中文摘要：

根据天然气扩散、物质平衡原理、烃浓度封闭机理和气源岩层之间扩散时间的相互匹配关系建立了评价泥质气源岩层内天然气扩散损失量的6种扩散模式以及不同模式下气源岩层天然气扩散损失量的计算方法，为定量评价部分烃浓度封闭期间气源岩层天然气扩散量、页岩气扩散量提供了可能。源岩层在受到部分烃浓度封闭期间的天然气扩散量，假设此期间不存在烃浓度封闭，则为源岩层的扩散气量与该期间上覆气源岩的扩散气量之差。利用所得模型对黔南坳陷黄页1井九门冲组页岩进行了实际应用，结果显示，黄页1井九门冲组页岩不考虑烃浓度封闭条件下的扩散气量远大于考虑烃浓度封闭条件下的扩散气量。在评价泥质气源岩层扩散量时如果存在烃浓度封闭作用，应加以考虑。

英文摘要：

Quantificationally evaluating the natural gas diffusion loss from source rocks is significant to assess shale gas resource. Based on principles of natural gas diffusion, mass balance, hydrocarbon concentration sealing and the matching relations among diffusion time of different source rocks, six kinds of models were established to assess natural gas diffusion loss from source rocks. It is possible to assess the natural gas diffusion loss from source rocks during the partly hydrocarbon concentration sealing and shale gas. The diffusion loss from partly hydrocarbon concentration sealing source rocks can be calculated by the diffusion loss from source rocks without hydrocarbon concentration sealing and overlying gas source rocks. The models were applied to the Jiumenchong Formation of the Lower Cambrian, southern Guizhou sag. The diffusion loss with hydrocarbon concentration sealing effect considered is lower than that without hydrocarbon concentration sealing effect. So hydrocarbon concentration sealing should be taken into consideration to assess the natural gas diffusion loss from source rocks.