Method of enhancing hydraulic fracturing using ultra lightweight proppants

A method of hydraulically fracturing a subterranean formation having natural fractures, comprising:

• injecting into the formation a pad fluid containing a substantially neutrally buoyant ultra lightweight (ULW) proppant having an apparent specific gravity less than or equal to 2.45 and an average particle size between from about 12/20 to about 40/70 mesh, wherein the amount of ULW proppant in the pad fluid is an amount sufficient to initiate bridging of the ULW proppant in at least some of the natural fractures in the formation, thereby reducing the permeability of such natural fractures;
• and
• further subjecting the formation to hydraulic fracturing by introducing into the formation a fracturing fluid containing a proppant, wherein the flow of the fracturing fluid into the natural fractures is impeded by the bridging of the ULW proppant in the pad fluid.

A method of enhancing the fracture length during hydraulic fracturing of a coal bed having cleats, comprising creating a fracture in the coal bed by injecting into the coal bed a fluid comprising an ultra lightweight (ULW) proppant having an apparent specific gravity less than or equal to 2.45 and an average particle size between from about 12/20 to about 40/70 mesh, bridging at least some particulates of ULW proppant in at least some of the cleats and thereby reducing the permeability of at least some of the cleats in the coal bed;

• and subjecting the coal bed to hydraulic fracturing by pumping a fracturing fluid into the formation wherein the flow of the fracturing fluid to at least some of the cleats is reduced by the bridged ULW proppant thereby extending the length of the fracture created in the formation.

A method of producing fluids from a subterranean formation having natural fractures comprising:

• controlling leak-off to at least some of the natural fractures by introducing into the formation a pad fluid comprising an ultra lightweight (ULW) proppant having an apparent specific gravity less than or equal to 2.45 and an average particle size between from about 12/20 to about 40/100 mesh, wherein the ULW proppant initiates a fracture in the formation and agglomerating the ULW proppant in the natural fractures such that bridging of the ULW proppant occurs in such natural fractures;
• subjecting the formation to hydraulic fracturing by introducing into the formation a fracturing fluid containing a proppant, wherein the flow of the fracturing fluid into the natural fractures is impeded by the bridging of the ULW proppant in the pad fluid and further wherein the bridged natural fractures exhibit conductivity to produced fluids during the hydraulic fracturing.