黄骅坳陷新近系砂质辫状河储层构型——以羊三木油田典型区为例

Study on Architecture Characteristics of Neogene Sandy Braided River Reservoir in Huanghua Depression: Taking the Typical Area of Yangsanmu Oilfield as an Example

针对我国东部老油田新近系河流相油藏大部分进入高含水期,剩余油分布复杂的现状,选取典型砂质辫状河沉积区羊三木油田,密闭取心与测井相结合,开展密井网区储层构型刻画。结果显示研究区发育心滩、辫状河道、溢岸沉积和泛滥平原4种4级储层构型单元。心滩内部发育泥砾型和落淤层型2类3级构型界面。泥砾在5级和3级构型界面处均有发育,但厚度不同,当泥砾层厚> 0. 3 m时位于5级界面,厚度<0. 3 m时一般位于3级界面。解剖了研究区心滩平面结构,指出滩头、滩主体、滩尾和滩翼不同部位的落淤层发育差异。结合岩心、测井及现代沉积,建立了研究区4级和3级储层构型模式。

Most Neogene fluvial reservoirs in old oilfields in eastern China have entered high water cut stage,and the distribution of remaining oil is complex. The reservoir configuration of a typical sandy braided river sedimentary area,Yangsanmu Oilfield is described by combining sealed coring with logging in dense well pattern area. The result shows that four types of grade 4 reservoir architecture units are developed in the study area,namely,braided bar,braided channel,overbank deposit and floodplain. There are two types of grade 3 architectural interfaces in the interior of the braided bar,i. e. mud gravel deposit and silting layers. The mud gravel deposit develops at grade 5 interface and grade 3 interface,but their thickness is different. The mud gravel deposit with a thickness of more than 0. 3 m is located at the interface of grade 5,and the mud gravel with a thickness of less than 0. 3 m is generally located at the interface of grade3. Dissection of the horizontal structure of the braided bar in the study area shows that the development of silting layer is different in different parts of the braided bar,the head,the main body,the tail and the wing. The reservoir configuration models of grade 4 and 3 in the study area are established according to core,well logging data and modern sediments.