固井二界面泥饼仿地成凝饼与凝灰岩成岩的关联性

为了解固井二界面泥饼仿地成凝饼(MTA)的地质成岩作用,采用XRD、TG、SEM+EDX和XRF荧光分析测试技术对MTA与凝灰岩火山沉积作用成岩反应的关联性进行研究。结果表明:泥饼改性剂在MTA成岩反应中所起的作用与火山碎屑物质在凝灰岩成岩反应中所起的作用相类似,且物相和化学组成基本一致;凝饼形成剂将凝灰岩火山沉积作用成岩流体的缓慢形成过程直接化为一种现存成岩流体,加快了成岩反应速度,控制了反应产物的类型,二者的特征成岩现象和反应产物均有相似性,且均存在FeS2垃圾矿物析晶现象;随着养护时间延长,MTA凝饼的硅和铝含量均降低,而钙含量增加,即MTA的固化反应过程与火山灰质材料被碱激发后发生的"脱铝—结硅—吸钙"化学反应模式相一致。

Association between tuff diagenesis and mud cake to agglomerated cake(MTA)at cement-formation interface

In order to investigate the geologic diagenesis of mud cake to agglomerated cake(MTA) at cement-formation interface,the analysis and testing technology such as X-ray diffraction(XRD),thermogravimetric analysis(TG),scanning electron microscope & EDX(SEM & EDX) and X-ray fluorescence(XRF) were used to study the association of MTA and diagenetic reaction of tuff volcanic process.The results show that,the effect of mud cake modifier in the MTA diagenetic reaction is similar to that of pyroclastic material in the tuff diagenetic reaction,and the phases and chemical compositions are basically consistent.The forming agent of agglomerated cake is similar to the fluid of diagenetic reaction of tuff volcanic process,so the velocity of diagenetic reaction can be accelerated and the reaction products can be controlled,too.The characteristic diagenetic phenomenon and reaction products of the two are similar,and the crystallization phenomenon of FeS2 occurred in both,which is a kind of rubbish mineral.The silicon content and aluminum content in the agglomerated cake decreased while the calcium content increased with time.The curing reaction process of MTA is consistent with alkali-activated pozzolanic materials chemical reaction model,in which the chemical reaction model is dealuminization,junction silicon and calcium absorption.