碳酸盐建造天然储层及其在地质历史中的演化

流体分布特征及其在储层中的运移取决于岩石的储集性和层序内部结构。块状储层一般是礁或浮游生物建造,部分属地台底栖生物建造,其中流体可进行垂向和横向运移;层状储层是典型的底栖生物建造,具不同渗透性的岩层成互层状,以横向运移为主;岩性圈闭储层产于未补偿拗陷的沥青质-硅质、粘土-碳酸盐建造。层状储层遍及整个显生宙,但其相型、孔隙空间的组成及特征均有所改变。礁块储层的意义在地质历史中随其厚度及非均质性的增加均有所增长。在中生代末的浮游生物建造中常有块状储层。岩性圈闭储层自泥盆纪以来零星出现于较年轻的沉积中。

TYPES OF NATURAL RESERVOIRS IN CARBONATE FORMATONS AND THEIR EVOLUTION IN EARTH HISTORY

Character of fluid distribution and their in-reservolr migration are defined by two parame-ters: the reservoir properties of rocks and the inner structure of a sequence, i. e. the spatial distributionof layers with different permeability. Massive reservoirs are common in reefal and planktonogenic formations, partially in piatformalbenthogenic formations. Migration is relatively even in vertical as well as lateral directions. Stratalreservoirs are typical for benthogenic formations. Layers with different permeability are interbedded insuch reservoirs that is why the lateral migration is of clear predominance. Lithologically isolated reser-voirs occur in bitumenous-siliceous clay-carbonate formations of non-compensate depression. In-reservoir migration is weak being caused by rock pressure and energy of hydrocarbons themselves. Stratal reservoirs existed throughout all Phaneronic although their facies types, composition andcharacter of pore space were changing. The relative role of massive reefal mervoirs increaed in timealong with their thickness and inhomogenueity. At the end of Mesozoic massive reservoirs in planktono-genic formations appered. Lithologically isolated reservoirs are known from Devonian, sporadically bo-curing in younger sediments.