Compressibility test

This test determines the pore volume compressibility of a rock sample under reservoir condition. The constant stress σ1 simulates the overburden while the radial stress σ3 is controlled in such a way that the radial deformation of the sample is zero throughout the test (uniaxial strain test). A pore pressure is injected and then varied e.g. to simulate the depletion of the reservoir.

The axial deformation of the samples gives the bulk volume change while the squeeze out of the pore fluid gives the pore volume change. Variations of this procedure like testing under a hydrostatic stress condition are also applicable.

The test can be carried out with saturated samples (water, brine, oil) from ambient conditions up to a temperature of 150°C and an operating pressure of up to 140 MPa (σ2 = σ3). Sample dimensions applied so far are length : diameter = 2:1 with specimen diameters of 1” to 2”.


Experimental setup
test σ1 σ3 ε1 ε3 Pp measured
pore pressure variation constant f(ε3) ≠ 0 = 0 variable Δl
at prevented lateral strain variable free constant


Example for a three-cycle test path


21.02.2018 10:12

AAPG ACE 2018 in Salt Lake City (19.-23.05.2018)

Gesteinslabor will present brandnew results from the frontline of research at one of the key events for petroleum geologists.

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21.02.2018 08:45

TSK 2018 in in Jena (21.-23.03.2018)

Gesteinslabor will take part at the distinguished conference dealing with tectonics, structural geology and crystalline rocks.

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31.01.2018 12:06

Spring meeting 2018 in Celle

Following a well established tradition, also in 2018 DGMK and ÖGEW will host their annual conference in the Congress Union Celle.

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