Abstract

Hydrogen index, HI, and original hydrogen index, HI_o, are important indicators for measuring the hydrocarbon generation potential of the source rock. Through addressing the shortcomings of existent HI_o models, improved models are proposed to improve the coincidence between calculated and measured results. According to the statistics of rock pyrolysis and TOC data of 1,249 cores taken in seven basins, key parameters of HI_o models for types I, II_a, II_b, and III kerogen are obtained, complements quantitative evaluation methods for effective source rocks and provides a theoretical basis for evaluating in situ transformation of shale oil and hydrocarbon generating potential of deep source rocks. These models have been applied to evaluate the in situ transformed shale oil in the Yanchang Formation of the Ordos Basin, and the result reveals: (1) the transformed shale oil amounts to 375.9 × 10⁸ t, and natural gas to 4.17 × 10¹² m³; the average resource abundance of shale oil is 114.6 × 10⁴ t/km²; the new organic porosity originated averages 6.9%; and the sweet spot zones of shale oil are mainly distributed on the north of Zhengning and Well Mu78; (2) in situ transformation would increase in situ resources, gas-to-oil ratio, porosity and permeability, and improve the productivity of shale oil in the Chang 7 member.

摘要

氢指数HI和原始氢指数HI _o是测量烃源岩生烃潜力的重要指标。通过解决现有的HI _o模型的缺点，提出了改进的模型以改善计算结果与测量结果之间的一致性。根据七个流域采取1,249内核的岩石热解和TOC数据，HI的关键参数的统计_Ø型号为I型，II_一，二_b获得了III干酪根，补充了有效烃源岩的定量评价方法，为评价深层烃源岩的页岩油和生烃潜力提供了理论依据。这些模型已用于评价鄂尔多斯盆地延长组的原位改造页岩油，结果表明：（1）转化页岩油量为375.9×10 ⁸ t，天然气量为4.17×10 ^12。 m ³ ; 页岩油的平均资源丰富度为114.6×10 ⁴ t / km ²; 新产生的有机孔隙度平均为6.9％；页岩油的甜点区主要分布在正宁和木78井以北。（2）原位转化将增加Chang 7区块的原地资源，气油比，孔隙度和渗透率，并提高页岩油的生产率。