During cementing operations, the time required for a cement slurry to set is
of primary concern. Under an ideal situation, minimal time would be required
to successfully pump the slurry, which immediately upon placement, begins
to develop compressive strength. However, if insufcient time is allowed to
fully pump the cement, it will be necessary to drill the cement remaining in the
casing string. Remedial operations such as this are very costly. Conversely,
cements that are successfully placed, but require considerable time to
cure, consume valuable rig time, which is also quite costly. Laboratory tests
should be conducted under simulated reservoir conditions to examine the
actual thickening time of the slurry. The OFITE Benchtop Consistometer
was specically engineered to determine the thickening time of well cements
under simulated downhole pressures and temperatures.
Description
Features
A cement is mixed and poured into the slurry cup assembly. The slurry cup
is placed into the test vessel and pressure is increased via an air-driven
hydraulic pump. A PID temperature controller governs an internal heater,
which maintains the necessary temperature prole, while a magnetic drive
mechanism rotates the slurry cup assembly at 150 RPM. A potentiometer
controls an output voltage, which is directly proportional to the amount of
torque the cement exerts upon an API-approved paddle. A chart recorder
registers cement consistency and temperature as a function of time.
Temperature and consistency are digitally displayed via LED indicators.
-Maximum Pressure: 16,000 PSI (110.3 MPa)
-Maximum Temperature: 400°F (204.4°C)
-Pressure generated via an air-driven hydraulic pump
-Drive table is rotated with a magnetic drive
-External cooling jacket aids cooling of test cell
-Electronic timer with alarm, elapsed 0.1 minute resolution
-Deadweight calibration unit included
-Temperature and consistency alarms provide automatic shutdown
-Safety head with rupture disk are provided
-Unit is fully capable of testing cements in strict accordance to the
1. Carefully remove the instrument from the wooden crate and place it on a
stable surface.
2. Connect an air or nitrogen (100 – 150 PSI / 690 – 1,035 kPa) supply to the
air supply on the back of the instrument.
This unit uses ¼" NPT female connectors for all supply lines.
3. Connect the drain and coolant supply lines, also on the back of the unit.
4. Make sure all electrical switches are turned off and the unit is grounded.
Make the necessary electrical connections in accordance with local
codes.
5. Plug the cable into the top port on the unit cabinet and connect the other
end to the port on the back of the Control Box.
6. If you are using a computer, connect the Control Box to the computer with
the supplied cable. Newer units connect via a USB cable (#130-79-16).
Older units use an RS-232 (serial) cable (#130-79-15).
7. To ll the oil reservoir, remove the oil reservoir cap and pour mineral oil
into the reservoir until it is full. Replace the cap. Make sure the seal is air
tight. Use the sight glass on the side of the reservoir to check the oil level.
The oil level should be about ½" from the top of the sight glass.
The OFITE Benchtop Consistometer includes a Eurotherm Chessell 6100A
chart recorder for displaying and recording test data. It features a removable
drive for easily transferring test data to a PC for processing. The unit is setup
to automatically record data onto the disk during the test. However, for this
feature to work, you must have the disk inserted into the drive when the unit
is powered on. Otherwise, the data must be manually archived at the end of
the test.
Eject Button
It is strongly recommended that you carefully study the Eurotherm
Chessell 6100A instruction manual before using this equipment.
To manually archive test data:
1. Press the “Root Menu” button.
2. Press “Operator” from the root menu.
3. At the top of the screen, choose “Archive” and then choose “Disk”.
The chart recorder is shipped to you with a pre-programmed conguration
le. It is highly recommended that you do not change any of these settings.
However, in case of emergency, it is possible to restore your conguration
from the disk that is shipped with the unit.
1. At the top of the screen, press “Save/
Restore” and choose “Restore”.
2. Make sure all four options are selected,
then touch the “File Name” eld.
3. Press the up arrow to access the root
directory.
4. Select “Removable” and press the down
arrow to access the disk.
5. Choose the le titled “Cong” and press
“Open”.
6. When the progress bar at the top of the
screen stops, the restore process is
complete.
the “Go To” button at the top of the screen.
Choose the data point you wish to view and
click “OK”.
Setup
Eurotherm
The Eurotherm Model 3504 controls the temperature and displays the
pressure. When running a test with the computer, the software automatically
programs the controller. However, when running a test without the computer,
the controller must be programmed manually. It is strongly recommended
that operators carefully study the Model 3504 instruction manual before
attempting to program the controller.
When running a test without the computer, always build the program prior to
mixing the slurry and loading the slurry cup.
The Eurotherm 3504 can store up to eight custom programs. Each program
consists of multiple segments. In a segment, the temperature setpoint can be
changed or held for a certain amount of time.
Each program also can consist of two channels; one for temperature and one
for pressure. Since the Benchtop Consistometer does not offer automatic
pressure control, only Channel 1 should be programmed.
Temperature
Selector
Pressure
PageScroll
To edit a program:
1. Press the “Page” button until the display reads “Program Edit”.
2. Use the up and down arrows to select the program you want to edit.
3. Press the “Scroll” button to move to the Channel parameter.
4. Use the up and down arrows to select Channel 1.