新疆石油地质
新疆石油地質
신강석유지질
XINJIANG PETROLEUM GEOLOGY
2009年
5期
557-559
,共3页
孔玉华%沈新安%李桂秋%单守会%李刚
孔玉華%瀋新安%李桂鞦%單守會%李剛
공옥화%침신안%리계추%단수회%리강
准噶尔盆地%火山岩%氧同位素%沉积环境%碳同位素%孔隙
準噶爾盆地%火山巖%氧同位素%沉積環境%碳同位素%孔隙
준갈이분지%화산암%양동위소%침적배경%탄동위소%공극
Junggar basin%volcanic rocks%oxygen isotope%carbon isotope%sedimentary environment%pore
准噶尔盆地陆西地区火山岩孔隙中充填的碳酸盐岩对储集层物性产生巨大影响,通过对碳酸盐充填物的氧碳稳定同位素分析表明,δ~(13)C和δ~(18)O值均较轻且Z值较低,反映其形成于淡水环境,碳酸盐结晶温度大致分3种情况:早成岩作用阶段早期占大多数,部分形成于表生风化淋滤阶段,个别形成于热液作用阶段.通过氧同位素与古地温间的关系,推测碳酸盐充填物的结晶时间大致为晚三叠世到早侏罗世.烃源岩低成熟至成熟早期,靠近生烃凹陷的低凸带上,受淡水淋滤作用,火山岩中仍然存在部分未被碳酸盐岩充填的气孔.烃源岩大量排烃期,靠近凹陷区受溶蚀作用较强,可能存在相对优质的火山岩储集层发育区.
準噶爾盆地陸西地區火山巖孔隙中充填的碳痠鹽巖對儲集層物性產生巨大影響,通過對碳痠鹽充填物的氧碳穩定同位素分析錶明,δ~(13)C和δ~(18)O值均較輕且Z值較低,反映其形成于淡水環境,碳痠鹽結晶溫度大緻分3種情況:早成巖作用階段早期佔大多數,部分形成于錶生風化淋濾階段,箇彆形成于熱液作用階段.通過氧同位素與古地溫間的關繫,推測碳痠鹽充填物的結晶時間大緻為晚三疊世到早侏囉世.烴源巖低成熟至成熟早期,靠近生烴凹陷的低凸帶上,受淡水淋濾作用,火山巖中仍然存在部分未被碳痠鹽巖充填的氣孔.烴源巖大量排烴期,靠近凹陷區受溶蝕作用較彊,可能存在相對優質的火山巖儲集層髮育區.
준갈이분지륙서지구화산암공극중충전적탄산염암대저집층물성산생거대영향,통과대탄산염충전물적양탄은정동위소분석표명,δ~(13)C화δ~(18)O치균교경차Z치교저,반영기형성우담수배경,탄산염결정온도대치분3충정황:조성암작용계단조기점대다수,부분형성우표생풍화림려계단,개별형성우열액작용계단.통과양동위소여고지온간적관계,추측탄산염충전물적결정시간대치위만삼첩세도조주라세.경원암저성숙지성숙조기,고근생경요함적저철대상,수담수림려작용,화산암중잉연존재부분미피탄산염암충전적기공.경원암대량배경기,고근요함구수용식작용교강,가능존재상대우질적화산암저집층발육구.
The study of the volcanic rocks in Luxi area of Junggar basin indicates that the carbonate minerals placing in pores has great effect on the reservoir property.The oxygen-carbon stable isotopes in them are analyzed,showing that the values of δ~(13)C and δ~(18)O are lighter and Z value is low,which reflect they are formed in fresh water environment.Based on the carbonate crystallization temperature they occur in three settings:the most carbonate minerals are formed in the early stage of early diagenesis,some formed in the weathered and leaching stage,a few in the hydrothermal stage.Through the relationship between the oxygen isotope and the paleo-temperature,it is deduced that the crystallization time of spacing carbonate minerals could be from Late Triassic to Early Jurassic.The source rocks reach the stage of low maturity to early high maturity.They are distributed in low swell zone adjacent to the source sag and subjected to freshwater leaching process.In the volcanic rocks there still exists part of the pores not filled by the carbonate minerals.In period of major hydrocarbon expulsion from the source rocks,the nearer the source sag,the stronger the solution is,and there could be relatively premium volcanic reservoirs in this area.