Nutrient for inhibiting sulfate reducing bacteria in oilfield water and application of nutrient

Abstract

The invention relates to a nutrient for inhibiting sulfate reducing bacteria in oilfield water and application of the nutrient. The nutrient contains the following components by weight percent: 20-95 percent of cane molasses or beet molasses, and / or 1-45 percent of ammonium phosphate, and / or 0.5-10 percent of ammonium chloride, and / or 0.5-2.5 percent of ammonium sulfate, and / or 1-18.5 percent of ammonium nitrate, and / or 0.05-49 percent of sodium nitrate; and / or 0.05-1 percent of diammonium hydrogen phosphate, and / or 0.05-1.2 percent of disodium hydrogen phosphate, and / or 0.5-2 percent of dipotassium phosphate and / or 0.05-1.5 percent of potassium dihydrogen phosphate. The nutrient with weight accounting for 0.5-5 percent of weight of filled water is taken, is dissolved by using constructional injection water or oilfield surface water and is squeezed into stratum by a pump truck through a water injection well. The nutrient can activate nitrifying bacteria flora in source bacteria flora of stratum water or oilfield source water and can inhibit the growth of sulfate reducing bacteria. After 16 hours to 52 days, the content of sulfate reducing bacteria is 0-102 / mL. The yield of crude oil is increased by 10 percent to 30 percent.

Description

technical field [0001] The invention relates to a method for inhibiting sulfate bacteria by using microorganisms, in particular to a nutrient and application thereof for inhibiting sulfate-reducing bacteria by using original microorganisms while improving oil recovery. Background technique [0002] There are a variety of native bacteria in the surface water and formation water of the secondary and tertiary oil recovery processes, among which the most harmful to the oil field surface oil recovery system is the sulfate reducing bacteria (Sulfate Reducing Basteria, abbreviated as SRB), the sulfate reducing bacteria SRB is a group The general term for a variety of bacteria that can reduce sulfate to hydrogen sulfide under anaerobic conditions, including bacteria of the genus Desultphovibrio and Desulphfotomaculum, widely present in oilfield sewage reinjection systems and oil reservoirs in an oxygen-deficient environment. The activity of SRB flora can produce toxic gas H 2 S, t...

AI Technical Summary

Problems solved by technology

[0014] CN1995694 relates to an oil displacement method in which sewage is injected into original microorganisms for enhanced crude oil recovery. The invention utilizes various microorganisms brought into oil reservoirs during long-term water injection and adapted to the reservoir environment for oil displacement, and avoids the adaptation of microorganisms and oil reservoirs. However, the defect of this invention is that during the construction of the formation, due to the use of aerobic fermentation, aerobic bacteria and anaerobic bacteria compete for survival in the formation, and since denitrifying bacteria are anaerobic bacteria, it is difficult to Medium growth, when beneficial microorganisms are consumed at concentrations below 10-10 3 per mL, it needs to be re-cultivated on the ground to a concentration of 3×10 8 Then re-inject and replenish. This method of using this microorganism to ferment on the ground and re-inject into the formation increases the cost of nutrient solution; secondly, a certain concentration of dissolved oxygen is always required during the construction process. If high-quality crude oil is used as a carbon source, the injected air will aggravate the corrosion of pipelines and equipment, which not only increases the construction cost, but also may cause combustion in high-temperature oil reservoirs; and the injection process requires that the maximum value of sulfate-reducing bacteria be less than 10 3 pcs / mL, the applicable range of water quality is narrower