Radioisotope logging tracer underground screening method

Abstract

The invention discloses a radioisotope logging tracer underground screening method. The method comprises the following steps that a mixed tracer is added into an isotope bin of a screening device; the valve is opened, and the isotope tracer agent is soaked in the injected water; the valve is closed, and the injected water in the isotope bin is in a static state; in the static state, the tracers in the isotope bin are layered, the tracers with the same specific gravity as the injected water are suspended, and the isotope logging tracers with the specific gravity closest to the specific gravity of the injected water of the to-be-logged section can be screened out; the tracer most matched with the specific gravity of the injected water can be screened out, the problem that isotope logging data are unqualified due to the fact that the specific gravity of the tracer is not matched is solved, and the method is particularly significant to water injection and fine logging of different logging blocks and different mineralization degrees of an oil field. The breakage rate and the isotope desorption rate of the tracer agent are detected by replacing an expensive and huge ultrahigh pressure generating device during ground detection with the high pressure and the real temperature environment of underground injected water, and the problems of radioactive contamination and data distortion are solved.

Description

technical field [0001] The invention relates to the technical field of oil field logging tools, in particular to a method for downhole screening of radioactive isotope logging tracers. Background technique [0002] Water injection is the basis for stable production of oilfields and an important means to improve the effect of water injection development and the sustained and stable production of oilfields. It is precisely because of this that injection profile logging is the core content of water injection production and water flooding. The logging data is used to monitor single well injection performance. , reveal interlayer and intralayer contradictions, and provide scientific basis for adjusting injection profiles (such as layered injection profile control, water plugging profile control, acidizing, fracturing); provide well logging data for adjustment of well group and regional injection-production relationship; through The study of injection profile logging and the analy...

AI Technical Summary

Problems solved by technology

The optimal situation for isotope injection profile logging is that the specific gravity of the isotope is the same as that of the injected water, and the tracer is suspended in the water. Otherwise, the tracer will float and sink, which will cause the distortion of the logging data. Well data is unqualified

However, the water injection methods of each reservoir in the oilfield are different, the water quality varies greatly, and the salinity of groundwater in different regions is also very different, and even the proportion of water in the same well will change with the depth and temperature, so the existing isotope The method used by well logging tracer manufacturers to sort the specific gravity of tracers on the ground is difficult to take into account the differences in the specific gravity of injected water in different logging blocks and different well depths, and it is difficult to meet the current logging needs of layered water injection and fine water displacement in most oil fields

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