This website uses cookies. You have the possibility to transfer personal data on this website. Your website visit can be evaluated by external companies. Find out more in our privacy policy.

 

Triaxial compression test accompanied by ultrasonic and permeability measurements

A specimen of the low permeability and low porosity Dethlingen Sandstone (k: 0.04 mD, φ: 4.5%) was exposed to a low confining pressure of 10 MPa and a peak axial stress of 250 MPa. The test run is displayed in the graph below. While the stress-strain curve (in green) still takes an apparently linear course, the shear wave velocity (red crosses) is the first to exceed a maximum and subsequently slows down. This reflects the beginning of micro crack formation, and the resulting inner destruction of the sample cylinder. As soon as the micro cracks start to connect, P waves (pink triangles) also decelerate and permeability (to gas ; blue curve) increases instantaneously. From the relationship of the velocity changes between the P and S wave it can be inferred that fracturing follows the main compressive stress σ1 and that the micro cracks are oriented perpendicular to the least principle stress σ3 (for details see (Braun & Jahns 1998).

A A A
                                Login
 

News

Gesteinslabor publishes its first webinar

Gesteinslabor is contributing to the educational program of AAPG and has just published a webinar about geothermal energy.

Read more …

Gesteinslabor at AAPG's ERC in Vienna

Also in 2019 Gesteinslabor is contributing to the wide variety of AAPG's conferences.

Read more …

DGMK Spring Meeting 2019

Also in 2019 Gesteinslabor will be present at the DGMK Spring Meeting in Celle (25-26/04).

Read more …

AAPG interview

Invited by AAPG's director of innovation & emerging science and technology Susan Nash, Carlo Dietl from Gesteinslabor shares his ideas about geothermal energy and its future in this Learn! Blog interview.

Read more …