四川盆地中三叠统雷口坡组沉积特征及有利储集相带
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摘要
为了查明四川盆地中三叠统雷口坡组沉积特征与有利储集相带分布规律,为该区天然气勘探寻找新的接替区,以海相碳酸盐岩层序地层学和储层沉积学理论体系为指导,在岩心标志、测录井标志以及不整合等层序界面标志的基础上,对中三叠统雷口坡组进行了沉积相识别和层序地层划分,进而圈定了各层序时期平面沉积相边界,并编制了四川盆地中三叠统雷口坡组各体系域内层序-岩相古地理图,预测了有利储集相带分布区。研究结果表明:四川盆地中三叠统雷口坡组为一套较浅水的碳酸盐岩台地相沉积体系,主要发育局限台地、蒸发台地、台地边缘和开阔台地等4种相类型。雷口坡期受到早印支运动的影响,盆地内部呈现东高西低、大隆大凹的沉积格局。地壳抬升作用使得部分地层遭受长期暴露剥蚀作用并在顶部形成风化壳,致雷口坡组顶部部分地层缺失。以沉积相划分、层序界面识别标志为依据,四川盆地中三叠统雷口坡组划分出4个三级层序和8个体系域。盆地中部古隆起及其周缘白云岩坪和西北部绵竹-剑阁隆起的台缘滩具有较好的储集物性和有效的储盖组合特征,为盆地有利储集相带分布区,因而成为四川盆地中三叠统雷口坡组最为有力的勘探目标。
In order to look for new fairways for future gas exploration in the Sichuan Basin,we worked on revealling the sedimentary characteristics and distribution of favorable reservoir facies in the Middle Triassic Leikoupo Formation. The study took marine carbonate sequence stratigraphy and reservoir sedimentology theory as guidance. Based on the markers in logging data,from cores,and sequence boundaries including unconformity,we conducted the sequence stratigraphy division and identification of sedimentary facies. Then spatial boundaries of sedimentary facies in each sequence are delineated,and the lithofacies paleogeographic map of each system tract in every sequence are compiled to predict favorable reservoir facies distribution. The results show that the Middle Triassic Leikoupo Formation in the Sichuan Basin develops a set of shallow water carbonate platform sedimentary system,including 4 major sedimentary facies,namely,restricted platform,evaporitic platform,platform edge and open platform. In general,the formation appears to be higher in the east and plunges to the west,with significant uplift and sag within the platform driven by early Indosinian tectonic movement.Due to basement uplift,some of the upper sections of the formation are eroded by long-term exposure,companied by de-velopment of a weathering crust. Furthermore,based on sedimentary facies recognition and sequence interface markers,we divided the Middle Triassic Leikoupo Formation into 4 third-tier sequences and 8 system tracts: the paleo-uplift in the central basin and its surrounding dolomite flat,and the platform edge bank of the northwestern Mianzhu and Jiange uplifts,are favorable reservoir facies because of their better reservoir properties and effective coupling of reservoir and caprock. Therefore,we conclude that these fairways are the most favorable areas for future exploration in the Middle Triassic Leikoupo Formation in the Sichuan Basin.
In order to look for new fairways for future gas exploration in the Sichuan Basin,we worked on revealling the sedimentary characteristics and distribution of favorable reservoir facies in the Middle Triassic Leikoupo Formation. The study took marine carbonate sequence stratigraphy and reservoir sedimentology theory as guidance. Based on the markers in logging data,from cores,and sequence boundaries including unconformity,we conducted the sequence stratigraphy division and identification of sedimentary facies. Then spatial boundaries of sedimentary facies in each sequence are delineated,and the lithofacies paleogeographic map of each system tract in every sequence are compiled to predict favorable reservoir facies distribution. The results show that the Middle Triassic Leikoupo Formation in the Sichuan Basin develops a set of shallow water carbonate platform sedimentary system,including 4 major sedimentary facies,namely,restricted platform,evaporitic platform,platform edge and open platform. In general,the formation appears to be higher in the east and plunges to the west,with significant uplift and sag within the platform driven by early Indosinian tectonic movement.Due to basement uplift,some of the upper sections of the formation are eroded by long-term exposure,companied by de-velopment of a weathering crust. Furthermore,based on sedimentary facies recognition and sequence interface markers,we divided the Middle Triassic Leikoupo Formation into 4 third-tier sequences and 8 system tracts: the paleo-uplift in the central basin and its surrounding dolomite flat,and the platform edge bank of the northwestern Mianzhu and Jiange uplifts,are favorable reservoir facies because of their better reservoir properties and effective coupling of reservoir and caprock. Therefore,we conclude that these fairways are the most favorable areas for future exploration in the Middle Triassic Leikoupo Formation in the Sichuan Basin.
