Method and Acidizing Tool for Deep Acid Stimulation Using Ultrasound

Abstract

A method of deep acid stimulation for a zone to be treated in an underground formation using an acidizing tool, the method including the steps of introducing the acidizing tool into the well bore, introducing the acid formulation onto the well bore wall at the treatment zone and introducing ultrasound energy into the underground formation at the treatment zone. The subsequent acid penetration depth is deeper than the initial acid penetration depth. A method of stress fracturing a portion of an underground formation includes the steps of introducing the acidizing tool into a well bore and introducing the acid formulation and the ultrasound energy at the focused treatment point. The weakened acidized spots in combination with the stress on the underground formation causes oriented stress-induced fractures to form that are fluidly coupled with the well bore. An acidizing tool includes an acid delivery system and an ultrasonic transmitter.

Description

CROSS-REFERENCE TO RELATED PATENT APPLICATIONS[0001]This application claims priority from U.S. Provisional Application No. 61 / 568,279, filed Dec. 8, 2011. For purposes of United States patent practice, this application incorporates the contents of the Provisional Application by reference in its entirety.TECHNICAL FIELD OF THE INVENTION[0002]The field of invention relates to a method and device for improving the effectiveness of a matrix acidizing technique by increasing the depth of penetration of the acid throughout a subterranean carbonate formation.BACKGROUND OF THE INVENTION[0003]It is a common practice to acidize subterranean formations in order to increase the permeability thereof. For example, in the petroleum industry, acidizing fluid can be injected into a well in order to increase the permeability of a surrounding hydrocarbon bearing formation, thereby facilitating the flow of hydrocarbonaceous fluids into the well from the formation. Such acidizing techniques may be carri...

AI Technical Summary

Benefits of technology

[0010]A method of stress fracturing a portion of an underground formation includes the step of introducing the acidizing tool into a well bore such that it is positioned proximate to a focused treatment point. The focused treatment point is associated with a portion of the underground formation under stress. The acidizing tool is operable to direct the acid formulation and the ultrasound energy at the focused treatment point. The method includes the step of introducing at the same time the acid formulation and the ultrasound energy at the foc

Problems solved by technology

However, a common difficulty encountered in acidizing these types of formations is presented by the rapid reaction rate of the acidizing fluid with those portions of the formation with which it first comes into contact.

This is particularly serious in ma

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