Blocking remover for reservoir of oil well

Abstract

The invention discloses a blocking remover for a reservoir of an oil well. The blocking remover is applied to the technical field of oil extraction in an oil field, comprises an agent A and an agent B, and is characterized in that the weight percentage of the agent A is 25-35%; the weight percentage of the agent B is 65-75%; the agent A comprises the following components by weight: 45-50% of petroleum mixed xylene, 1-2% of nonyl phenol polyoxyethylene (4) ether, and the balance of 0# diesel oil; the agent B comprises the following components by weight: 6-10% of glacial acetic acid or sulfamic acid, 2-2.5% of ammonium bifluoride, 2% of ammonium chloride, 1-2% of citric acid, 1.5-2% of corrosion inhibitor 7801, 3-5% of tertiary butanol, 0.5-1% of octyl phenol polyoxyethylene (10) ether and the balance of water. The blocking remover has the following effects that: the agent A and the agent B are respectively prepared so as to be beneficial to storing the blocking remover for a long time, the agent A of the blocking remover has strong dissolving capacity on crude oil heavy components, such as wax colloid asphalt, and the washing oil efficiency on oil sand is more than 90%. The dissolving rate of the agent B of the blocking remover on carbonate is more than 80%, and the corrosion speed on N80 steel is low and is smaller than 2 g / m<2>.h.

Description

technical field [0001] The invention relates to the technical field of oil recovery in oil fields, in particular to a plug-removing agent for decontaminating oil well reservoirs. Background technique [0002] At present, during the production of oil wells, reservoir pollution exists in various links such as drilling, workover, well washing and measures. During the production process of oil wells in low-permeability sandstone reservoirs, due to the poor compatibility of foreign fluids and reservoirs during operations, well washing and other processes, and Influenced by factors such as the intrusion of solid phase particles, oil well reservoirs are polluted by clay swelling, salt scale, iron corrosion products, emulsification, etc.; due to the degassing of crude oil near the wellbore, the oil phase permeability decreases, resulting in wax and colloidal asphalt in crude oil Such heavy components stay in the formation around the well, causing reservoir pollution. Its production...

AI Technical Summary

Problems solved by technology

Although surfactants have a certain ability to wash oil, their ability to dissolve wax, colloidal asphalt and other crude oil heavy component deposits is limited, and the effect on removing organic fouling is relatively poor

[0003] Although various oilfields have researched and developed a variety of plugging removal technologies based on the characteristics of oilfield reservoirs, due to the variety of factors and complex reasons that cause oil well reservoir pollution, the commonly used acidizing plugging removal and plugging removal agents with single performance are not effective