可溶有机质对泥页岩储集物性的影响
|
摘要
可溶有机质是有机质的重要组成部分,为了研究可溶有机质对泥页岩储集物性的影响,对川东北地区龙马溪组和大隆组页岩进行了TOC、岩石热解、扫描电镜、氩离子抛光+扫描电镜等分析,并对页岩进行可溶有机质萃取及开展氮气和甲烷吸附等对比实验。结果表明:(1)可溶有机质在页岩中,特别是在低成熟页岩中主要赋存于干酪根、黏土矿物和草莓体黄铁矿等颗粒的表面及大中孔中;(2)萃取可溶有机质后大隆组页岩比表面积和甲烷吸附量均明显增加,而龙马溪组页岩的比表面积和甲烷吸附量没有明显变化,说明低成熟页岩中可溶有机质能阻碍孔隙的连通和降低对气体的吸附能力,但在高—过成熟阶段可溶有机质很少,对比表面积和甲烷吸附量没有影响;(3)可溶有机质含量与大隆组页岩孔隙分形维数之间具有明显的负相关性,而与龙马溪组页岩孔隙分形维数之间具有正相关性,反映出可溶有机质对低成熟和高成熟页岩孔隙的均匀性方面起相反的作用;(4)萃取可溶有机质后,大隆组与龙马溪组2套页岩的孔隙分形维数均呈降低的趋势,说明可溶有机质被去除后,页岩的孔隙连通性和均匀性变好。通过本次研究,确定了可溶有机质是影响页岩储集物性的重要因素之一,特别是表征低成熟页岩储层物性时要充分考虑可溶有机质的影响。
Soluble organic matter is an important part of organic matter. In order to study the effect of soluble organic matter on shale reservoir properties,the shales of Longmaxi Formation and Dalong Formation in northeastern Sichuan Basin were analyzed in the aspects of TOC content,rock pyrolysis,scanning electronic microscope, scan-ning electron microscopy combined with argon ion polishing,and the extraction of soluble organic matter and low-pressure N_2 and methane adsorption experiments were carried out. The results show that:(1)Soluble organic matters are mainly existing in the surface and meso-macropore of kerogen,clay minerals and framboid pyrites in shales,especially low-maturity shales.(2)The specific surface area and methane adsorption capacity of extracted shale samples increased obviously compared with raw shale samples from Dalong Formation,while there are no obvious changes of specific surface area and methane adsorption capacity between the extracted shale samples and raw shale samples from Longmaxi Formation, indicating that the soluble organic matters in low-maturity shales could hinder the connectivity of pores and decrease methane adsorption capacity,but it has no obvious effect of soluble organic matter on high-maturity shales due to a low content of soluble matter in these shales.(3)Soluble organic matter content has a significant negative correlation with fractal dimension for Dalong shales,but has a positive correction for Longmaxi shales, indicating that soluble organic matter has an opposite effect on the pore heterogeneity for these two sets of shales with different maturities.(4)After extracting the soluble organic matter,fractal dimension values has a decreasing phenomenon for both extracted Dalong and Longmaxi shales,suggesting that the connectivity and uniformity of the pores are improved due to removing the soluble organic matter existing in shale pores. Therefore, through this study,soluble organic matter is deemed to an important factor of reservoir properties of shale,and it should be taken into consideration when characterizing the physical properties of the low-maturity shales.
