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
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  • 英文篇名: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
  • 作者:FAN ; Cunhui ; ZHONG ; Cheng ; ZHANG ; Yu ; QIN ; Qirong ; HE ; Shun
  • 英文作者:FAN Cunhui;ZHONG Cheng;ZHANG Yu;QIN Qirong;HE Shun;State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Southwest Petroleum University;State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Chengdu University of Technology;Collaborative Innovation Center of Shale Gas Resources and Environment, Southwest Petroleum University;School of Geoscience and Technology, Southwest Petroleum University;
  • 英文关键词:main controlling factors;;enrichment;;conservation;;shale gas;;Dingshan area
  • 中文刊名:DZXW
  • 英文刊名:地质学报(英文版)
  • 机构:State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Southwest Petroleum University;State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Chengdu University of Technology;Collaborative Innovation Center of Shale Gas Resources and Environment, Southwest Petroleum University;School of Geoscience and Technology, Southwest Petroleum University;
  • 出版日期:2019-06-15
  • 出版单位:Acta Geologica Sinica(English Edition)
  • 年:2019
  • 期:v.93
  • 基金:The Open Fund (PLC20180404) of the State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation (Chengdu University of Technology);; The Open Fund (PLN 201718) of State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation (Southwest Petroleum University);; The Open Fund(SEC-2018-04)of Collaborative Innovation Center of Shale Gas Resources and Environment (Southwest Petroleum University)
  • 语种:英文;
  • 页:DZXW201903003
  • 页数:25
  • CN:03
  • ISSN:11-2001/P
  • 分类号:36-60
摘要
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 latestage 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.
        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 latestage 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.
引文
Bowker,K.A.,2007.Barnett Shale gas production,Fort Worth Basin:Issues and discussion.AAPG Bulletin,91(4):523-533.
    Chen,M.J.,Kang,Y.L.,Zhang,T.S.,Wu,K.L.,and Chen,Z.X.,2018.Methane adsorption behavior on shale matrix at in-situ pressure and temperature conditions:Measurement and modeling.Fuel,228:39-49.
    Cui,J.W.,Zhu,R.K.,Li,S.X.,and Zhang,Z.Y.,2017.Oderly accumulation theory of shale system petroleum resource and its prospecting significance-a case study of chang 7 member of Yanchang Formation in Ordos Basin.Acta Geologica Sinica(English Edition),91(s1):265-266.
    Curtis,J.B.,2002.Fractured shale-gas systems.AAPG Bulletin,86(11):1921-1938.
    Curtis,M.E.,Sondergeld,C.H.,Ambrose,R.J.,Rai,C.S.,2012.Microstructural investigation of gas shales in two and three dimensions using nanometer-scale resolution imaging.AAPGBulletin,96(4):665-677.
    Ding,Y.H.,and Ren,L.,2014.The application of natural gamma spectrometry log to limestone reservoir in T oilfield of Middle East.Geophysical&Geochemical Exploration,38(5):890-894.
    Dong,D.Z.,Gao,S.k.,Huang,J.L.,Guan,Q.Z.,Wang,S.F.,and Wang,Y.M.,2014.A discussion on the shale gas exploration and development prospect in the Sichuan Basin.Natural Gas Industry,31(12):1-15(in Chinese with English abstract).
    Dong,D.Z.,Wang,Y.M.,Huang,X.N.,Zhang,C.C.,Guan,Q.Z.,Huang,J.L.,Wang,S.F.,and Li,X.J.,2016.Discussion about geological characteristics,resource evaluation methods and its key parameters of shale gas in China.Natural Gas Geoscience,27(9):1583-1601(in Chinese with English abstract).
    Dong,D.Z.,Wang,Y.M.,Li,X.J.,Zou,C.N.,Guan,Q.Z.,Zhang,C.C.,Huang,J.L.,Wang,S.F.,Wang,H.Y.,Liu,H.L.,Bai,W.H.,Liang,F.,Lin,W.,Zhao,Q.,Liu,D.X.,and Qiu,Z.,2016.Breakthrough and prospect of shale gas exploration and development in China.Natural Gas Industry,3(1):12-26(in Chinese with English abstract).
