稀井区烃源岩有机碳的地球物理预测方法---珠江口盆地恩平凹陷恩平组烃源岩勘探实例

Source-rock organic carbon prediction with geophysical approach in the sparsely-drilled area:A case study of Enping Depression,the Pearl Mouth Basin.

烃源岩总有机碳（TOC）含量是烃源岩评价的基础，亦是油气资源量计算中的关键参数。稀井区由于钻井数据的稀缺，难以进行烃源岩TOC定量评价；在密井区，利用烃源岩TOC体定量预测技术可厘清生烃凹陷中烃源岩TOC的三维空间展布特征。本文基于恩平和惠州两凹陷地质背景、测井和地震信息等方面的相似性分析，通过类比，将适用于密井区惠州凹陷的成熟的烃源岩TOC体定量预测技术成功地应用于稀井区恩平凹陷。研究结果表明：恩平凹陷恩平组烃源岩TOC值大多为1％～2％，属于中等烃源岩；个别地区TOC值超过2％，属于优质烃源岩。

The total organic carbon(TOC)is the basis of the source rock evaluation,and is also the key parameter in calculation of the petroleum resource. Because of the scarcity of drilling data in the sparsely-drilled area,the quantitative evaluation of the organic carbon content for source rock is difficult.The distribution characteristics of the TOC in 3Dspace in the dense drilling area can be effectively portrayed by the quantitative prediction technology.This approach was successfully predicted source rock TOC in Huizhou Depression,a dense drilling area.Based on a good similarity of geological background,logging and seismic data between Huizhou Depression and Enping Depression,we predict source rock TOC in Enping Depression,a sparsely-drilled area with this approach.The prediction results show that TOC values of source rock in Enping Formation,Enping Depression range most from 1% to 2%,a fair source rock, and TOC values with more than 2%in some place represent a good source rock.