Hydraulic fracturing method for low permeability formations

Claim 1

A METHOD OF FORMING A VERTICAL FRACTURE IN A THICK SUBTERRANEAN FORMATION HAVING A PREFERRED VERTICAL FRACTURE ORIENTATION FROM A WELL PENETRATING SAID FORMATION, COMPRISING THE STEPS OF: INJECTING FRACTURING FLUID IN A SINGLE STAGE VIA SAID WELL INTO SAID FORMATION AT A PRESSURE SUFFICIENT TO FORM AND PROPAGATE A VERTICAL FRACTURE INTO SAID FORMATION, SAID FRACTURING FLUID BEING INJECTED AT A RATE NO GREATER THAN ABOUT 0.5 BARREL PER MINUTE PER FOOT OF FORMATION, ABD BEING COMPRISED OF A LIQUID HAVING AN APPARENT VISCOSITY OF LESS THAN ABOUT 100 CENTIPOISES AND CONTAINING A PROPPANT IN AN AMOUNT NO GREATER THAN ABOUT FOUR POUNDS PER GALLON; AND CONTINUING TO INJECT SAID FRACTURING FLUID VIA SAID WELL INTO SAID FORMATION UNTIL AT LEAST 330,000 GALLONS OF SAID FRACTURING FLUID ARE INJECTED THEREINTO.

Claim 2

A METHOD OF FORMING A VERTICAL FRACTURE IN A THICK SUBTERRANEAN FORMATION HAVING A PREFERRED VERTICAL FRACTURE ORIENTATION FROM A WELL PENETRATING SAID FORMATION, COMPRISING THE STEPS OF: INJECTING FRACTURING FLUID IN A SINGLE STAGE VIA SAID WELL INTO SAID FORMATION AT A PRESSURE SUFFICIENT TO FORM AND PROPAGATE A VERTICAL FRACTURE INTO SAID FORMATION, SAID FRACTURING FLUID BEING INJECTED AT A RATE NO GREATER THAN ABOUT 0.5 BARREL PER MINUTE PER FOOT OF FORMATION, ABD BEING COMPRISED OF A LIQUID HAVING AN APPARENT VISCOSITY OF LESS THAN ABOUT 100 CENTIPOISES AND CONTAINING A PROPPANT IN AN AMOUNT NO GREATER THAN ABOUT FOUR POUNDS PER GALLON; AND CONTINUING TO INJECT SAID FRACTURING FLUID VIA SAID WELL INTO SAID FORMATION UNTIL AT LEAST 330,000 GALLONS OF SAID FRACTURING FLUID ARE INJECTED THEREINTO.

Claim 5

The method of cliam 3 werein said proppant is sand.

Claim 6

The method of cliam 3 werein said proppant is sand.

Claim 7

A method of forming a vertical fracture in a subterranean formation having a thickness of at least 100 feet and having a preferred vertical fracture orientation, said formation being penetrated by a well having a drainage radius of at least 1,320 feet, comprising the steps of: injecting a high leak-off aqueous fracturing fluid in a single state via said well into said formation at a pressure sufficient to form and propagate a vertical fracture into said formation, said fracturing fluid being injected at a rate no greater than about 0.5 barrel per minute per foot of formation, and being comprised of a liquid having an apparent viscosity of less than about 100 centipoises and containing a proppant in an amount no greater than about three pounds per gallon; and continuing to inject said fracturing fluid via said well into said formation until at least 330,000 gallons of said fracturing fluid are injected thereinto.

Claim 8

A method of forming a vertical fracture in a subterranean formation having a thickness of at least 100 feet and having a preferred vertical fracture orientation, said formation being penetrated by a well having a drainage radius of at least 1,320 feet, comprising the steps of: injecting a high leak-off aqueous fracturing fluid in a single state via said well into said formation at a pressure sufficient to form and propagate a vertical fracture into said formation, said fracturing fluid being injected at a rate no greater than about 0.5 barrel per minute per foot of formation, and being comprised of a liquid having an apparent viscosity of less than about 100 centipoises and containing a proppant in an amount no greater than about three pounds per gallon; and continuing to inject said fracturing fluid via said well into said formation until at least 330,000 gallons of said fracturing fluid are injected thereinto.

Claim 9

A method of forming a plurality of vertical fractures in a subterranean formation having a thickness of at least 200 feet and having at least one stratum that partitions said subterranean formation into at least a first reservoir and a second reservoir, each reservoir having a thickness of at least 100 feet, said formation being penetrated by a well, comprising the steps of: a. injecting a high leak-off fracturing fluid in a single stage via said well into said first reservoir at a pressure sufficient to form and propagate a vertical fracture into said first reservoir, said fracturing fluid being injected at a rate no greater than about 0.5 barrel per minute per foot of said first reservoir, and being comprised of a liquid having an apparent viscosity of less than about 100 centipoises and containing a proppant in an amount no greater than about 4 pounds per gallon; b. continuing to inject said fracturing fluid via said well into said first reservoir until at least 330,000 gallons of said fracturing fluids are injected thereinto; and c. repeating steps (a) and (b) in said second reservoir.

Claim 10

A method of forming a plurality of vertical fractures in a subterranean formation having a thickness of at least 200 feet and having at least one stratum that partitions said subterranean formation into at least a first reservoir and a second reservoir, each reservoir having a thickness of at least 100 feet, said formation being penetrated by a well, comprising the steps of: a. injecting a high leak-off fracturing fluid in a single stage via said well into said first reservoir at a pressure sufficient to form and propagate a vertical fracture into said first reservoir, said fracturing fluid being injected at a rate no greater than about 0.5 barrel per minute per foot of said first reservoir, and being comprised of a liquid having an apparent viscosity of less than about 100 centipoises and containing a proppant in an amount no greater than about 4 pounds per gallon; b. continuing to inject said fracturing fluid via said well into said first reservoir until at least 330,000 gallons of said fracturing fluids are injected thereinto; and c. repeating steps (a) and (b) in said second reservoir.