石油与天然气地质 ›› 1999, Vol. 20 ›› Issue (1): 1-6.doi: 10.11743/ogg19990101

• 论文 •    下一篇

断裂开启与地层中温压瞬态变化的数学模拟

罗晓容   

  1. 中国科学院地质研究所, 北京 100029
  • 收稿日期:1998-10-20 出版日期:1999-03-25 发布日期:2012-01-18
  • 基金项目:

    中国科学院“九五”攻关重点项目(KZ952-S1-428)

MATHEMATICAL MODELING OF TEMPERATUREPRESSUREZTRANSIENT VARIATION IN OPENING FRACTURES AND SEDIMENTARY FORMATIONS

Luo Xiaorong   

  1. Geological Institute, Academia Sinica, Beijing
  • Received:1998-10-20 Online:1999-03-25 Published:2012-01-18

PDF (PC)

758

被引次数

39

摘要：

针对莺歌海盆地明显的今古地温异常特征,设计和推导了一个平板断裂开启二维数学模型。通过分析断裂开启后在断裂面及由其连通的渗透性地层中流体流动和流体压力的瞬态变化过程,得出了一个反映各个地层和水动力学因素对该过程影响效应的时间特征常数。断裂面的流体传输系数和含水层的水动力传导率分别控制了流经断裂面的峰值流量和保持峰值流量的时间长度。开启断裂造成的地下热流体的垂向流动是造成地下热异常的重要原因。但要形成在莺歌海盆地泥拱构造带上观察到的蒙脱石伊利石转化、镜煤反射率等地热指标的异常,则需要沿该构造上部断裂面发生长时间、大流量的热流体流动。

关键词: 断裂开启, 超压, 热流体, 瞬态过程, 数学模拟

Abstract:

Based on the geothermal anornaly and pore pressure distribution in Yinggehai Basin,South China Sea,a 2D mathematical model is established and applied to analyze the transient variation process of fluid flow and fluid pressure within paralle opening fractures and in the connected permeable formations.A characteristic time constent was obtained to illustrate the influences of stratigraphic and hydrodynamic factors on the process.The fluid transmisson coefficient of the fracture surfaces and the hydraulic conductivity of the fracture surfaces control the peak flow and the time duration keeping this flow through the fracture respectively.The vertical flow of underground thermal fluid resulted from the opening fracture is the important cause of geothermal anomaly.However,the existences of high abnormal thermal indexes,such as the smectite lillite transformation and vitrinite reflectivity observed in Yinggehai Basin,should be the results of a large flow of hot fluid along the vertical fractures during a long period.

Key words: fracture opening, overpressure, hot fluid, transient, process, mathematical modeling