Indigenous microbial sustained-release long-acting nutrient for oil recovery

Abstract

The invention belongs to the field of the petroleum industry, and particularly relates to a sustained-release long-acting nutrient for improving the valid period of indigenous microbial oil recovery. The invention adopts the technical principle that the conventional nutrient is prepared from water-soluble raw materials such as diammonium hydrogen phosphate, urea, ammonium nitrate, sodium nitrate, amino acid, molasses and the like. The raw materials are water-soluble, have different adsorption capacities in a stratum and different moving speeds, are easily drained and lost, and have short valid period. The nutrient is immobilized by adopting an immobilization method with hydrogel and the like and slowly released in the stratum; and organic phosphate, low molecular weight protein powder and the like are slowly hydrolyzed in the stratum to generate the nutrient required by indigenous bacteria. The using concentration of the sustained-release nutrient is 0.2 to 2.0 percent. The valid period of indigenous bacteria oil recovery is prolonged, so that the nutrient can enter the deep part of an oil deposit, and the efficiency of the indigenous microbial oil recovery is improved.

Description

technical field [0001] The invention relates to an oil recovery additive in oilfield tertiary oil recovery technology, in particular to a slow-release long-acting nutritional agent for oil recovery by original microorganisms. Background technique [0002] Microbial oil recovery technology was proposed by American scientists in 1926 and has been researched and applied for more than 80 years. It has been 60 years since the original microbial oil recovery was proposed by former Soviet scientists in the 1950s, and it has been applied in more than 20 oilfield blocks in Russia, increasing oil by more than 600,000 tons. It has been used in Chinese oil fields such as Dagang, Shengli and other oil fields for almost 10 years, and the oil increase has exceeded 100,000 tons. [0003] Chinese patent CN1231655 discloses a microbial oil recovery method that prolongs the effective period of microbial oil displacement. According to the monitoring results of the oil well production fluid, nu...

AI Technical Summary

Problems solved by technology

This method has dual effects, and its disadvantage is that the suspension is poorly injectable and difficult to construct

[0007] Therefore, most of the existing nutrient solutions are water-soluble, such as diammonium hydrogen phosphate, urea, ammonium nitrate, sodium nitrate, amino acids, molasses, etc., which have different adsorption capacities and migration speeds in the formation, are easy to lose and wear, and have a short validity period.

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