Photoelectric flow logging instrument

Abstract

The invention relates to the technical field of geological exploration, and provides a photoelectric flow logging instrument. The photoelectric flow logging instrument comprises a moving part, a photoelectric sensing part and a comparison unit; the moving part is provided with a light hole; the photoelectric sensing part includes a light-emitting part and a light-sensitive part, the moving part isarranged between the light-emitting part and the light-sensitive part, and the moving part moves to enable the light-emitting part, the light hole and the light-sensitive part to be collinear to break over a light path; the comparison unit is connected to the output end of the light-sensitive part, the comparison unit outputs a preset result, the preset result is a comparison result of a light intensity signal output by the light-sensitive part and a preset value, and the preset result corresponds to the fluid clarity degree. The photoelectric flow logging instrument uses the photoelectric conversion principle to solve the problem of magnetic interference, and the clarity of the fluid can be measured.

Description

technical field [0001] The invention relates to the technical field of geological exploration, in particular to a photoelectric flow logging instrument. Background technique [0002] In mine hydrogeological exploration, the aquifers exposed in pumping wells and self-overflow wells will replenish each other through boreholes due to their different water levels, resulting in longitudinal water flow in boreholes. The variation of the velocity of longitudinal water flow in the well at different depths is closely related to the number, thickness, depth of the aquifer layer, the flow rate of each aquifer layer, the hydraulic state (water gushing or water absorption), permeability and its non-uniformity, etc. The working method of using downhole instruments to detect the vertical flow velocity and aperture change of groundwater in the borehole is called flow logging. [0003] In the 1980s, my country began to apply flow logging technology in mine hydrogeological exploration, and i...

AI Technical Summary

Problems solved by technology

[0006] 1. During the drilling construction process, the iron pins produced by the drilling tool grinding the rock remain in the borehole. When the flow logging tool moves in the well, these iron pins will be adsorbed on the permanent magnet of the sensor, so that the impeller The moment of inertia of the reed switch changes, so the measurement accuracy is reduced. When the iron pin is absorbed to a certain extent, the impeller will be stuck with the fixed frame of the reed switch, resulting in the sensor not working properly.

In this case, the probe can only be removed from the well to remove the iron pin on the impeller, and then re-measure. Therefore, to complete the measurement of a wellbore inspection hole requires repeated work many times, which seriously affects the detection accuracy and work efficiency.

[0007] 2. When the flow logging tool is moving at a constant speed in the well, the rotation signal of the turbine can be detected regardless of whether the well fluid is clear, so this flow logging tool cannot detect the quality of the hole washing within the full hole depth range

Since the mud produced by rock powder enters the pores and fissures of the aquifer through the pressure of the well fluid during the drilling process, the borehole for flow logging must be washed before the pumping test to ensure that each aquifer If the holes are unblocked, the detection accuracy will be affected if the holes are not washed thoroughly, and weak aquifers may even be missed, but the quality of the holes is difficult to judge

[0008] 3. The downhole instruments and surface instruments of the original equipment are in the analog measurement mode, and the signal transmission between the downhole and the surface is in parallel transmission mode. Three transmission cables are required to measure the three parameters of flow rate, well diameter and well temperature at the same time, while the ground instruments (coalfield digital measurement well system) is a serial communication method, the measurement parameters only need one cable to transmit, and the original flow logging instrument is not compatible with it, so in the drilling full-parameter digital logging work, the flow logging work needs to use special ground instruments, Moreover, the measured parameter data cannot be directly entered into the coalfield digital logging database, which makes on-site construction and data processing extremely inconvenient

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