霸县凹陷牛驼镇凸起潜山内幕古流体和现今流体特征研究
|
摘要
霸县凹陷牛驼镇凸起潜山内幕储层发育且勘探程度低,通过牛驼镇凸起潜山内幕方解石脉体及围岩的岩石学、同位素、包裹体等特征的研究,分析了古流体来源、期次和演化特征,再结合现今地层水特征,总结了流体活动对油气成藏的影响。研究结果表明:研究区发育3种类型方解石脉体(Cal1、Cal2和Cal3),其中加里东运动早期形成的Cal1型脉体与围岩同位素特征相似,认为流体来源于海相围岩。加里东运动晚期形成的Cal2型脉体可分为2期,其中裂缝边部的早期脉体Cal2-1与围岩同位素特征也相似,流体也来源于围岩;位于中心的晚期脉体Cal2-2相对围岩具有δ~(13)C相似、δ~(18)O亏损和~(87)Sr/~(86)Sr富集的特征,流体包裹体具有较低均一温度(<50℃)和盐度(1.3wt%~3.5wt%Na Cl),认为流体来源于大气水和围岩的混合。喜马拉雅运动Es3-Es4期形成的Cal3型脉体相对围岩具有δ~(13)C和δ~(18)O亏损、~(87)Sr/~(86)Sr富集的特征,流体包裹体具有高均一温度(142~210℃),认为流体来源于岩浆活动。这些特征表明研究区存在3次流体活动,流体分别来源于海相围岩、大气水和岩浆活动,没有烃类流体活动的证据。研究区现今地层水具有低矿化度(2~3 g/L)、高钠氯系数(1~1.2)的特征,与邻近霸县生油洼槽的古近系地层水有很大差异,说明油气的保存条件及其与霸县洼槽水动力联系均较差。综合古流体和现今流体特征,认为研究区潜山内幕的流体活动特征不利于油气的成藏。
The inner buried-hills with low degree of exploration,widely occur in Niutuozhen uplift of Baxian Sag. Vein calcites and host rocks were investigated using petrology,isotope and fluid-inclusion to determine theorigin,stage and evolution character of paleofluids. Combining the characteristics of present formation water,the influence of fluid flow on petroleum entrapment were summarized. The results show that three types of calcite veins have been found( Cal1,Cal2 and Cal3). The stable isotopes of the earliest calcites( Cal1),formed in the early stage of the Caledonian Orogeny,were equivalent to the host marine carbonates,which indicated that Cal1 were associated with host rocks. The subsequent calcite veins( Cal2) formed in the later stage of the Caledonian Orogeny could be divided into two periods. First,the early calcite veins( Cal2-1) in the edge of the fissure displayed isotopic compositions similar to those of the host rocks,which suggested that Cal2-1 were also associated with the host rocks. The late calcite vein( Cal2-2) in the middle of the fissure displayed similar δ~(13)C,depletedδ~(18)O,and higher~(87) Sr/~(86) Sr relative to host rocks. The characteristic of fluid-inclusion suggested the entrapment temperature was less than 50 ℃,and the saline of fluid inclusions in Cal2-2 were relative low,ranging from1. 3wt% to 3. 5wt% Na Cl. The outcomes have been interpreted as the result of the mixing of host marine carbonates with atmospheric fresh water. The latest calcite veins( Cal3) with hot homogenization temperature( T_h= 142℃ to 210 ℃) fluid inclusions,formed at the stage of the Es3 to Es4during the Himalayan Orogeny,displaying depleted δ~(18)O and δ~(13)C,and higher~(87) Sr/~(86) Sr relative to the host rocks,were derived from magmation. Based on the above data,the fluid flow history could be broken down into three stages which were from host marine carbonates,atmospheric fresh water and magmation,respectively. The evidence of hydrocarbon fluid flow has not been found and the present formation water has a low total dissolved solids( 2 to 3 g/L),high r Na/r Cl( 1 to1. 2). There are large differences between Niutuozhen uplift and its surrounding hydrocarbon generation subsags in the chemical characteristics of present formation water. These proved that the condition of oil and gas preservation is poor and there is no connection between Niutuozhen uplift and Baxian Sag in dynamic fluid field. Combined comprehensively the evolution of the fluid flow and the chemical characteristics of present formation water,the paper argues that the feature of fluid flow is unsuitable for petroleum entrapment.
