基于测井资料的烃源岩有机碳含量测井评价方法研究——以鄂尔多斯盆地甘泉地区山西组为例

Logging evaluation method of the organic carbon content of source rocks based on logging data:A case study of Shanxi Formation in Ganquan area,Ordos Basin

烃源岩有机碳含量是烃源岩评价的重要参数之一,受岩心样品数量和分析化验成本的限制,仅通过实验室测定烃源岩有机碳含量评价烃源岩有机质丰度的方法已经无法满足非常规油气精细勘探的需求。通过大量的文献调研,系统总结了烃源岩有机碳含量测井评价方法原理及其局限性,结合鄂尔多斯盆地甘泉地区山西组地质特征与烃源岩测井响应特征,建立了烃源岩有机碳含量预测模型,对比分析了不同模型预测精度及其适用性。研究认为:自然伽马测井法、密度测井法、改进ΔLog R法和多元回归法对研究区山西组烃源岩有机碳含量定量评价均具有较强的适用性,其中多元回归法适用性最好,这可为今后基于测井资料计算鄂尔多斯盆地甘泉地区山西组烃源岩有机碳含量提供一定的方法和思路。

The organic carbon content of hydrocarbon source rocks is one of the important parameters for hydrocarbon source rock evaluation.Due to the limitation of the number of core samples and the cost of analysis and testing,the method of evaluating the organic matter abundance of hydrocarbon source rocks only by measuring the organic carbon content of source rocks in the laboratory can no longer meet the demand of unconventional oil-gas fine exploration.Through extensive literature research,it was systematically summarized the principles of logging evaluation methods for the organic carbon content of source rocks and their limitations.Combined with the geological characteristics and logging response characteristics of source rocks of Shanxi Formation in the Ganquan area of Ordos Basin,it was established a prediction model for the organic carbon content of source rocks.The prediction accuracy of different models and their applicability were compared and analyzed.It is concluded that the natural gamma logging method,density logging method,improvedΔLogR method,and multiple regression method have strong applicability to the quantitative evaluation of organic carbon content of Shanxi Formation source rocks in the study area,among which the multiple regression method is more applicable.This can provide certain methods and ideas to calculate the organic carbon content of hydrocarbon source rocks in Shanxi Formation in the Ganquan area of Ordos Basin based on logging data in the future.