重庆周缘龙马溪组和牛蹄塘组页岩有机质孔隙发育特征
|
摘要
针对牛蹄塘组页岩气勘探开发过程中存在产气量较低,产气持续时间较短等问题,以渝东南下志留统龙马溪组页岩和渝东北下寒武统牛蹄塘组页岩为对象进行对比,重点剖析2套页岩的孔隙储集能力及其演化特征。结果表明:龙马溪组页岩和牛蹄塘组页岩的有机质孔隙发育特征存在较大差别:龙马溪组页岩内部的固体干酪根有机质孔隙数量少,孔径小,连通性差,但其焦沥青内部有机质孔隙数量多,孔径大,连通性好。牛蹄塘组页岩内部的固体干酪根和焦沥青均不发育有机质孔隙。储层热演化程度对页岩有机质孔隙的发育有着直接的控制作用。龙马溪组页岩由于古埋深较牛蹄塘组页岩浅,所经历的热演化作用相对较弱,适宜的热演化程度保留了龙马溪组页岩焦沥青内部大量的有机质孔隙,但其固体干酪根由于演化时间相对较长,有机质孔隙数量减少。渝东北牛蹄塘组页岩埋深过大,储层过度演化达到变质期导致其内部固体干酪根和焦沥青均不发育有机质孔隙。针对牛蹄塘组页岩气的高效勘探开发应寻找热演化程度适中的页岩分布区。
In the exploration and development process of shale gas in Niutitang Formation,there are problems such as low gas production and short duration. By comparing the Lower Silurian Longmaxi shale in southeastern Chongqing with the Lower Cambrian Niutitang shale in northeastern Chongqing,the pore reservoir capacity and evolution characteristics of the two sets of shale were analyzed. The results show that there are significant differences in organic pore development characteristics of the Longmaxi shale and the Niutitang shale. The organic pores inside solid kerogen in the Longmaxi shale have a small number,small pore size and poor connectivity,but the amount and size of organic pores in pyrobitumen are large,and the connectivity is good. The solid kerogen and pyrobitumen in the Niutitang shale do not develop organic pores. The degree of reservoir thermal evolution has a direct control effect on the development of organic pores in shale. The Longmaxi shale is relatively weak in thermal evolution as palaeo-buried depth is shallower than the Niutitang shale. The appropriate degree of thermal evolution preserves a large amount of organic pores in the pyrobitumen of the Longmaxi shale,but the solid kerogen has a relatively long evolution time and the number of organic pores decreased. The palaeo-buried depth of the Niuzhitang shale in northeastern Chongqing is too large,and reservoir reached the metamorphic period due to excessive evolution,resulting in the absence of organic pores in the solid kerogen and pyrobitumen. For the efficient exploration and development of shale gas in the Niutitang Formation,a shale distribution area with moderate thermal evolution should be sought.
In the exploration and development process of shale gas in Niutitang Formation,there are problems such as low gas production and short duration. By comparing the Lower Silurian Longmaxi shale in southeastern Chongqing with the Lower Cambrian Niutitang shale in northeastern Chongqing,the pore reservoir capacity and evolution characteristics of the two sets of shale were analyzed. The results show that there are significant differences in organic pore development characteristics of the Longmaxi shale and the Niutitang shale. The organic pores inside solid kerogen in the Longmaxi shale have a small number,small pore size and poor connectivity,but the amount and size of organic pores in pyrobitumen are large,and the connectivity is good. The solid kerogen and pyrobitumen in the Niutitang shale do not develop organic pores. The degree of reservoir thermal evolution has a direct control effect on the development of organic pores in shale. The Longmaxi shale is relatively weak in thermal evolution as palaeo-buried depth is shallower than the Niutitang shale. The appropriate degree of thermal evolution preserves a large amount of organic pores in the pyrobitumen of the Longmaxi shale,but the solid kerogen has a relatively long evolution time and the number of organic pores decreased. The palaeo-buried depth of the Niuzhitang shale in northeastern Chongqing is too large,and reservoir reached the metamorphic period due to excessive evolution,resulting in the absence of organic pores in the solid kerogen and pyrobitumen. For the efficient exploration and development of shale gas in the Niutitang Formation,a shale distribution area with moderate thermal evolution should be sought.
