鄂尔多斯盆地西南部上古生界烃源岩特征及其对天然气藏形成与分布的控制作用
|
摘要
利用有机质丰度、类型、成熟度及生气强度指标对鄂尔多斯盆地西南部上古生界烃源岩进行综合分析,确定主力气源岩及平面分布特征,并与苏里格地区气源条件进行对比,分析气源条件对天然气藏形成与分布的控制作用。研究表明,研究区上古生界烃源岩包括山西组、太原组的煤层和暗色泥岩,其中煤层是主力烃源岩,平均厚度为4.7m,苏里格地区煤层平均厚度为14m。烃源岩有机质丰度较高,山西组和太原组煤层残余有机碳均值分别为54.94%和66.96%,泥岩残余有机碳均值分别为2.88%和1.75%;干酪根碳同位素值介于-24.56‰~-22.05‰之间,属于Ⅲ型干酪根;镜质体反射率介于1.6%~3.2%之间,均值为2.3%,整体处于高成熟—过成熟阶段;研究区生气强度介于(8~20)×108 m3/km2之间,而苏里格地区的介于(11~29)×108 m3/km2之间。与苏里格地区相比,研究区气源条件略显较差。研究区的气源条件对气藏的形成与分布起着明显的控制作用。平面上研究区的产气井主要分布在煤层厚度大于4m,生气强度大于10×108 m3/km2的区域,且存在随着烃源岩条件的变好含气性也变好的趋势;纵向上天然气垂向运移距离与煤层厚度和生气强度存在良好的正相关关系,煤层厚度越大、生气强度越高,天然气垂向运移距离越远。
By using abundance,type,maturity and gas generation intensity of organic matter,the comprehensive analysis of Upper Paleozoic source rocks in southwest Ordos Basin has been made to determine the plane distribution characteristics of main gas reservoirs,and the controlling effects of gas source rock on the formation are analyzed,which has been compared with that in the Sulige area.The Upper Paleozoic source rocks are composed of coal and dark mudstone of Shanxi Formation,Taiyuan Formation,of which coal seams are main source rocks.The average thickness of coal seams is 4.7min the study area,while 14 min Sulige.Source rocks are abundant in organic matters.That is,the mean residual TOCin coal seam of the second member of Shanxi Formation and Taiyuan Formation are 54.94%and 66.96%,respectively and in mudstone are 2.88% and 1.75%,respectively;The carbon isotope of kerogen varies from-24.56‰to-22.05‰,indicating that the kerogen belongs to typeⅢ;Vitrinite reflectance of organic matter is 1.6%-3.2%,with an average of 2.3%,which is at high to over-mature stage.Gas generation intensity is mainly between(8-20)×108 m3/km2,while between(11-29)×108 m3/km2 in Sulige region.Compared with the condition of gas source rocks of Sulige region,condition in the study area is slightly bad.Condition of source rocks controls the formation and distribution of gas reservoir in the study area.Horizontally,gas-producing wells are mainly distributed in coal seams with thickness more than 4mand gas generation intensity greater than 10×108 m3/km2,showing a trend that the better the source rocks,the more the hydrocarbon content.Vertically,it has a good positive correlation among the vertical migration distance of gas migration,the thickness of coal seam and gas generation intensity.That is,the vertical migration distance of gas becomes farther along with greater thickness of coal seam and higher gas generation intensity.
