What Does In-Situ Stress Test Mean?
An in-situ stress test is carried out to determine the stresses in rocks through which drilling operations may have to be carried out because stress conditions in faults, dykes and joints often change significantly. In-situ stress is of great importance in geotechnical engineering because they form the basis for conducting sub-surface drilling operations.
Identifying high risk zones based on stress field is essential for engineers to implement appropriate control methods to prevent failure and loss.
Trenchlesspedia Explains In-Situ Stress Test
There are different methods of carrying out in-situ stress measurement and it is necessary to understand the applicability and limitation of each technique.
Hydraulic fracturing: Conventional hydraulic fracturing and hydraulic tests on pre-existing fractures (HTPF)
Overcoring: Displacement measurements, soft stress cells, overcoring without pilot holes, borehole breakout, flat jack, borehole slotting, core discing and acoustic emissions.
Of these, hydraulic fracturing is the most preferred and suitable method for normal faulting. These test methods may not be comprehensive on their own; these tests in conjunction with other field tests can give a fair idea of sub-surface conditions to make informed decisions.