岩石密闭热释方法评价页岩含油性特征——以四川盆地侏罗系大安寨段为例

Evaluation of oil content in shale by sealed thermal desorption: a case study of Jurassic Da'anzhai Member, Sichuan Basin

罗超 张焕旭 张纪智 石学文 徐志尧 张宇 吴伟

LUO Chao ZHANG Huanxu ZHANG Jizhi SHI Xuewen XU Zhiyao ZHANG Yu WU Wei

中国石油 西南油气田公司 页岩气研究院, 成都 610051 页岩气评价与开采四川省重点实验室, 成都 610051 苏州冠德能源科技有限公司, 江苏 苏州 215129 中国石油 西南油气田公司 勘探事业部, 成都 610041

Shale Gas Research Institute, Southwest Oil & Gas Field Company, PetroChina, Chengdu, Sichuan 610051, China Shale Gas Evaluation and Exploitation Key Laboratory of Sichuan Province, Chengdu, Sichuan 610051, China Suzhou Grand Energy Technology Co., Ltd., Suzhou, Jiangsu 215129, China Exploration Division, Southwest Oil & Gas Field Company, PetroChina, Chengdu, Sichuan 610041, China

为解决页岩含油性评价受限于游离烃蒸发损失的难题，并考虑页岩含油性评价目的和井场快速分析的需求，在结合井场低温密闭粉碎技术、改进传统岩石热解方法的基础上，建立了一种岩石密闭热释方法定量评价岩石中游离烃含量的方法。对四川盆地侏罗系自流井组大安寨段页岩进行方法对比分析表明，岩石热解方法获得S0值为0.001~0.046 mg/g，S1值为0.165~4.648 mg/g，而密闭热释方法获得S0值为0.026~0.984 mg/g，S1值为0.113~5.989 mg/g；密闭热释方法获得的S1值与岩石热解方法获得的S1值基本相等，而S0值提高了1~2个数量级。通过改进升温程序，井场密闭热释方法分别获得不加热条件下、90℃以前、90~300℃时单位质量岩石中的烃含量，这不仅获得了更加丰富的含油性数据，而且缩短了检测周期，满足了井场快速分析的需求。结合泥浆气测、页岩地化参数、储层流体性质等参数，评价了研究井大安寨段页岩含油量“甜点”，为页岩油含油性评价提供了一种新的实验手段。

The oil content in shale is still a contentious issue due to the evaporative losses of free hydrocarbon. Considering the objective of the evaluation of oil content in shale and the demand of fast analysis at wellsite, a newly developed sealed rock thermal desorption method is introduced to quantify the content of free hydrocarbon in rock samples which combined the technique of sealed crushing at low temperature and improved the traditional rock pyrolysis (Rock-Eval). Comparison experiments have been conducted on Jurassic Da'anzhai shale from the Sichun Basin. The S0 value ranges from 0.001 to 0.046 mg/g, with S1 value from 0.165 to 4.648 mg/g by routine method of rock pyrolysis. The S0 value by the sealed thermal desorption method, which ranges from 0.026 to 0.984 mg/g, is about 1-2 order of magnitude higher than that of Rock-Eval. By improving the heating program, the sealed thermal desorption method can obtain the hydrocarbon content per unit mass of rock at temperatures of 5, 5-90 and 90-300℃, which not only obtains abundant oil-bearing data, but also shortens detection time. Combined with parameters such as mud gas measurement, shale geochemical parameters, and reservoir fluid properties, the "sweet spots" of shale oil in the Da'anzhai Member of the study well were evaluated, providing a new experimental method for evaluating the oil content of shale oil.

国家自然科学基金青年科学基金项目 41502150;中国石油股份公司重大现场试验项目 2019F-31-01

https://doi.org/10.11781/sysydz202204712