引文
[1]赵文智,李建忠,杨涛,等.中国南方海相页岩气成藏差异性比较与意义.石油勘探与开发,2016,43(4):499-510.ZHAO W Z,LI J Z,YANG T,et al.Geological difference and its significance of marine shale gases in South China.Petroleum Exploration and Development,2016,43(4):499-510.
[2]LOUCKS R G,REED R M,RUOOEL S C,et al.Spectrum of pore types and networks in mudrocks and a descriptive classification for matrix-related mudrock pores.AAPG Bulletin,2012,96(6):1071-1098.
[3]LOUCKS R G,REED R M,RUPPEL S C,et al.Morphology,genesis,and distribution of nanometer-scale pores in siliceous mudstones of the Mississippian Barnett Shale.Journal of Sedimentary Research,2009,79(12):848-861.
[4]CLARKSON C R,SOLANO N,BUSTIN RM,et al.Pore structure characterization of North American shale gas reservoirs using USANS/SANS,gas adsorption,and mercury intrusion.Fuel,2013,103:606-616.
[5]MILLIKEN K L,RUDNICKI M,AWWILLER D N,et al.Organic matter-hosted pore system,Marcellus Formation(Devonian),Pennsylvania.AAPG Bulletin,2013,97(2):177-200.
[6]SLATT R M,O'BRIEN N R.Pore types in the Barnett and Woodford gas shales:Contribution to understanding gas storage and migration pathways in fine-grained rocks.AAPG Bulletin,2011,95(12):2017-2030.
[7]TIAN H,PAN L,XIAO X M,et al.A preliminary study on the pore characterization of Lower Silurian black shales in the Chuandong Thrust Fold Belt,southwestern China using low pressure N2adsorption and FE-SEM methods.Marine and Petroleum Geology,2013,48:8-19.
[8]TIAN H,PAN L,ZHANG T W,et al.Pore characterization of organic-rich lower Cambrian shales in Qiannan depression of Guizhou Province,southwestern China.Marine and Petroleum Geology,2015,62:28-43.
[9]余川,周洵,方光建,等.地层温压条件下页岩吸附性能变化特征:以渝东北地区龙马溪组为例.岩性油气藏,2018,30(6):10-17.YU C,ZHOU X,FANG G J,et al.Adsorptivity of shale under the formation temperature and pressure:a case of Longmaxi Formation in northeastern Chongqing.Lithologic Reservoirs,2018,30(6):10-17.
[10]JI W M,SONG Y,RUI Z H,et al.Pore characterization of isolated organic matter from high matured gas shale reservoir.International Journal of Coal Geology,2017,174:31-40.
[11]陈居凯,朱炎铭,崔兆帮,等.川南龙马溪组页岩孔隙结构综合表征及其分形特征.岩性油气藏,2018,30(1):55-62.CHEN J K,ZHU Y M,CUI Z B,et al.Pore structure and fractal characteristics of Longmaxi shale in southern Sichuan Basin.Lithologic Reservoirs,2018,30(1):55-62.
[12]JIAO K,YAO S P,LIU C,et al.The characterization and quantitative analysis of nanopores in unconventional gas reservoirs utilizing FESEM-FIB and image processing:an example from the lower Silurian Longmaxi shale,Upper Yangtze region,China.International Journal of Coal Geology,2014,128:1-11.
[13]MA Y,ZHONG N N,LI D H,et al.Organic matter/clay mineral intergranular pores in the Lower Cambrian Lujiaping shale in the north-eastern part of the Upper Yangtze area,China:a possible microscopic mechanism for gas preservation.International Journal of Coal Geology,2015,137:38-54.
[14]WANG P F,JIANG Z X,JI W M,et al.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,2016,72:122-138.
