic deformation and are considered as potentially important strata for shale gas exploration. Naturally deformed samples from the main source rocks are selected from the Lower Cambrian Lujiaping Formation in the Dabashan Thrust-fold Belt to investigate nanometer- to micrometer-sized structures. A combination of scanning electron microscope (SEM), low-pressure nitrogen adsorption (LPNA), and low-field nuclear magnetic resonance (NMR) suggests that the pore types are dominantly fracture-related pores with a lesser abundance of mineral-hosted pores. These two pore types account for the 90% of total pore space. Organic matter (OM)-hosted pores are rare and make up a small part of the pore systems (less than 10%) due to high thermal maturity and intensive tectonic compression. Overall, the Lujiaping deformed, overmature samples have abundant nanometer- to micrometer-sized inorganic pores. High-resolution SEM images provide direct evidence of the formation of nano- and microsized structures such as OM–clay aggregates and silica nanograins. OM–clay aggregates are commonly observed in samples, which also exhibit abundant open microfractures and interparticle pores. Quartz can occur as silica nanograins and botryoids typically 20–100 nm in size, which may influence porosity through the creation or occupying interparticle pore space.

show abstract

Section: Geological Background and Sample Characterizationmentioning

confidence: 98%

Section: Geological Background and Sample Characterizationmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Tectonic and Thermal Controls on the Nano-Micro Structural Characteristic in a Cambrian Organic-Rich Shale

Zhu

Huang

et al. 2019

Minerals

View full text Add to dashboard Cite

show abstract

“…The vitrinite reflectance test was carried out using a Leica DM4500P polarizing microscope and a 6-hole QDI308 microscopic spectrophotometer with a minimum sampling area ≤1 μm 2 (Chen et al, 2018;Kang et al, 2018). The measurement of the vitrinite reflectance was conducted according to the international standards "GB/T 6948" and "SY/T 5124-2010".…”

Section: Vitrinite Reflectance Analysismentioning

confidence: 99%

Geological Factors Controlling the Accumulation and High Yield of Marine‐Facies Shale Gas: Case Study of the Wufeng‐Longmaxi Formation in the Dingshan Area of Southeast Sichuan, China

Fan

Zhong

Zhang

et al. 2019

Acta Geologica Sinica (Eng)

View full text Add to dashboard Cite

The main geological factors controlling the accumulation and yield of marine‐facies shale gas reservoirs are the focus of the current shale gas exploration and development research. In this study, the Wufeng‐Longmaxi Formation in the Dingshan area of southeast Sichuan was investigated. Shale cores underwent laboratory testing, which included the evaluation of total organic carbon (TOC), vitrinite reflectance (Ro), whole‐rock X‐ray diffraction (XRD), pore permeability, and imaging through field emission scanning electron microscopy (FE‐SEM). Based on the results of natural gamma ray spectrum logging, conventional logging, imaging logging, and seismic coherence properties, the exploration and development potential of shale gas in the Dingshan area have been discussed comprehensively. The results showed that (1) layer No. 4 (WF2‐LM4) of the Wufeng‐Longmaxi Formation has a Th/U ratio <2 and a Th/K ratio of 3.5‐12. Graptolites and pyrite are relatively abundant in the shale core, indicating sub‐high‐energy and low‐energy marine‐facies anoxic reducing environments. (2) The organic matter is mainly I‐type kerogen with a small amount of II1‐type kerogen. There is a good correlation among TOC, Ro, gas content, and brittle minerals; the fracturing property (brittleness) is 57.3%. Organic and inorganic pores are moderately developed. A higher pressure coefficient is correlated with the increase in porosity and the decrease in permeability. (3) The DY1 well of the shale gas reservoir was affected by natural defects and important late‐stage double destructive effects, and it is poorly preserved. The DY2 well is located far from the Qiyueshan Fault. Large faults are absent, and upward fractures in the Longmaxi Formation are poorly developed. The well is affected by low tectonic deformation intensity, and it is well preserved. (4) The Dingshan area is located at the junction of the two sedimentary centers of Jiaoshiba and Changning. The thickness of the high‐quality shale interval (WF2‐LM4) is relatively small, which may be an important reason for the unstable production of shale gas thus far. Based on the systematic analysis of the geological factors controlling high‐yield shale gas enrichment in the Dingshan area, and the comparative analysis with the surrounding typical exploration areas, the geological understanding of marine shale gas enrichment in southern China has been improved. Therefore, this study can provide a useful reference for shale gas exploration and further development.

show abstract

Review of Molecular Simulation Method for Gas Adsorption/desorption and Diffusion in Shale Matrix

et al. 2018

View full text Add to dashboard Cite

Shale gas enrichment conditions in the frontal margin of Dabashan orogenic belt, south China

Cited by 4 publications

References 26 publications

Tectonic and Thermal Controls on the Nano-Micro Structural Characteristic in a Cambrian Organic-Rich Shale

Tectonic and Thermal Controls on the Nano-Micro Structural Characteristic in a Cambrian Organic-Rich Shale

Geological Factors Controlling the Accumulation and High Yield of Marine‐Facies Shale Gas: Case Study of the Wufeng‐Longmaxi Formation in the Dingshan Area of Southeast Sichuan, China

Review of Molecular Simulation Method for Gas Adsorption/desorption and Diffusion in Shale Matrix

Contact Info

Product

Resources

About