Method for removing and preventing wax of mechanical recovery well by microorganism

Abstract

The invention discloses a method for removing and preventing wax of a mechanical recovery well by a microorganism wax removal and prevention composite bactericide. In the method, the microorganism composite bactericide is injected into a well bottom, and the concentration of the composite bactericide in well bottom liquid is not lower than 100mg / L, and is up to 50,000 mg / L; and an agent adding cycle is 10 to 28 days to ensure that the wax content of crude oil is reduced until the standard is met. Through a wax removal and prevention experiment of eight wells on which wax can be precipitated easily, compared with a method for removing and preventing wax by using a chemical wax removal and prevention agent, the method has the advantages that: the using amount of the microorganism wax removal and prevention agent is recued by more than 40 percent, the cost is saved by 20 to 50 percent, the agent adding cycle is more than two times the conventional agent adding cycle, and the economic benefit is obvious; moreover, during experiment, current of the mechanical recovery well changes slightly, and the current is in a stable state basically, and the effect is better or equal to that of the chemical wax removal and prevention agent. Therefore, the method has the advantages of low environmental pollution, low cost, long action period, high economic benefit and wide application range, plays an important role in the wax removal and prevention of the field of oil exploitation, and has wide application prospect.

Description

technical field [0001] The invention belongs to a method for removing and preventing wax in the field of petroleum exploitation, in particular to a method for removing and preventing wax in mechanical recovery wells by using a microbial compound bacterial agent. Background technique [0002] Wax removal is an important topic in oil well production management (Li Hongying, Zhang Jinjun. The influence of wax on the rheology of crude oil, Oil and Gas Storage and Transportation, 2002, 21(11): 6-12). Due to the differences in the physical properties of crude oil and the production conditions of oil wells, the wax deposition conditions of oil wells are different, and the wax removal and prevention process should also be adjusted at any time. At present, methods such as dosing of chemicals (chemical wax remover and anti-paraffin), installation of downhole solid slow-release agent, heat washing for wax removal, resin coating for wax removal, and paraffin eliminator are mainly used t...

AI Technical Summary

Problems solved by technology

At present, oil production sites mainly use methods such as adding medicine (chemical wax remover), installing downhole solid slow-release agent, thermal washing to remove wax, resin coating to prevent wax, and anti-paraffin eliminator to remove and prevent wax. There are problems such as large amount of wax, high frequency of dosing, short action time, and environmental pollution. With the increase of new wells put into production, the consumption of chemical wax-removing and anti-wax agents will increase. Air enters and returns from the oil pipe through the oil well pump, which not only affects the production, but also causes different degrees of pollution to the oil layer

[0003] The existing microbial paraffin removal technology is tested in mechanical production wells, but a single bacterial agent is usually used. The problem is that there are many kinds of bacteria surviving in the reservoir, which is affected by the reservoir environment, especially the temperature. , dissolved oxygen, oxidation-reduction potential and nutrients, lead to large differences in the metabolic activity and quantity of various microorganisms, especially in local areas of different oil layers, it is difficult for a single bacterial agent to form a competitive advantage, and its application effect is bound to be greatly reduced

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