西昌盆地奥陶系大箐组油气成藏地质条件评价
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摘要
西昌盆地奥陶系上统大箐组白云岩厚度大,分布面积广,多见溶蚀孔洞,周边野外露头可见沥青,井下取心多段见气泡冒出,表明其具有一定的勘探潜力。目前西昌盆地大箐组勘探程度低,油气地质条件尚不清楚,有待持续进行深入的研究工作。因此根据野外剖面、钻井取心与测井等资料,结合区域地质背景,在前人基础上进一步对西昌盆地大箐组油气地质条件开展系统研究。结果认为:①西昌盆地大箐组发育大套厚层滩相晶粒白云岩,溶蚀孔洞较为发育,为较好储集层;②上覆志留系下统龙马溪组灰黑色页岩厚度大,可为大箐组白云岩良好烃源与直接盖层;③大箐组白云岩野外与镜下均见沥青,表明大箐组具备油气成藏条件;④位于米市坳陷中部区域七里坝背斜带未见通天断裂,油气保存条件相对较好。结论认为:七里坝背斜带可作为该区大箐组下一步天然气勘探主攻方向。
Upper Ordovician Daqing Formation, composed of thick dolomite, is widely distributed in Xichang Basin. Solution pores are common, bitumen may be directly seen in outcrop, and gas bubble also emerges from many intervals during downhole coring, all indicating a certain exploration potential. At present, however, this formation is less explored and its hydrocarbon geological conditions have been made unclear. So, these conditions were studied systematically based on some data on profile, drilling, coring, and logging, as well as previous research, combined with regional geological setting. Results show that,(1) in this basin, there is a large set of thick shoal-facies dolomite developed in Daqing Formation, in which solution pores are common, so it is better reservoirs;(2) it is overlain by grayish black, and thick shale of Lower Silurian Longmaxi Formation, which can serve as better source rock and direct caprock for Daqing dolomite reservoirs;(3) bitumen is discovered in outcrop or thin section, indicating that Daqing Formation is favorable for hydrocarbon accumulation; and(4) there are no fractures extending to the surface appeared in Qiliba anticline, central Mishi depression, revealing better preservation. In conclusion, Qiliba anticline can be taken as the main exploration direction of Daqing Formation in this area.
Upper Ordovician Daqing Formation, composed of thick dolomite, is widely distributed in Xichang Basin. Solution pores are common, bitumen may be directly seen in outcrop, and gas bubble also emerges from many intervals during downhole coring, all indicating a certain exploration potential. At present, however, this formation is less explored and its hydrocarbon geological conditions have been made unclear. So, these conditions were studied systematically based on some data on profile, drilling, coring, and logging, as well as previous research, combined with regional geological setting. Results show that,(1) in this basin, there is a large set of thick shoal-facies dolomite developed in Daqing Formation, in which solution pores are common, so it is better reservoirs;(2) it is overlain by grayish black, and thick shale of Lower Silurian Longmaxi Formation, which can serve as better source rock and direct caprock for Daqing dolomite reservoirs;(3) bitumen is discovered in outcrop or thin section, indicating that Daqing Formation is favorable for hydrocarbon accumulation; and(4) there are no fractures extending to the surface appeared in Qiliba anticline, central Mishi depression, revealing better preservation. In conclusion, Qiliba anticline can be taken as the main exploration direction of Daqing Formation in this area.
引文
[1]王运生,李云岗.西昌盆地的形成与演化[J].成都理工学院学报,1996,22(1):85-90.Wang Yunsheng&Li Yungang.Formation and evolution of Xichang Basin[J].Journal of Chengdu Institute of Technology,1996,22(1):85-90.
[2]杜金虎,邹才能,徐春春,等.川中古隆起龙王庙组特大型气田战略发现与理论技术创新[J].石油勘探与开发,2014,41(3):268-277.Du Jinhu,Zou Caineng,Xu Chunchun,et al.Theoretical and technical innovations in strategic discovery of a giant gas field in Cambrian Longwangmiao Formation of central Sichuan paleo-uplift,Sichuan Basin[J].Petroleum Exploration and Development,2014,41(3):268-277.