引文
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[7]谭秀成,李凌,刘宏,等.四川盆地中三叠统雷口坡组碳酸盐台地巨型浅滩化研究[J].海相油气地质,2014,44(3):457-471.Tan Xiucheng,Li Ling,Liu Hong,et al.Mega-shoaling in carbonate platform of the Middle Triassic Leikoupo Formation,Sichuan Basin,Southwest China.Science China:Earth Sciences,44(3):457-471.
[8]周进高,辛勇光,谷明峰,等.四川盆地中三叠统雷口坡组天然气勘探方向[J].天然气工业,2010,30(12):16-19.Zhou Jingao,Xin Yongguang,Gu Mingfcng,et al.Direction of gas exploration in the Middle Triassic Leikoupo Formation of the Sichuan Basin[J].Natural Gas Industry,2010,30(12):16-19.
[9]孙玮,刘树根,秦川,等.川中磨溪与龙女寺雷口坡组构造特征及油气成藏差异性[J].成都理工大学学报:自然科学版,2009,36(6):654-661.Sun Wei,Liu Shugen,Qin Chuan,et al.Differences of structure and hydrocarbon accumulation characteristics of middle triassic Leikoupo formation between Moxi structure and Longnvsi structure in central Sichuan,China[J].Journal of Chengdu University of Technology:Science&Technology Edition,2009,36(6):654-661.
[10]黄东,张健,杨光,等.四川盆地中三叠统雷口坡组地层划分探讨[J].西南石油大学学报:自然科学版,2011,33(3):89-95.Huang Dong,Zhang Jian,Yang Guang,et al.The discussion of stratum division and stratum for the Leikoupo formation of Middle Triassic in Sichuan Basin[J].Journal of Southwest Petroleum University:Science&Technology Edition,2011,33(3):89-95.
[11]周彦,谭秀成,刘宏,等.磨溪气田嘉一段鲡粒灰岩储层特征及成因机制[J].西南石油大学学报:自然科学版,2007,29(4):30-33.Zhou Yan,Tan Xiu,cheng,Liu Hong,et al.Oolitic limestone reservoir c;haracteristics and its genetic mechanism of Jia-2 member in Moxi gas field[J].Journal of southwest petroleum university:Science&Technology Edition,2007,29(4):30-33.
[12]胡明毅,魏国齐,李思田,等.四川盆地嘉陵江组层序—岩相古地理特征和储层预测[J].沉积学报,2010,28(6):1145-1152.Hu Mingyi,Wei Guoqi,Li Sitian,et al.Characteristics of sequencebased lithofacies and paleogeography and Reservoir Prediction of the Jialingjiang Formation in Sichuan Basin[J].Acta Sedimentologica Sinica,2010,28(6):1145-1152.
[13]沈安江,周进高,辛勇光.四川盆地雷口坡组白云岩储层类型及成因[J].海相油气地质,2008,13(4):19-28.Shen Anjiang,Zhou Jingao,Xin Yongguang.Origin of Triassic Leikoupo dolomite reservoirs in Sichuan Basin[J].Marine Origin Petroleum Geology,2008,13(4):19-28.
[14]曾德铭,王兴志,石新,等.四川盆地西北部中三叠统雷口坡组滩体及储集性[J].沉积学报,2010,28(1):42-49.Zeng Deming,Wang Xingzhi,Shi Xin,et al.Characteristic and reservoir property of the Leikoupo Formation of Middle Triassic in northwestern Sichuan Basin[J].Acta Scdimcntologica Sinica,2010,28(1):42-49.
[15]林良彪,陈洪德,张长俊.四川盆地西北部中三叠世雷口坡期岩相古地理[J].沉积与特提斯地质,2007,27(3):51-58.Lin Liangbiao,Chen Hongde,Zhang Changjun.Sedimentary facies and palaeogeography of northwestern Sichuan Basin during the Leikoupoan Middle Triassic[J].Sedimentary Geology and Tethyan Geology,2007,27(3):51-58.
[16]冯增昭,鲍志东,李尚武,等.中国南方早中三叠世岩相古地理加[M].北京:石油工业出版社,1997:105-117.Feng Zengzhao,Bao Zhidong,Li Shangwu,et al.Lithofacies 1’aleogeography of the Early and Middle Triassic in South China[M].Beijing:Petroleum Industry Press,1997:105-117.
