Emergency treatment method for shale gas fracturing flow-back fluid

Abstract

The invention provides a shale gas fracturing flow-back fluid emergency treatment method, which can carry out reduction emergency treatment when a flow-back fluid amount exceeds a storage capacity greatly or heavy rainfall occurs so as to eliminate the risk of overflowing, and comprises the following steps: detecting the mineralization degree of a flow-back fluid in a flow-back fluid storage pool;when the mineralization degree of the flow-back fluid is below 45000 mg / L, introducing the supernatant of the flow-back fluid in the flow-back fluid storage pool into a quick mixing pool, and addinga pH regulator and a coagulant into the quick mixing pool; introducing the supernatant in the quick mixing pool into a reaction pool, and adding a softener; introducing the supernatant in the reactionpool into a flocculation pool, and adding a flocculating agent; introducing the supernatant of the flocculation pool into a tubular microfiltration membrane, and carrying out solid-liquid separation;adding NaClO into the clear liquid separated by the microfiltration membrane, and carrying out oxidation treatment; and adding NaHSO3 into the effluent after oxidation treatment to reduce the contentof residual chlorine, adding HCl to adjust the pH value, introducing the effluent into a reverse osmosis system, and carrying out desalination treatment to respectively generate fresh water and strong brine, wherein the fresh water can meet the discharge requirement.

Description

technical field [0001] The invention relates to the technical field of waste treatment, in particular to an emergency treatment method for shale gas fracturing flowback fluid. Background technique [0002] Shale gas fracturing flowback fluid refers to the fluid returned to the surface after the hydraulic fracturing of shale reservoirs. The flowback fluid has the characteristics of high chemical oxygen content, high suspended solids content, high salinity, complex composition, and difficult biochemical degradation. If it leaks or overflows to the surface, it will cause serious pollution to soil, surface water, and groundwater. Proper disposal of fracturing flowback fluid has become one of the key issues in the sustainable development of shale gas. [0003] At present, the disposal of shale gas fracturing flowback fluid is mainly based on "reusing a large amount and reinjecting a small amount". Before reuse, simple filtration and supplementary additives are performed to reduc...

AI Technical Summary

Problems solved by technology

Due to the large amount of liquid in the early stage of flowback, the flowback liquid may exceed the capacity of the storage tank and overflow, especially high-intensity rainfall may also cause the flowback liquid to overflow from the storage tank, polluting the soil, surface water and groundwater environment

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