[15]王玉满,李新景,陈波,等.海相页岩有机质炭化的热成熟度下限及勘探风险.石油勘探与开发,2018,45(3):385-395.WANG Y M,LI X J,CHEN B,et al.Lower limit of thermal maturity for the carbonification of organic matters in marine shales and its exploration risk.Petroleum Exploration and Development,2018,45(3):385-395.
[16]姜生玲,汪生秀,洪克岩,等.渝东北地区下古生界页岩气聚集条件及资源潜力.岩性油气藏,2017,29(5):11-18.JIANG S L,WANG S X,HONG K Y,et al.Accumulation conditions of Lower Paleozoic shale gas and its resources in northeastern Chongqing.Lithologic Reservoirs,2017,29(5):11-18.
[17]刘忠宝,冯动军,高波,等.上扬子地区下寒武统高演化页岩微观孔隙特征.天然气地球科学,2017,28(7):1096-1107.LIU Z B,FENG D J,GAO B,et al.Micropore characteristics of high thermal evolution shale in the Lower Cambrian series in Upper Yangtze area.Natural Gas Geoscience,2017,28(7):1096-1107.
[18]沈瑞,胡志明,郭和坤,等.四川盆地长宁龙马溪组页岩赋存空间及含气规律.岩性油气藏,2018,30(5):11-17.SHEN R,HU Z M,GUO H K,et al.Storage space and gas content law of Longmaxi shale in Changning area,Sichuan Basin.Lithologic Reservoirs,2018,30(5):11-17.
[19]赵建华,金之钧,金振奎,等.岩石学方法区分页岩中有机质类型.石油实验地质,2016,38(4):514-520.ZHAO J H,JIN Z J,JIN Z K,et al.Petrographic methods to distinguish organic matter type in shale.Petroleum Geology&Experiment,2016,38(4):514-520.
[20]王香增,张丽霞,雷裕红,等.低熟湖相页岩内运移固体有机质和有机质孔特征:以鄂尔多斯盆地东南部延长组长7油层组页岩为例.石油学报,2018,39(2):141-151.WANG X Z,ZHANG L X,LEI Y H,et al.Characteristics of migrated solid organic matters and organic pores in low maturity lacustrine shale:a case study of the shale in Chang 7 Oil-bearing formation of Yanchang Formation,southeastern Ordos Basin.Acta Petrolei Sinica,2018,39(2):141-151.
[21]刘树根,邓宾,钟勇,等.四川盆地及周缘下古生界页岩气深埋藏-强改造独特地质作用.地学前缘,2016,23(1):11-28.LIU S G,DENG B,ZHONG Y,et al.Unique geological features of burial and superimposition of the Lower Paleozoic Shale gas across the Sichuan Basin and its back.Earth Science Frontiers,2016,23(1):11-28.
[22]TISSOT B P,PELET R,UNGERER P H.Thermal history of sedimentary basins,maturation indices,and kinetics of oil and gas generation.AAPG Bulletin,1987,71(12):1445-1466.
[23]TISSOT B P.Influence of nature and diagenesis of organic matter in formation of petroleum.AAPG Bulletin,1974,58(3):499-506.
[24]郭秋麟,武娜,任洪佳,等.中低成熟阶段页岩有机质孔预测模型探讨.岩性油气藏,2017,29(6):1-7.GUO Q L,WU N,REN H J,et al.Prediction models of organic pores in shale with low to moderate maturity.Lithologic Reservoirs,2017,29(6):1-7.
[25]GUO X J,SHEN Y H,HE S L.Quantitative pore characterization and the relationship between pore distributions and organic matter in shale based on Nano-CT image analysis:a case study for a lacustrine shale reservoir in the Triassic Chang 7 member,Ordos Basin,China.Journal of Natural Gas Science and Engineering,2015,27:1630-1640.