By using abundance,type,maturity and gas generation intensity of organic matter,the comprehensive analysis of Upper Paleozoic source rocks in southwest Ordos Basin has been made to determine the plane distribution characteristics of main gas reservoirs,and the controlling effects of gas source rock on the formation are analyzed,which has been compared with that in the Sulige area.The Upper Paleozoic source rocks are composed of coal and dark mudstone of Shanxi Formation,Taiyuan Formation,of which coal seams are main source rocks.The average thickness of coal seams is 4.7min the study area,while 14 min Sulige.Source rocks are abundant in organic matters.That is,the mean residual TOCin coal seam of the second member of Shanxi Formation and Taiyuan Formation are 54.94%and 66.96%,respectively and in mudstone are 2.88% and 1.75%,respectively;The carbon isotope of kerogen varies from-24.56‰to-22.05‰,indicating that the kerogen belongs to typeⅢ;Vitrinite reflectance of organic matter is 1.6%-3.2%,with an average of 2.3%,which is at high to over-mature stage.Gas generation intensity is mainly between(8-20)×108 m3/km2,while between(11-29)×108 m3/km2 in Sulige region.Compared with the condition of gas source rocks of Sulige region,condition in the study area is slightly bad.Condition of source rocks controls the formation and distribution of gas reservoir in the study area.Horizontally,gas-producing wells are mainly distributed in coal seams with thickness more than 4mand gas generation intensity greater than 10×108 m3/km2,showing a trend that the better the source rocks,the more the hydrocarbon content.Vertically,it has a good positive correlation among the vertical migration distance of gas migration,the thickness of coal seam and gas generation intensity.That is,the vertical migration distance of gas becomes farther along with greater thickness of coal seam and higher gas generation intensity.
引文
[1]Ma Xinhua.Natural gas exploration and development situation in Ordos Basin[J].Petroleum Exploration and Development,2005,32(4):50-53.[马新华.鄂尔多斯盆地天然气勘探开发形势分析[J].石油勘探与开发,2005,32(4):50-53.]
[2]Guo Jianyu,Zhang Dalin,Deng Hongwen,et al.Resource assessment methodology of oil and gas in the areas of low-degree prospecting[J].Petroleum Geology and Recovery Efficiency,2006,13(6):43-45.[郭建宇,张大林,邓宏文,等.低勘探程度区域油气资源评价方法[J].油气地质与采收率,2006,13(6):43-45.]
[3]Zhao Zhengzhang,Zhao Xianzheng,He Haiqing.China′s recent oil and gas exploration results in new area and prospect for future development[J].China Petroleum Exploration,2002,7(3):1-6.[赵政璋,赵贤正,何海清.中国石油近期新区油气勘探成果及面临的挑战与前景展望[J].中国石油勘探,2002,7(3):1-6.]
[4]Fu Jinhua,Duan Xiaowen,Xi Shengli.Characteristics of Upper Paleozoic gas reservoirs in Ordos Basin[J].Natural Gas Industry,2000,20(6):16-19.[付金华,段晓文,席胜利.鄂尔多斯盆地上古生界气藏特征[J].天然气工业,2000,20(6):16-19.]
[5]Chen Quanhong,Li Wenhou,Jiang Peihai,et al.The analysis of hydrocarbon accumulation condition of Upper Paleozoic of the southwest Ordos Basin[J].Petroleum Geology&Experiment,2007,29(6):554-559.[陈全红,李文厚,姜培海,等.鄂尔多斯盆地西南部上古生界油气成藏条件分析[J].石油实验地质,2007,29(6):554-559.]
[6]Zhang Jinliang,Zhang Jingong,Hong Feng,et al.Geologic controls of deep basin gas accumulations in the lower Permian sequence of the Ordos Basin[J].Natural Gas Geoscience,2005,16(4):526-534.[张金亮,张金功,洪峰,等.鄂尔多斯盆地下二叠统深盆气藏形成的地质条件[J].天然气地球科学,2005,16(4):526-534.]
[7]Chang Xiangchun,Wang Mingzhen.Unconventional gas system of Upper Paleozoic in Ordos Basin[J].Natural Gas Geoscience,2005,16(6):732-735.[常象春,王明镇.鄂尔多斯盆地上古生界非常规含气系统[J].天然气地球科学,2005,16(6):732-735.]
[8]Yang Hua,Xi Shengli,Wei Xinshan,et al.Evolution and and natural gas enrichment of multi-cycle superimposed basin in Ordos Basin[J].China Petroleum Exploration,2006,11(1):17-24.[杨华,席胜利,魏新善,等.鄂尔多斯多旋回叠合盆地演化与天然气富集[J].中国石油勘探,2006,11(1):17-24.]
