Method and Apparatus for Resonant Over-Pressured Well Fracturing

摘要

The method and apparatus for enhancing of the formation fracturing around a wellbore the regime of resonance by means of applying vibrations to the formation surrounding wellbore which is undergoing pressures exceeding the fracture gradient pressure of the formation. The method includes the steps of arranging a device attached to the end of tubing inside the wellbore in the vicinity of perforations, providing a fracturing fluid via tubing into a device for generating vibrations on a resonant frequency fr in accordance with following expression:;fr=c2πr1.2HL(r+W),;where fr is the frequency of resonance, c is a speed of sound in fluid, π equals 3.1415, r is the required width of fracture, H is a combined thickness of a casing and a cement bond surrounding the casing, W is a distance on a casing arch between an adjacent perforations, L is the required length of fracture.

主权项

1. A method for enhancing of forming at least one fracture in a formation having a wellbore penetrating said formation and communicating therewith through a multiplicity of perforations by providing vibrations on a resonant frequency and comprising the steps of:
a) arranging a device for generating vibrations and said device is attached to an end of a tubing inside the wellbore in a vicinity of said perforations; b) providing a pressured fracturing fluid in said wellbore at a pressure exceeding a fracture gradient pressure of said formation; c) generating vibrations by said device for generating vibrations on the resonant frequency determined by the following expression:fr=c2πr1.2HL(r+W),where fr is the resonant frequency, c is a speed of sound in the fracturing fluid, π equals 3.1415, r is a required width of fracture, H is a combined thickness of the casing and a cement bond surrounding the casing, W is a distance on the casing arch between an adjacent perforations, L is a required length of fracture.