Abstract: 　Based on the analysis of the lithology of the Lower Permian Shanxi Formation and Benxi Formation reservoirs in the Upper Paleozoic of the Yulin gas field. The influence of sea water temperature and seepage flow rate on the hot oil pipeline unsteady heat transfer is analyzed, the results show that: the relatively greater the see water seepage flow rate is; the longer the radius of the thermal effect in the seepage flow direction of soil temperature field around the pipeline, the shorter the radius of thermal effect vertical to the seepage flow direction, and with the flow velocity increases, the average temperature throughout the soil region increased, the time of the soil temperature to stabilize decreased.

Key words: Quartz sandstone gas layer, Lithology recognition, Photoelectric cross section, Gas reservoir

摘要： 对榆林气田上古生界下二叠系山西组及本溪组储层的岩性进行研究分析，结果表明榆林气田山西组及本溪组存在与岩屑砂岩不同石英砂岩气层，石英砂岩与灰岩在部分条件下具有假似性，在测井采集和定性解释时难以区分。针对这一问题，基于榆林气田不同组段岩层中子、密度、声波等测井资料，结合光电截面参数等建立解释图版、准确识别岩性、建立解释模型等方法，对榆林气田的石英砂岩气层进行识别评价，并得出研究区石英砂岩气层的识别标准，为准确识别榆林区块的气藏奠定了基础，可指导气田开发。

关键词: 石英砂岩气层, 岩性识别, 光电截面, 气层