塔中地区海相烃源岩测井评价

摘要

To the low organic abundance and strong heterogeneity of the marine hydrocarbon source rock, this paper analyzes the well logging response characteristics of the marine hydrocarbon source rock in Tazhong area, and builds the plate for quantitative identification of Ordovician source rock in Tazhong area and the classification and identification model for marine source rock in the studied area. In the evaluation of organic matter abundance, the elastic parameters of hydrocarbon source rock, the ratio of uranium and thorium content, the difference of natural gamma, and the resistivity in Tazhong area are used as the input layers, and a BP neural network model based on the genetic algorithm is built. Practice shows that the TOC value predicated by this method is as accurate and reliable as the rock sample analysis result, providing the basis for the evaluation of effective hydrocarbon source rock.%针对海相烃源岩具有有机质丰度低和非均质性强的特点,分析了塔中地区海相烃源岩的测井响应特征,建立了塔中奥陶系烃源岩定量识别的图版及适合研究区海相烃源岩的分类识别模型.在有机质丰度评价方面,利用塔中地区烃源岩弹性参数、铀钍含量比、自然伽马的差值及电阻率作为输入层,建立了基于遗传算法的BP神经网络模型.实践表明,采用该方法预测的TOC值与岩石样品分析结果同样精确可靠,为评价有效烃源岩提供了依据.