Self-suspended propping agent and preparation method thereof

Abstract

The invention belongs to the field of fluid mineral product exploration such as petroleum, natural gas and shale gas, and provides a self-suspended propping agent which is prepared by wrapping or partially wrapping a granular framework with a water-soluble high polymer material; the framework consists of solid granules which are sufficient in mechanical strength for bearing crack closing stress and are selected from one or multiple of quartz sand, ceramsite, metal granules, spherical glass granules, sintered monohydrallite, sintered alumina, sintered zirconium oxide, synthetic resin, precoated sand and crushed fruit shell granules; the amount of the water-soluble high polymer material accounts for 0.1-5wt% of that of the framework. The self-suspended propping agent provided by the invention does not need to be fractured by using fracturing fluid which is added with organic macromolecules and is high in cost, and can be fractured by using natural water which can be obtained at any place directly, so that pollution is reduced, and the cost can be lowered. By adopting the self-suspended propping agent provided by the invention, friction resistance of the fracturing fluid can be reduced, and a fracturing support system adopting the self-suspended propping agent has properties which are generally identical to those of conventional fracturing fluid, and is easy to convey and discharge backwards.

Description

technical field [0001] The invention belongs to the field of fluid mineral exploitation such as oil, natural gas and shale gas, and in particular relates to a proppant for strengthening cracks through propping and a preparation method thereof. Background technique [0002] Oilfield crude oil has high viscosity and the fractures of oil reservoirs are narrow. In order to increase oil recovery and reduce costs, fracturing proppant fracturing and propping fracturing are usually used to improve fracture conductivity. Proppants are deposited in formed fractures in the formation, preventing the fractures from closing when the pressure decreases. According to literature, three liquid systems are mainly used in shale gas fracturing in the United States: direct liquid nitrogen injection, nitrogen foam injection, and drag-reducing water. In addition to the cost advantage, drag reducing water can pump a large amount of water and a small amount of proppant under high displacement, and c...

AI Technical Summary

Problems solved by technology

On the other hand, the polymer compound used in the drag reduction water enters the formation along with the clear water, and the viscosity of the drag reduction water increases, which consumes a lot of pump power during flowback, which is not conducive to all flowback; Molecular compounds plug the pores of the formation, resulting in reduced oil production

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