Method for synthesizing aluminum citrate cross-linking agent in low carbon solvent

Abstract

The invention relates to a method for synthesizing an aluminum citrate cross-linking agent in a low carbon solvent. (1) the weight part proportions of chemical raw materials are as follows: 100-140 parts of methanol, 40-60 parts of ethanol, 40-100 parts of citric acid, 30-60 parts of aluminium chloride hexahydrate, 10-20 parts of sodium hydroxide and 20-30 parts of water. (2) the method comprises the following chemical reaction process steps of: firstly mixing methanol and ethanol according to the proportion under a normal pressure; adding citric acid to the above mixture to make citric acid dissolved completely; adding aluminium chloride hexahydrate under stirring; heating to a temperature of 40-80 DEG C; reacting for 4 hours; dropwise adding a sodium hydroxide solution slowly to adjust a pH value to 5.5-8.5; finally, adding a residual component of water, stirring uniformly, and thus the aluminum citrate cross-linking agent is obtained. The aluminum citrate cross-linking agent synthesized by the method has stable gel-forming properties and controllable gel-forming time, and has no sulfate ions and nitrate ions. The synthetic process is gent and easy to operate, has no generation of industrial waste materials, and is economic and environment-friendly.

Description

technical field [0001] The invention relates to a method for synthesizing aluminum citrate in a low-carbon solvent. technical background [0002] With the end of the era of primary and secondary oil recovery, the plugging performance of oilfield formations continues to decline, resulting in lower and lower oil production rates. It is difficult to achieve high recovery rates with pure water flooding and polymer flooding. Therefore, in tertiary oil recovery, an additive is added to cross-link the polymer to increase the residual resistance coefficient. The most widely used polymer is partially hydrolyzed polyacrylamide (HPAM), and the main additive is aluminum citrate, which is more environmentally friendly than the earliest chromium acetate and chromium citrate. Searched on the Internet of the State Intellectual Property Office: On July 24, 2002, the patent of "Preparation Method of Aluminum Citrate Crosslinking Agent with High Aluminum Content" was announced, the patent num...

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Problems solved by technology

[0002] With the end of the era of primary and secondary oil recovery, the plugging performance of oilfield formations continues to decline, resulting in lower and lower oil production rates. Pure water flooding and polymer flooding have been difficult to achieve high recovery.

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