Temporary plugging agent for temporary plugging diversion for overcoming high stress difference in shale gas fracturing, and preparation method thereof

Abstract

The invention discloses a temporary plugging agent for temporary plugging diversion for overcoming a high stress difference in shale gas fracturing. The temporary plugging agent is prepared through reacting vegetable gum, sodium polyacrylate, ammonium polyphosphate, sodium rosinate and polyethylene glycol. A preparation method of the temporary plugging agent comprises the following steps: adding acertain amount of distilled water into a reaction container, adding the vegetable gum, sodium polyacrylate, ammonium polyphosphate, sodium rosinate and polyethylene glycol, stirring all above substances and the distilled water, heating the obtained reaction solution to 80 DEG C, continuing constant temperature stirring for 2 h until all the substances are completely dissolved, then cooling the obtained solution to 50 DEG C, discharging the cooled solution, and performing vacuum drying to obtain a head product. The temporary plugging agent is obtained by compounding natural polymer compounds,has a good degradation performance, has a degradation rate reaching up to 100%, has strong temperature resistance, can resist to a temperature reaching up to 180 DEG C, and has a high compressive strength reaching up to 80 MPa; and a degradation solution formed by degrading the temporary plugging agent has no damages or pollution, so the temporary plugging agent is safe, and is environment to theenvironment.

Description

Technical field [0001] The invention belongs to the technical field of oilfield production increase, and in particular relates to a temporary plugging agent for shale gas fracturing to overcome high stress difference temporary plugging and steering and a preparation method thereof. Background technique [0002] Shale gas is an unconventional natural gas resource, with huge reserves of technologically exploitable worldwide. In recent years, with breakthroughs in production technology, the United States has realized the commercial exploitation of shale gas, which has broad prospects for the large-scale utilization of shale gas. [0003] In the process of shale gas fracturing, in order to overcome the high stress difference and change the flow direction of the original liquid to achieve the purpose of generating new fractures, a high-strength temporary plugging agent has been developed for the temporary plugging of shale gas wells. The dissolution performance of the agent is tested i...

AI Technical Summary

Problems solved by technology

[0007] Another purpose of the present invention is to solve the defects of the existing temporary plugging agent: the temporary plugging agent composed of inorganic salts will cause permanent blockage of the formation, which is not conducive to the later oil and gas exploitation, and the cross-linked polymer temporary plugging agent needs to be added to break the gel The gel can be broken only by using a special agent, which increases the construction period and increases the cost. At the same time, there are technical problems such as poor solubility of cross-linked polymers. We provide a temporary plugging agent for shale gas fracturing to overcome high stress difference temporary plugging and diversion.

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