泥页岩洗油效果的延时缓慢加热热解谱评价方法

Evaluation method of ESH pyrogram for hydrocarbon cleaning effect in shale

针对现有洗油方法无法有效评价泥页岩洗油效果的问题,提出了1种改进型的延时缓慢加热(extended slowing heating,ESH)岩石热解评价方法,通过比较洗油前、后岩石热解谱的变化来判断洗油效果。改进型的ESH热解技术根据泥页岩中有机质的性质将其含烃组分划分为轻质自由烃、FHR和固相有机质3个部分,解决了常规Rock Eval II热解技术无法有效区分自由烃和固相有机质的问题。分析了具有不同干酪根富含度样品的Rock Eval II和ESH热解谱差别,给出了富/贫干酪根样品的ESH热解谱洗油效果评价标准。实验数据显示,根据泥页岩样品洗油前、后ESH热解谱中3个组分的变化来评价洗油效果更加准确。

As to the existing methods are unable to evaluate hydrocarbon cleaning effect in shale properly, a modified ESH （ex tended slow heating） pyrolysis evaluation method was proposed by comparing the pyrogram changes between natural and cleaned samples. Conventional Rock Eval II pyrolysis technique has defects in differentiating hydrocarbon components and solid organic matter matrix of the shale. The ESH pyrolysis technique solved these defects by dividing the hydrocarbons into three composi- tions, including light free hydrocarbon, FHR and solid organic matter. The differences between the ESH and Rock-Eval If pyro- grams of samples with different kerogen richness are experimentally researched. The evaluation criterions of ESH pyrogram for the complete cleaning of the kerogen-rich shale sample are provided. The experimental results prove that the ESH pyrogram is more reasonable for evaluating the cleaning effect of hydrocarbon （the free hydrocarbon cleaning level and the integrity of solid or- ganic matter） in shale than Rock-Eval lI pyrogram.