Experimental Research On Stress Sensitivity Of Physical Parameters In Unconsolidated Sandstone

The unconsolidated sandstone reservoir has low consolidation strength. It shows strong stress sensitivity when the effective stress of reservoir changes. And also unconsolidated sandstone reservoir plays an important role in hydrocarbon resources of China. Therefore, systematic research of unconsolidated sandstone stress sensitivity is of great significance for the efficient development of unconsolidated sandstone reservoir. Since coring from the underground rock, the in-situ stress state was destroyed, and resulting in porosity and permeability of the rock changing. The experiment of reservoir stress sensitivity was made under the simulated in-situ stress state, moreover the same fluid as reservoir was used.Some methods, such as laboratory testing and finite element analysis, were mainly adopted in this paper. First of all, relevant laboratory equipment, methods of improvement,and related experimental rules or processes were described. Then relevant tests were carried on the unconsolidated sandstone in the block of BinNan ShangEr. The experimental results showed that, for the value of Biot of unconsolidated sandstone, the changes were not sensible with the effective stress, however, permeability and elastic modulus changing obviously. Finally, the dynamic models of permeability and elastic modulus of unconsolidated sandstone reservoir are proposed, and also based on the dynamic models, dynamic development of reservoir fracturing of single-phase flow was simulated in this paper and the real-time changes of the reservoir parameters and the reservoir capacity were given. Research showed that reservoir parameters near crack were changed apparently and fracturing capacity was significantly lower than conventional percolation model because of fluid-structure interaction. This research results have some exciting impact on the reservoir development of stronger stress sensitivity.