Patent ID: 7096943
Filing Date: 2006-08-29
Classification: E21B

Abstract:
1. A method for fracturing a rock formation next to a well bore using a frac pad fluid and collecting the fluid from the rock formation through the well bore, the well bore vertical, horizontal, or any angle between vertical and horizontal, the method for fracturing used for increasing production of oil, gas and other fluids from the rock formation, the steps comprising: creating a permeable annulus between a production casing and a well bore wall with a permeable material, the material having a desired average permeability to produce a desired, fluid-flow friction-pressure-loss from fluid flow along an annulus-flow-path; creating a first pressure gradient by controlling a flow rate of the frac pad fluid through a portion of the permeable annulus located ahead of a hydraulic fracture propagating along a well bore axis, the first pressure gradient greater than an average gradient of a rock formations frac-extension pressure; creating a second fluid pressure gradient by friction loss of the frac pad fluid flowing through combined parallel paths in the permeable annulus and the hydraulic fracture propagating outward from the well bore axis; creating a frac producing stress field in the rock formation and along a portion of the permeable annulus by maneuvering an intersection of the first and second pressure gradients of the frac pad fluid; creating a frac pad fluid pressure at the intersection of the first and second pressure gradients of the frac pad fluid, which is greater than the rock formations frac-extension pressure; and controlling a back pressure on a discharge of the frac pad fluid from the permeable annulus, thereby controlling the first pressure gradient to a desired value greater than the average gradient of the rock formations frac-extension pressure along the well bore axis and creating the frac pad fluid pressure at the intersection of the first and second pressure gradients of the frac pad fluid, which is greater than the rock formations frac-extension pressure, thereby controlling the growth of the hydraulic fracture along the length of the permeable annulus.