[3]徐春春,沈平,杨跃明,等.乐山-龙女寺古隆起震旦系-下寒武统龙王庙组天然气成藏条件与富集规律[J].天然气工业,2014,34(3):1-7.Xu Chunchun,Shen Ping,Yang Yueming,et al.Accumulation conditions and enrichment patterns of natural gas in the Lower Cambrian Longwangmiao Fm reservoirs of the Leshan-Longnüsi Paleohigh,Sichuan Basin[J].Natural Gas Industry,2014,34(3):1-7.
[4]周进高,徐春春,姚根顺,等.四川盆地下寒武统龙王庙组储集层形成与演化[J].石油勘探与开发,2015,42(2):158-166.Zhou Jingao,Xu Chunchun,Yao Genshun,et al.Genesis and evolution of Lower Cambrian Longwangmiao Formation reservoirs,Sichuan Basin,SW China[J].Petroletum Exploration and Development,2015,42(2):158-166.
[5]赵澄林,朱筱敏.沉积岩石学[M].3版.北京:石油工业出版社,2001.Zhao Chenglin&Zhu Xiaomin.Sedimentary petrography[M].3rd ed.Beijing:Petroleum Industry Press,2001.
[6]高树生,胡志明,安为国,等.四川盆地龙王庙组气藏白云岩储层孔洞缝分布特征[J].天然气工业,2014,34(3):103-109.Gao Shusheng,Hu Zhiming,An Weiguo,et al.Distribution characteristics of dolomite reservoir pores and caves of Longwangmiao Fm gas reservoirs in the Sichuan Basin[J].Natural Gas Industry,2014,34(3):103-109.
[7]杜金虎,张宝民,汪泽成,等.四川盆地下寒武统龙王庙组碳酸盐缓坡双颗粒滩沉积模式及储层成因[J].天然气工业,2016,36(6):1-10.Du Jinhu,Zhang Baomin,Wang Zecheng,et al.Sedimentary model and reservoir genesis of dual grain banks at the Lower Cambrian Longwangmiao Fm carbonate ramp in the Sichuan Basin[J].Natural Gas Industry,2016,36(6):1-10.
[8]董大忠,施振生,管全中,等.四川盆地五峰组-龙马溪组页岩气勘探进展、挑战与前景[J].天然气工业,2018,38(4):67-74.Dong Dazhong,Shi Zhensheng,Guan Quanzhong,et al.Progress,challenges and prospects of shale gas exploration in the Wufeng-Longmaxi reservoirs in the Sichuan Basin[J].Natural Gas Industry,2018,38(4):67-74.
[9]聂海宽,金之钧,马鑫,等.四川盆地及邻区上奥陶统五峰组-下志留统龙马溪组底部笔石带及沉积特征[J].石油学报,2017,38(2):160-174.Nie Haikuan,Jin Zhijun,Ma Xin,et al.Graptolites zone and sedimentary characteristics of Upper Ordovician Wufeng Formation-Lower Silurian Longmaxi Formation in Sichuan Basin and its adjacent areas[J].Acta Petrolei Sinica,2017,38(2):160-174.
[10]Ran Bo,Liu Shugen,Jansa L,et al.Reservoir characteristics and preservation conditions of Longmaxi Shale in the upper Yangtze block,South China[J].Acta Geologica Sinica(English Edition),2016,90(6):2182-2205.
[11]刘丽华,徐强,范明祥.西昌盆地构造特征和含油气条件分析[J].天然气工业,2003,23(5):34-38.Liu Lihua,Xu Qiang&Fan Mingxiang.Structural Features and oil-gas bearing conditions in Xichang Basin[J].Natural Gas Industry,2003,23(5):34-38.