Soluble organic matter is an important part of organic matter. In order to study the effect of soluble organic matter on shale reservoir properties,the shales of Longmaxi Formation and Dalong Formation in northeastern Sichuan Basin were analyzed in the aspects of TOC content,rock pyrolysis,scanning electronic microscope, scan-ning electron microscopy combined with argon ion polishing,and the extraction of soluble organic matter and low-pressure N_2 and methane adsorption experiments were carried out. The results show that:(1)Soluble organic matters are mainly existing in the surface and meso-macropore of kerogen,clay minerals and framboid pyrites in shales,especially low-maturity shales.(2)The specific surface area and methane adsorption capacity of extracted shale samples increased obviously compared with raw shale samples from Dalong Formation,while there are no obvious changes of specific surface area and methane adsorption capacity between the extracted shale samples and raw shale samples from Longmaxi Formation, indicating that the soluble organic matters in low-maturity shales could hinder the connectivity of pores and decrease methane adsorption capacity,but it has no obvious effect of soluble organic matter on high-maturity shales due to a low content of soluble matter in these shales.(3)Soluble organic matter content has a significant negative correlation with fractal dimension for Dalong shales,but has a positive correction for Longmaxi shales, indicating that soluble organic matter has an opposite effect on the pore heterogeneity for these two sets of shales with different maturities.(4)After extracting the soluble organic matter,fractal dimension values has a decreasing phenomenon for both extracted Dalong and Longmaxi shales,suggesting that the connectivity and uniformity of the pores are improved due to removing the soluble organic matter existing in shale pores. Therefore, through this study,soluble organic matter is deemed to an important factor of reservoir properties of shale,and it should be taken into consideration when characterizing the physical properties of the low-maturity shales.
引文
[1]MILLKIN K L,RUDNICKI M,AWWILLER D,et al.Organic matter-hosted pore system,Marcellus Formation(Devonian),Pennsylvnia.AAPG Bulletin,2013,97(2):177-200.
[2]李可,王兴志,张馨艺,等.四川盆地东部下志留统龙马溪组页岩储层特征及影响因素.岩性油气藏,2016,28(5):52-58.LI K,WANG X Z,ZHANG X Y,et al.Shale reservoir characteristics and influencing factors of the Lower Silurian Longmaxi Formation in the eastern Sichuan Basin.Lithologic Reservoirs,2016,28(5):52-58.
[3]彭波,刘羽琛,漆富成,等.湘西北地区新元古界陡山沱组页岩气成藏条件.岩性油气藏,2017,29(4):47-54.PENG B,LIU Y C,QI F C,et al.Shale gas accumulation conditions of Neoproterozoic Doushantuo Formation in NW Hunan province.Lithologic Reservoirs,2017,29(4):47-54.
[4]胡博文,李斌,鲁东升,等.页岩气储层特征及含气性主控因素--以湘西北保靖地区龙马溪组为例.岩性油气藏,2017,29(3):83-91.HU B W,LI B,LU D S,et al.Characteristics and main controlling factors of shale gas reservoirs:a case from Longmaxi Formation in Baojing area,NW Hunan province.Lithologic Reservoirs,2017,29(3):83-91.
[5]崔景伟,朱如凯,吴松涛,等.黄铁矿在页岩有机质富集、生排烃与页岩油聚集中的作用.地质论评,2013,59(增刊1):783-784.CUI J W,ZHU R K,WU S T,et al.The effect of pyrite on organic matter enrichment,hydrocarbon generation and expulsion and oil accumulation in shale.Geological Review,2013,59(Suppl 1):783-784.
[6]LIN W,MASTALERZ M,SCHIMMELMANN A,et al.Influence of Soxhlet-extractable bitumen and oil on porosity in thermally maturing organic-rich shales.International Journal of Coal Geology,2014,132(12):38-50.
[7]HU H Y,ZHANG T W,WIGGINS-CAMACHO J D,et al.Experimental investigation of changes in methane adsorption of bitumen-free Woodford shale with thermal maturation induced by hydrous pyrolysis.Marine and Petroleum Geology,2015,59(1):114-128.
[8]刘国恒,黄志龙,姜振学,等.湖相页岩液态烃对页岩吸附气实验的影响--以鄂尔多斯盆地延长组页岩为例.石油实验地质,2015,37(5):648-654.LIU G H,HUANG Z L,JIANG Z X,et al.effect of liquid hydrocarbons on gas adsorption in a lacustrine shale:a case study of the Yanchang Formation,Ordos Basin.Petroleum Geology and Experiment,2015,37(5):648-654.
