冀中坳陷北部奥陶系储层形成机理与分布模式

为解决冀中坳陷北部奥陶系潜山储层认识不清的问题,在岩心观察基础上,运用钻井、测井、分析化验等资料,对该区储层基本特征、成因类型、主控因素进行研究。结果表明,该区发育4套白云岩孔隙型和1套岩溶缝洞型储集层。岩性主要为泥-粉晶白云岩、灰质白云岩,其次为泥晶灰岩,储集空间主要发育晶间(溶)孔、构造裂缝和溶蚀孔洞等。通过储层基本特征研究,明确了有利储层的形成主要受到岩石类型、裂缝发育程度和岩溶作用强度等因素的控制,岩石类型是控制储层形成的基础,裂缝发育程度是制约储层形成的关键,岩溶作用强度控制储层的优劣。据此建立了冀中坳陷北部奥陶系区域层状、区域块-层复合状和局部块状3种储层发育模式,为研究区成藏模式的建立和勘探部署提供了依据。

Formation Mechanism and Distribution Models of Ordovician Reservoirs in Northern Jizhong Depression

In order to solve the problem of unclear understanding of Ordovician buried hill reservoirs in northern Jizhong depression, on the basis of core observation, the basic characteristics, genetic types and main controlling factors of reservoirs in this area were studied by using drilling, well logging, analysis and laboratory data, etc. The results show that 4 sets of dolomite pore type and 1 set of karst fractured-vuggy type reservoirs are developed in this area. Lithology is mainly micritic-powdered crystal dolomite and calcareous dolomite, followed by micritic limestone. The reservoir space mainly includes intercrystalline (dissolution) pores, structural fractures and dissolution pores, etc. Through the study of the basic characteristics of the reservoirs, it is confirmed that the formation of favorable reservoirs is mainly controlled by factors such as rock type, fracture development degree and karstification intensity; rock type is the basis for controlling reservoir formation; fracture development degree is the key to restrict reservoir formation; karstification intensity controls reservoir advantages and disadvantages. Based on this, three reservoir development models of Ordovician in the northern Jizhong depression are established, namely, regional stratified model, regional massive-stratified composite model and local massive model, which provides basis for the establishment of reservoir-forming models and exploration deployment.