Deep blockage removal process of biological enzyme composite acid

Abstract

The invention relates to the technical field of oil field blockage removal, in particular to a deep blockage removal process of biological enzyme composite acid. The deep blockage removal process of the biological enzyme composite acid comprises the following steps that (1) a biological enzyme blockage removal agent is injected into an oil well; (2) the composite acid is injected into the oil well; (3) displacement fluid is injected into the oil well; and (4) shut-in reaction is carried out. According to the deep blockage removal process of the biological enzyme composite acid, the formula andthe dosage of the composite acid are adjusted according to the actual situation on site, polymer macromolecules wrapped outside inorganic impurities are effectively degraded, the inorganic impuritieswrapped in the polymer macromolecules are fully exposed, fully erosion of the inorganic impurities by the subsequent acidification process is facilitated, so that the formation blockage of oil and water wells is removed in limiting and complete modes, the formation permeability is restored, and oil fields can recover the production capacity normally.

Description

technical field

[0001] The invention relates to the technical field of plugging removal in oil fields, in particular to a deep plugging removal technology of biological enzyme compound acid. Background technique

[0002] In low permeability oilfields, the reservoir development is poor, the reservoir pore radius is small, the clay content and shale content are high, and the median particle size is small. A slight clogging of this type of oil layer during the development process can result in a significant reduction in the production of the oil well, and an increase in the injection pressure of the water injection well, making injection difficult. At the same time, due to the characteristics of small pores, enhanced pore-throat effect, and high specific surface area of ​​low-permeability oilfield reservoirs, it directly has a significant impact on fluid flow, and the lower the permeability, the stronger the impact. As the injected water continues to advance, the seepage resis...