Microbe tracing method for oil deposit well

Abstract

The microbe tracing method for oil deposit well includes the following steps: water quality analysis and autochthonous microbe analysis of the formation water; screening from available aerobic or facultative anaerobic microbe as tracing microbe, which has at least one of the three parameters of thallus form, colony form and growth temperature different from that of the autochthonous microbe of the aerobic or facultative anaerobic in the formation water and can maintain its life in the form of spore or other hypnozoite in the deposit environment; depositing the screened microbe into the deposit; sampling from corresponding oil producing well for detection; and performing analysis on deposit characteristic and deposited water flow characteristic based on the detection result. The said method is scientific and economic and has low cost, wide detection range, high sensitivity and no harm to human and environment.

Description

technical field [0001] The invention relates to an oilfield exploitation method, in particular to a tracer method in the oilfield exploitation method. Background technique [0002] Oilfield exploitation generally firstly goes through the stage of primary oil recovery in which the energy of the reservoir itself is used for self-spraying production. As time goes by, the formation energy is continuously consumed, and eventually self-spraying production cannot be performed. At this time, water injection into the reservoir is generally used to maintain the formation energy. This enters the stage of secondary oil recovery. After primary and secondary oil recovery, only about 30% of the original crude oil reserves of the oil reservoir can be recovered, and a large amount of crude oil remains in the oil reservoir. Reservoir heterogeneity is one reason for this. Due to the heterogeneity of the reservoir, the injected water will first channel in the oil layer with high permeability,...

AI Technical Summary

Problems solved by technology

[0005] The above-mentioned tracers have been used in some oil fields, but some disadvantages have been found in the process of use: for example, radioisotope tracers need to be placed and tested by special departments; dye tracers have a large amount of adsorption on the formation surface, and the analysis of interference factors Many, unstable, and will fail when they stay in the formation for more than 5 days; low-molecular alcohol tracers have poor biological stability and must be used together with fungicides; anionic inorganic salt tracers are used in large amounts (5%-10%), It will pollute the formation water or cause the mineralization of the formation water, among which the price of iodide ion is high (NaI is about 120,000 yuan per ton), etc.

In addition, some tracers also have hazards to human body, high economic cost, complex detection techniques, expensive detection equipment, pollution to the environment, etc., which further limit their application.