If you are just trying to see which wells are running down you can monitor the wellhead pressure of each well and the manifold pressure. The differnace will be proportial to the flow from each well.
We use this method along with the tracer flow testing above.
The way I think to go is like kevin suggested, measuring the pressure. Will add an Orifice and DP transmitter and will collect the data, monitoring rate of changes in the Orifice DP.
Other thing is to try and measure the two phase flow with the Portable Ultrasonic Flow Meter.
Thanks to all - ilan
As a senior engineer, you just delegate the task of designing and implementing a two-phase flow meter to Reuven. I guarantee it will get done, and very interestingly.
I like Kevin's approach. If you can do careful flow tests on the wells, with James tubes and weir boxes, you can generate curves for steam and brine flow vs wellhead pressure. Then, when the wells are in service, the curves can be used to reasonably approximate the operational steam and brine flows.
There are orifice plate correlations for two-phase flow, but as was previously mentioned they are very dependent on flow regime. Also, to get reasonable results, the pressure drop across the orifice must be fairly high, more than 20 psi, which is not good for the well production. I don't like any orifice plate in a two-phase line for that reason alone. Millions are spent on the well and piping system in order to get the fluid to the plant and it doesn't make sense to me to put any intentional restriction in the pipeline.
I like Kevin's dual tracer concept also, but have never used it.
Reuven has a world-wide reputation for resourcefulness and correcting engineer's mistakes in the field. I was joking about him devising a two-phase flow meter.
I know of two patents for geothermal two-phase flow, although I don't know the details of the devices. One patent is held by Paul Spielman, a reservoir engineer at Coso, and the other by Doug Jung at Two-phase Engineering and Research in Santa Rosa, CA.
Neither of the devices have reached the commercial stage as yet, but it might be worthwhile to contact the inventors. It seems that there should be a strong demand for commercial two-phase flow meters.
To All
May be you all will find it interesting to know.
I contacted a small company with great idea.
They developed a small sensor, based on heating cooling and temp. measuring (all in one sensor) that can calculate in two phase flow (Steam and water or cooler gas - liquid systems like air conditioning system) the precentage of liquid in the gas flow. The instrument gives an on line measuring which is fed into the PLC / DCS for dataloging or control.
The instrument is already in use by aircrafts air conditioning system and the company is now checking the option to convert it to steam - water aplications. If any of you think it interesting please leave a note to Dr. Gadi Golan from ATCT (
I know that this thread is a bit old, but here is a link to the web site of a company that has technology that listens to the flow and interprets the sounds produced by turbulence to determine the flow rate. They also claim to be able to measure multiple phase flows. It might be helpful, if you are still concerned about your two phase flow measurement problem.
Why not use a tangential type separator to separate the gas from liquid. The gas will exit the top of the separator & the liquid out the bottom. Then you can use the appropriate meter for each phase.