天然ガス田における地表沈下に関する研究

抄録

In natural gas fields, it is recognized that the surface subsidence is occured due to the pumping of gas-content-water.
So, we studied characteristic behavior of subsidence and available prediction method of subsidence.
The analytical method we showed in this report mainly consists of two parts.One is the seepage analysis with finite element technique to obtain the plan-distribution of piezometric head in gas seams, the other is the calculation of subsidence using the above piezometric head, on the assumption that the ground behaves as a elastic material.
The following results were obtained:
The subsidence in natural gas fields is caused by the decrease of piezometric head in gas seams due to the extraction of gas-content-water, and the subsidence is proportional to the decrease of piezometric head.
And, it is found that the results of our analytical method very agree with those of actual measurements.