    Fan,C.H.,He,S.,Zhang,Y.,Qin,Q.R.,and Zhong,C.,2018.Development Phases and Mechanisms of Tectonic Fractures in the Longmaxi Formation Shale of the Dingshan Area in Southeast Sichuan Basin,China.Acta Geologica Sinica(English Edition),92(6):2351-2366.
    Feng,D.J.,Hu,Z.Q.,Gao,B.,Peng,Y.M.,and Du,W.,2016.Analysis of Shale Gas Reservoir-Forming Condition of Wufeng Formation-Longmaxi Formation in Southeast Sichuan Basin.Geological Review,62(6):1521-1532(in Chinese with English abstract).
    Fu,J.L.,Ding,W.L.,Zeng,W.T.,He,J.H.,and Wang,Z.,2016.Influence of Structure of Northwest Guizhou Area on Preservation of Lower Cambrian Shale Gas Reservoirs.Journal of Southwest Petroleum University,38(5):22-32(in Chinese with English abstract).
    Guo,X.S.,2014.Rules of Two-Factor Enrichiment for Marine Shale Gas in Southern China-Understanding from the Longmaxi Formation Shale Gas in Sichuan Basin and Its Surrounding Area.Acta Geologica Sinica,88(7):1209-1218(in Chinese with English abstract).
    Guo,X.S.,Hu,D.F.,Li,Y.P.,Wei,Z.H.,Wei,X.F.,and Liu,Z.J.,2017.Geological factors controlling shale gas enrichment and high production in Fuling shale gas field.Petroleum Exploration and Development,44(4):481-491.
    Guo,X.S.,Hu,D.F.,Wen,Z.D.,and Liu,R.B.,2014.Major factors controlling the accumulation and high productivity in marine shale gas in the Lower Paleozoic of Sichuan Basin and its periphery:A case study of the Wufeng-Longmaxi Formation of Jiaoshiba area.Geology in China,41(3):893-901(in Chinese with English abstract).
    Guo,T.L.,and Zhang,H.,2014.Formation and enrichment mode of Jiaoshiba shale gas field,Sichuan Basin Petroleum Exploration and Development,41(1):31-40.
    Guo,T.L.,2016.Discovery and characteristics of the Fuling shale gas field and its enlightenment and thinking.Earth Science Frontiers,2016,23(1):29-43(in Chinese with English abstract).
    Guo,T.L.,and Liu,R.B.,2013.Implications from marine shale gas exploration breakthrough in complicated structural area at high thermal stage:Taking Longmaxi Formation in Well JY1as an example.Natural Gas Geoscience,2013,24(4):643-651(in Chinese with English abstract).
    Guo,X.S.,Hu,D.F.,Li,Y.P.,Liu,R.B.,and Wang,Q.B.,2014.Geological features and reservoiring mode of shale gas reservoirs in Longmaxi Formation of the Jiaoshiba Area.Acta Geologica Sinica(English Edition),88(6):1811-1821.
    He,Z.L.,Nie,H.K.,and Zhang,Y.Y.,2016.The main factors of shale gas enrichment of Ordovician Wufeng FormationSilurian Longmaxi Formation in the Sichuan Basin and its adjacent areas.Earth Science Frontiers,23(2):8-17(in Chinese with English abstract).
    He,J.H.,Ding,W.L.,Jiang,Z.X.,Wang,R.Y.,and Sun,Y.X.,2016.Logging identification and characteristic analysis of the lacustrine organic-rich shale lithofacies:A case study from the Es 3 L,shale in the Jiyang Depression,Bohai Bay Basin,Eastern China.Journal of Petroleum Science and Engineering,145:238-255.
