Well Integrity Technical Section

There has been a lot of effort put into simulating the mechanical behavior of annular cement. A key requirement is to know when the cement sheath fails (and how) and when it starts deforming plastically. Since cement behind pipe is confined, Unconfined Compressive Strength (UCS) has to be complemented by triaxial tests, in which a sample is squeezed laterally while being pressed.

As is the sad norm in our industry, there are very few usable tests out in the literature. Building types, on the other hand, have been producing tons of tests with concrete. Unfortunately, cement paste (the variety we pump in wells) seems to behave differently when you don't stuff it full with pebbles.

I have found three sources with high quality data, which are listed below. Would you know of others in the public domain, or have test results catching dust in your archive that you'd be willing to share?

• Hansen, T.C., 1995, "Triaxial tests with concrete and cement paste", report ABK R319, Denmark Technical University (43 data points)
• Thiercelin, M. et al., 1998, "A soil mechanics approach to predict cement sheath behavior", SPE 47375 (4 data points)
• Sakai, Y. et al., 2016, "Mechanical Behavior of Cement Paste and Alterations of Hydrates under High-Pressure Triaxial Testing", Journal of Advanced Concrete Technology, volume 14 (3 data points).

Thanks in advance,