Single bore-hole test procedure

摘要

In a single borehole test for determining the transmissivity and storage coefficient of liq.-satd. rock, esp. a ground water-pervious layer, in which the liq. column, in hydrostatic pressure equilibrium within the borehole, is used simultaneously for stimulation and measurement, (a) initial stimulation of the rock is effected via the liq. column by means of sudden initial pressure increase by a gas pressure pulse in the cylinder space between the liq. level and the sealed top of the borehole; (b) this stimulation is maintained by additional, permanently controlled gas pressure increase in the cylinder space so that the measured effective pressure increase in the liq. column is held constant during the entire stimulation and measurement phase; (c) time-dependent recording and registration of the drop and rate of drop of liq. level in the casing or in the region of the dense borehole wall are carried out during the entire stimulation and measurement phase; and (d) time-dependent derivation of the continuously decreasing flow rate from the borehole into the rock, through the open borehole wall in the region of the test section, is carried out on the basis of the continuously decreasing drop and rate of drop of the liq. level.Also claimed is test equipment for carrying out the above test method.