Measuring and testing – Liquid analysis or analysis of the suspension of solids in a... – Content or effect of a constituent of a liquid mixture
Patent
1990-06-05
1992-01-28
Raevis, Robert
Measuring and testing
Liquid analysis or analysis of the suspension of solids in a...
Content or effect of a constituent of a liquid mixture
7386121, G01N 1100, G01F 100
Patent
active
050834525
DESCRIPTION:
BRIEF SUMMARY
The present invention relates to a method for determining the composition and flow condition of a medium flowing through a structural detail influencing the flow. Acoustic signals generated from the medium flowing through said structural detail are collected at the surface of the latter. By structural detail is meant a device through which a medium is flowing. It may be a valve, a duct, or a pipe, or a choke mechanism which is shaped to provide strong turbulence/cavitation in the medium or part of the medium.
In connection with monitoring multiphase production flow as for example, in oil wells when it is desirable to control production rate, i.e. the ratio of oil/gas, and in the production of water, and when monitoring production in cases with resulting sand production, continuous monitoring of the production parameters may be of great importance.
In installations comprising special structural details which control the production process by direct mechanical influence on the flow conditions, e.g. various kinds of choke devices for pressure control, state monitoring of said devices will be important, especially if they are difficult to access, e.g. in connection with sub sea installations and in case of unmanned remote controlled plants. Due to the fact that changes of the structural turbulence/cavitation causing details are represented in the detected acoustic spectrum of signals, it will be possible to record mechanical changes (e.g. wear, changes of the choking ratio, any possible deposits).
There are various known methods and devices for monitoring fluctuations of flow, mainly based on various kinds of methods for detecting fluctuations of pressure in a pipe system with turbulent flow. In this connection we refer to DE-AS Nos. 14 73 019 and 14 98 271, as well as to NO-PS No. 141 327. An unfavourable aspect of said known systems is that physical intervention in the pipe system is required to gauge the pressure.
U.S. Pat. No. 4,392,374 discloses a device for sensing inhomogeneities, e.g. gas bubbles, in liquid flow guided in a pipeline. An electromechanical detector means is attached to the outside of the pipe to provide acoustic connection. The device is designed to constitute a band pass filter excluding undesired vibration frequencies. It is, among others, disadvantageous in said known concept that essential information signals are lost due to filtration, and that the detector is quite dependent on firm clamping on the pipe.
In NO-PS No. 140 838 a monitoring device for solids, e.g. sand, in a fluid flow through a pipeline is disclosed. The device is acoustically connected with the pipeline, via a liquid filled space, and is placed at a pipe bend. Due to inertia relative to the fluid some of the grains of sand may move along the pipe wall which may result in acoustic signals. Such slight impingements will be acoustically recorded by the detector means. In case of a pure fluid or a fluid, e.g. comprising air and water, there will be approximately zero reaction from the detector. If the pipeline carries gas containing a condensate precipitations may be caused to form on the inside of the pipe and there is, thus, a hazard of a considerably reduced detection efficiency when the fluid contains grains of sand later on.
According to the invention known disadvantages and deficiencies of the known devices are avoided due to the fact that turbulence/cavitation is created in the medium passing through, by the aid of the structural detail. Acoustic energy signals are thus generated and propagate in the structure, and the acoustic energy signals are transformed by the aid of acoustic sensor means having an acoustic connection with the structural detail, into transmittable signals which are processed by the aid of relevant analytical methods in order to provide interpretable information on the composition and flowing conditions of the passing medium.
A method is, thus, provided by the invention which by the aid of simple means permits scanning and recording of acoustic signals generated by turbulence and cavitation,
REFERENCES:
patent: 4019384 (1977-04-01), Herzl
patent: 4339661 (1982-07-01), Pitt et al.
patent: 4587849 (1986-05-01), Gross
patent: 4639593 (1987-01-01), Stetson et al.
patent: 4674337 (1987-06-01), Jonas
patent: 4836032 (1989-06-01), Redus et al.
patent: 4856344 (1989-08-01), Hunt
Kau Shu-Cheng
Raevis Robert
Sensorteknikk A/S
LandOfFree
Method for recording multi-phase flows through a transport syste does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method for recording multi-phase flows through a transport syste, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method for recording multi-phase flows through a transport syste will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1853584