[12]石鸿翠,江晨曦,孙美静,等.鄂尔多斯盆地南部上古生界泥岩盖层封闭性能评价[J].油气地质与采收率,2015,22(2):9-16.Shi Hongcui,Jiang Chenxi,Sun Meijing,et al.Sealing capability assessment of mudstone caprock in the Upper Paleozoic,south Ordos Basin[J].Petroleum Geology and Recovery Efficiency,2015,22(2):9-16.
[13]冯冲,黄志龙,童传新,等.莺歌海盆地莺歌海组二段泥岩盖层封闭性综合评价[J].地球科学与环境学报,2011,33(4):373-377.Feng Chong,Huang Zhilong,Tong Chuanxin,et al.Comprehensive Evaluation on the Sealing Ability of Mudstone Cap Rock in Member 2 of Yinggehai Formation of Yinggehai Basin[J].Journal of Earth Sciences and Environment,2011,33(4):373-377.
[14]马中远,黄苇,张黎,等.塔中北坡柯坪塔格组泥岩盖层特征及控油作用[J].特种油气藏,2014,21(1):64-67.Ma Zhongyuan,Huang Wei,Zhang Li,et al.Features of the Kepingtage Formation mudstone cap rock and its oil controlling in Tazhong north slope[J].Special Oil&Gas Reservoirs,2014,21(1):64-67.
[15]李慧勇,徐长贵,刘廷海,等.陆相盆地薄层泥岩盖层形成机制、特征与油气成藏关系--以辽东湾地区中南部为例[J].石油实验地质,2010,32(1):19-23.Li Huiyong,Xu Changgui,Liu Tinghai,et al.The formation Mechanisms and Characteristics of Thin-layer Mudstone Caprock and Its Relationship with Hydrocarbon Accumulation in the Terrestrial Basin--An Example of Thin-layer Mudstone Caprock in the South-central Liaodong Bay[J].Petroleum Geology and Experiment,2010,32(1):19-23.
[2]杜金虎,邹才能,徐春春,等.川中古隆起龙王庙组特大型气田战略发现与理论技术创新[J].石油勘探与开发,2014,41(3):268-277.Du Jinhu,Zou Caineng,Xu Chunchun,et al.Theoretical and technical innovations in strategic discovery of a giant gas field in Cambrian Longwangmiao Formation of central Sichuan paleo-uplift,Sichuan Basin[J].Petroleum Exploration and Development,2014,41(3):268-277.
[3]徐春春,沈平,杨跃明,等.乐山-龙女寺古隆起震旦系-下寒武统龙王庙组天然气成藏条件与富集规律[J].天然气工业,2014,34(3):1-7.Xu Chunchun,Shen Ping,Yang Yueming,et al.Accumulation conditions and enrichment patterns of natural gas in the Lower Cambrian Longwangmiao Fm reservoirs of the Leshan-Longnüsi Paleohigh,Sichuan Basin[J].Natural Gas Industry,2014,34(3):1-7.
[4]周进高,徐春春,姚根顺,等.四川盆地下寒武统龙王庙组储集层形成与演化[J].石油勘探与开发,2015,42(2):158-166.Zhou Jingao,Xu Chunchun,Yao Genshun,et al.Genesis and evolution of Lower Cambrian Longwangmiao Formation reservoirs,Sichuan Basin,SW China[J].Petroletum Exploration and Development,2015,42(2):158-166.
[5]赵澄林,朱筱敏.沉积岩石学[M].3版.北京:石油工业出版社,2001.Zhao Chenglin&Zhu Xiaomin.Sedimentary petrography[M].3rd ed.Beijing:Petroleum Industry Press,2001.
[6]高树生,胡志明,安为国,等.四川盆地龙王庙组气藏白云岩储层孔洞缝分布特征[J].天然气工业,2014,34(3):103-109.Gao Shusheng,Hu Zhiming,An Weiguo,et al.Distribution characteristics of dolomite reservoir pores and caves of Longwangmiao Fm gas reservoirs in the Sichuan Basin[J].Natural Gas Industry,2014,34(3):103-109.