[9]李成成,周世新,李靖,等.鄂尔多斯盆地南部延长组泥页岩孔隙特征及其控制因素.沉积学报,2017,35(2):315-329.LI C C,ZHOU S X,LI J,et al.Pore characteristics and controlling factors of the Yanchang Formation mudstone and shale in the south of Ordos Basin.Acta Sedimentologica Sinica,2017,35(2):315-329.
[10]VALENZA J J,DRENZEK N,MARQUES F,et al.Geochemical controls on shale microstructure.Geology,2013,41(5):611-614.
[11]郭慧娟,王香增,张丽霞,等.抽提前/后成熟页岩对氮气、二氧化碳的吸附特征及其对孔隙研究的意义.地球化学,2014,43(4):408-414.GUO H J,WANG X Z,ZHANG L X,et al.Adsorption of N2and CO2on mature shales before and after extraction and its implication for investigations of pore structures.Geochimica,2014,43(4):408-414.
[12]潘磊,肖贤明,周秦.可溶有机质对表征页岩储层特性的影响.天然气地球科学,2015,26(9):1729-1736.PAN L,XIAO X M,ZHOU Q.Influence of soluble organic matter on characterization of shale reservoir.Natural Gas Geoscience,2015,26(9):1729-1736.
[13]李建忠,董大忠,陈更生,等.中国页岩气资源前景与战略地位.天然气工业,2009,29(5):11-16.LI J Z,DONG D Z,CHEN G S,et al.Prospects and strategic position of shale gas resources in China.Natural Gas Industry,2009,29(5):11-16.
[14]梁狄刚,郭彤楼,陈建平,等.中国南方海相生烃成藏研究的若干新进展(一):南方四套区域性海相烃源岩的分布.海相油气地质,2008,13(2):1-16.LIANG D G,GUO T L,CHEN J P,et al.Some progresses on studies of hydrocarbon generation and accumulation in marine sedimentary regions,southern China(Part 1):Distribution of four regional marine source rocks.Marine Origin Petroleum Geology,2008,13(2):1-16.
[15]孙丽娜,张明峰,吴陈君,等.油页岩生排烃模拟实验中不同液态烃产物特征.岩性油气藏,2017,29(6):23-31.SUN L N,ZHANG M F,WU C J,et al.Features of liquid hydrocarbon in different states in oil shale during hydrous pyrolysis.Lithologic Reservoirs,2017,29(6):23-31.
[16]罗进雄,何幼斌.中上扬子地区二叠系烃源岩特征.天然气地球科学,2014,25(9):1416-1425.LUO J X,HE Y B.Characteristics of the Permian source rocks in the Middle and Upper Yangtze region.Natural Gas Geoscience,2014,25(9):1416-1425.
[17]雷裕红,王晖,罗晓容,等.鄂尔多斯盆地张家滩页岩液态烃特征及对页岩气量估算的影响.石油学报,2016,37(8):952-961.LEI Y H,WANG H,LUO X R,et al.The characteristics of liquid hydrocarbon in Zhangjiatan shale,Ordos Basin and its effects on the estimation of shale gas amount.Acta Petrolei Sinica,2016,37(8):952-961.
[18]崔景伟,邹才能,吴松涛,等.页岩孔隙研究新进展.地球科学进展,2012,27(12):1319-1325.CUI J W,ZOU C N,WU S T,et al.New advances in shale porosity research.Advances in Earth Science,2012,27(12):1319-1325.
[19]CHALMERS G R L,BUSTIN R M.Lower Cretaceous gas shales in northeastern British Columbia,PartⅠ:Geological controls on methane sorption capacity.Bulletin of Canadian Petroleum Geology,2008,56(1):1-22.