[9]Li Desheng.Return to petroleum geology of Ordos Basin[J].Petroleum Exploration and Development,2004,31(1):1-7.[李德生.重新认识鄂尔多斯盆地油气地质学[J].石油勘探与开发,2004,31(1):1-7.]
[10]Yang Suizheng,Jin Wenhua,Li Zhenhong.Multicycle superimposed basin form and evolution of Ordos Basin[J].Natural Gas Geoscience,2006,17(4):494-498.[杨遂正,金文化,李振宏.鄂尔多斯多旋回叠合盆地形成与演化[J].天然气地球科学,2006,17(4):494-498.]
[11]Yang Yihua,Bao Hongping,Jia Yani,et al.Analysis on control factors of sandstone reservoir of the Upper Paleozoic in Ordos Basin[J].Journal of Paleogeography,2008,10(1):25-32.[杨奕华,包洪平,贾亚妮,等.鄂尔多斯盆地上古生界砂岩储集层控制因素分析[J].古地理学报,2008,10(1):25-32.]
[12]Qin Jianzhong.Source Rock of China[M].Beijing:Science Press,2005:252-258.[秦建忠.中国烃源岩[M].北京:科学出版社,2005:252-258.]
[13]Lu Shuangfang,Zhang Min.Petroleum Geochemistry[M].Beijing:Petroleum Industry Press,2008:201-219.[卢双舫,张敏.油气地球化学[M].北京:石油工业出版社,2008:201-219.]
[14]Wang Feng,Tian Jingchun,Chen Rong,et al.Analysis on controlling factors and characteristics of sandstone reservoir of He 8(Upper Paleozoic)in the northern Ordos Basin[J].Acta Sedmentologicy Sinica,2009,27(2):238-245.[王峰,田景春,陈蓉,等.鄂尔多斯盆地北部上古生界盒8储层特征及控制因素分析[J].沉积学报,2009,27(2):238-245.]
[15]Zhao Jingzhou.Conception,classification and resource potential of unconventional hydrocarbons[J].Natural Gas Geoscience,2012,23(3):393-406.[赵靖舟.非常规油气有关概念、分类及资源潜力[J].天然气地球科学,2012,23(3):393-406.]
[16]Zhao Jingzhou,Fu Jinhua,Yao Jingli,et al.Quasi-continuous accumulation model of large tight sandstond gas field in Ordos Basin[J].Acta Petrolei Sinica,2012,33(S1):37-52.[赵靖舟,付金华,姚泾利,等.鄂尔多斯盆地准连续型致密砂岩大气田成藏模式[J].石油学报,2012,10(S.1):37-52.]
[17]Cao Qing,Zhao Jingzhou,Fu Jinghua,et al.Gas source conditions of quasi-continuous of the Upper Paleozoic in Ordos Basin[J].Oil&Gas Geology,2013,34(5):584-590.[曹青,赵靖舟,付金华,等.鄂尔多斯盆地上古生界准连续型气藏气源条件[J].石油与天然气地质,2013,34(5):584-590.]
[18]Ding Xiaoqi,Zhang Shaonan,Zhou Wen,et al.Characteristics and genesis of the Upper Paleozoic tight sandstone reservoirs in the northern Ordos Basin[J].Oil&Gas Geology,2007,28(4):491-496.[丁晓琪,张哨楠,周文,等.鄂尔多斯盆地北部上古生界致密砂岩储层特征及其成因探讨[J].石油与天然气地质,2007,28(4):491-496.]
[19]Li Jun,Zhao Jingzhou,Fan Yuanfang,et al.Gas migration mechanism of quasi-continuous accumulation in the Upper Paleozoic of Ordos Basin[J].Oil&Gas Geology,2013,34(5):592-600.[李军,赵靖舟,凡元芳,等.鄂尔多斯盆地上古生界准连续型气藏天然气运移机制[J].石油与天然气地质,2013,34(5):592-600.]
