Reversible gel temporary plugging agent for water injection well and temporary plugging workover process

Abstract

The embodiment of the invention discloses a reversible gel temporary plugging agent for a water injection well and a temporary plugging workover process, and belongs to the technical field of oil exploitation. The reversible gel temporary plugging agent is obtained by compounding following a plurality of raw materials: starch, acrylic acid, acrylamide, chromium acetate, ammonium bisulfite, ammonium persulfate, sodium hydroxide, formaldehyde, graphene particles, walnut shell particles and the like, has the characteristics of controllable gelling time and gel breaking time, absorbability and slow release property, and completely meets the requirements of a water injection well temporary plugging process for string inspection operation. When applied, the reversible gel temporary plugging agent is high in temporary plugging speed, safe and stable, the effect of well opening operation is achieved, the reversible gel temporary plugging agent suitable for different operation requirements is screened by detecting the gelatinizing time of the prepared reversible gel temporary plugging agent, the degradation time of colloid and the compressive strength of the colloid, and the adaptability ofreversible gel is greatly improved.

Description

technical field [0001] The embodiment of the present invention relates to the technical field of petroleum exploitation, in particular to a reversible gel temporary plugging agent for water injection wells and a temporary plugging and workover process. Background technique [0002] Lost circulation refers to the phenomenon that when there are cracks or caves in the rock and the pressure of the leaky zone is lower than the pressure of the drilling fluid column, the drilling fluid enters the leaky zone under the action of positive pressure difference to cause leakage. After the lost circulation occurs, the drilling fluid keeps leaking into the fractures or caves, and the circulation cannot be completed, and the phenomenon of "only entering and exiting" occurs. In serious cases, the wellhead may not return the working fluid at all, making the drilling operation unable to continue. [0003] Temporary plugging agent is a substance that can temporarily reduce formation permeabilit...

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Problems solved by technology

[0004] However, the gel temporary plugging agents used in the prior art often have low strength, and the plugging materials are diluted or dispersed under the high pressure of the killing fluid, so they cannot play the role of plugging in the leaking zone, which is difficult for serial inspection operations. bring uncertainty

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