Preparation method for self-suspension propping agent in laboratory

Abstract

The invention belongs to the technical field of yield increasing and fracturing of petroleum engineering and provides a method for preparing a self-suspension propping agent in a laboratory. The method comprises the following steps: taking quartz sand/ceramsite/propping agent as aggregates; pre-treating with an organic solvent and treating the surface with a coupling reagent; polymerizing and coating; and crushing, drying, pelletizing and then packaging. A coating polymerizing product (as shown in the figure) is acquired through the polybasic polymerization of the reactant and acrylamide/sodium acrylate/functional monomer/cross-linking agent. The expansion times of the prepared self-suspension propping agent is 3-12 times; the self-suspension propping agent can be completely hydrated within 1min-2min; the hydrated layer is stably expanded at 2 DEG C to 193 DEG C; the self-suspension propping agent swells once encountering with water, the volume density is reduced from 2.4g/cm3 to 1.3g/cm3 and the excellent self-suspension characteristic after the clean water system swelling is presented. The self-suspension propping agent prepared in the laboratory can realize the onsite mixing for hydraulic fracturing construction, the water for fracturing is greatly reduced, the labor cost is lowered and the application prospect is wide.

Description

technical field [0001] The invention relates to the application field of oil, natural gas, shale oil and gas and other unconventional fracturing stimulation technologies, in particular to a laboratory preparation method of a self-suspending proppant. Background technique [0002] In recent years, unconventional oil and gas such as tight oil and tight gas have become development hotspots. Unconventional oil and gas have low porosity (porosity less than 7%), low permeability (permeability less than 1×10 -3 μm 2 ), pore throat diameter less than 1 μm, micro-fracture development, local ultra-low water saturation, high capillary pressure, abnormally high formation pressure, high damage potential and other engineering geological characteristics. For the development of such reservoirs, new technologies are needed to improve reservoir permeability, and hydraulic fracturing is one of the most durable and critical stimulation techniques. [0003] According to statistics, global oil...

AI Technical Summary

Problems solved by technology

At present, the conventional fracturing process includes the pre-stage, sand-carrying stage, and displacement stage. According to the geological characteristics, from plastic formation to brittle formation, cross-linked guar gum fracturing fluid, cross-linked foam fracturing fluid, linear glue, and mixed fracturing fluid are used respectively. Fracture fluid and slick water, but these fracturing fluids have the disadvantages of incomplete gel breaking and high residue content. The fracturing fluid needs to use thickeners or strengthening agents, which will cause different degrees of residue damage, adsorption damage, and even blockage of the support. agent filled layer, which is not conducive to fracturing stimulation

Water-based fracturing fluids are also likely to cause problems such as clay swelling and flowback difficulties, resulting in poor recovery after fracturing of oil and gas production layers, or even normal production

At the same time, hydraulic fracturing consumes a huge amount of water resources, which has potential pollution to water resources and the environment

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