    He,Z.L.,Nie,H.K.,Zhao,J.H.,Liu,W.X.,Bao,F.,and Zhang,W.T.,2017,Types and Origin of Nanoscale Pores and Fractures in Wufeng and Longmaxi Shale in Sichuan Basin and Its Periphery.Journal of Nanoscience and Nanotechnology,17(9):6626-6633.
    Hu,D.F.,Zhang,H.R.,Ni,K.,and Yu,G.C.,2014.Main controlling factors for gas preservation conditions of marine shales in southeastern margins of the Sichuan Basin.Natural Gas Industry,7(10):905-915(in Chinese with English abstract).
    Huang,R.C.,Wei,X.F.,and Wang,Q.,2017.Key Factors of Shale Gas Accumulation in Dingshan Area of Southeastern Sichuan Basin.Marine Origin Petroleum Geology,22(2):25-30(in Chinese with English abstract).
    Huang,Y.,Zhang,X.L.g,Xiong,T.,and Zhang,T.W.,2017.Profiling of Relationship between Shale Organic Matter Enrichment Mechanism and Gas-bearing Property-A Case Study of Well QQ No.1.Coal Geology of China,29(12):5-11+30(in Chinese with English abstract).
    Ito,T.,Ohbuchi,A.,Nakajima,T.,and Xue,Z.Q.,2017.Identifying the source of natural gamma-rays in shallowmarine siliciclastic strata and their significance for shale evaluation:A case study of the CO2 storage aquifer at the Nagaoka site,Japan.Journal of Natural Gas Science and Engineering,46:782-92.
    Jarvie,D.M.,Hill,R.J.,Ruble,T.E.,Pollastro,R.M.,2007.Unconventional shale-gas systems:The Mississippian Barnett Shale of north-central Texas as one model for thermogenic shale-gas assessment.AAPG Bulletin,91(4):475-499.
    Jiang,Z.X.,Tang,X.L.,Li,Z.,Huang,H.X.,Yang,P.P.,Yang,X.,Li,W.B.,and Hao,J.,2016.The whole-aperture pore structure characteristics and its effect on gas content of the Longmaxi Formation shale in the southeastern Sichuan basin.Earth Science Frontiers,23(2):126-134(in Chinese with English abstract).
    Jin,Z.J.,2012.Formation and accumulation of oil and gas in marine carbonate sequences in Chinese sedimentary basins.Science in China(Earth Sciences),55(03):368-385.
    Jin,Z.J.,Nie,H.K.,Liu,Q.Y.,Zhao,J.H.,and Jiang,T.,2018,Source and seal coupling mechanism for shale gas enrichment in upper Ordovician Wufeng Formation-Lower Silurian Longmaxi Formation in Sichuan Basin and its periphery.Marine and Petroleum Geology,97:78-93.
    Ju,Y.W.,Bu,H.L.,and Wang,G.C.,2014.Main Characteristics of Shale Gas Reservoir and Its Effect on the Reservoir Reconstruction.Advances in Earth Science,29(4):492-506(in Chinese with English abstract).
    Kang,J.W.,Sun,Y.Y.,Men,Y.P,Yu,Q.,Yan,J.F.,Lin,J.S.,and Liu,J.,2018.Shale gas enrichment conditions in the frontal margin of Dabashan orogenic belt,south China.Journal of Natural Gas Science and Engineering,54:11-24.
    Kim,J.,Kim,D.,Lee,W.,Lee,Y.,and Kim,H.,2016.Impact of total organic carbon and specific surface area on the adsorption capacity in Horn River shale.Journal of Petroleum Science and Engineering,149:331-339.
    Li,Q.H.,Chen,M.,Jin,Y.,Wang,F.P.,Hou,B.G,and Zhang,B.W.,2012.Indoor evaluation method for shale brittleness and improvement.Chinese Journal of Rock Mechanics and Engineering,31(8):1680-1685(in Chinese with English abstract).
    Li,Y.F.,Sun,W.,Liu,X.W.,Zhang,D.W.,Wang,Y.C.and Liu,Z.Y.,2018.Study of the relationship between fractures and highly productive shale gas zones,Longmaxi Formation,Jiaoshiba area in eastern Sichuan.Petroleum Science,15:498-509.
