
Echometer Company
Model – H Manual
Phone: (940) 767-4334
5001 Ditto Lane
Page 11
Fax: (940) 723-7507
Wichita Falls, Texas 76302, U.S.A.
E-Mail:
General Operation Procedures
Operation of the instrument is simple. First, the acoustic wellhead (gas gun) should be attached to the casing
annulus or tubing-head valve, and the cable should be connected between the microphone and the instrument.
The valve between the casing annulus and the flow line or between the tree wing valve and the flow line should
be closed to prevent the well gas from venting into the flow line causing excessive noise. Then the instrument is
powered up and the user selects the mode of acquisition, prepares the gas gun for firing, generates the acoustic
pulse, stops data acquisition, reviews the data and saves the record to the instrument memory. When acquisition
of data at the well is complete, the microphone cable is disconnected from the gas gun, wellhead valves are
returned to their original position, pressure is relieved and the gas gun removed from the well. The following
sections illustrate in detail a mode of operation of the instrument and software.
Operation of the Model H with the Compact Gas Gun
The compact gas gun is operated either in the COMPRESSION (Explosion) mode or the RAREFACTION
(Implosion) mode. The operator should use the Compression (explosion) technique when the casing pressure is
less than approximately 100 psig. The Rarefaction (implosion) technique may be used whenever the casing
pressure is sufficient to obtain a good record.
Compression (Explosion) Mode
Expansion of gas from the Echometer gas gun is used to generate a pressure pulse. The pressure pulse is
positive since the gas chamber is charged to a pressure that exceeds the well pressure by at least 100-psi.
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Securely attach the Echometer Gas Gun to the Casing or Tubing Valve.
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Close the Well Pressure Bleed Valve and Filler Bleed Chamber Valve.
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Lift the Cocking Arm to close the internal gas valve. This prevents debris from entering the volume
chamber.
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Open the Well Valve to the Echometer Gas Gun slowly and close the casing or wing valve to the flow
line.
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Measure the Well Pressure using the precision pressure gauge.
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Record Time and Well pressure.
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Fill the volume chamber with gas (CO2 or N2) to at least 100-psi (or more when a high background
noise level is present) in excess of the Well Pressure.
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Connect the coaxial cable from the microphone to the Input of the Model H.
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Power up Instrument by pressing the left soft key.
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Navigate to the acquisition screen following the Explosion Pulse path as described in the following
section.
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Generate pressure pulse by pulling Trigger Ring, after the message “Waiting for Shot to be Fired” is
displayed.
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Inspect the record and repeat the shot if the signal quality is not satisfactory.
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Record Time and Well Pressure.
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Close the Valve between Echometer Gas Gun and the well.
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Open the Well Pressure Bleed Valve and release the pressure.
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Open the Casing Valve or Wing Valve to the flow line.
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Remove the Echometer Gas Gun from the Casing or Tubing Valve.