[17]Enos P.Sawatsky L H.Pore networks in Holocene carbonate sediments[J].Journal of Sedimentary Petrology1981,51(5):961-986.
[18]谭秀成,罗冰,李卓沛,等.川中地区磨溪气田嘉二段砂屑云岩储集层成因[J].石油勘探与开发,2011,38(3):268-273.Tan Xiucheng,Luo Bing,Li Zhuopei,et al.Jia2 member doloarenite reservoir in the Moxi gas field,middle Sichuan Basin[J].Petroleum Exploration and Develonment,2011,38(3):268-273.
[19]Mazzullo S J,Harris P M.Mesogenetic dissolution:its role in porosity developmlent in carbonate reservoir.[J].AAPG Bulletin.1992,76(5):607-620.
[20]李凌,谭秀成,丁熊,等.四川盆地雷口坡组台内滩与台缘滩沉积特征差异及对储层的控制[J].石油学报,2011,32(1):70-76.Li Ling,Tan Xiucheng,Ding Xiong,et al.Difference in depositional characteristics between intra-platform and marginal-platform shoals in Leikoupo formation in Sic;huan Basin and its impact on reservoirs[J].Acta Petrolei Sinica.2011,32(1):70-76.
[2]刘志丽,童金南.中国南方中三叠世地层及沉积古地理分异[J].沉积学报,2001,19(3):327-332.Liu Zhili,Tong Jinnan.The middle triassic stratigraphy and sedimentary paleogeography of south China[J].Acta Sedimentologica Sinica,2001,19(3):327-332.
[3]何镜宇,孟祥化.沉积岩和沉积相模式及建造[M].北京:地质出版社,1987:281-282.He Jingyu,Meng Xianghua.Sedimentary rock and sedimentary facies and construction[M].Beijing:Geological Press,1987:281-282.
[4]李凌,谭秀成,周素彦,等.四川盆地雷口坡组层序岩相古地理[J].西南石油大学学报:自然科学版,2012,34(4):13-22.Li Ling,Tan Xiucheng,Zhou Suyan,et al.Sequence lithofacies paleography of leikoupo formation,sichuan basin[J].Journal of Southwest Petroleum University:Science&Technology Edition,2012,34(4):13-22.
[5]辛勇光,周进高,倪超,等.四川盆地中三叠世雷口坡期障壁型碳酸盐岩台地沉积特征及有利储集相带分布[J].海相油气地质,2013,18(2):1-7.Xin Yongguang,Zhou Jingao,Ni Chao,et al.Sedimentary facies features and favorable lithofacies distribution of Middle Triassic Leikoupo barriered carbonate platform in Sichuan Basin[J].Marine Origin Petroleum Geology,2013,18(2):1-7.
[6]吕玉珍,倪超,张建勇,等.四川盆地中三叠统雷口坡组有利沉积相带及岩相古地理特征[J].海相油气地质,2013,18(1):26-32.Lv Yuzhen,Ni Chao,Zhang Jianyong,et al.Favorable sedimentary facies zones and lithofacies palaeogeography of Middle Triassic Leikoupo Formation in Sichuan Basin[J].Marine Origin Petroleum Geology,2013,18(1):26-32.
[7]谭秀成,李凌,刘宏,等.四川盆地中三叠统雷口坡组碳酸盐台地巨型浅滩化研究[J].海相油气地质,2014,44(3):457-471.Tan Xiucheng,Li Ling,Liu Hong,et al.Mega-shoaling in carbonate platform of the Middle Triassic Leikoupo Formation,Sichuan Basin,Southwest China.Science China:Earth Sciences,44(3):457-471.
[8]周进高,辛勇光,谷明峰,等.四川盆地中三叠统雷口坡组天然气勘探方向[J].天然气工业,2010,30(12):16-19.Zhou Jingao,Xin Yongguang,Gu Mingfcng,et al.Direction of gas exploration in the Middle Triassic Leikoupo Formation of the Sichuan Basin[J].Natural Gas Industry,2010,30(12):16-19.
[9]孙玮,刘树根,秦川,等.川中磨溪与龙女寺雷口坡组构造特征及油气成藏差异性[J].成都理工大学学报:自然科学版,2009,36(6):654-661.Sun Wei,Liu Shugen,Qin Chuan,et al.Differences of structure and hydrocarbon accumulation characteristics of middle triassic Leikoupo formation between Moxi structure and Longnvsi structure in central Sichuan,China[J].Journal of Chengdu University of Technology:Science&Technology Edition,2009,36(6):654-661.
