Water injection well multi-slug profile control method

Abstract

The invention provides a water injection well multi-slug profile control method. A multi-slug injection method is adopted, wherein a first slug adopts an organic jelly glue aqueous solution system including volume expansion grains; and a last slug comprises two stages, the first stage adopts an organic jelly glue aqueous solution system including volume expansion grains, and a profile control agent adopted by the second stage is a microsphere deep profile control modifying and flooding agent. In the water injection well multi-slug profile control method, a jelly glue type profile control agent selected and used by the first slug can form a powerful 'baffle' at the well bottom water injection front end, and the phenomena that a medicament is subsequently injected, and oily sludge directly dashes into an extraction oil well are avoided. In the last slug, the sizes of micro hole passageways are reduced through expansion performance of polymeric microspheres, depressurization and augmented injection are conducted through adsorbability of the polymeric microspheres, and well group oil production is increased through displacement performance of the polymeric microspheres. In the injection method adopting the three slugs, while consuming the oily sludge in a massive dose mode, the second slug enters large hole passageways and cracks to block a high-permeability layer band.

Description

technical field [0001] The invention relates to the technical field of profile control of water injection wells in oil fields, in particular to a multi-slug profile control method for water injection wells. Background technique [0002] Oily sludge profile control is a chemical treatment method that effectively utilizes the mud components and oil components in the oily sludge to block the pores formed by water injection in the water injection layer. According to the physical properties of the oily sludge itself, adding an appropriate amount of suspending agent can not only suspend the solid particles in it, prolong the suspension time, increase the injection depth, but also effectively improve the plugging strength. Adding an appropriate amount of additives can disperse the oil components evenly and form a uniform and stable emulsion. When the emulsion reaches a certain depth in the formation, the emulsified suspension system is decomposed by the formation water and the ads...

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Problems solved by technology

[0004] In view of the above-mentioned defects and problems of the prior art, the purpose of the present invention is to provide a multi-slug profile control method for water injection wells, which solves the problem of loose structure in the performance of the existing single oily sludge profile control system, the control effect on large pores and the The control area is limited, and the injected water is easier to detour and re-form technical problems such as breakthroughs

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