The inner buried-hills with low degree of exploration,widely occur in Niutuozhen uplift of Baxian Sag. Vein calcites and host rocks were investigated using petrology,isotope and fluid-inclusion to determine theorigin,stage and evolution character of paleofluids. Combining the characteristics of present formation water,the influence of fluid flow on petroleum entrapment were summarized. The results show that three types of calcite veins have been found( Cal1,Cal2 and Cal3). The stable isotopes of the earliest calcites( Cal1),formed in the early stage of the Caledonian Orogeny,were equivalent to the host marine carbonates,which indicated that Cal1 were associated with host rocks. The subsequent calcite veins( Cal2) formed in the later stage of the Caledonian Orogeny could be divided into two periods. First,the early calcite veins( Cal2-1) in the edge of the fissure displayed isotopic compositions similar to those of the host rocks,which suggested that Cal2-1 were also associated with the host rocks. The late calcite vein( Cal2-2) in the middle of the fissure displayed similar δ~(13)C,depletedδ~(18)O,and higher~(87) Sr/~(86) Sr relative to host rocks. The characteristic of fluid-inclusion suggested the entrapment temperature was less than 50 ℃,and the saline of fluid inclusions in Cal2-2 were relative low,ranging from1. 3wt% to 3. 5wt% Na Cl. The outcomes have been interpreted as the result of the mixing of host marine carbonates with atmospheric fresh water. The latest calcite veins( Cal3) with hot homogenization temperature( T_h= 142℃ to 210 ℃) fluid inclusions,formed at the stage of the Es3 to Es4during the Himalayan Orogeny,displaying depleted δ~(18)O and δ~(13)C,and higher~(87) Sr/~(86) Sr relative to the host rocks,were derived from magmation. Based on the above data,the fluid flow history could be broken down into three stages which were from host marine carbonates,atmospheric fresh water and magmation,respectively. The evidence of hydrocarbon fluid flow has not been found and the present formation water has a low total dissolved solids( 2 to 3 g/L),high r Na/r Cl( 1 to1. 2). There are large differences between Niutuozhen uplift and its surrounding hydrocarbon generation subsags in the chemical characteristics of present formation water. These proved that the condition of oil and gas preservation is poor and there is no connection between Niutuozhen uplift and Baxian Sag in dynamic fluid field. Combined comprehensively the evolution of the fluid flow and the chemical characteristics of present formation water,the paper argues that the feature of fluid flow is unsuitable for petroleum entrapment.
引文
[1]周从安,李先平,辛玮江,等.冀中坳陷牛驼镇凸起潜山内幕勘探成藏条件研究[J].中国石油勘探,2010(2):29
[2]查明,尉亚民,高长海,等.牛驼镇凸起南段潜山勘探潜力分析[J].岩性油气藏,2011,23(2):10-14.
[3]杨海盟,戴俊生,汪必峰,等.牛驼镇凸起发育过程[J].东北石油大学学报,2014,38(6):22-29.
[4]MARFIL R,CAJA M A,TSIGE M,et al.Carbonate-cemented stylolites and fractures in the Upper Jurassic limestones of the eastern Iberian Range,Spain;a record of palaeofluids composition and thermal history[J].Sedimentary Geology,2005,178(3):237-257.
[5]KATZ D A,BERLI G P,SWART P K,et al.Tectonic-hydrothermal brecciation associated with calcite precipitation and permeability destruction in Mississippian carbonate reservoirs,Montana and Wyoming[J].American Association of Petroleum Geologists Bulletin,2006,90(11):1803-1841.
[6]赵贤正,金凤鸣,张以名,等.富油凹陷隐蔽型潜山油气藏精细勘探[M].北京:石油工业出版社,2010:46-60.
[7]GOLDSTEIN R H.Fluid inclusions in sedimentary and diagenetic system[J].Litho,2001,55(1):159-193.
[8]SLATER D J,YARDLEY B W D,SPIRO B,et al.Incipient metamorphism and deformation in the Variscides of SW Dyfed,Wales:first steps towards isotopic equilibrium[J].Journal of Metamorphic Geology,2007,12(3):237-248.
[9]CARTWRIGHT I,POWER W L,OLIVER N H S,et al.Fluid migration and vein formation during deformation and greenschistfacies metamorphism at Ormiston Gorge,Central Australia[J].Journal of Metamorphic Geology,1994,12(4):373-386.
[10]TAYLOR H P Jr,FRECHEN J,DEGENS E T et al.Oxygen and carbon isotope studies of carbonatites from the Laacher See District,West Germany and the AlnDistrict Sweden[J].Geochimica et Cosmochimica Acta,1967,31:407-430.
[11]VEIZER J,HOEFS J.The nature of18O/16O and13C/12C secular trends in sedimentary carbonate rocks[J].Geochimica et Cosmochimica Acta,1976,40:1387-1395.
[12]TOYODA K,HORIUCHI H,TOKONAMI M,et al.Dupal anomaly of Brazilian carbonatites:Geochemical correlations with hotspots in the South Atlantic and implications for the mantle source[J].Earth and Science Letter,1994,126(4):315-331.
[13]曹剑,胡文瑄,姚素平,等.准噶尔盆地石炭-二叠系方解石脉的碳、氧、锶同位素组成与含油气流体运移[J].沉积学报,2007,25(5):722-729.
[14]PROSSER D J,DAWS J A,FALLICK A E,et al.Geochemistry and diagenesis of stratabound calcite cement layers within the Rannoch Formation of Brent Group Murchison Field,North Viking Graben(North North Sea)[J].Sedimentary Geology,1993,87:139-164.
[15]HUDSON J D.Stable isotopes and limestone lithification[J].Journal of the Geological Society,London,1977,133(6):637-660.
[16]AL-AASM I S,CONIGLIO M,DESROCHERS A,et al.Formation of complex fibrous calcite veins in Upper Triassic strata of Wrangellia Terrain,British Columbia,Canada[J].Sedimentary Geology,1995,100(1):83-95.
