烃源岩有机碳含量的测井响应特征与定量预测模型——以珠江口盆地文昌组烃源岩为例

WELL LOGS RESPONSE AND PREDICTION MODEL OF ORGANIC CARBON CONTENT IN SOURCE ROCKS-A CASE STUDY FROM THE SOURCE ROCK OF WENCHANG FORMATION IN THE PEARL MOUTH BASIN

徐思煌 朱义清

Xu Sihuang Zhu Yiqing

中国地质大学, 构造与油气资源教育部重点实验室, 武汉, 430074 2. 中国地质大学研究生院, 武汉, 430074

Key Laboratory of Tectonics and Petroleum Resources of Ministry of Education, China University of Geosciences, Wuhan, Hubei 430074, China 2. Graduate School, China University of Geosciences, Wuhan, Hubei 430074, China

利用测井资料评价烃源岩,能够弥补烃源岩取心少、实测样品分布不连续的不足。富含有机质的烃源岩在测井上具有电阻率高、中子孔隙度高、声波时差高、伽马高、密度低等基本特征。测井资料不仅可用来定性识别烃源岩,而且还能定量预测有机碳含量。近半世纪不断探索出的预测模型,可概括为定性识别模型、单参数等效体积模型、双参数交汇图半定量模型、多元回归模型、测井曲线叠合模型(即ΔlogR技术)、模糊数学模型6种类型。珠江口盆地惠州凹陷及番禺4洼文昌组烃源岩实测有机碳含量与同井段电阻率、中子、声波、伽马和密度等测井参数之间的相关程度比较均衡,因此由这5种测井参数构成的五元回归方程代表着最佳定量预测模型。对番禺4洼一口井文昌组进行了全井段有机碳含量预测,经岩性描述、实测有机碳含量检验,认为预测效果良好。

The evaluation of source rocks from well loggings can make up for the insufficiency of source rock core and discontinuity of samples examined.Organic-rich source rocks show relative increase in response to resistivity,neutron,sonic transit time and gamma loggings and decrease in response to density logs.Based on this response relationship,well logging data not only can be used to identify qualitatively source rocks from non-source rocks,but also predict quantificationally organic carbon content in source rocks.The predicting models proposed during past fifty years can be summed up as qualitative identification model,volume model,cross plot model,regression equation model,ΔlogR technique,and fuzzy model.The TOC of Wenchang Formation source rock in Huizhou Depression and Panyu 4 Sag in the Pearl River Mouth Basin shows similar degree of correlation respectively to resistivity,neutron,sonic transit time,gamma and density.So,the five variate regression equation should be the best prediction model for this study area.The organic carbon content of whole Wenchang Formation of one well in Panyu 4 sag predicted by this numerical model,and it shows good results verified by the lithological description and the TOC test of core samples in this well.

国家油气重大专项课题(2008ZX05023-01)

https://doi.org/10.11781/sysydz201003290