Comparison of gas migration test and building structural strength of slurry in the aspect of limiting gas invasion

The problem of eliminating natural gas microflows through the cement slurry while bonding has been investigated by scientists in a number of scientific and research centers. Works have been undertaken to define the causes of gas migration and predict possibilities of interchannel communication in the hardened cement slurry. In the course of bonding cement slurry changes its state from liquid through gel to solid. Accordingly, the gas migration effects should be taken into account in the formation of these phases. The results of tests of gas migration in the course of binding and building structural strength have been presented in this paper. Both research methods have been compared and a high dependence of parameters defined by each of them has been found. The research works were conducted with the use of innovative apparatuses thanks to which the phenomena taking place in the course of binding can be observed. This gives the possibility of working out recipes of sealing slurries applicable to deposits where the risk of occurrence of gas migration is high.