[17]SASS E,BEIN A,LABIN A A.Oxygen isotope composition of diagenetic calcite in organic-rich rocks evidence for18O depletion in marine anaerobic pore water[J].Geology,1991,19(8):839-842.
[18]PALMER M R,EDMOND J M.The strontium isotope budget of the modern ocean[J].Earth and Planetary Science Letters,1989,92(1):11-26.
[19]PALMER M R,ELDERFIELD H.Sr isotope composition of seawater over the past 75 Myr[J].Nature,1985,314(2):526-528.
[20]陈墨香,黄歌山,张文仁,等.冀中牛驼镇凸起地温场的特点及地下热水的开发利用[J].地球科学,1982(3):239
[21]柯林斯A G.油田水地球化学[M].林文庄,王秉枕,译.北京:石油工业出版社,1984:146-162.
[2]查明,尉亚民,高长海,等.牛驼镇凸起南段潜山勘探潜力分析[J].岩性油气藏,2011,23(2):10-14.
[3]杨海盟,戴俊生,汪必峰,等.牛驼镇凸起发育过程[J].东北石油大学学报,2014,38(6):22-29.
[4]MARFIL R,CAJA M A,TSIGE M,et al.Carbonate-cemented stylolites and fractures in the Upper Jurassic limestones of the eastern Iberian Range,Spain;a record of palaeofluids composition and thermal history[J].Sedimentary Geology,2005,178(3):237-257.
[5]KATZ D A,BERLI G P,SWART P K,et al.Tectonic-hydrothermal brecciation associated with calcite precipitation and permeability destruction in Mississippian carbonate reservoirs,Montana and Wyoming[J].American Association of Petroleum Geologists Bulletin,2006,90(11):1803-1841.
[6]赵贤正,金凤鸣,张以名,等.富油凹陷隐蔽型潜山油气藏精细勘探[M].北京:石油工业出版社,2010:46-60.
[7]GOLDSTEIN R H.Fluid inclusions in sedimentary and diagenetic system[J].Litho,2001,55(1):159-193.
[8]SLATER D J,YARDLEY B W D,SPIRO B,et al.Incipient metamorphism and deformation in the Variscides of SW Dyfed,Wales:first steps towards isotopic equilibrium[J].Journal of Metamorphic Geology,2007,12(3):237-248.
[9]CARTWRIGHT I,POWER W L,OLIVER N H S,et al.Fluid migration and vein formation during deformation and greenschistfacies metamorphism at Ormiston Gorge,Central Australia[J].Journal of Metamorphic Geology,1994,12(4):373-386.
[10]TAYLOR H P Jr,FRECHEN J,DEGENS E T et al.Oxygen and carbon isotope studies of carbonatites from the Laacher See District,West Germany and the AlnDistrict Sweden[J].Geochimica et Cosmochimica Acta,1967,31:407-430.
[11]VEIZER J,HOEFS J.The nature of18O/16O and13C/12C secular trends in sedimentary carbonate rocks[J].Geochimica et Cosmochimica Acta,1976,40:1387-1395.
[12]TOYODA K,HORIUCHI H,TOKONAMI M,et al.Dupal anomaly of Brazilian carbonatites:Geochemical correlations with hotspots in the South Atlantic and implications for the mantle source[J].Earth and Science Letter,1994,126(4):315-331.
[13]曹剑,胡文瑄,姚素平,等.准噶尔盆地石炭-二叠系方解石脉的碳、氧、锶同位素组成与含油气流体运移[J].沉积学报,2007,25(5):722-729.
[14]PROSSER D J,DAWS J A,FALLICK A E,et al.Geochemistry and diagenesis of stratabound calcite cement layers within the Rannoch Formation of Brent Group Murchison Field,North Viking Graben(North North Sea)[J].Sedimentary Geology,1993,87:139-164.
[15]HUDSON J D.Stable isotopes and limestone lithification[J].Journal of the Geological Society,London,1977,133(6):637-660.
[16]AL-AASM I S,CONIGLIO M,DESROCHERS A,et al.Formation of complex fibrous calcite veins in Upper Triassic strata of Wrangellia Terrain,British Columbia,Canada[J].Sedimentary Geology,1995,100(1):83-95.
[17]SASS E,BEIN A,LABIN A A.Oxygen isotope composition of diagenetic calcite in organic-rich rocks evidence for18O depletion in marine anaerobic pore water[J].Geology,1991,19(8):839-842.
[18]PALMER M R,EDMOND J M.The strontium isotope budget of the modern ocean[J].Earth and Planetary Science Letters,1989,92(1):11-26.
[19]PALMER M R,ELDERFIELD H.Sr isotope composition of seawater over the past 75 Myr[J].Nature,1985,314(2):526-528.
[20]陈墨香,黄歌山,张文仁,等.冀中牛驼镇凸起地温场的特点及地下热水的开发利用[J].地球科学,1982(3):239
[21]柯林斯A G.油田水地球化学[M].林文庄,王秉枕,译.北京:石油工业出版社,1984:146-162.