[20]Zhao Jingzhou,Bai Yubin,Cao Qing,et al.Quasi-continuous hydrocarbon accumulation:A new pattern for large tight sand oilfield in Ordos Basin[J].Oil&Gas Geology,2012,33(6):811-827.[赵靖舟,白玉彬,曹青,等.鄂尔多斯盆地准连续型低渗透—致密砂岩大油田成藏模式[J].石油与天然气地质,2012,33(6):811-827.]
[21]Wang Xiaomei,Zhao Jingzhou,Liu Xinshe,et al.Distribution of formation water in tight sandstone reservoirs of western Sulige Gasfield,Ordos Basin[J].Oil&Gas Geology,2012,33(5):802-810.[王晓梅,赵靖舟,刘新社,等.苏里格气田西区致密砂岩储层地层水分布特征[J].石油与天然气地质,2012,33(5):802-810.]
[2]Guo Jianyu,Zhang Dalin,Deng Hongwen,et al.Resource assessment methodology of oil and gas in the areas of low-degree prospecting[J].Petroleum Geology and Recovery Efficiency,2006,13(6):43-45.[郭建宇,张大林,邓宏文,等.低勘探程度区域油气资源评价方法[J].油气地质与采收率,2006,13(6):43-45.]
[3]Zhao Zhengzhang,Zhao Xianzheng,He Haiqing.China′s recent oil and gas exploration results in new area and prospect for future development[J].China Petroleum Exploration,2002,7(3):1-6.[赵政璋,赵贤正,何海清.中国石油近期新区油气勘探成果及面临的挑战与前景展望[J].中国石油勘探,2002,7(3):1-6.]
[4]Fu Jinhua,Duan Xiaowen,Xi Shengli.Characteristics of Upper Paleozoic gas reservoirs in Ordos Basin[J].Natural Gas Industry,2000,20(6):16-19.[付金华,段晓文,席胜利.鄂尔多斯盆地上古生界气藏特征[J].天然气工业,2000,20(6):16-19.]
[5]Chen Quanhong,Li Wenhou,Jiang Peihai,et al.The analysis of hydrocarbon accumulation condition of Upper Paleozoic of the southwest Ordos Basin[J].Petroleum Geology&Experiment,2007,29(6):554-559.[陈全红,李文厚,姜培海,等.鄂尔多斯盆地西南部上古生界油气成藏条件分析[J].石油实验地质,2007,29(6):554-559.]
[6]Zhang Jinliang,Zhang Jingong,Hong Feng,et al.Geologic controls of deep basin gas accumulations in the lower Permian sequence of the Ordos Basin[J].Natural Gas Geoscience,2005,16(4):526-534.[张金亮,张金功,洪峰,等.鄂尔多斯盆地下二叠统深盆气藏形成的地质条件[J].天然气地球科学,2005,16(4):526-534.]
[7]Chang Xiangchun,Wang Mingzhen.Unconventional gas system of Upper Paleozoic in Ordos Basin[J].Natural Gas Geoscience,2005,16(6):732-735.[常象春,王明镇.鄂尔多斯盆地上古生界非常规含气系统[J].天然气地球科学,2005,16(6):732-735.]
[8]Yang Hua,Xi Shengli,Wei Xinshan,et al.Evolution and and natural gas enrichment of multi-cycle superimposed basin in Ordos Basin[J].China Petroleum Exploration,2006,11(1):17-24.[杨华,席胜利,魏新善,等.鄂尔多斯多旋回叠合盆地演化与天然气富集[J].中国石油勘探,2006,11(1):17-24.]
[9]Li Desheng.Return to petroleum geology of Ordos Basin[J].Petroleum Exploration and Development,2004,31(1):1-7.[李德生.重新认识鄂尔多斯盆地油气地质学[J].石油勘探与开发,2004,31(1):1-7.]
[10]Yang Suizheng,Jin Wenhua,Li Zhenhong.Multicycle superimposed basin form and evolution of Ordos Basin[J].Natural Gas Geoscience,2006,17(4):494-498.[杨遂正,金文化,李振宏.鄂尔多斯多旋回叠合盆地形成与演化[J].天然气地球科学,2006,17(4):494-498.]
