It enables the users to calculate some parameters such as coefficient of consolidation, compression index, recompression index, and preconsolidation pressure depending on the type and stress history of the soil.
The findings showed that the operation time, energy consumption and coefficient of performance of compression cooling system and thermoelectric hybrid cooling system were 16,380 s, 8636.8 kJ and 5.3 and 15,000 s, 7911 kJ and 5.4, respectively, indicating a better performance for the hybrid cooling system.
Ding and Ma (2012) and Li et al. (2009) conducted a large number of researches on rock compression coefficient and got the sensitive factors of compression coefficient.
Therefore, only the changes in pore volume with pore pressure are concerned in oil and gas engineering, so traditionally the pore volume compression coefficient of rocks is named as rock compression coefficient in oil and gas engineering.
Open image in new window Fig. 3 Sketch map of test procedures of compression coefficient under the high-temperature cycle.
Therefore, when the maximum effective confining pressure was low, the plastic deformation of the rock was small after each test of compression coefficient.
In order to study the change laws of compression coefficient of heavy oil reservoirs in the late stage of multi-cycle steam stimulation, the authors carried out experiments on the influences of temperature, especially temperature and pore pressure cyclic changes in rock compression coefficient.
The higher the temperature was, the less the rocks can recover from the deformation after the first test of compression coefficients, which therefore resulted in a larger difference in compression coefficients in the first and second cycles.
Due to the large initial compression coefficient of the reservoir at high temperature, the difference in compression coefficients at different temperatures gradually reduced after multiple cycles of temperature and pore pressure.
In addition, the test results of compression coefficients after the 5th and 6th cycles only have a difference of 2%.
