鄂尔多斯盆地延长组长页岩层段岩石热导率特征及启示

Thermal conductivity properties of rocks in the Chang 7 shale strata in the Ordos Basin and its implications for shale oil in situ development

崔景伟 侯连华 朱如凯 李士祥 吴松涛

CUI Jingwei HOU Lianhua ZHU Rukai LI Shixiang WU Songtao

1. 中国石油勘探开发研究院, 北京 100083; 2. 中国石油 长庆油田公司 勘探开发研究院, 西安 710018

1. Research Institute of Petroleum Exploration and Development, CNPC, Beijing 100083, China; 2. Research Institute of Petroleum Exploration and Development, Changqing Oilfield, CNPC, Xi'an, Shaanxi 710018, China

原位转化技术是中国陆相页岩油攻关的重点领域，鄂尔多斯盆地三叠系延长组长7页岩层段岩石热物性，特别是高温热物性研究尚处空白，严重制约原位转化工程优化和可行性评价。选取长7页岩发育区内多口取心井新鲜样品，利用热导仪、差示扫描量热仪和热膨胀仪，获得长7页岩层段泥质粉砂岩、凝灰岩、泥岩和页岩的热扩散系数、比热容、热膨胀系数以及热导率参数。长7页岩层段不同岩性的岩石热扩散系数和热导率存在差异，且随砂质含量降低而降低，即泥质粉砂岩>凝灰岩>泥岩>页岩。热扩散系数和热导率具有各向异性，水平方向是垂直方向的1~3.5倍，且其差异随温度升高而增大。随温度升高，岩石热扩散系数呈降低趋势、比热容呈增大趋势、热导率呈先降低后增大趋势。页岩热物性的各向异性最强，各向异性是岩石非均质性的体现，与微观纹层相关；砂岩各向异性可能与岩石不同方向上渗透率相关。

In situ conversion is a key area of China’s continental shale oil research. The thermal properties of rocks in the seventh member of the Triassic Yanchang Formation (Chang 7) in the Ordos Basin, especially the high temperature thermal properties are still unknown, which seriously restricts the optimization and feasibility evaluation of in situ conversion. Some fresh samples were collected from the Chang 7 shale layer and tested with a quick thermal conductivity meter, differential scanning calorimetry and thermal expansion instrument to obtain the thermal diffusivity, specific heat capacity, thermal expansion coefficient, and thermal conductivity parameter of muddy siltstones, tuffs, mudstones and shale. The thermal diffusivity and thermal conductivity of rocks with different lithologies in the Chang 7 member are different, and decrease with the decrease of sandy content, namely argillaceous siltstones > tuffstones > mudstones > shale. The thermal diffusivity and thermal conductivity have anisotropy, and the horizontal direction is 1 to 3.5 times the vertical direction, and the difference increases as the temperature increases. With the increase of temperature, the thermal diffusivity of rock decreases, the specific heat capacity of rocks increases and the thermal conductivity first decreases and then increases. The anisotropy of shale thermal properties is the strongest, which is a manifestation of rock heterogeneity, and is related to microscopic strata. The sandstone anisotropy may be related to permeability in different directions of rock.

国家重点基础研究发展计划（973计划）"中国陆相致密油（页岩油）形成机理与富集规律"（2014CB239000）资助。

https://doi.org/10.11781/sysydz201902280