[26]薛莲花,杨巍,仲佳爱,等.富有机质页岩生烃阶段孔隙演化:来自鄂尔多斯延长组地质条件约束下的热模拟实验证据.地质学报,2015,89(5):970-978.XUE L H,YANG W,ZHONG J A,et al.Porous evolution of the organic-rich shale from simulated experiment with geological constrains,samples from Yanchang Formation in Ordos Basin.Acta Geologica Sinica,2015,89(5):970-978.
[27]聂海宽,金之钧,边瑞康,等.四川盆地及其周缘上奥陶统五峰组-下志留统龙马溪组页岩气“源-盖控藏”富集.石油学报,2016,37(5):557-571.NIE H K,JIN Z J,BIAN R K et al.The“source-cap hydrocarbon-controlling”enrichment of shale gas in Upper Ordovician Wufeng Formation-Lower Silurian Longmaxi Formation of Sichuan Basin and its surrounding.Acta Petrolei Sinica,2016,37(5):557-571.
[28]吉利明,吴远东,贺聪,等.富有机质泥页岩高压生烃模拟与孔隙演化特征.石油学报,2016,37(2):172-181.JI L M,WU Y D,HE C,et al.High-pressure hydrocarbon-generation simulation and pore evolution characteristics of organicrich mudstone and shale.Acta Petrolei Sinica,2016,37(2):172-181.
[29]赵文智,王兆云,王东良,等.分散液态烃的成藏地位与意义.石油勘探与开发,2015,42(4):401-413.ZHAO W Z,WANG Z Y,WANG D L,et al.Contribution and significance of dispersed liquid hydrocarbons to reservoir formation.Petroleum Exploration and Development,2015,42(4):401-413.
[30]胡宗全,杜伟,彭勇民,等.页岩微观孔隙特征及源-储关系:以川东南地区五峰组-龙马溪组为例.石油与天然气地质,2015,36(6):1001-1008.HU Z Q,DU W,PENG Y M,et al.Microscopic pore characteristics and the source-reservoir relationship of shale:a case study from the Wufeng and Longmaxi Formations in southeast Sichuan Basin.Oil&Gas Geology,2015,36(6):1001-1008.
[31]曹涛涛,邓模,刘虎,等.可溶有机质对泥页岩储集物性的影响.岩性油气藏,2018,30(3):43-51.CAO T T,DENG M,LIU H,et al.Influences of soluble organic matter on reservoir properties of shale.Lithologic Reservoirs,2018,30(3):43-51.
[2]LOUCKS R G,REED R M,RUOOEL S C,et al.Spectrum of pore types and networks in mudrocks and a descriptive classification for matrix-related mudrock pores.AAPG Bulletin,2012,96(6):1071-1098.
[3]LOUCKS R G,REED R M,RUPPEL S C,et al.Morphology,genesis,and distribution of nanometer-scale pores in siliceous mudstones of the Mississippian Barnett Shale.Journal of Sedimentary Research,2009,79(12):848-861.
[4]CLARKSON C R,SOLANO N,BUSTIN RM,et al.Pore structure characterization of North American shale gas reservoirs using USANS/SANS,gas adsorption,and mercury intrusion.Fuel,2013,103:606-616.
[5]MILLIKEN K L,RUDNICKI M,AWWILLER D N,et al.Organic matter-hosted pore system,Marcellus Formation(Devonian),Pennsylvania.AAPG Bulletin,2013,97(2):177-200.
[6]SLATT R M,O'BRIEN N R.Pore types in the Barnett and Woodford gas shales:Contribution to understanding gas storage and migration pathways in fine-grained rocks.AAPG Bulletin,2011,95(12):2017-2030.
[7]TIAN H,PAN L,XIAO X M,et al.A preliminary study on the pore characterization of Lower Silurian black shales in the Chuandong Thrust Fold Belt,southwestern China using low pressure N2adsorption and FE-SEM methods.Marine and Petroleum Geology,2013,48:8-19.
[8]TIAN H,PAN L,ZHANG T W,et al.Pore characterization of organic-rich lower Cambrian shales in Qiannan depression of Guizhou Province,southwestern China.Marine and Petroleum Geology,2015,62:28-43.
