Abstract: Laboratory tests were conducted to investigate how pressure differential and soaking time influence oil and gas protection results, and the corresponding temporary plugging results were also evaluated. Testing results showed that the permeability decreases with the increase of soaking time and pressure differential, and if suitable drilling fluid is selected, better temporary plugging result can be achieved because of the good compatibility of solid grains with formation throats. When applying the temporary plugging, it should be focused on the dominating throats that are important to formation permeability, not simply considering the average size of the throat. After adopting the suitable reservoir protecting measures, good results were obtained in Well Hua X4.