辽河西部凹陷曙103块潜山油藏储层特征

摘要

Block Shu-103 buried hill in the west depression of Liaohe oilfield consists of dolomicrite, lime dolostone and dolomite limestone. Its main reservoir space includes solution cavities and pores, fractures, micro-pores and micro-fractures. The solution cavities and pores are common in the block, and divided into mega-, meso-, and small-cavern, as well as solution pore according to size. The mega-and meso-caverns are lack of reservoir capability due to caving and filling, the small-cavern and pores tend to survive and be major reservoir spaces in the block. High-angular fractures are main factor affecting reservoir petrophysics. Their dominant direction is NESW in accordance with regional structural line. The pressure test shows that micro-pores and micro-fractures act as main reservoir space providing hydrocarbon after a period of exploitation instead of macro-pores and fractures.Production status and correlation of pay members between wells show that the reservoir petrophysic properties are controlled by paleogeographic position, structural position and petrologic cycle. Good reservoir members are mainly located at upper parts of the hill.%辽河西部凹陷曙103块潜山由中元古界长城系高于庄组泥-粉晶白云岩、灰质白云岩和白云质灰岩组成，其主要的储集空间包括溶蚀孔洞、构造裂缝及微孔微缝等。该区溶蚀孔洞非常发育，根据其规模可分为大、中、小型溶洞及溶孔，其中大、中型溶洞常因坍塌和充填而失去储集能力，而小型溶洞和溶孔等则成为该潜山的主要储集空间。高角度构造缝对该储层储集空间的贡献最大，其优势发育方位为北东-南西向，与区域构造线方位一致。压力测试结果表明，该区储层中显微级的微孔和微裂缝经过一段时间的开采后，替代宏观溶孔和裂缝而成为主要的供油空间，这表明它也是很重要的储集空间。对各井开采现状及采油层段的对比研究表明，曙103块潜山储层的发育受古地貌位置、构造位置及沉积旋回的控制，好的储层段主要分布在潜山顶面及地貌高点。