[9]余川,周洵,方光建,等.地层温压条件下页岩吸附性能变化特征:以渝东北地区龙马溪组为例.岩性油气藏,2018,30(6):10-17.YU C,ZHOU X,FANG G J,et al.Adsorptivity of shale under the formation temperature and pressure:a case of Longmaxi Formation in northeastern Chongqing.Lithologic Reservoirs,2018,30(6):10-17.
[10]JI W M,SONG Y,RUI Z H,et al.Pore characterization of isolated organic matter from high matured gas shale reservoir.International Journal of Coal Geology,2017,174:31-40.
[11]陈居凯,朱炎铭,崔兆帮,等.川南龙马溪组页岩孔隙结构综合表征及其分形特征.岩性油气藏,2018,30(1):55-62.CHEN J K,ZHU Y M,CUI Z B,et al.Pore structure and fractal characteristics of Longmaxi shale in southern Sichuan Basin.Lithologic Reservoirs,2018,30(1):55-62.
[12]JIAO K,YAO S P,LIU C,et al.The characterization and quantitative analysis of nanopores in unconventional gas reservoirs utilizing FESEM-FIB and image processing:an example from the lower Silurian Longmaxi shale,Upper Yangtze region,China.International Journal of Coal Geology,2014,128:1-11.
[13]MA Y,ZHONG N N,LI D H,et al.Organic matter/clay mineral intergranular pores in the Lower Cambrian Lujiaping shale in the north-eastern part of the Upper Yangtze area,China:a possible microscopic mechanism for gas preservation.International Journal of Coal Geology,2015,137:38-54.
[14]WANG P F,JIANG Z X,JI W M,et al.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,2016,72:122-138.
[15]王玉满,李新景,陈波,等.海相页岩有机质炭化的热成熟度下限及勘探风险.石油勘探与开发,2018,45(3):385-395.WANG Y M,LI X J,CHEN B,et al.Lower limit of thermal maturity for the carbonification of organic matters in marine shales and its exploration risk.Petroleum Exploration and Development,2018,45(3):385-395.
[16]姜生玲,汪生秀,洪克岩,等.渝东北地区下古生界页岩气聚集条件及资源潜力.岩性油气藏,2017,29(5):11-18.JIANG S L,WANG S X,HONG K Y,et al.Accumulation conditions of Lower Paleozoic shale gas and its resources in northeastern Chongqing.Lithologic Reservoirs,2017,29(5):11-18.
[17]刘忠宝,冯动军,高波,等.上扬子地区下寒武统高演化页岩微观孔隙特征.天然气地球科学,2017,28(7):1096-1107.LIU Z B,FENG D J,GAO B,et al.Micropore characteristics of high thermal evolution shale in the Lower Cambrian series in Upper Yangtze area.Natural Gas Geoscience,2017,28(7):1096-1107.
[18]沈瑞,胡志明,郭和坤,等.四川盆地长宁龙马溪组页岩赋存空间及含气规律.岩性油气藏,2018,30(5):11-17.SHEN R,HU Z M,GUO H K,et al.Storage space and gas content law of Longmaxi shale in Changning area,Sichuan Basin.Lithologic Reservoirs,2018,30(5):11-17.
[19]赵建华,金之钧,金振奎,等.岩石学方法区分页岩中有机质类型.石油实验地质,2016,38(4):514-520.ZHAO J H,JIN Z J,JIN Z K,et al.Petrographic methods to distinguish organic matter type in shale.Petroleum Geology&Experiment,2016,38(4):514-520.
[20]王香增,张丽霞,雷裕红,等.低熟湖相页岩内运移固体有机质和有机质孔特征:以鄂尔多斯盆地东南部延长组长7油层组页岩为例.石油学报,2018,39(2):141-151.WANG X Z,ZHANG L X,LEI Y H,et al.Characteristics of migrated solid organic matters and organic pores in low maturity lacustrine shale:a case study of the shale in Chang 7 Oil-bearing formation of Yanchang Formation,southeastern Ordos Basin.Acta Petrolei Sinica,2018,39(2):141-151.
