黄骅坳陷孔南地区碎屑岩潜山内幕储层特征及控制因素

黄骅坳陷孔南地区上古生界碎屑岩潜山是重要的油气勘探领域，勘探程度非常低，其主力勘探层系 下石盒子组储层特征及控制因素研究尚属空白。 综合利用岩石薄片、铸体薄片、扫描电镜及物性分析等资 料，对研究区下石盒子组潜山内幕储层特征及控制因素进行了深入研究。 结果表明：下石盒子组属于辫状 河沉积体系，岩石类型主要为河道微相的灰色中—粗粒岩屑石英砂岩和长石岩屑砂岩；潜山内幕储层的 储集空间以次生粒间溶蚀孔和构造裂缝为主，孔隙度为 5%～10% ，渗透率为 0.5～10.0 mD ，属特低孔、 （超）低渗的裂缝 - 孔隙型储层。 沉积、成岩和构造作用是控制储集层优劣的 3 大因素，其中微相、岩相和 构造作用决定潜山内幕储层的形成与发育，优质储层在平面上主要分布于河道、心滩砂体与裂缝带叠合 区。 综合研究认为， Ⅰ 类储层位于逆冲推覆带主体部位，是今后获得潜山内幕勘探突破的首选储层。

Characteristics of inner buried hill clastic reservoirs and their main controlling factors in Kongnan area,Huanghua Depression

The Upper Paleozoic clastic buried hill is an important field for oil and gas exploration in Kongnan area of Huanghua Depression, and the lower Shihezi Formation is the main gas formation with low degree of exploration. The study on the reservoir characteristics and controlling factors of lower Shihezi Formation is still a blank field. Based on the analysis of ordinary thin sections, cast thin section, scanning electronic microscope and physical properties, this paper studied reservoir characteristics of the lower Shihezi Formation in Kongnan area and their influencing factors. The result shows that clastic rock reservoir of the lower Shihezi Formation belongs to braided river sedimentary system, rock types are mainly gray medium-coarse graind lithic quartz sandstone and feldspathic sandstone of channel microfacies, the reservoir space of inner buried hill mainly includes secondary intergranular dissolved pores and structural fracture, the porosity and permeability are 5%～10% and 0.5～10 mD respectively, and the reservoir is a cracked-poroustype with super-low porosity and extra low permeability. Deposition, diagenesis and tectonization are the three factors controlling the reservoir quality, of which microfacies, lithofacies and tectonization determine the formation and development of buried hill inner reservoir, and favorable reservoirs are laterally distributed in the stacked area of channel and diara sand and fracture-developed zones. This comprehensive study shows that the reservoir of type Ⅰ is located in the principal part of the thrust structure zone and the main reservoirs to increase production in the future.