深层白云岩中硅质流体活动及其对储层发育的影响

Siliceous fluid activity in deep dolomite and its effect on dolomite reservoir development was less concerned in previous researches. In this project, we will take the deep Cambrian dolomite in the Tarim basin and Sinian Dengying formation dolomite in the north of China as typical examples to investigate the origin and time of siliceous fluid activity and the key geological control factors according to petrology, mineralogy, and geochemistry,such as the related tectonic / magmatic events, discuss the relationship and sequence of the fillment of quartz and dolomite and hydrocarbon fluid activity, and evaluate the influence of siliceous fluid on the development of the deep dolomite reservoir. By fluid - rock interaction experiments, we study the control factors for filling - dissolution of quartz in dolomite. Combining with geological background, we also discuss influence process of siliceous fluid on development of deep dolomite reservoir as well as predict degree and scope of the influence. The results will improve the knowledge of the developing mechanism of the deep dolomite reservoir in China and will also be applied in the oil and gas exploration. In that, the study is significant in both theory and practice.

深层白云岩储层中的硅质地质流体活动及其对储层的影响以往关注较少。本项申请，拟以我国南方震旦系灯影组和塔里木盆地寒武系深层白云岩为典型实例,通过分析硅质流体作用下孔洞充填物的岩石学、矿物学和地球化学特征，查明硅质流体的成因来源、活动时代/期次及相关构造/岩浆活动等关键地质控制因素，剖析硅质充填与白云石充填及油气充注等的成岩演化关系，评价硅质流活动对储层形成的影响。通过硅质流体-白云岩相互作用模拟实验，探讨硅质交代和石英矿物生长（充填）-溶蚀的影响控制因素，以及流体-岩石相互作用机制。结合基本地质背景，探讨硅质流体对储层形成影响的过程、范围和程度。研究成果有助于丰富完善中国深层白云岩储层形成机制，并应用于区域油气勘探生产，因而具有重要的基础科学与实践意义。

我国四川盆地等深层白云岩储层中的常见大量的石英矿物充填或硅质交代现象，表明硅质地质流体活动异常活跃，但硅质流体对深层白云岩储层的影响一直关注较少。本项目以四川盆地震旦系灯影组深层白云岩为典型实例进行解剖，详细分析了硅质流体作用下孔洞充填物的岩石学、矿物学和地球化学特征，查明了硅质流体的成因来源、活动时代/期次及相关构造/岩浆活动等关键地质控制因素，明确了硅质充填与白云石充填及油气充注等的成岩演化关系，探讨硅质交代和石英矿物生长（充填）-溶蚀的影响控制因素以及流体-岩石相互作用机制。建立了硅质流体对储层形成影响的地质模式，明确了对储层影响过程。研究发现富硅质流体是深部岩浆热源驱动下的地层水或大气降水深循环的结果，并且这些流体与岩浆发生了广泛的物质能量交换；富硅质流体对深层白云岩储层影响主要表现在使储层致密化，但能增加白云岩骨架抗压实能力，对储集空间保持有着重要的意义。