Fracturing method for subterranean reservoirs

Abstract

A method of creating multiple fractures in a well traversing a formation is described using pressurized fluids in a highly deviated or horizontal section of the well at a pressure above the fracturing pressure of the formation, wherein for creating a fracture the pressurized fluid is alternated between an acid fracturing fluid and a proppant loaded fluid, such that the proppant blocks the flow of pressurized fluid into a fracture created during a previous step of the method and the subsequently pressurized acid fracturing fluid creates a new fracture at a location along the highly deviated or horizontal section different from the location of the previously created fracture.

Description

FIELD OF THE INVENTION[0001]The invention relates to subterranean reservoirs, particularly hydrocarbon reservoirs. More specifically, the invention pertains to methods of fracturing wells drilled as horizontal or highly deviated open holes into subterranean reservoirs, particularly carbonate reservoirs.BACKGROUND[0002]Hydrocarbons (oil, natural gas, etc.) are typically obtained from a subterranean geologic formation (i.e., a “reservoir”) by drilling a well that penetrates the hydrocarbon-bearing formation. A typical well is drilled as a vertical well into the subsurface. However, in recent times drilling practice evolved to include drilling of highly deviated (from the vertical) or horizontal wells to improve the contact of the well with a specific formation layer or pay zone.[0003]Prior to production, the well is completed with the installation of production facilities, such as casing, production pipes and pumps. The hydrocarbon industry distinguishes between two basic types of com...

AI Technical Summary

Benefits of technology

This patent describes a method for creating multiple fractures in a wellbore by using pressurized fluids. The method involves alternating between an acid fracturing fluid and a proppant loaded fluid to create new fractures at different locations along the wellbore. The proppant blocks the flow of fluid into the fracture and prevents further growth of the fracture. The method can be used to generate multiple fractures connected by the wellbore at multiple points along the wellbore without the need for zonal isolation. The invention also takes advantage of the tendency of proppant to cause a near well screenout of an existing fracture. Overall, the method provides a more efficient way to create multiple fractures in a wellbore.

Problems solved by technology

Sufficient pressure is applied to the acidizing fluid to cause the formation to break down with the resultant production of one or more fractures therein.

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