Abstract:

The damage of water block is that capillary force existing in gas-liquid interface of formation pore passage obstructs the flow of oil and gas. Results studied in worldwide have shown that the water block affects seriously development effects and becomes one type of the major damages for low permeability gas reservoirs. It has resulted in serious consequences. Bench-scale heating tests have been carried out to water sensitive sandstone core to determine the effect of heat on effective permeability. Results indicate that heat treatment can improve the damage of water block. Experimental results show that the intense heat vaporizes bound and blocked water, destroys clay lattices, and ultimately increases the permeability of clay-rich formations, then removes or postpones water block damage.

Key words: water block, low permeability pools, clay mineral, heat treatment