埋藏环境下碳酸盐岩建设性成岩作用类型、特征及其意义

本文通过对南方中扬子地区和北方鄂尔多斯盆地西缘的寒武系、奥陶系埋藏成岩作用的详细研究,认为:（1）埋藏破裂、裂隙作用虽然能使岩石孔隙度有所增加。但更重要的是连通原已存在的孔隙。从而提高岩石的孔隙度和渗透率:（2）埋藏白云化作用形成的晶间孔、缝、晶内孔、晶间溶孔等是油气储集的一种最有利的空间;（3）与构造作用相关的埋藏溶解作用和深部埋藏作用能形成有意义的油气储集场所。上述3冲作用相互叠加时。岩石的孔隙度和渗透率将急剧提高。本文提出鄂尔多斯北缘和东缘奥陶系是油气勘探的战略远景区。同时首次提出了识别埋藏白云石化作用和埋藏溶解作用的标志和际准。

TYPES AND CHARACTERSTICS OF CARBONATE ROCK CONSTRUCTIVE DIAGENESIS IN BURIAL ENVIRONMENT

Through the study on the burial diagenesis of Cambrian system and Ordovician system in Middlle Yangtze and in Ordos basin, the author considered that the constructive diagenesis of carbonate rock played an important role in increasing porosity and permeabili ty.Under the burial environment . the constructive diagenesis can be divided into three types; (1) fracture diagenesis it is formed by ground stress and tectonic stress under burial environment. Although the fracture and fissure can increase porosity a little, its main role is connection with the original space which was separated each other. So the reserved capacity of carbonate will be improved. (2) burial dolomitization - the inter-crystalline holes, fissures, intracrystalline holes and intercrystalline dissolved holes formed by burial dolomitization are valuable space for the reservoir of oil and gas. (3) burial dissolution this is an important problem in burial diagenesis domain. For it can produce high porosity of dissolved pore, hole, fissure, it also can provide main space to nature gas and oil.