Well The Sound Transmission Loss Measurement Study, And Based On Spread Spectrum Underground Level

In the oil well mining process, we needs to the parameter of the temperature, pressure and fluid position on oil well to carry on the survey. Fluid position is a very important parameter.The former mine shaft fluid position survey mainly is produces the high efficiency sound pulse signal through the explosive sound source. We used microphone receive echo signal, artificial carries on to the echo signal curve analyzes estimates the fluid position. This method has the error in a big way. This article proposed the method uses the controllable acoustic source, the launch compares low power the frequency spectrum expansion signal, carries on matched filtering processing in the receiving end to the echo signal, determines the characteristic echo through the examination correlation peak the position, thus calculates the fluid position.This article first introduced the acoustics basic principle as well as the sound wave in each kind of truncation tube dissemination, use the sound electricity analogy method in this foundation to simplify the oil well port model, has carried on the theoretical analysis to the oil field oil well port place sound transmission loss; Again contrasts the explosive sound fluid position measurement system and based on the wide frequency method fluid position measurement system, to carries on the brief introduction based on wide frequency method fluid position survey development system each part of constitutions, the skeleton leaves this system model from the whole; Then contrasts two kind of systems the signal processing methods, introduced in this foundation the wide frequency principle, and the treating processes carries on the description to the signal, has compared the wide frequency gain emphatically which the different length pseudo-random code institute brings; Finally has carried on the analysis and the discussion to the discharge pipe modelling measurement result.