[21]刘树根,邓宾,钟勇,等.四川盆地及周缘下古生界页岩气深埋藏-强改造独特地质作用.地学前缘,2016,23(1):11-28.LIU S G,DENG B,ZHONG Y,et al.Unique geological features of burial and superimposition of the Lower Paleozoic Shale gas across the Sichuan Basin and its back.Earth Science Frontiers,2016,23(1):11-28.
[22]TISSOT B P,PELET R,UNGERER P H.Thermal history of sedimentary basins,maturation indices,and kinetics of oil and gas generation.AAPG Bulletin,1987,71(12):1445-1466.
[23]TISSOT B P.Influence of nature and diagenesis of organic matter in formation of petroleum.AAPG Bulletin,1974,58(3):499-506.
[24]郭秋麟,武娜,任洪佳,等.中低成熟阶段页岩有机质孔预测模型探讨.岩性油气藏,2017,29(6):1-7.GUO Q L,WU N,REN H J,et al.Prediction models of organic pores in shale with low to moderate maturity.Lithologic Reservoirs,2017,29(6):1-7.
[25]GUO X J,SHEN Y H,HE S L.Quantitative pore characterization and the relationship between pore distributions and organic matter in shale based on Nano-CT image analysis:a case study for a lacustrine shale reservoir in the Triassic Chang 7 member,Ordos Basin,China.Journal of Natural Gas Science and Engineering,2015,27:1630-1640.
[26]薛莲花,杨巍,仲佳爱,等.富有机质页岩生烃阶段孔隙演化:来自鄂尔多斯延长组地质条件约束下的热模拟实验证据.地质学报,2015,89(5):970-978.XUE L H,YANG W,ZHONG J A,et al.Porous evolution of the organic-rich shale from simulated experiment with geological constrains,samples from Yanchang Formation in Ordos Basin.Acta Geologica Sinica,2015,89(5):970-978.
[27]聂海宽,金之钧,边瑞康,等.四川盆地及其周缘上奥陶统五峰组-下志留统龙马溪组页岩气“源-盖控藏”富集.石油学报,2016,37(5):557-571.NIE H K,JIN Z J,BIAN R K et al.The“source-cap hydrocarbon-controlling”enrichment of shale gas in Upper Ordovician Wufeng Formation-Lower Silurian Longmaxi Formation of Sichuan Basin and its surrounding.Acta Petrolei Sinica,2016,37(5):557-571.
[28]吉利明,吴远东,贺聪,等.富有机质泥页岩高压生烃模拟与孔隙演化特征.石油学报,2016,37(2):172-181.JI L M,WU Y D,HE C,et al.High-pressure hydrocarbon-generation simulation and pore evolution characteristics of organicrich mudstone and shale.Acta Petrolei Sinica,2016,37(2):172-181.
[29]赵文智,王兆云,王东良,等.分散液态烃的成藏地位与意义.石油勘探与开发,2015,42(4):401-413.ZHAO W Z,WANG Z Y,WANG D L,et al.Contribution and significance of dispersed liquid hydrocarbons to reservoir formation.Petroleum Exploration and Development,2015,42(4):401-413.
[30]胡宗全,杜伟,彭勇民,等.页岩微观孔隙特征及源-储关系:以川东南地区五峰组-龙马溪组为例.石油与天然气地质,2015,36(6):1001-1008.HU Z Q,DU W,PENG Y M,et al.Microscopic pore characteristics and the source-reservoir relationship of shale:a case study from the Wufeng and Longmaxi Formations in southeast Sichuan Basin.Oil&Gas Geology,2015,36(6):1001-1008.
[31]曹涛涛,邓模,刘虎,等.可溶有机质对泥页岩储集物性的影响.岩性油气藏,2018,30(3):43-51.CAO T T,DENG M,LIU H,et al.Influences of soluble organic matter on reservoir properties of shale.Lithologic Reservoirs,2018,30(3):43-51.