    Liu,S.G.,Ma,W.X.,Jansa,L.,Huang,W.M.,Zeng,X.L.,and Zhang,C.J.,2011.Characteristics of the shale gas reservoir rocks in the Lower Silurian Longmaxi Formation,east Sichuan basin,China.Acta Petrologica Sinica,31(2):187-219.
    Loucks,R.G.,Reed,R.M.,Ruppel,S.C.,and Hammes,U.,2012.Spectrum of pore types and networks in mudrocks and a descriptive classification for matrix-related mudrock pores.AAPG Bulletin,96(6):1071-1098.
    Loucks,R.G.,Reed,R.M.,Ruppel,S.C.,and Jarvie,D.M.,2009.Morphology,Genesis,and Distribution of Nanometer-Scale Pores in Siliceous Mudstones of the Mississippian Barnett Shale.Journal of Sedimentary Research,79(12):848-861.
    Luo,W.,Hou,M.C.,Liu,X.C.,Huang,S.G.,Chao,H.,Zhang,R.,and Deng,X.,2018.Geological and geochemical characteristics of marine-continental transitional shale from the Upper Permian Longtan formation,Northwestern Guizhou,China.Marine and Petroleum Geology,89:58-67.
    Mei,L.F.,Liu,Z.Q.,Tang,J.G.,Shen,C.B.,and Fan,Y.F.,2010.Mesozoic Intra-Continental Progressive Deformation in Western Hunan-Hubei-Eastern Sichuan Provinces of China:Evidence from Apatite Fission Track and Balanced CrossSection.Earth Science,35(2):161-174(in Chinese with English abstract).
    Mou,C.L.,Zhou,K.K.,Liang,W.,and Ge,X.Y.,2011.Early Paleozoic Sedimentary Environment of Hydrocarbon Source Rocks in the Middle-Upper Yangtze Region and Petroleum and Gas Exploration.Acta Geologica Sinica,85(4):526-532(in Chinese with English abstract).
    Nie,H.K.,Bao,S.J.,Gao,B.,Bian,R.K.,Zhang,P.X.,Wu,X.L.,Ye,X.,and Chen,X.J.,2012.A study of shale gas preservation conditions for the Lower Paleozoic in Sichuan Basin and its periphery.Earth Science Frontiers,19(3):280-294(in Chinese with English abstract).
    Nie,H.K.,Jin,Z.J.,Bian,R.K.,and Du,W.,2016.The“sourcecap hydrocarbon-controlling”enrichment of shale gas in Upper Ordovician Wufeng Formation-Lower Silurian Longmaxi Formation of Sichuan Basin and its periphery.Acta Petrolei Sinica,37(5):557-571(in Chinese with English abstract).
    Nie,H.K.,Zhang,J.C.,Bao,S.J.,Bian,R.K.,Song,X.J.,and Liu,J.B.,2012.Shale gas accumulation conditions of the Upper Ordovician-Lower Silurian in Sichuan Basin and its periphery.Oil and Gas Geology,33(3):335-345(in Chinese with English abstract).
    Nie,H.K.,Jin,Z.J.,and Zhang,J.C.,2018.Characteristics of three organic matter pore types in the Wufeng-Longmaxi Shale of the Sichuan Basin,Southwest China.Scientific Reports,8:7014.
    Orem,W.,Tatu,C.,Varonka,M.,Lerch,H.,Bates,A.,Engle,M.,Crosby,L.,and McIntosh,J.,2014.Organic substances in produced and formation water from unconventional natural gas extraction in coal and shale.International Journal of Coal Geology,126(5):20-31.
    Rickman,R.,Mullen,M.,Petre,E.,Grieser,B.,and Kundert,D.,2008.A Practical Use of Shale Petrophysics for Stimulation Design Optimization:All Shale Plays Are Not Clones of the Barnett Shale.In:Proceedings,SPE Technical Conference and Exhibition.Society of Petroleum Engineers,Denver,Colorado,USA,21-24.
