成像测井裂缝自动化精细描述

Automatic Fine Description Technology of Fractures with Imaging Logging

针对成像测井解释中,裂缝发育参数(宽度、长度、密度、面孔率等)及裂缝的产状类型,以储层的总体属性为研究对象,以计算机编程为手段,研究裂缝的自动化精细描述方法。分析裂缝发育参数曲线的自动分层、统计读值,生成储层裂缝表及裂缝自然表的算法;在厘定单一裂缝按倾角、方位的数值化分类准则的基础上,综合考虑目的层段裂缝的空间分布及可能的交切关系,将其组合类型划分为水平缝、垂直缝、低角缝、高角缝、高角斜交缝、低角斜交缝、混和斜交缝、杂乱斜交缝等8种,分别给出了其统计定义及基于主频分析的具体判别算法。通过理论分析,统计确定储层中裂缝的主要走向,根据其与地应力方向的夹角大小判断其在压裂时开启的难易性质。使用CIFLog测井解释平台开发了地质统计模块,处理结果与基于成像测井图像的人工分析一致,在深层火山岩、塔东碳酸盐岩等储层的成像测井解释中,提高了解释生产效率,并有效地指导了压裂施工方案设计,为储层的压裂改造提供了关键的参考信息。

Imaging logging can provide fracture parameters(width,length,density,face porosity,etc.)and the fracture type,but it often takes a lot of time to process imaging logging by manual processing.In this paper,the overall property of the reservoir is taken as the research object,and a method of automatically and finely describing the fractures is studied by means of programming.The method realizes automatic stratification and statistics of the corresponding fracture values by analyzing the curves of fracture parameters.At the same time,it can also generate the reservoir fracture table and the natural fracture table.In addition,on the basis of determining the numerical classification criterion of single fracture according to inclination angle and orientation,the method also comprehensively considers the spatial distribution of the fractures in the target interval and the possible intersection relationship,so that,the combination type of fracture is divided into the following eight types:horizontal fracture,vertical fracture,low-angle fracture,high-angle fracture,high-angle oblique joint fracture,low-angle oblique joint fracture,mixed oblique joint fracture,messy oblique joint fracture,etc.The statistical definition and the specific discriminant algorithm based on the main frequency analysis for each fracture type are also given.Through statistical analysis,the main strike of the fracture in the reservoir is determined,and the difficulty of opening while fracturing is judged according to the angle between the strike and the direction of the geo stress.The corresponding geostatistical module was developed using the CIFLog logging interpretation platform,and the processing results of the imaging logging are consistent with the manual analysis.This module has been well applied in the imaging logging interpretation of deep volcanic rocks and Tadong carbonate rocks.It not only improves the interpretation efficiency,but also effectively guides the design of the fracturing plan,and provides key reference information for the fracturing of the reservoir.