Method for explaining thick oil reservoir bed by using T2 relaxation spectrum

Abstract

The present invention relates to a method capable of utilizing T2 relaxation spectrum to interpret heavy oil reservoir. It is characterized by that said invention utilizes the difference of distributed zones of heavy oil, movable water and irreducible water on the T2 relaxation spectrum to separate them so as to attain the goal of effectively and accurately judging that the heavy oil reservoir is eater-flooded or not. The invented method includes the following steps: sampling, nuclear magnetic resonance analysis and T2 relaxation spectrum analysis and interpretation.

Description

Technical field: [0001] The invention relates to a method for judging the water flooding condition of a reservoir in the drilling process of a heavy oil oil field, which belongs to the application of nuclear magnetic resonance technology in the field of petroleum industry. Background technique: [0002] In the middle and late stages of heavy oil field production, electrical logging and geochemical analysis are mainly used to interpret newly drilled wells, especially inspection wells and observation wells, and to judge whether they are flooded. However, in the process of application, the electrical measurement method is affected by factors such as rock skeleton, mineral composition, and formation water salinity, especially after water flooding, the injection of water changes the formation water salinity, forming "multi-type water" Phenomenon, the water saturation calculated by Alzie’s formula is poorly compared with the water saturation calculated before flooding, and it is i...

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Problems solved by technology

However, in the process of application, the electrical measurement method is affected by factors such as rock skeleton, mineral composition, and formation water salinity, especially after water flooding, the injection of water changes the formation water salinity, forming "multi-type water" Phenomenon, the water saturation calculated by Alzie’s formula is poorly compared with the water saturation calculated before flooding, and it is impossible to accurately judge whether the reservoir is flooded; the geochemical analysis method is mainly to detect the abundance of hydrocarbons in the reservoir. It is impossible to directly detect the existence of water, and it is only possible to judge whether the reservoir is flooded by relative analysis and exclusion method.

Therefore, neither of the existing two methods can meet the needs of accurately judging the water flooding status of heavy oil reservoirs.

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