[7]杜金虎,张宝民,汪泽成,等.四川盆地下寒武统龙王庙组碳酸盐缓坡双颗粒滩沉积模式及储层成因[J].天然气工业,2016,36(6):1-10.Du Jinhu,Zhang Baomin,Wang Zecheng,et al.Sedimentary model and reservoir genesis of dual grain banks at the Lower Cambrian Longwangmiao Fm carbonate ramp in the Sichuan Basin[J].Natural Gas Industry,2016,36(6):1-10.
[8]董大忠,施振生,管全中,等.四川盆地五峰组-龙马溪组页岩气勘探进展、挑战与前景[J].天然气工业,2018,38(4):67-74.Dong Dazhong,Shi Zhensheng,Guan Quanzhong,et al.Progress,challenges and prospects of shale gas exploration in the Wufeng-Longmaxi reservoirs in the Sichuan Basin[J].Natural Gas Industry,2018,38(4):67-74.
[9]聂海宽,金之钧,马鑫,等.四川盆地及邻区上奥陶统五峰组-下志留统龙马溪组底部笔石带及沉积特征[J].石油学报,2017,38(2):160-174.Nie Haikuan,Jin Zhijun,Ma Xin,et al.Graptolites zone and sedimentary characteristics of Upper Ordovician Wufeng Formation-Lower Silurian Longmaxi Formation in Sichuan Basin and its adjacent areas[J].Acta Petrolei Sinica,2017,38(2):160-174.
[10]Ran Bo,Liu Shugen,Jansa L,et al.Reservoir characteristics and preservation conditions of Longmaxi Shale in the upper Yangtze block,South China[J].Acta Geologica Sinica(English Edition),2016,90(6):2182-2205.
[11]刘丽华,徐强,范明祥.西昌盆地构造特征和含油气条件分析[J].天然气工业,2003,23(5):34-38.Liu Lihua,Xu Qiang&Fan Mingxiang.Structural Features and oil-gas bearing conditions in Xichang Basin[J].Natural Gas Industry,2003,23(5):34-38.
[12]石鸿翠,江晨曦,孙美静,等.鄂尔多斯盆地南部上古生界泥岩盖层封闭性能评价[J].油气地质与采收率,2015,22(2):9-16.Shi Hongcui,Jiang Chenxi,Sun Meijing,et al.Sealing capability assessment of mudstone caprock in the Upper Paleozoic,south Ordos Basin[J].Petroleum Geology and Recovery Efficiency,2015,22(2):9-16.
[13]冯冲,黄志龙,童传新,等.莺歌海盆地莺歌海组二段泥岩盖层封闭性综合评价[J].地球科学与环境学报,2011,33(4):373-377.Feng Chong,Huang Zhilong,Tong Chuanxin,et al.Comprehensive Evaluation on the Sealing Ability of Mudstone Cap Rock in Member 2 of Yinggehai Formation of Yinggehai Basin[J].Journal of Earth Sciences and Environment,2011,33(4):373-377.
[14]马中远,黄苇,张黎,等.塔中北坡柯坪塔格组泥岩盖层特征及控油作用[J].特种油气藏,2014,21(1):64-67.Ma Zhongyuan,Huang Wei,Zhang Li,et al.Features of the Kepingtage Formation mudstone cap rock and its oil controlling in Tazhong north slope[J].Special Oil&Gas Reservoirs,2014,21(1):64-67.
[15]李慧勇,徐长贵,刘廷海,等.陆相盆地薄层泥岩盖层形成机制、特征与油气成藏关系--以辽东湾地区中南部为例[J].石油实验地质,2010,32(1):19-23.Li Huiyong,Xu Changgui,Liu Tinghai,et al.The formation Mechanisms and Characteristics of Thin-layer Mudstone Caprock and Its Relationship with Hydrocarbon Accumulation in the Terrestrial Basin--An Example of Thin-layer Mudstone Caprock in the South-central Liaodong Bay[J].Petroleum Geology and Experiment,2010,32(1):19-23.