资阳地区震旦系古岩溶储层特征及测井评价

LOGGING EVALUATION ON PALEO KARST RESERVOIR IN SINIAN OF ZIYANG AREA

位于四川盆地的资阳地区在震旦系灯影组中发现了继威远震旦系气藏之后的又一大型气藏。区内７ 口钻井揭露的地层显示本区灯影组主要由一套厚层状白云岩构成，基质岩块具低孔低渗特点。有效的储集空间是由受古岩溶作用产生的溶蚀孔洞和构造作用产生的裂缝共同构成。溶洞具有数量多、大洞多、发育集中的特点，裂缝具多成因、多期次、多产状的特点。对这套以缝洞型为主的储层，由常规测井资料计算单一的物性参数（如孔隙度等）的方法难以对其作出合理评价。

A large gas reservoir in Ziyang area has been discovered recently Dengying Formation of Sinian. Seven drilling reveal that Dengying Formation is composed of a set of thick- layered dolostone. The matrix rock is of low porosity and permeability .The effective spaces in the reservoir comprises both karst caves produced by action of paleo-karst and fractures produced by tectonic action. A large quantity of karst caves, among which there are many large ones,developed and concentrated in the same area. Tectoclase is characterized by multiple genesis,different periods,varied patterns. If we simply calculate the physical parameter by regular logging data ,it is difficult to evaluate the reservior reasonably.A relative good result could be obtained to evaluate the reservoir by use of method of synthetic probability values of caves and fractures from logging data.