[11]Yang Yihua,Bao Hongping,Jia Yani,et al.Analysis on control factors of sandstone reservoir of the Upper Paleozoic in Ordos Basin[J].Journal of Paleogeography,2008,10(1):25-32.[杨奕华,包洪平,贾亚妮,等.鄂尔多斯盆地上古生界砂岩储集层控制因素分析[J].古地理学报,2008,10(1):25-32.]
[12]Qin Jianzhong.Source Rock of China[M].Beijing:Science Press,2005:252-258.[秦建忠.中国烃源岩[M].北京:科学出版社,2005:252-258.]
[13]Lu Shuangfang,Zhang Min.Petroleum Geochemistry[M].Beijing:Petroleum Industry Press,2008:201-219.[卢双舫,张敏.油气地球化学[M].北京:石油工业出版社,2008:201-219.]
[14]Wang Feng,Tian Jingchun,Chen Rong,et al.Analysis on controlling factors and characteristics of sandstone reservoir of He 8(Upper Paleozoic)in the northern Ordos Basin[J].Acta Sedmentologicy Sinica,2009,27(2):238-245.[王峰,田景春,陈蓉,等.鄂尔多斯盆地北部上古生界盒8储层特征及控制因素分析[J].沉积学报,2009,27(2):238-245.]
[15]Zhao Jingzhou.Conception,classification and resource potential of unconventional hydrocarbons[J].Natural Gas Geoscience,2012,23(3):393-406.[赵靖舟.非常规油气有关概念、分类及资源潜力[J].天然气地球科学,2012,23(3):393-406.]
[16]Zhao Jingzhou,Fu Jinhua,Yao Jingli,et al.Quasi-continuous accumulation model of large tight sandstond gas field in Ordos Basin[J].Acta Petrolei Sinica,2012,33(S1):37-52.[赵靖舟,付金华,姚泾利,等.鄂尔多斯盆地准连续型致密砂岩大气田成藏模式[J].石油学报,2012,10(S.1):37-52.]
[17]Cao Qing,Zhao Jingzhou,Fu Jinghua,et al.Gas source conditions of quasi-continuous of the Upper Paleozoic in Ordos Basin[J].Oil&Gas Geology,2013,34(5):584-590.[曹青,赵靖舟,付金华,等.鄂尔多斯盆地上古生界准连续型气藏气源条件[J].石油与天然气地质,2013,34(5):584-590.]
[18]Ding Xiaoqi,Zhang Shaonan,Zhou Wen,et al.Characteristics and genesis of the Upper Paleozoic tight sandstone reservoirs in the northern Ordos Basin[J].Oil&Gas Geology,2007,28(4):491-496.[丁晓琪,张哨楠,周文,等.鄂尔多斯盆地北部上古生界致密砂岩储层特征及其成因探讨[J].石油与天然气地质,2007,28(4):491-496.]
[19]Li Jun,Zhao Jingzhou,Fan Yuanfang,et al.Gas migration mechanism of quasi-continuous accumulation in the Upper Paleozoic of Ordos Basin[J].Oil&Gas Geology,2013,34(5):592-600.[李军,赵靖舟,凡元芳,等.鄂尔多斯盆地上古生界准连续型气藏天然气运移机制[J].石油与天然气地质,2013,34(5):592-600.]
[20]Zhao Jingzhou,Bai Yubin,Cao Qing,et al.Quasi-continuous hydrocarbon accumulation:A new pattern for large tight sand oilfield in Ordos Basin[J].Oil&Gas Geology,2012,33(6):811-827.[赵靖舟,白玉彬,曹青,等.鄂尔多斯盆地准连续型低渗透—致密砂岩大油田成藏模式[J].石油与天然气地质,2012,33(6):811-827.]
[21]Wang Xiaomei,Zhao Jingzhou,Liu Xinshe,et al.Distribution of formation water in tight sandstone reservoirs of western Sulige Gasfield,Ordos Basin[J].Oil&Gas Geology,2012,33(5):802-810.[王晓梅,赵靖舟,刘新社,等.苏里格气田西区致密砂岩储层地层水分布特征[J].石油与天然气地质,2012,33(5):802-810.]