Precursor compositions for ceramic proppants

Abstract

A precursor composition for the production of granulated ceramic material to be used as hydraulic fracture proppant, comprises 20 to 55% pyroxene, and 15 to 50% olivine. The remaining component is quartz and / or feldspar. The precursor composition can be sintered in a broader temperature range. The resulting proppant material shows high mechanical strength and resistance to acids, and also higher stability under hydrothermal conditions than the prior art.

Description

[0001] This application is a continuing application under 35 USC 111(a) of PCT / EP2006 / 067725 filed Oct. 24, 2006, and claims priority to that International Application (PCT / EP2006 / 067725 filed Oct. 24, 2006) and to European application No. 06 405 332.5 filed Aug. 4, 2006, which is incorporated herein by reference.TECHNICAL FIELD [0002] The present invention relates to precursor compositions for the production granulated ceramic material, particularly ceramic proppants, methods for producing granulated ceramic material, and ceramic proppants, according to the preamble of the independent claims. STATE OF THE ART [0003] In order to enhance the yield of oil and gas wells, the permeability of rock can be increased by hydraulic fracturing. By applying hydraulic pressure in the borehole, fractures within the rock are generated, connecting the pores and thus increasing hydrocarbon / gas flow. To hold the fractures constantly open after a hydraulic fracturing treatment, so called proppant is s...

AI Technical Summary

Benefits of technology

"The present invention provides a method and composition for producing granulated ceramic material, particularly ceramic proppants, with a broader sintering temperature range. This is achieved by using a magnesium metasilicate based precursor composition that contains magnesium metasilicate in the form of pyroxene, olivine, and quartz / feldspar. The precursor composition also contains MgO, SiO2, FeO, Al2O3, CaO, Na2O, TiO2, and P2O5 in specific amounts. The resulting ceramic particles have a residual olivine content not exceeding 3-5% w / w, and a glass phase content in the range of 15-20% w / w. The invention also provides a method for producing proppants with high mechanical strength and resistance to acids and heat insulating properties. The invention also includes a method for producing low-weight fillers in concrete and plastic, as well as heat insulating and soundproof filling materials."

Problems solved by technology

Such proppants, however, are quickly destroyed under the harsh conditions in the fractures.

High viscosity fluids, however, are known to have negative effects on the permeability of certain types of geological formations, i.e. coals.

Highly viscous fluids are based on guar gel, which is rather expensive.

In addition, less viscous fluids allow the use of pumps with less performance, which also saves costs.

This results in porous glass balls with rough surfaces.

The disclosed proppants show low strength and considerable dust formation when used, due to the remaining fire retardant powder.

This results in very low permeability and insignificant increase of oil recovery after hydraulic fracturing.

), the manufacture of such proppants is complicated and expensive.

This results in magnesium metasilicate crystal growth and phase transformation during the cooling process, which also reduces the quality of the produced proppant.