[10]黄东,张健,杨光,等.四川盆地中三叠统雷口坡组地层划分探讨[J].西南石油大学学报:自然科学版,2011,33(3):89-95.Huang Dong,Zhang Jian,Yang Guang,et al.The discussion of stratum division and stratum for the Leikoupo formation of Middle Triassic in Sichuan Basin[J].Journal of Southwest Petroleum University:Science&Technology Edition,2011,33(3):89-95.
[11]周彦,谭秀成,刘宏,等.磨溪气田嘉一段鲡粒灰岩储层特征及成因机制[J].西南石油大学学报:自然科学版,2007,29(4):30-33.Zhou Yan,Tan Xiu,cheng,Liu Hong,et al.Oolitic limestone reservoir c;haracteristics and its genetic mechanism of Jia-2 member in Moxi gas field[J].Journal of southwest petroleum university:Science&Technology Edition,2007,29(4):30-33.
[12]胡明毅,魏国齐,李思田,等.四川盆地嘉陵江组层序—岩相古地理特征和储层预测[J].沉积学报,2010,28(6):1145-1152.Hu Mingyi,Wei Guoqi,Li Sitian,et al.Characteristics of sequencebased lithofacies and paleogeography and Reservoir Prediction of the Jialingjiang Formation in Sichuan Basin[J].Acta Sedimentologica Sinica,2010,28(6):1145-1152.
[13]沈安江,周进高,辛勇光.四川盆地雷口坡组白云岩储层类型及成因[J].海相油气地质,2008,13(4):19-28.Shen Anjiang,Zhou Jingao,Xin Yongguang.Origin of Triassic Leikoupo dolomite reservoirs in Sichuan Basin[J].Marine Origin Petroleum Geology,2008,13(4):19-28.
[14]曾德铭,王兴志,石新,等.四川盆地西北部中三叠统雷口坡组滩体及储集性[J].沉积学报,2010,28(1):42-49.Zeng Deming,Wang Xingzhi,Shi Xin,et al.Characteristic and reservoir property of the Leikoupo Formation of Middle Triassic in northwestern Sichuan Basin[J].Acta Scdimcntologica Sinica,2010,28(1):42-49.
[15]林良彪,陈洪德,张长俊.四川盆地西北部中三叠世雷口坡期岩相古地理[J].沉积与特提斯地质,2007,27(3):51-58.Lin Liangbiao,Chen Hongde,Zhang Changjun.Sedimentary facies and palaeogeography of northwestern Sichuan Basin during the Leikoupoan Middle Triassic[J].Sedimentary Geology and Tethyan Geology,2007,27(3):51-58.
[16]冯增昭,鲍志东,李尚武,等.中国南方早中三叠世岩相古地理加[M].北京:石油工业出版社,1997:105-117.Feng Zengzhao,Bao Zhidong,Li Shangwu,et al.Lithofacies 1’aleogeography of the Early and Middle Triassic in South China[M].Beijing:Petroleum Industry Press,1997:105-117.
[17]Enos P.Sawatsky L H.Pore networks in Holocene carbonate sediments[J].Journal of Sedimentary Petrology1981,51(5):961-986.
[18]谭秀成,罗冰,李卓沛,等.川中地区磨溪气田嘉二段砂屑云岩储集层成因[J].石油勘探与开发,2011,38(3):268-273.Tan Xiucheng,Luo Bing,Li Zhuopei,et al.Jia2 member doloarenite reservoir in the Moxi gas field,middle Sichuan Basin[J].Petroleum Exploration and Develonment,2011,38(3):268-273.
[19]Mazzullo S J,Harris P M.Mesogenetic dissolution:its role in porosity developmlent in carbonate reservoir.[J].AAPG Bulletin.1992,76(5):607-620.
[20]李凌,谭秀成,丁熊,等.四川盆地雷口坡组台内滩与台缘滩沉积特征差异及对储层的控制[J].石油学报,2011,32(1):70-76.Li Ling,Tan Xiucheng,Ding Xiong,et al.Difference in depositional characteristics between intra-platform and marginal-platform shoals in Leikoupo formation in Sic;huan Basin and its impact on reservoirs[J].Acta Petrolei Sinica.2011,32(1):70-76.