Method and apparatus for hydraulic fracturing

摘要

A method of treating a consolidated formation having a wellbore therein. Tubing including a stress relieving tool is provided in the wellbore. An interval in the wellbore wherein the stress relieving tool is located is isolated. The stress relieving tool is actuated to apply mechanical force radially to an uncased inner diameter surface of the wellbore for providing a reduced stress zone of the formation. Fluid pressure is increased in the wellbore to fracture the formation within the reduced stress zone.

主权项

1. A stress relieving tool comprising:
an elongate tubular having a channel therethrough; a first actuator sleeve positioned on the tubular, the first actuator sleeve axially movable along the tubular and in fluid communication with the channel for advancing the first actuator sleeve along the tubular in a first direction in response to fluid pressure in the channel; a first tapered sleeve of decreasing outer diameter in the first direction positioned on the tubular in series with the first actuator sleeve and axially movable along the tubular; a second tapered sleeve of increasing outer diameter in the first direction positioned on the tubular in series with the first tapered sleeve; and a c-ring positioned on the tubular between the first and second tapered sleeves; wherein:
an inner diameter of the c-ring is equal to an outer diameter at a first portion of the first tapered sleeve, and at a second portion of the second tapered sleeve;the first tapered sleeve is advanced in the first direction by the first actuator sleeve when the first actuator sleeve is advanced in the first direction;the c-ring is urged radially outward when the first tapered sleeve is advanced underneath the c-ring; andthe second tapered sleeve is anchored to the tubular to remain immobile relative to the first tapered sleeve.