The effect of fracturing fluid leak-off on the productivity of high permeability oil reservoirs

During hydraulic fracturing of permeable reservoirs then is concern that fr acturing fluid leak-off may cause a reduction in permeability. One importan t criterion of a successful fracturing treatment is limited formation damag e. This study focussed on investigating the alteration of permeability with distance from the fracture face, during fracturing fluid leak-off, and its subsequent recovery during production. Experiments were conducted in a 2-in. diameter and 12-in. long dynamic flui d loss core holder. Ten-in. long berea sandstone core samples of varying pe rmeabilities were used. Four different types of fracturing fluids were test ed. Also, the effect of fluid loss additive on regain permeability was in,i nvestigated. The movable oil phase in the core sample was either mineral or crude oil. The variation of return permeability with time and distance was determined along the length of the core sample. Effects of shut-in time, fluid loss ad ditive, fracturing fluids, flow rates during flowback, and oil composition on regain permeability of oil reservoirs are presented in this paper.