CAJ | 학술논문

通过显微岩石矿物学分析、扫描电镜与能谱分析、阴极发光分析等确定了伴随川西坳陷中侏罗统沙溪庙组砂岩孔隙流体演化形成的自生矿物类型与产出关系，利用包裹体温度分析、同位素地质温度分析等确定了主要自生矿物的形成时期，主要利用电子探针微区成分分析技术测定了不同阶段形成的自生矿物的化学组成，并运用同位素分析、地层水分析、粘土矿物X－射线衍射分析等技术进一步获得了孔隙流体的演化特征。沙溪庙组砂岩孔隙流体早期富镁、富铁、偏碱性，随着埋深的增加和烃类的进入等逐渐向偏酸性演化，在转化过程中形成了绿泥石、石英、方解石、高岭石等矿物。自生绿泥石消耗了镁离子和铁离子，钠长石的溶蚀提供了钠离子，烃类注入提供了酸性流体，导致孔隙流体最终演化为现今富钠、富钙、偏酸性的CaCl2型地层水特征。溶蚀作用改善了储层的储集性，自生绿泥石孔隙衬垫保护了原生孔隙，有利于形成有利储层。
통과현미암석광물학분석、소묘전경여능보분석、음겁발광분석등학정료반수천서요함중주라통사계묘조사암공극류체연화형성적자생광물류형여산출관계，이용포과체온도분석、동위소지질온도분석등학정료주요자생광물적형성시기，주요이용전자탐침미구성분분석기술측정료불동계단형성적자생광물적화학조성，병운용동위소분석、지층수분석、점토광물X－사선연사분석등기술진일보획득료공극류체적연화특정。사계묘조사암공극류체조기부미、부철、편감성，수착매심적증가화경류적진입등축점향편산성연화，재전화과정중형성료록니석、석영、방해석、고령석등광물。자생록니석소모료미리자화철리자，납장석적용식제공료납리자，경류주입제공료산성류체，도치공극류체최종연화위현금부납、부개、편산성적CaCl2형지층수특정。용식작용개선료저층적저집성，자생록니석공극츤점보호료원생공극，유리우형성유리저층。
Water-rock-hydrocarbon interactions in the Middle Jurassic Shaximiao Formation sandstones,Western Sichuan, were studied to determine the relationship between authigenic mineral types and hydrocarbon generation through analyses of petrographic data,and scanning electron microscopy and cathode luminescence results.Formation timing of major au-thigenic minerals was also determined with analyses of inclusion temperature and isotope geo-temperature.Electron micro-probe was employed to measure the chemical compositions of the minerals of different forming ages.Isotope analyses and formation water analyses were combined with X-ray diffraction to describe the evolving features of pore fluids of the forma-tion.The result shows that the pore fluid in the Shaximiao Formation was originally characterized by high contents of Mg2 +and Fe2 +,and high pH value.As burial depth increased and hydrocarbon entered,the fluid gradually turned acid and formed minerals such as chlorite,quartz,calcite,kaolinite,and etc,during the process.With authigenic chlorite con-suming Mg2 +,and Fe2 +,feldspar providing Na +and the charging of hydrocarbon providing acidic fluids,the pore fluids finally turned into this CaCl2 type low-pH formation water with high content of Na +and Ca2+.It should be noted that there are two factors that were favorable for the formation of good reservoirs:dissolution improved storage capacity of res-ervoirs and authgenic chlorite formed pore rim and helped preserving primary pores during the diagenetic process.