Method for co-producing oil fracturing proppant and xonotlite by using high alumina fly ash

Abstract

The invention provides a method for coproducing a petroleum fracturing proppant and xonotlite by using high-alumina fly ash. The method comprises the following steps: (1) mixing the high-alumina fly ash with a sodium hydroxide solution, then, carrying out a desiliconisation reaction, and carrying out solid-liquid separation, so as to obtain a liquid-phase desiliconised solution and solid-phase desiliconised fly ash; (2) adding lime cream into the desiliconised solution, carrying out a reaction, and then, carrying out filtering and washing, so as to obtain active calcium silicate; (3) mixing active calcium silicate with water, then, carrying out a hydrothermal synthesis reaction, and then, carrying out filtering, washing and drying, so as to obtain the xonotlite; (4) mixing the desiliconised fly ash with auxiliaries, and then, carrying out grinding, watered granulating and grading, so as to obtain raw granules; and (5) calcining the raw granules, thereby obtaining the petroleum fracturing proppant. According to the method provided by the invention, the petroleum fracturing proppant and an xonotlite heat insulating material can be simultaneously prepared, the source of raw materials is wide, the production cost is low, no secondary waste is discharged, the pile-up of the high-alumina fly ash is greatly reduced, and the environmental benefit is remarkable.

Description

technical field [0001] The invention relates to comprehensive utilization of fly ash as a resource, in particular to a method for co-producing petroleum fracturing proppant and xonotlite by using high-alumina fly ash. Background technique [0002] Fracturing proppants are round and spheric solid particles that fill and prop hydraulic fractures so that they do not reclose. In the process of hydraulic fracturing, fracturing equipment such as high-pressure pumps on the ground are used to continuously inject fracturing fluid with high viscosity beyond its absorption capacity into the oil layer through the wellbore, so that a higher pressure is formed on the oil layer. With the continuous injection of cracking fluid, the pressure continues to rise. When the pressure is higher than the formation pressure near the borehole wall and the expansion strength of the formation rock, the oil layer will be fractured to form fractures of different sizes and lengths. The role of proppant Th...

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Problems solved by technology

[0003] At present, the main proppant used in the market is artificial ceramsite proppant, whose main components are mullite and corundum, which are generally prepared by sintering bauxite with high alumina content at high temperature; the proppant prepared from such raw materials Although the strength is high, the density is high, which is not conducive to pumping, which affects its wide application in the construction process. Therefore, it has become a research hotspot in this direction to find oil fracturing proppants with moderate strength, low density, and favorable for on-site construction.

[0004] At the same time, my country's thermal power plants emit more than 400 million tons of fly ash every year, and the transportation and large-scale storage of fly ash have caused serious problems of land occupation and environmental pollution.

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