Well Treating Agents of Metallic Spheres and Methods of Using the Same

Abstract

Hollow non-porous metallic spheres may be used in treatment of subterranean formations, including hydraulic fracturing and sand control methods, such as gravel packing. The spheres typically having a diameter ranging from about 4 mesh to about 100 mesh. When employed in deep water environments having high closure stresses, the spheres have a thicker wall and are characterized by the higher ASG, typically between 2.5 to about 4.0. The ASG of the spheres, when less harsh environments are encountered, is generally ultra lightweight (ULW) with an ASG less than or equal to 2.0. Fracture conductivity may be increased by the placement of the hollow non-porous metallic spheres as a partial monolayer.

Description

[0001]This application claims the benefit of U.S. patent application Ser. No. 60 / 897,679, filed on Jan. 26, 2007, wherein is herein incorporated by reference.FIELD OF THE INVENTION[0002]This invention relates to methods and compositions useful for subterranean formation treatments, such as hydraulic fracturing and sand control. In particular, this invention relates to the use of hollow substantially non-porous metallic spheres in sand control methods such as gravel packing, frac pack treatments, etc., as well as proppant material in hydraulic fracturing.BACKGROUND OF THE INVENTION[0003]Stimulation procedures often require the use of well treating materials having high compressive strength. In hydraulic fracturing, such materials must further be capable of enhancing the production of fluids and natural gas from low permeability formations.[0004]In a typical hydraulic fracturing treatment, fracturing treatment fluid containing a solid proppant material is injected into the wellbore at...

AI Technical Summary

Benefits of technology

[0015]The coating may be applied to a portion of the metallic spheres or to the entire circumference of the spheres. The coating may function as a sealant to prevent invasion of the carrier fluid (as well other fluids in the wellbore) into the core. The coating may further provide greater anti-corrosive characteristics to the well treating composite.

[0018]The well treating agent and composite defined herein exhibit high compressive strength. Fracturing may therefore be conducted at closure stresses greater than about 500 psi and at temperatures ranging from ambient to 500° F. For example, spheres of a 1 mm diameter and an ASG of about 1.3 are capable of withstanding up to 20,000 psi. The high compressive strength exhibited by the spheres may be attributable to the stiffness of the metal. The high compressive strength may further be attributable to the cylindrical shape of the spheres upon them being subjected to high pressures. As high pressure is applied, such as by a mechanical press, the metallic spheres start to deform between the two platens and the two points of contact begin to cave. As the area exposed to the load increases, the deformed particulates resemble oriented cylinders. Such cylinders, along with their short length, offer tremendous strength to the particulates.

[0022]The well treating agents of the invention, as well as composites comprising such well treating agents, may further be used in sand control. In such applications, the hollow non-porous metallic spheres (or composites) are typically introduced into the wellbore in a slurry of the carrier fluid. At least a portion of the well treating agent (or composite) is placed adjacent the subterranean formation to form a fluid-permeable pack. The pack is capable of reducing or substantially preventing the passage of formation particles from the subterranean formation into the wellbore. At the same time, formation fluids from the subterranean formation are permitted to pass into the wellbore.

Problems solved by technology

Proppant transport is often difficult with such proppants.

In conventional sand packs, tightly held packs often are characterized by insufficient interconnected interstitial spaces between abutting particulates.

Unfortunately, partial monolayer fracturing has been difficult to achieve with state-of-the-art proppants.

When such migration occurs, such grains and fines typically reduce the rate of hydrocarbon production from the well.

In addition, such grains and fines can cause serious damage to well tubulars and to well surface equipment.

Concerns exist however that ULW particulates do not demonstrate the chemical resistance properties required of particulates for use in gravel packing.

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