[20]崔景伟,朱如凯,崔京钢.页岩孔隙演化及其与残留烃量的关系:来自地质过程约束下模拟实验的证据.地质学报,2013,87(5):730-736.CUI J W,ZHU R K,CUI J G.Relationship of porous evolution and residual hydrocarbon:Evidence from modeling experiment with geological constrains.Acta Geologica Sinica,2013,87(5):730-736.
[21]MASTALERZ M,SCHMMELMANN A,DROBNIAK A,et al.Porosity of Devonian and Mississippian New Albany shale across a maturation gradient:Insights from organic petrology,gas adsorption,and mercury intrusion.AAPG Bulletin,2013,97(10):1621-1643.
[22]GUO H J,JIA W L,PENG P A,et al.Evolution of organic matter and nanometer-scale pores in an artificially matured shale undergoing two distinct types of pyrolysis:a study of the Yanchang Shale with Type II kerogen.Organic Geochemistry,2017,105(3):56-66.
[23]李恒超,刘大永,彭平安,等.人工熟化过程中可溶有机质对页岩孔隙特征的影响.地球化学,2017,46(5):466-475.LI H C,LIU D Y,PENG P A,et al.Effect of extractable organic matter on pore characteristics of shales treated by artificial heating.Geochimica,2017,46(5):466-475.
[24]梁利喜,熊健,刘向君,等.川南地区龙马溪组页岩孔隙结构的分形特征.成都理工大学学报(自然科学版),2016,42(6):700-708.LIANG L X,XIONG J,LIU X J,et al.Fractal characteristics of pore structure of Longmaxi Formation shale in south of Sichuan Basin,China.Journal of Chengdu University of Technology(Science and Technology Edition),2016,42(6):700-708.
[25]王志伟,卢双舫,王民,等.湖相、海相泥页岩孔隙分形特征对比.岩性油气藏,2016,28(1):88-93.WANG Z W,LU S F,WANG M,et al.Fractal characteristics of lacustrine shale and marine shale.Lithologic Reservoirs,2016,28(1):88-93.
[26]AVNIR D,JARONIEC M.An isotherm equation for adsorption on fractal surfaces of heterogeneous porous materials.Langmuir,1989,5(6):1431-1433.
[27]WANG M,XUE H T,TIAN S S,et al.Fractal characteristics of Upper Cretaceous lacustrine shale from the Songliao Basin,NEChina.Marine and Petroleum Geology,2015,67(11):144-153.
[28]范泓澈,黄志龙,袁剑,等.高温高压条件下甲烷和二氧化碳溶解度试验.中国石油大学学报(自然科学版),2011,35(2):6-11.FAN H C,HUANG Z L,YUAN J,et al.Experiment on solubility of CH4and CO2at high temperature and high pressure.Journal of China University of Petroleum,2011,35(2):6-11.
[2]李可,王兴志,张馨艺,等.四川盆地东部下志留统龙马溪组页岩储层特征及影响因素.岩性油气藏,2016,28(5):52-58.LI K,WANG X Z,ZHANG X Y,et al.Shale reservoir characteristics and influencing factors of the Lower Silurian Longmaxi Formation in the eastern Sichuan Basin.Lithologic Reservoirs,2016,28(5):52-58.
[3]彭波,刘羽琛,漆富成,等.湘西北地区新元古界陡山沱组页岩气成藏条件.岩性油气藏,2017,29(4):47-54.PENG B,LIU Y C,QI F C,et al.Shale gas accumulation conditions of Neoproterozoic Doushantuo Formation in NW Hunan province.Lithologic Reservoirs,2017,29(4):47-54.
[4]胡博文,李斌,鲁东升,等.页岩气储层特征及含气性主控因素--以湘西北保靖地区龙马溪组为例.岩性油气藏,2017,29(3):83-91.HU B W,LI B,LU D S,et al.Characteristics and main controlling factors of shale gas reservoirs:a case from Longmaxi Formation in Baojing area,NW Hunan province.Lithologic Reservoirs,2017,29(3):83-91.
