Low-density propping agent taking flint clay as raw material and preparation method thereof

Abstract

The invention discloses a low-density propping agent taking flint clay as a raw material and a preparation method thereof. The propping agent is prepared by simply compounding raw flint clay, underburnt flint clay and easily ground sandstone, adding a small amount of aids, performing wet-process ball-milling, ageing, drying, granulating, performing stoving and sintering, and polishing. A mode that materials and dry hot air are fed from the bottom is adopted during drying, and a drying process of an internal grinding device is added, so that spray-drying and pulverizing machines are removed, the investment is saved, and the working environment is purified; the raw flint clay and the processed flint clay are compounded and can bring the respective advantages into full play; the raw flint clay is easily subjected to ball milling, and the burning loss components of the raw flint clay form pores to reduce the density of the propping agent; mullite formed in underburnt flint clay tailings is utilized to disperse a glass phase and achieve an enhancement effect; SiO2 is introduced by the sandstone to react with aluminum oxide in the raw flint clay to produce the glass phase, which is favorable for improving the bonding capability of a mullite phase and sealing the pores formed by the burning loss of the flint clay.

Description

technical field [0001] The invention relates to a low-density proppant for oil, natural gas and shale gas development and a preparation method thereof, belonging to the technical field of new materials. Background technique [0002] Proppant is the core material for hydraulic fracturing to extract oil and natural gas. It is injected into the underground rock formation of the oil and gas well together with the pressure fluid at high pressure. When the rock formation is fractured under high pressure, the proppant is filled in the cracks of the rock formation, so that the oil and gas channels formed by the fracturing remain unobstructed after the fracturing process is terminated. To obtain high conductivity and maintain continuous high and stable production of oil and gas wells and prolong the production life of oil and gas wells. The fracture resistance or strength of the proppant is one of its important performance indicators. Additionally, the density of the proppant is ve...

AI Technical Summary

Problems solved by technology

But there are also some disadvantages, that is, after wet ball milling, the mud needs to be further spray-dried. In the traditional spray-drying method, the upper part is fed with hot air for drying, and the middle part is fed with mud, or the upper part is fed with hot air and mud at the same time. The powder particles formed at this time Large particle size and many hollow particles are not conducive to the particle size required for the proppant to be rolled into balls. Therefore, after spray drying, it still needs to go through the high-speed pulverizer powder process

This not only increases equipment and plant investment, but also increases energy consumption, and increases dust pollution to the workshop

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