用固体潮观测资料将钻孔应变变化换算为地层的应力变化

利用钻孔应变观测值中潮汐频段部分和钻孔岩芯的弹性系数,将钻孔应变换算为地层应力的格值,用此格值可将钻孔应变的非潮汐变化换算成该地地层的非潮汐应力变化.从潮汐模型研究和潮汐观测结果来看,勒夫数受地球大结构的影响,空间变化不大,据此可用勒夫数的模型值去求定标定应力.由钻孔应变观测值求定钻孔应变的面应力系数和差应力系数,而不必知道耦合介质的力学性能.探头周围介质若非各向同性时,应力系数可用椭圆的解析式拟合.此外,还讨论了同井、同台、台网的校核问题,以及应力场模型的拟合和漂移的分离问题.

CONVERTING VARIATION OF BORE-HOLE STRAIN INTO ONE OF STRATA STRESS BY EARTH TIDE OBSERVATION

The scale value, which is converted from the bore hole strain, by nse of the observed values in tidal frequency band of the bore hole strain and the elastic coefficients of the bore hole corescan can be used for coverting non tidal variation of the bore hole strain into variation of the non tidal stress of the same stratum. From studies on the tidal models and observed results,the spatial variation of Love number is not great because of the influence of the greater tectonics in the earth,the modeled stress can be evaluated with the model values of the bore hole strain without the mechanical properties of the coupled media. As there are anisotropy in the media surrounding the sonde,the stress coefficients may be fitted with the analytical function of the ellipsoid. Besides the questions about the collations of co station co well and the network, as well as the separation of the drift are all discussed in the paper.