考虑岩石结构的砂砾岩有效储层测井判识方法

以东营凹陷盐家沙四上亚段砂砾岩体为研究对象,通过岩心、试油及气测资料提取有效储层样本,观察其岩心、薄片及成像测井图像特征,发现有效储层在宏观和微观上都表现为岩石结构相对均匀、分选较好的含砾砂岩或砾状砂岩.数字岩心模拟也表明,孔隙度相同,但岩石结构不同,电阻率响应差异较大,因此,判识储层的有效性应考虑区分岩石结构差异.实际资料处理中,在测井曲线最优分层、测井相聚类判识岩性大类的基础上,利用成像测井图像模式,对岩性大类进行结构细分,采用"岩石结构+电性下限"双重条件限定有效储层的思路,建立多信息融合逐步判识有效储层的半定量方法,并取得较好的应用效果.

Identification Method of Effective Reservoir for Glutenite Body Using Well Logging Based on Rock Texture

This paper deals with the research on Yanjia region glutenite body of the upper Es4 in the northern steep slope zone of Dongying Depression.Effective reservoir samples are taken by core drilling,formation testing and gas logging data,and observing the relationship among the core,thin section and image logging,it is found that the effective reservoir appears as well sorted pebbly sandstone and conglomeratic sandstone in macroscale and microscale.The simulating of digital core also indicates that the difference of pore configuration which is derived from different rock textures is the major impact factor for electric resistivity response,so various rock textures should be well considered when identify the validity of reservoir using well logging.Therefore,during the data processing,detailed identification of rock textures by image model of image logging,based on automatic layering of conventional logging curve and automatic identification of lithologic category by means of logging facies cluster method,is indispensable.With the newly double constrains of rock texture and lower limit of electrical property on effective reservoir,this semi-quantitative method is preliminarily proposed to be a preferable application for multi-information identification of effective reservoir.