Sapphire optical fiber probe sensor used for measuring gas holdup under oil well

Abstract

The invention relates to a sapphire optical fiber probe sensor used for measuring gas holdup under an oil well, which comprises a probe, an optical fiber coupler, a light source and a light detector, the probe is a sapphire sensitive probe, the optical fiber coupler is a Y-shaped optical fiber coupler, the light source is infrared source, the sapphire sensitive probe and the Y-shaped optical fiber coupler are sealed in a stainless steel protective casing, and the infrared source and the light detector are sealed in a stainless steel sealed chamber connected to the stainless steel protective casing. The sapphire optical fiber probe sensor used for measuring gas holdup under the oil well has the advantages of high sensitivity, less optical loss, high measurement accuracy, reliable performance, electromagnetic interference resistance, corrosion resistance, oil contamination resistance, high pressure resistance, high temperature resistance, good electrical insulating property, safety explosion resistance, long usage life, exquisite structure, small volume, light weight and less power consumption, and the sapphire optical fiber probe sensor enables real-time and on-line measurement for gas holdup of oil-air-water three-phase flows in a narrow space under the oil well.

Description

technical field [0001] The invention belongs to the field of sensors, and relates to a sapphire fiber optic probe sensor used for measuring the gas holdup rate of an oil well downhole, in particular to a sapphire fiber optic probe sensor used for measuring the gas holdup rate of an oil-gas-water three-phase flow downhole in an oil well. Background technique [0002] Most oilfields in China are continental deposits, characterized by low porosity, low permeability and multi-layer systems. Due to the long-term water injection development, the water content of oil wells has been continuously rising. At present, many oil fields in China are in the high water cut stage with a comprehensive water cut of more than 90%. At this time, if the downhole pressure of the oil well is lower than the bubble point pressure of the oil, natural gas will be precipitated from the oil, thus generating oil, gas and water three-phase flow. In this case, it is necessary to measure the gas holdup of d...

AI Technical Summary

Problems solved by technology

However, because the existing optical fiber sensors for gas holdup measurement use large semiconductor lasers, photocells, and spectroscopic mirrors, it is impossible to realize the small package of the sensor, which makes it impossible to use it in the small space of the oil well.

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