泥岩形成的前积反射
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摘要
在塔里木盆地于奇地区上三叠统的大套泥岩中发现了一个由低速泥岩形成的自东向西的叠瓦状前积地震反射,它本身由三个朵叶体组成,每个朵叶的面积约为30～45km2,厚度为15～20m。如今有三口钻井揭示该前积反射为较低速深灰色纯泥岩所形成,发育于较高速的深灰、暗褐灰色含钙质泥岩背景中。前积体反映的古沉积斜坡坡度约为2.1°。因沉积背景为半深—深湖相,故该前积体可能为湖底泥质重力流沉积。在该区北部靠近轮南断裂附近下降盘相同层位还存在一个自北向南的前积反射,YQ2井揭示该前积体也由低速泥岩构成。
An imbricateed progradational reflection caused by low velocity shale is found in Upper Triassic thick massive mudstones.It flows westward and consists of three irregular planar oval shaped lobes,each with 15~20m thick and 30~45km2 sizes.Three borehole data reveal that it is dark grayish pure shale and sandwiched within a background of dark grayish and brown-grayish calcareous claystone.The progradational reflection indicates a clinoform of 2.1 degree of ancient depositional surface.As the depositional background is deeper lacustrine environment,the progradational reflection may be muddy gravity flow deposits.Another similar southward progradational reflection occurred in the same horizon.It is close to down-thrown block of Lunnan Fault,a tectonic fault as the southern boundary of Saya uplift.Well YQ2 located at the southern frontier of the reflection reveals that the progradtional reflection is also caused by a low velocity of shale.Despite seen rarely,shale progradations are seldom found on outcrops.Lack of coarse sediment may be consequence of fine lilthology of eroded source area.
An imbricateed progradational reflection caused by low velocity shale is found in Upper Triassic thick massive mudstones.It flows westward and consists of three irregular planar oval shaped lobes,each with 15~20m thick and 30~45km2 sizes.Three borehole data reveal that it is dark grayish pure shale and sandwiched within a background of dark grayish and brown-grayish calcareous claystone.The progradational reflection indicates a clinoform of 2.1 degree of ancient depositional surface.As the depositional background is deeper lacustrine environment,the progradational reflection may be muddy gravity flow deposits.Another similar southward progradational reflection occurred in the same horizon.It is close to down-thrown block of Lunnan Fault,a tectonic fault as the southern boundary of Saya uplift.Well YQ2 located at the southern frontier of the reflection reveals that the progradtional reflection is also caused by a low velocity of shale.Despite seen rarely,shale progradations are seldom found on outcrops.Lack of coarse sediment may be consequence of fine lilthology of eroded source area.
引文
[1]张纪易.塔里木盆地轮南地区三叠系沉积相分析.新疆石油地质,1992,13(4):322～337Zhang Jiyi.Analysis of sedimentary facies of Triassicstrata in Lunnan area of Tarim Basin.XinJiang Pe-troleum Geology,1992,13(4):322～337
[2]佩顿编,牛毓荃等译.地震地层学在油气勘探中的应用.北京:石油工业出版社,1980,106～153
[3]陆邦干主编.中国典型地震剖面图册.北京:石油工业出版社,1989,78～114
[4]蒲仁海.前积反射的地质解释.石油地球物理勘探,1994,29(4):490～497Pu Renhai.Geological interpretation of progradationalreflections.OGP,1994,29(4):490～497
[5]Spencer H W.Seismic expression and geological sig-nificance of a lacustrine delta in Neogene deposits ofthe western Snake Plain,Idaho.AAPG Bullitine,1994,78(1):102～121
[6]王旭,刘树晖,叶德胜等.塔里木盆地东北地区三叠系、侏罗系砂岩的压实作用及其石油地质意义.石油实验地质,1993,15(1):49～58Wang Xu,Liu Shuhui,Ye Desheng et al.On the sand-stone compaction of JURA-TRIAS system and the pe-troleum geological significance in northeast Tarim Ba-sin.Petroleum Geology&Experiment,1993,15(1):49～58
[7]胡少华.基于地震资料的构造—沉积综合分析法——一种剥蚀厚度恢复新方法.石油地球物理勘探,2004,39(4):478～483Hu Shaohua.Integrative structural-sedimentary analy-sis method based on seismic data:a new method for re-storing denuded thickness.OGP,2004,39(4):478～483
[8]Brown A R.Pitfalls in 3Dseismic interpretation.Key-note presentation at the 11th Annual 3-D Seismic Sym-posium,Denver.The Leading Edge,2005,24(7):716～720
[2]佩顿编,牛毓荃等译.地震地层学在油气勘探中的应用.北京:石油工业出版社,1980,106～153
[3]陆邦干主编.中国典型地震剖面图册.北京:石油工业出版社,1989,78～114
[4]蒲仁海.前积反射的地质解释.石油地球物理勘探,1994,29(4):490～497Pu Renhai.Geological interpretation of progradationalreflections.OGP,1994,29(4):490～497
[5]Spencer H W.Seismic expression and geological sig-nificance of a lacustrine delta in Neogene deposits ofthe western Snake Plain,Idaho.AAPG Bullitine,1994,78(1):102～121
[6]王旭,刘树晖,叶德胜等.塔里木盆地东北地区三叠系、侏罗系砂岩的压实作用及其石油地质意义.石油实验地质,1993,15(1):49～58Wang Xu,Liu Shuhui,Ye Desheng et al.On the sand-stone compaction of JURA-TRIAS system and the pe-troleum geological significance in northeast Tarim Ba-sin.Petroleum Geology&Experiment,1993,15(1):49～58
[7]胡少华.基于地震资料的构造—沉积综合分析法——一种剥蚀厚度恢复新方法.石油地球物理勘探,2004,39(4):478～483Hu Shaohua.Integrative structural-sedimentary analy-sis method based on seismic data:a new method for re-storing denuded thickness.OGP,2004,39(4):478～483
[8]Brown A R.Pitfalls in 3Dseismic interpretation.Key-note presentation at the 11th Annual 3-D Seismic Sym-posium,Denver.The Leading Edge,2005,24(7):716～720
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