[5]崔景伟,朱如凯,吴松涛,等.黄铁矿在页岩有机质富集、生排烃与页岩油聚集中的作用.地质论评,2013,59(增刊1):783-784.CUI J W,ZHU R K,WU S T,et al.The effect of pyrite on organic matter enrichment,hydrocarbon generation and expulsion and oil accumulation in shale.Geological Review,2013,59(Suppl 1):783-784.
[6]LIN W,MASTALERZ M,SCHIMMELMANN A,et al.Influence of Soxhlet-extractable bitumen and oil on porosity in thermally maturing organic-rich shales.International Journal of Coal Geology,2014,132(12):38-50.
[7]HU H Y,ZHANG T W,WIGGINS-CAMACHO J D,et al.Experimental investigation of changes in methane adsorption of bitumen-free Woodford shale with thermal maturation induced by hydrous pyrolysis.Marine and Petroleum Geology,2015,59(1):114-128.
[8]刘国恒,黄志龙,姜振学,等.湖相页岩液态烃对页岩吸附气实验的影响--以鄂尔多斯盆地延长组页岩为例.石油实验地质,2015,37(5):648-654.LIU G H,HUANG Z L,JIANG Z X,et al.effect of liquid hydrocarbons on gas adsorption in a lacustrine shale:a case study of the Yanchang Formation,Ordos Basin.Petroleum Geology and Experiment,2015,37(5):648-654.
[9]李成成,周世新,李靖,等.鄂尔多斯盆地南部延长组泥页岩孔隙特征及其控制因素.沉积学报,2017,35(2):315-329.LI C C,ZHOU S X,LI J,et al.Pore characteristics and controlling factors of the Yanchang Formation mudstone and shale in the south of Ordos Basin.Acta Sedimentologica Sinica,2017,35(2):315-329.
[10]VALENZA J J,DRENZEK N,MARQUES F,et al.Geochemical controls on shale microstructure.Geology,2013,41(5):611-614.
[11]郭慧娟,王香增,张丽霞,等.抽提前/后成熟页岩对氮气、二氧化碳的吸附特征及其对孔隙研究的意义.地球化学,2014,43(4):408-414.GUO H J,WANG X Z,ZHANG L X,et al.Adsorption of N2and CO2on mature shales before and after extraction and its implication for investigations of pore structures.Geochimica,2014,43(4):408-414.
[12]潘磊,肖贤明,周秦.可溶有机质对表征页岩储层特性的影响.天然气地球科学,2015,26(9):1729-1736.PAN L,XIAO X M,ZHOU Q.Influence of soluble organic matter on characterization of shale reservoir.Natural Gas Geoscience,2015,26(9):1729-1736.
[13]李建忠,董大忠,陈更生,等.中国页岩气资源前景与战略地位.天然气工业,2009,29(5):11-16.LI J Z,DONG D Z,CHEN G S,et al.Prospects and strategic position of shale gas resources in China.Natural Gas Industry,2009,29(5):11-16.
[14]梁狄刚,郭彤楼,陈建平,等.中国南方海相生烃成藏研究的若干新进展(一):南方四套区域性海相烃源岩的分布.海相油气地质,2008,13(2):1-16.LIANG D G,GUO T L,CHEN J P,et al.Some progresses on studies of hydrocarbon generation and accumulation in marine sedimentary regions,southern China(Part 1):Distribution of four regional marine source rocks.Marine Origin Petroleum Geology,2008,13(2):1-16.
[15]孙丽娜,张明峰,吴陈君,等.油页岩生排烃模拟实验中不同液态烃产物特征.岩性油气藏,2017,29(6):23-31.SUN L N,ZHANG M F,WU C J,et al.Features of liquid hydrocarbon in different states in oil shale during hydrous pyrolysis.Lithologic Reservoirs,2017,29(6):23-31.
[16]罗进雄,何幼斌.中上扬子地区二叠系烃源岩特征.天然气地球科学,2014,25(9):1416-1425.LUO J X,HE Y B.Characteristics of the Permian source rocks in the Middle and Upper Yangtze region.Natural Gas Geoscience,2014,25(9):1416-1425.
