沉积盆地内侵入岩席对富含有机质围岩热影响的热传输模型研究

Heat-transfer-model analysis of thermal effect of intrusive sills on organic-rich host rocks in sedimentary basins

以澳大利亚Gunnedah盆地Bellata-1井作为实例,采用3种主要的热传导模型,数值模拟了火成侵入岩席对相邻烃源岩的热影响.结果表明:(1)假设岩浆瞬间侵入且考虑地层孔隙水气化的复杂热传导模型估计的围岩的接触温度最高,假设岩浆瞬间侵入但忽略地层孔隙水气化的简单热传导模型次之,而假设岩浆缓慢侵入的简单热传导模型的估计值最低.(2)岩浆瞬间侵入的简单热传导模型预测的岩席对围岩的热影响范围最高,缓慢侵入的热传导模型最低,岩浆的缓慢侵入方式在降低侵入体对相邻围岩的热影响方面,可以比孔隙水的气化作用更为显著.(3)岩浆瞬间侵入的简单热传导模型的计算结果与镜质体反射率温标最为吻合,说明岩浆为瞬间侵入且孔隙水的气化及流动在低渗透率且超高压的地层内受到了限制.

This study presents a numerical investigation of the thermal effect of an intrusive sill on organic-rich host rocks based on three types of different heat conduction models.The Bellata-1well in the northen Gunnedah Basin(Australia) is selected as an example.Results indicate: 1) the contact temperature(Tc) based on the model of instantaneous intrusion with pore-water evaporization is highest among three types of heat conduction models,whereas Tc computed by the model of finite-time intrusion without pore-wat...