变系数ΔlogR方法及其在泥页岩有机质评价中的应用  

Variable-coefficient △logR model and its application in shale organic evaluation

作　　者：刘超[1,2] 卢双舫[3] 薛海涛[3] 

机构地区：[1]东北石油大学地球科学学院,大庆163318 [2]大庆油田有限责任公司勘探开发研究院,大庆163712 [3]中国石油大学(华东)非常规油气研究院,青岛266580

出　　处：《地球物理学进展》2014年第1期312-317,共6页Progress in Geophysics

基　　金：国家973项目(2011CB211701);中石油科技创新基金(2011D-5006-0101);黑龙江省普通高等学校新世纪优秀人才培养计划(1252-NCET-012)联合资助

摘　　要：为提高△logR方法对陆相地层有机质评价的适应性,通过修改模型系数、引入新的测井参数,提出变系数的△logR方法.研究发现,△logR方法中孔隙度曲线和电阻率曲线间的比例系数与预测结果误差密切相关,将其视为变量并合理地确定其值能明显减少预测误差;有机质具有低波阻抗的特点,对重矿物欠发育地层,利用波阻抗信息和电测信息可以很好地评价有机质含量.将变系数△logR方法应用于罗69井TOC和氯仿沥青"A"评价,应用结果表明,变系数△logR方法有利于减少TOC的预测误差,也适合对氯仿沥青"A"评价,TOC对应的比例系数"K_(TOC)"小于氯仿沥青"A"对应比例系数"K_A",TOC预测相对误差小于氯仿沥青"A"相对误差,与理论分析相符.变系数△logR方法为评价泥页岩残余烃(油)量提供了新的参考方法.Some problems which have made the evaluation results less reliable or even led to wrong conclusions arised when AlogR model is used to evaluate organic content of shales, especially shales from continental basins, because of differences, such as mineral composition and content et al between continental shales and marine shales. In this article, we mainly deal with the way that can help improve the applicability and accuracy of model in the evaluation of shale heterogeneities. As a result, variable-coefficient AlogR model is put forward by modifying ＂K＂ value, adding new logging curves et al then TOC and chloroform asphalt ＂A＂ is evaluated respectively based on datas form well Luo 69. It is concluded that reasonable ＂K＂ between porosity curve and resistivity curve is the comprehensive result of porosity, kerogen and hydrocarbon content, more importantly, ＂K ＂ value and prediction error is closely related; Instead of the old manually way, a new method which takes advantage of curve shape, lithology information and can help get the baseline value quickly by using computer to do it automatically is proposed. Density log which can help provide more information in most cases is used in Variable-coefficient AlogR model in view of source rocks, especially high-quality source rocks, have lower wave impedance. The case of well Luo 69 shows that Variable- coefficient AlogR model is good for TOC evaluation and can also be a feasible method for chloroform asphalt ＂A＂ evaluating, meanwhile TOC usually corresponds to lower ＂K＂ and higher precision than chloroform asphalt ＂ A＂. Variable-coefficient AlogR model has provided a new way for the evaluation of residual hydrocarbon content in shales.

关 键 词：测井 烃源岩 有机碳 氯仿沥青“A” 泥页岩 非均质性 

分 类 号：P631[天文地球—地质矿产勘探]