FREQUENTLY ASKED QUESTIONS

4. What are the considerations in mounting and use?

1.) Flow Rates and Mounting of the Measurement Section

The orientation does not matter if the flow rate is above approximately 3 feet/second. This assures a homogeneous mixture in the measurement section. If there is gas present, the preferred orientation is with the electronics end down and the flow from the bottom to the top. This assures that the free gas is removed from the section instead of accumulating it at one end. If the flow rate is very low (below 2 ft./sec), then the preferred orientation is the electronics upward and the flow from the top to the bottom. This is so that the water does not accumulate in the section. If the section is mounted horizontally and the flow rate is low sand may also accumulate in the section. Flow in the main line must be high enough to prevent separation for a low water-cut unit where a hot tap on the side of a pipeline with a pilot tube in the upstream section is used. The measurement section should not be at the lowest or the highest place in a piping line unless due consideration is given to the hold up of water, oil and gas (by maintaining high flow rates).

2.) High temperature Units

For high temperature (>100 degrees C fluid temperature) operation, the electronics should be mounted football down due to the necessity of keeping the electronics portion below 120 degrees F ambient. Otherwise, the heat rises and prevents the aluminum explosion proof box from radiating the heat to the ambient air. The electronics includes a very small built in heater to keep the electronics, which are temperature sensitive, at a temperature of 160 degrees F. As the enclosure temperature (around the electronics) gets above approximately 120 degrees F, the heater starts to go out of regulation and therefore, there is a greater error in the measurement. There are several versions of the Phase Dynamics measurement section for various temperature ranges. When the fully brazed system is selected for very high temperatures, THE ELECTRONICS ON THE END OF THE MEASUREMENT SECTION SHOULD BE AIR PURGED WITH DRY INSTRUMENT AIR IN ORDER TO MAINTAIN THE OSCILLATOR AT A REASONABLE TEMPERATURE. Contact the factory about the requirements for air purging.

3.) Electrical Considerations

Cables and Grounding

Included with each system is a system cable and a green grounding wire. The system cable must be pulled from measurement section end back to the mail electronics due to the military type connector on one end. The green ground wire is to meet CSA requirements and also to assure a good earth ground between the measurement section and the electronics. This prevents ground loops from being carried in the system cable's shield.

In all cases, the AC Input board should have an earth ground wire connected. In addition to the safety aspects, this assures a solid instrument ground.

Flow Meter Input Connections

Pulsed flow inputs need to be at least 0.070 Volts and a maximum of 15 Volts. A magnetic pickup can be directly tied in without a preamp if the cables are run in conduit and are not excessive in length. A solid ground connection must be made at the flow-meter and at the Phase Dynamic's electronics in order to assure extra pulses are not obtained.

Current flow inputs can be used in conjunction with other devices in the current loop only if the Phase Dynamics is the last instrument on the loop's path nearest to the ground leg.

5. What makes Phase Dynamics different from the other Technologies?

The patented measurement method which allows the oscillator to change frequency with the changing water-cut provides for up to 1000 times the sensitivity of other technologies. This is the reason that water continuous measurements in the high water-cut region can be done. Prior methods just did not have the sensitivity to water in the 60-90% water-cut regions. This same method gives long term reproducibility and stability of measurement because of the simplicity of the circuitry. The engineering, materials, and methods are based on a military style of design. Connectors, board layout, and designs follow methods which were learned during employment with Texas Instruments in the military electronics divisions.

6. What input and output options are available?

1.) Digital Communications.

The RS-422 option can include a multidrop software as a purchased option so that one RS-422 line can talk to multiple units. This must be specified at the time of purchase since the standard unit does not include multidrop capabilities. When the multidrop option for the RS-422 is implemented the RS-485 is no longer available for use. The RS-422 is implemented with ASCII protocol which is included at the back of the user's manual.

2.) 0-20mA and 4-20mA Outputs.

Standard as an output is the 0-20 mA or the 4-20 mA output of water cut. Totalization of the net oil and water can only be obtained from the digital communications bus.

3.) Well Select OPTIONAL Input using 0-20 mA and 4-20 mA.

An option for use of the flow 4-20 mA input as a well select is available. This option gives well selection up to 50 wells. This does preclude use of a current flow input for net oil.