There are two walls in eduation. One is visible walls of the builiding seperating the school from real lives; the other is invisible walls between disciplines.

If there is no solid in the fracturing fluid, and fluid viscosit is close to the viscosity of formation fluid, which will dominate the leakoff? A: Wall builiding. B: Fracturing fluid viscosity. C: Compressibility of formation fluids. D: Compressibility of fracturing fluid.