Apparatus and method for fracturing portions of an earth formation

摘要

A method of fracturing an earth formation is disclosed. The method includes: isolating a section of a borehole in the earth formation; introducing a fluid into the isolated section and pressurizing the isolated section from a first pressure to a second pressure; introducing a stress concentration to a borehole wall at least one location in the isolated section when the fluid is at the selected pressure or during the pressurization; and initiating a hydraulic fracture in the earth formation at the at least one location.

主权项

1. A method of fracturing an earth formation, comprising:
isolating a section of a borehole in the earth formation; introducing a fluid into the isolated section; increasing fluid pressure in the isolated section, and maintaining the isolated section at a substantially constant first pressure, the first pressure being of at least a magnitude sufficient to cause a fracture to form in the earth formation; pressurizing the isolated section from the first pressure to a second pressure, the second pressure being a fracture pressure that is greater than the first pressure; introducing a stress concentration to a borehole wall at at least one location in the isolated section when the fluid is at the second pressure or during the pressurization upon at least one of the fluid pressure reaching the second pressure and a selected flow rate or pressurization rate, wherein introducing the stress concentration to the borehole wall includes perforating the borehole wall at the at least one location; and initiating a hydraulic fracture in the earth formation at the at least one location.