Salt recrystallization inhibitor for oil and gas well and preparation method of salt recrystallization inhibitor

Abstract

The invention discloses a salt recrystallization inhibitor for an oil and gas well. The salt recrystallization inhibitor is prepared from the following components according to the 100 percent proportion of volume sum: 60 to 80 parts of organo metallic complex, 10 to 35 parts of inorganic complex, 2 to 8 parts of corrosion inhibitor and 2 to 8 parts of antiswelling agent. A preparation method of the salt recrystallization inhibitor for the oil and gas well is characterized by comprising the following steps of firstly, taking the components according to the proportion, and sequentially placing the various taken component raw materials into a reaction kettle; secondly, reacting at the temperature of 50 to 90DEG C; thirdly, drying a product obtained by reaction and synthesis; fourthly, crushing the dried product to obtain the inhibitor. The shape of a sodium chloride crystal can be changed from a cubic shape into a branch shape or a snowflake shape, so that the adhesive power of the crystal on a solid surface is reduced, and further the dissolubility of sodium chloride in water is increased; in addition, the salt recrystallization inhibitor is free of influence from calcium and magnesium ions, and salt block or holddown can be effectively prevented.

Description

technical field [0001] The invention relates to the field of oil and gas well exploitation, in particular to a salt recrystallization inhibitor for oil and gas wells and a preparation method thereof. Background technique [0002] When oil drilling encounters salt-gypsum layers, the dissolution of salt rock and gypsum can lead to the expansion of wellbore dissolution, resulting in poor rock-carrying problems such as drilling fluid; and the dissolution of salt and gypsum as cement in water causes the loss of rock around the well wall. The cemented support caused serious collapse; and the Na formed by the dissolution of the salt paste + , Ca 2+ and SO 4 2- Plasma pollutes the drilling fluid, which makes it difficult to control the rheology of the drilling fluid; at the same time, the dissolution of the salt paste and the temperature drop of the drilling fluid when the drilling fluid returns lead to the saturation of the brine, and the recrystallization of the salt causes the...

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Problems solved by technology

[0002] When oil drilling encounters salt-gypsum layers, the dissolution of salt rock and gypsum can lead to the expansion of wellbore dissolution, resulting in poor rock-carrying problems such as drilling fluid; and the dissolution of salt and gypsum as cement in water causes the loss of rock around the well wall. The cemented support caused serious collapse; and the Na formed by the dissolution of the salt paste + , Ca 2+ and SO 4 2- Plasma pollutes the drilling fluid, which makes it difficult to control the rheology of the drilling fluid; at the same time, the dissolution of the salt paste and the temperature drop of the drilling fluid when the drilling fluid returns lead to the saturation of the brine, and the recrystallization of the salt causes the diameter of the well to shrink, causing problems such as pipe sticking and other problems. Bring huge economic losses and seriously hinder the progress of oilfield exploration and development

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