Method for monitoring oil, water well sleeve axial strain by using optical fibre Brillouin sensor

Abstract

The invention relates to a method for monitoring the axial strain of an oil and water well casing by applying Brilliouin optical-fiber sensors, which mainly solves the problems existing in the prior art that the conventional electronic sensor can not monitor the casing erosion points of the whole well and is difficult to adapt the poor conditions in the well and the like. The method is characterized in that: the Brilliouin optical-fiber sensors encapsulated by fiber reinforced resin are put into the well with the single oil and water well casing and axially arranged along an oil and water well casing string; a monitoring cable in the well relatively close to the ground is connected with the Brilliouin optical-fiber sensors; the other end of the monitoring cable is connected with an optical-fiber strain analysis meter that is provided with a laser source to generate signals; as the Brilliouin optical-fiber sensors are axially arranged along the oil and water well casing string and deform together with the oil and water well casing string, the deformation amount Delta Epsilon of the Brilliouin optical-fiber sensors is the axial deformation amount of the oil and water well casing string. The method is characterized by being capable of monitoring the casing erosion points of the whole well.

Description

Technical field: [0001] The invention relates to a method for monitoring the axial strain of oil and water well casings in the field of oilfield casing damage research, in particular to a method for monitoring oil and water well casings based on the principle of Brillouin scattering using optical fiber Brillouin sensors Axial strain method. Background technique: [0002] At present, in oil and water well casing damage research in oil fields, the method of monitoring the axial deformation of the casing outside the casing is: a pressure measuring tool with a conventional electronic sensor is placed in the monitoring well section during the casing running process, and the sensor receives The pressure comes from the inner cavity of the rubber cylinder of the pressure measuring tool, and the sensor converts the formation pressure and temperature values ​​into analog electrical signals, which are transmitted to the ground through the signal cable. This monitoring method has the f...

AI Technical Summary

Problems solved by technology

[0003] In order to solve the problems existing in the existing conventional technologies for monitoring the axial strain of oil and water well casings, the use of conventional electronic sensors cannot monitor the casing damage points of the entire well section, and it is difficult to adapt to the harsh downhole conditions. The sensor monitors the axial strain of the oil and water well casing. After the method is implemented, it has the characteristics of monitoring the casing damage point of the whole well section, and the optical fiber Brillouin sensor used has been specially modified, which is very suitable for the harsh underground conditions. Use under environmental conditions

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