[17]雷裕红,王晖,罗晓容,等.鄂尔多斯盆地张家滩页岩液态烃特征及对页岩气量估算的影响.石油学报,2016,37(8):952-961.LEI Y H,WANG H,LUO X R,et al.The characteristics of liquid hydrocarbon in Zhangjiatan shale,Ordos Basin and its effects on the estimation of shale gas amount.Acta Petrolei Sinica,2016,37(8):952-961.
[18]崔景伟,邹才能,吴松涛,等.页岩孔隙研究新进展.地球科学进展,2012,27(12):1319-1325.CUI J W,ZOU C N,WU S T,et al.New advances in shale porosity research.Advances in Earth Science,2012,27(12):1319-1325.
[19]CHALMERS G R L,BUSTIN R M.Lower Cretaceous gas shales in northeastern British Columbia,PartⅠ:Geological controls on methane sorption capacity.Bulletin of Canadian Petroleum Geology,2008,56(1):1-22.
[20]崔景伟,朱如凯,崔京钢.页岩孔隙演化及其与残留烃量的关系:来自地质过程约束下模拟实验的证据.地质学报,2013,87(5):730-736.CUI J W,ZHU R K,CUI J G.Relationship of porous evolution and residual hydrocarbon:Evidence from modeling experiment with geological constrains.Acta Geologica Sinica,2013,87(5):730-736.
[21]MASTALERZ M,SCHMMELMANN A,DROBNIAK A,et al.Porosity of Devonian and Mississippian New Albany shale across a maturation gradient:Insights from organic petrology,gas adsorption,and mercury intrusion.AAPG Bulletin,2013,97(10):1621-1643.
[22]GUO H J,JIA W L,PENG P A,et al.Evolution of organic matter and nanometer-scale pores in an artificially matured shale undergoing two distinct types of pyrolysis:a study of the Yanchang Shale with Type II kerogen.Organic Geochemistry,2017,105(3):56-66.
[23]李恒超,刘大永,彭平安,等.人工熟化过程中可溶有机质对页岩孔隙特征的影响.地球化学,2017,46(5):466-475.LI H C,LIU D Y,PENG P A,et al.Effect of extractable organic matter on pore characteristics of shales treated by artificial heating.Geochimica,2017,46(5):466-475.
[24]梁利喜,熊健,刘向君,等.川南地区龙马溪组页岩孔隙结构的分形特征.成都理工大学学报(自然科学版),2016,42(6):700-708.LIANG L X,XIONG J,LIU X J,et al.Fractal characteristics of pore structure of Longmaxi Formation shale in south of Sichuan Basin,China.Journal of Chengdu University of Technology(Science and Technology Edition),2016,42(6):700-708.
[25]王志伟,卢双舫,王民,等.湖相、海相泥页岩孔隙分形特征对比.岩性油气藏,2016,28(1):88-93.WANG Z W,LU S F,WANG M,et al.Fractal characteristics of lacustrine shale and marine shale.Lithologic Reservoirs,2016,28(1):88-93.
[26]AVNIR D,JARONIEC M.An isotherm equation for adsorption on fractal surfaces of heterogeneous porous materials.Langmuir,1989,5(6):1431-1433.
[27]WANG M,XUE H T,TIAN S S,et al.Fractal characteristics of Upper Cretaceous lacustrine shale from the Songliao Basin,NEChina.Marine and Petroleum Geology,2015,67(11):144-153.
[28]范泓澈,黄志龙,袁剑,等.高温高压条件下甲烷和二氧化碳溶解度试验.中国石油大学学报(自然科学版),2011,35(2):6-11.FAN H C,HUANG Z L,YUAN J,et al.Experiment on solubility of CH4and CO2at high temperature and high pressure.Journal of China University of Petroleum,2011,35(2):6-11.