    Schlegel,M.E.,McIntosh,J.C.,Petsch,S.T.,Orem,W.H.,Jones,E.J.P.,and Martini,A.M.,2013.Extent and limits of biodegradation by in situ,methanogenic consortia in shale and formation fluids.Applied Geochemistry,28(28):172-184.
    Slatt,R.M.,and O'Brien,N.R.,2011.Pore types in the Barnett and Woodford gas shales:Contribution to understanding gas storage and migration pathways in fine-grained rocks.AAPGBulletin,95(12):2017-2030.
    Tang,H.M.,Wang,J.J.,Zhang,L.H.,Guo,J.J.,Chen,H.X.,Liu,J,Pang,M.,and Feng,Y.T.,2016.Testing method and controlling factors of specific surface area of shales.Journal of Petroleum Science and Engineering,143:1-7.
    Teklu,T.W.,Abass,H.H.,Hanashmooni,R.,Carratu,J.C.,and Ermila,M.,2017.Experimental investigation of acid imbibition on matrix and fractured carbonate rich shales.Journal of Natural Gas Science and Engineering,45:706-725.
    Tu,Y.,Zou,H.Y.,Meng,H.P.,Xia,Z.Y.,and Li,N.,2014.Evaluation criteria and classification of shale gas reservoirs.Oil and Gas Geology,35(1):153-158(in Chinese with English abstract).
    Wang,L.,Zhang,X.D.,Cao,H.H.,2015.Shale preparation using Ar-ion milling.Petroleum Geology and Experiment,37(4):525-529(in Chinese with English abstract).
    Wang,R.Y.,Gong,D.J.,Ding,W.L.,Leng,J.G.,Yin,S.,Wang,X.H.,and Sun,Y.X.,2016.Brittleness evaluation of the Lower Cambrian Niutitang shale in the Upper Yangtze region:A case study in the Cengong block,Guizhou Province.Earth Science Frontiers,23(1):87-95(in Chinese with English abstract).
    Wang,S.F.,Dong,D.Z.,Wang,Y.M.,Li,X.J.,Huang,J.L.,and Guan,Q.Z.,2015.A Comparative Study of the Geological Feature of Marine Shale Gas between China and the United States.Natural Gas Geoscience,26(9):1666-1678(in Chinese with English abstract).
    Wang,S.F.,Zou,C.N.,Dong,D.Z.,Wang,Y.M.,Huang,J.L.,and Guo,Z.J.,2014.Biogenic silica of organic-rich shale in Sichuan Basin and its significance for shale gas.Acta Scientiarum Naturalium Universitatis Pekinensis,50(3):476-486(in Chinese with English abstract).
    Wang,X.L.,Qin,Q.R.,Fan,C.H.,2017.Failure Characteristic and Fracture Evolution Law of Overburden of Thick Coal in Fully Mechanized Sub-level Caving Mining.Sains Malaysiana,46(11):2041-2048.
    Wang,X.L.,Qin,Q.R.,Fan,C.H.,2017.Research on comprehensive evaluation for grouting effect of broken and soft floor.Arabian Journal of Geosciences,10(19):420-428.
    Wang Y.M.,Wang S.F.,Dong D.Z.,Li X.J.,Huang J.L.,Zhang C.C.,and Guan Q.Z.,2016.Lithofacies characterization of Longmaxi Formation of the Lower Silurian,southern Sichuan.Earth Science Frontiers,23(1):119-133(in Chinese with English abstract).
    Wang,P.F.,Jiang,Z.X.,Ji,W.M.,Zhang,C.,Yuan,Y.,Chen,L.,and Yin,L.S.,2016.Heterogeneity of intergranular,intraparticle and organic pores in Longmaxi shale in Sichuan Basin,South China:Evidence from SEM digital images and fractal and multifractal geometries.Marine and Petroleum Geology,72:122-138.
