成岩作用之礦物組合

Mineral Assemblages in Sandstone Diagenesis

黃富文(Fu Wen Huang)

《鑛冶：中國鑛冶工程學會會刊》 28卷4期 (1984/12) Pp. 38-45

https://doi.org/10.30069/MM.198412_28(4).0003

摘要

成岩作用是指沉積物在達到變質程度前所經歷的種種變化。成岩作用包括沉積物的緻密作用、膠結作用、自生礦物的產生，以及舊有礦物之轉化或溶解等。成岩作用中自生礦物的產生，特别是自生性粘土礦物的產生會影響岩層的儲油性質，除此之外，自生性粘土尚可與鑽井用的泥漿發生反應，而引起鑽井上的困難以及生產層的破壞，因此辨識其種類及存在是極為重要的事。自生性粘土可分為Na_2O-Al_2O_3-SiO_2-H_2O系列，K_2O-Al_2O_3-SiO_2-H_2O系列以及CaO及MgO-AI_2O_3-SiO_2-H_2O系列。各系列均具特殊的物化環境以及產生不同的粘土礦物。除此之外，地下水的作用，氧化矽的地化性質，以及沸石類礦物在成岩作用中的轉變都在文中一併討論。為了要了解區域的成岩礦物組合，並利用之於石油探勘工作，我們必須重建沉積盆地之原始沉積物質及環境，其成岩礦物及砂岩孔隙在沉積歷史上長時間的變化及分佈，並用之研究碳氫化合物的發生，移棲的相互關係及相對時間，次生孔隙的發展以及石油封閉之形成。

並列摘要

Diagenesis means the changes which take place in a freshly deposited sediment until it reaches the stage of metamorphism. Diagenesis includes sediment compaction, cememtation, production of authigenic minerals, and transformation or dissolution of old minerals. The presence of diagenetic minerals, especially those of authigenic clay minerals in a sandstone reservoir may have profound effects on many rock properties. In addition, authigenic clays will react with drilling mud to cause drilling problems and formation damages. Therefore, it is vital to know their presence and identity. Authigenic clays are classified into Na_2O-AI_2O_3-SiO_2-H_2O system, K_2O-AI_2O_3-SiO_2-H_2O system, and CaO and MgO-AI_2O_3-SiO_2-H_2O system. Each system is considered with respect to its characteristic physiochemical environment which results in different clay minerals. Besides, function of underground water, geochemical property of silica, and transformation of zeolite minerals during diagenesis are also discussed. In order to understand the local diagenetic mineral assemblages and to use it in oil industries, we need to reconstruct initial materials and conditions of sedimentary basin, to predict distribution of diagenetic minerals and porosity in space through time, and to use it to learn the delicate interdependence and relative timing of hydrocarbon generation and migration, secondary porosity development and trap formation.