Oil field scale inhibitor, and preparation method and use method thereof

Abstract

The invention discloses an oil field scale inhibitor including a first scale inhibitor, a second scale inhibitor and a third scale inhibitor, wherein the first scale inhibitor includes: 8-10 parts ofsodium ethylenediamine tetramethylene phosphonate, 5-8 parts of aminotrimethylenephosphonic acid, 3-5 parts of hydroxyethylidene diphosphonic acid, and 5-8 parts of 2-phosphonobutane-1,2,4-tricarboxylic acid; the second scale inhibitor includes: 15-20 parts of maleic anhydride, 5-10 parts of acrylic acid, 5-8 parts of hydroxypropyl acrylate, and 0.5-1 part of ammonium persulfate; the third scale inhibitor includes: 10-12 parts of polyepoxysuccinic acid, 8-10 parts of polyaspartic acid, 5-8 parts of modified imidazolines, 0.5-1 part of modified quaternary ammonium salts, and 0.05-0.1 parts of sodium polyacrylate. The oil field scale inhibitor has stable properties; when being injected into an oil well, the scale inhibitor is slowly released, thus effectively relieving scaling on the wall cylinder and prolonging pump inspection period. The invention also provides a preparation method and a use method of the oil field scale inhibitor.

Description

technical field [0001] The invention relates to the technical field of oil recovery and development in oilfields, in particular to an oilfield scale inhibitor, a preparation method and a use method thereof. Background technique [0002] In the process of oilfield development, produced water and injected water contain Ca in varying degrees. 2+ , Mg 2+ , Ba2+, Sr2+, CO32-, SO42- and other scaling ions, with the change of external environment (temperature, pressure, etc.), lead to formation, wellbore and surface pipeline scaling. Commonly seen in oil fields are CaCO3 scale, CaSO4 scale, SrSO4 scale, BaSO4 scale, etc. Corrosion products, such as FeCO3, FeS, Fe(OH)2, Fe2O3, which have high solubility and high content, are easy to precipitate under certain conditions. Substances such as sodium chloride are included. Scaling mostly occurs within 400m above the oil well pump, and the parts prone to scaling are mainly concentrated on the inner wall of the tubing, the outer wall of...

AI Technical Summary

Problems solved by technology

[0004] However, the current scale inhibitors have problems of unstable properties and short action time. In actual use, scale inhibitors need to be injected into oil wells every day, which greatly increases labor costs.

Therefore, it is necessary to develop a scale inhibitor with stable properties and long acting time to solve the problem of damage to oil production equipment caused by wellbore scaling, so as to ensure the stable and normal production of oilfields