    Wei,X.F.,Zhao,Z.B.,Wang,Q.B.,Liu,Z.J.,Zhou,M.,and Zhang,H.,2017.Comprehensive Evaluation on Geological Conditions of the Shale Gas in Upper Ordovician Wufeng Formation-Lower Silurian Longmaxi Formation in Dingshan Area,Qijiang,Southeastern Sichuan.Geological Review,63(1):153-164.
    Xu,Q.L.,Liu,B.,Ma,Y.S.,Song,X.M.,Wang,Y.J.,and Chen,Z.X.,2017.Geological and geochemical characterization of lacustrine shale:A case study of the Jurassic Da'anzhai member shale in the central Sichuan Basin,southwest China.Journal of Natural Gas Science and Engineering,47:124-139
    Xue,B.,Zhang,J.H.,Tang,X.,Yang,C.,Cheng,Q.,Man,X.,and Dang,W.,2015.Characteristics of microscopic pore and gas accumulation on shale in Longmaxi Formation,northwest Guizhou.Acta Petrolei Sinica,36(2):138-149 and 173(in Chinese with English abstract)
    Zeng,W.T.,Zhang,J.C.,Ding,W.L.,Zhao,S.,Zhang,Y.Q.,Liu,Z.J.,and Jiu,K.,2013.Fracture development in Paleozoic shale of Chongqing area(South China).Part one:Fracture characteristics and comparative analysis of main controlling factors.Journal of Asian Earth Sciences,75(8):251-266.
    Zhai,G.Y.,Wang,Y.F.,Bao,S.J.,Guo,T.X.,Zhou,Z.,Chen,X.L.,and Wang,J.Z.Major Factors Controlling the Accumulation and High Productivity of Marine Shale Gas and Prospect Forecast in Southern China.Earth Science,2017,42(7):1057-1068(in Chinese with English abstract).
    Zhang,H.R.,Wang Q.,Ni K.,and Li C.Y.,2016.Six characteristics and main controlling factors of shale reservoirs in the Wufeng-Longmaxi formations,southeastern Sichuan Basin.Petroleum Geology and Experiment,38(3):320-325(in Chinese with English abstract).
    Zhao,J.H.,Jin,Z.J.,Jin,Z.K.,Wen,X.,Geng,Y.K.,Yan,C.N.,and Nie,H.K.,2016.Lithofacies types and sedimentary environment of shale in Wufeng-Longmaxi Formation,Sichuan Basin.Acta Petrolei Sinica,37(5):572-586(in Chinese with English abstract).
    Zhao,S.X.,Yang,Y.M.,Zhang,J.,Wang,L.S.,Wang,X.Z.,Luo,C.,and Tian,C.,2016.Micro-layers division and fine reservoirs contrast of Lower Silurian Longmaxi Formation shale,Sichuan Basin,SW China.Natural Gas Geoscience,27(3):470-487(in Chinese with English abstract).
    Zhou,Z.,Abass,H.,Li,X.,Bearinger,D.,and Frank,W.,2016.Mechanisms of imbibition during hydraulic fracturing in shale formations.Journal of Petroleum Science and Engineering,141:125-132.
    Zhu,T.,Cao,Y.,and Zhang,K.,2014.Typical shale gas reservoirs in USA and enlightenment to exploration and development.Petroleum Geology and Experiment,2014(6):718-724(in Chinese with English abstract).
    Zou,C.N.,Tao S.Z.,Bai,B.,Yang,Z.,Zhu,R.K.,Hou,L.H.,Yuan,X.J.,Zhang,G.S.,Wu,S.T.,Pang,Z.L.,and Wang,L.,2015.Differences and Relations between Unconventional and Conventional Oil and Gas.China Petroleum Exploration,20(1):1-16(in Chinese with English abstract).
    Zou,C.N.,Dong,D.Z.,Wang,S.J.,Li,J.Z.,Li,X.J.,Wang,Y.M.,Li,D.H.,and Cheng,K.M.,2010.Geological characteristics and resource potential of shale gas in China.Petroleum Exploration and Development,37(6):641-653.