Methods and compositions for consolidating proppant in subterranean fractures

Abstract

Improved methods and compositions for coating proppant particles with a hardenable resin composition, suspending the coated proppant particles in a fracturing fluid, and consolidating the proppant particles after being placed in fractures into permeable masses are provided. These methods and compositions are especially suitable for low temperature well, specifically those around the 60° F. to 225° F. ranges. Preferably, a liquid hardenable resin component is mixed with a liquid hardening agent component on-the-fly to form a hardenable resin composition. The hardenable resin composition is coated onto proppant particles on-the-fly that are conveyed from a source thereof to form resin-coated proppant particles in real-time. The resin-coated proppant particles are suspended in the fracturing fluid to be utilized down hole.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application is a Divisional of U.S. application Ser. No. 10 / 407,643 filed on Apr. 4, 2003, which is a Continuation-In-Part of U.S. application Ser. No. 10 / 041,142 filed on Jan. 8, 2002 and of U.S. application Ser. No. 10 / 163,185 filed on Jun. 2, 2002, now abandoned, and of U.S. application Ser. No. 10 / 183,200 filed on Jun. 26, 2002 and of U.S. application Ser. No. 10 / 260,888 filed on Sep. 30, 2002.BACKGROUND OF THE INVENTION [0002] 1. Field of the Invention [0003] The present invention relates to improved methods and compositions for consolidating proppant in subterranean fractures. [0004] 2. Description of the Prior Art [0005] Hydrocarbon-producing wells are often stimulated by hydraulic fracturing treatments. In hydraulic fracturing treatments, a viscous fracturing fluid, which also functions as a carrier fluid, is pumped into a producing zone to be fractured at a rate and pressure such that one or more fractures are formed in th...

AI Technical Summary

Benefits of technology

[0008] The present invention provides improved methods of coating proppant particles with a resin composition and suspending the coated proppant particles in a fracturing fluid, as well as improved hardenable resin compositions and components thereof. The resin compositions of this invention harden and thereby consolidate resin-coated proppant particles into permeable packs in fractures formed in subterranean zones that substantially prevent proppant flow-back.

Problems solved by technology

This results in unconsolidated proppant at the bottom of the fractures adjacent to the wellbore.

The flow-back of the proppant with the formation fluids may erode metal equipment, plug piping and vessels, and cause damage to valves, instruments and other production equipment.

Another problem encountered in the use of prior hardenable resin compositions for coating proppant particles is that the hardenable resin composition components, i.e., the liquid hardenable resin component and the liquid hardening agent component, have heretofore had very short shelf lives.

In addition, the hardenable resin composition components have heretofore had very low flash points, i.e., flash points of about 60° F. or below, making them dangerous to use.

When such precoated resin-coated proppant is consolidated after being placed by a hardening agent, the resulting consolidated proppant pack often does not have enough strength to prevent deterioration and proppant flow-back.