Neutral hard scale softening agent for three-component compound flooding screw pump well

Abstract

The invention belongs to the technical field of oil field chemistry and in particular relates to a neutral hard scale softening agent for a three-component compound flooding screw pump well, aiming at solving the problem that the screw pump well is excessively corroded by a scale cleaning agent so that the screw pump well cannot be washed with acid after scale is formed. The neutral hard scale softening agent is prepared from organic phosphate, organic phosphonate, a dispersant, alkali and water and the content of the components is as follows in percentage by weight: 10 percent to 40 percent of the organic phosphate, 2 percent to 10 percent of the organic phosphonate, 1 percent to 5 percent of the dispersant, 1 percent to 3 percent of the alkali and 50 percent to 80 percent of the water. The neutral hard scale softening agent provided by the invention can be used for scale removal and releasing of the three-component compound flooding screw pump well; the scale of parts including a screw pump rotor and the like is completely softened and fallen off and completely cleaned; the neutral hard scale softening agent has the advantages that the corrosion is low, any injury on a chromium-plated coating of the screw pump rotor is not caused, the coating of the rotor does not fall off, a condition that working is not carried out due to pump leakage is avoided and the production time efficiency of the screw pump well can be effectively ensured and the like.

Description

technical field [0001] The invention belongs to the technical field of oilfield chemistry, in particular to a neutral hard scale softener used in three-element compound flooding screw pump wells. Background technique [0002] In the process of oilfield water injection development, the generation of inorganic scale is a common problem encountered in production. Due to the existence of reservoir heterogeneity, the composition of rock minerals in different underground layers and the properties of fluid in the reservoir are different. When the oil well When underground fluids produced from several different formations are mixed in the wellbore or when the temperature and pressure of various fluids and the concentration of scale-forming ions in the fluid change greatly, it is easy to generate inorganic scale, and these scales will adhere to the Pump barrels, rotors, sucker rods and other parts of screw pump wells cause frequent leakage, rod breakage, and reduced pump efficiency i...

AI Technical Summary

Problems solved by technology

[0002] In the process of oilfield water injection development, the generation of inorganic scale is a common problem encountered in production. Due to the existence of reservoir heterogeneity, the composition of rock minerals in different underground layers and the properties of fluid in the reservoir are different. When the oil well When underground fluids produced from several different formations are mixed in the wellbore or when the temperature and pressure of various fluids and the concentration of scale-forming ions in the fluid change greatly, it is easy to generate inorganic scale, and these scales will adhere to the Pump barrels, rotors, sucker rods and other parts of screw pump wells cause frequent leakage, rod breakage, and reduced pump efficiency in screw pump wells, which seriously affect the production time rate and increase production costs.

[0003] At present, pickling measures are taken to remove scale in ASP flooding oil wells, which has a good scale removal effect on oil wells, but the hydrogen ions in these pickling agents will react quickly with the chrome-plated coating of the screw pump rotor. The chrome-plated coating on the rotor of the screw pump will fall off, and the gap between the stator and the rotor will increase, resulting in a decrease in pump efficiency after pickling and descaling, seriously affecting the recovery efficiency, and even causing the pump to be stuck.

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