碳酸盐岩层序地层格架对岩溶储层的控制作用——以渤海西南海域下古生界为例

以钻井、测井、地震以及岩心、薄片资料为基础，在划分三级层序的基础上，探讨了渤海西南海域下古生界层序地层特征及其对岩溶储层的控制作用。结果表明：1）三级层序界面附近发育碳、氧同位素负异常以及自然能谱Th/K正异常，基于此特征将下古生界划分为21个三级层序；2）白云岩是研究区主要的储集岩性，层序通过控制垂向岩性的变化进而控制了优质储层的发育；3）将白云岩发育的12个三级层序定义为"优势储集层序"，加里东期构造不整合与12个"优势储集层序"耦合控制了潜山型储层规模及其产能高低；寒武系内发育以溶蚀孔隙为主的内幕型岩溶储层，亦限定发育于"优势储集层序"之中。实际勘探中，优选风化界面与"优势储集层序"耦合区域优先钻探，同时兼顾内幕型储层，其是今后该区高效勘探的关键。

Characteristic of Sequence Stratigraphic Framework and Its Controls on Reservoir:A Case Study of Lower-Paleozoic Carbonate in Southwest Area of Bohai Sea

Based on the data of seismic, drilling, cores, and thin sections, the characteristics of the sequential stratigraphic framework and its controls on the Lower-Paleozoic karst reservoirs in southwest of Bohai Sea area were discussed. The results show that:1) There are negative carbon and oxygen isotopic anomalies and positive Th/K anomalies in the natural gamma spectrum near the third-order sequence boundary, and according to these characteristics the Lower Paleozoic is divided into 21 third-order sequences; 2) The dolomite is the most important reservoir rocks in the study area, and the sequences control the development of the high quality reservoir by controlling the change of vertical lithology; 3) The twelve third-order sequences where dolomite developed are defined as "dominant reservoir sequences", which control the scale of buried-hill reservoir and also the capacity of the production when coupled with the weathering interfaces of Caledonian movement. Inner-reservoirs are developed in the Cambrian with dissolved pores as the main spaces, and are also strictly controlled by the "dominant reservoir sequences". In future exploration, priority should be given to drilling in the areas where the "dominant reservoir sequences" coupled with weathering interfaces, while taking inner-reservoirs into account.