•The filtration and wall building characteristics of a drilling mud are important for providing :
–a relative measure of the amount of mud filtrate invasion into a porous and permeable formation,
–the amount of filter cake that will be deposited on the wall of the wellbore wherever filtration occurs.
–From a drilling view point, these properties give an indication of the amount of water (or oil) wetting that can take place in filtrate sensitive formations,
–and the potential for tight hole or differential sticking problems. For productive, hydrocarbon bearing formations,
–these properties give an indication of the amount of filtrate invasion and permeability damage that can be expected.
•Filtration tests are conducted under two different conditions –standard API filtration test •surface (or room) temperature
–The API High Temperature
–High Pressure test (HT-HP test)
•±150 degrees Celsius (300 degrees F) or bottom hole temperature Standard API Test Procedure:
•Pour the mud sample into the cell, secure the lid and make sure all valves are in the correct positions to permit the application of pressure to the sample to be filtered.
If necessary, place a fresh CO2cartridge in the holding cylinder and screw the cylinder on quickly and securely to puncture the cartridge .
Standard API Test Procedure:
•Place an appropriately sized, granulated cylinder under the filtration tube.
•Using the pressure gauge as an indicator, apply 700 kPa(100 psi) pressure to the sample and begin timing the test. Standard API Test Procedure:
•Collect the filtrate in the graduated cylinder for 30 minutes. At this time, remove the graduated cylinder, turn off and relieve the pressure on the test sample.
Standard API Test Procedure:
•Report the volume of collected fluid as the fluid loss in millimeters, making sure the volume is doubled if a “half area”filter press is used. •Disassemble the test cell, discard the mud, and use extreme care to save the filter paper with minimal disturbance to the filter cake. Remove excess mud from the filter cake by light washing, or lightly sliding a finger across the filter cake. Standard API Test Procedure: •Measure the thickness of the filter cake and report in millimeters.
If desirable, the filter cake texture may also be noted as being dry to slick, and mushy to firm to provide an indication of its friction factor and compressibility.
•Wash all components thoroughly fresh water, and wipe dry with a clean cloth or paper towel High Temperature
–High Pressure Filtration Test
•The following is the standard procedure adopted by the API for testing at ±149 degrees C (300 degrees F), and 3450 kPa(500 psi) differential pressure.
•Connect the heating jacket to the correct voltage, place a thermometer in the well of the jacket, and preheat the jacket to 155 deg.
C (311 degrees F). Adjust the thermostat in order to maintain a constant temperature
High Temperature
–High Pressure Filtration Test
•Take warm mud from the flowline, and preheat to 50-55 deg.
C (120 –130 degrees F) while stirring.
•Load the cell as recommended by the manufacturer.
Care should be exercised not to fill the cell closer that 15 mm from the top to allow for expansion.
High Temperature
–High Pressure Filtration Test
•Place the cell in the heating jacket with both the top and bottom valves closed.
Transfer the thermometer from the heating jacket to the well of the test cell.
•Place the pressure assembly on the top valve stem and lock into place. Place the bottom pressure receiver and lock into place.
Apply 700 kPa(100 psi) to both pressure units with the valves closed. Open the top valve, and apply 700 kPa(100 psi) while heating.
•When the temperature reached ±149 deg.c (300 deg. F), open the bottom valve and increase the pressure on the top assembly to 4150 kPa( .High Temperature
–High Pressure Filtration Test •When the temperature reached ±149 deg. C (300 deg. F), open the bottom valve and increase the pressure on the top assembly to 4150 kPa( 600 psi) to start filtration.
Collect the filtrate for 30 minutes, maintaining 149 deg.
C (300 deg F) temperature, ±2 deg. C.
•If desired, record the volume after 2 seconds.
If the back pressure rises above 700 kPa(100 psi) during the test, cautiously bleed off pressure by collecting a portion of the filtrate. Record the total volume.
.High Temperature
–High Pressure Filtration Test
•The filtrate volume should be corrected to a filter area of 4581 mm2. Double the filtrate volume and report.
•At the end of the test, close both valves.
Back the T-handle screw off the regulator, and bleed of the pressure from both regulators.
•Caution:
The filtration cell will still contain ±3500 kPa(500 psi) pressure.
Maintain the cell in a upright position and cool to room temperature. After the cell is cool, continue to hole the cell upright (cap down), and loosen the top valve to bleed off the pressure slowly. High Temperature –High Pressure Filtration Test
•After the cell has cooled and the pressure has been bled off, the cell may be inverted to loose the cap screws with an Allen wrench.
Remove the cap with a gentle rocking motion.
Carefully retain the filter cake for analysis and thoroughly clean and dry all components.
•Do not use the filtrate for chemical analysis.
High Temperature
–High Pressure Filtration Test
•If filter cake compressibility is desired, the test can be repeated using 1400 kPa(200 psi) on the top pressure unit, and 700 kPa(100 psi) for the bottom pressure unit.
•Record both temperature and pressure with the results of the filtration test at all times.
The temperature of 149 deg. C (300 deg. F) is normally selected, so as to be within the range where high temperature mud treating procedures and chemicals are required.
High Temperature –High Pressure Filtration Test Note: At any time when utilizing any HT-HP filter press, if the CO2pressure runs out in the middle of the test and a replacement cartridge has to used, remember to shut the top and bottom valves prior to replacing the CO2cartridge.
Remember the filtration cell will still contain 500 psi pressure
–a relative measure of the amount of mud filtrate invasion into a porous and permeable formation,
–the amount of filter cake that will be deposited on the wall of the wellbore wherever filtration occurs.
–From a drilling view point, these properties give an indication of the amount of water (or oil) wetting that can take place in filtrate sensitive formations,
–and the potential for tight hole or differential sticking problems. For productive, hydrocarbon bearing formations,
–these properties give an indication of the amount of filtrate invasion and permeability damage that can be expected.
•Filtration tests are conducted under two different conditions –standard API filtration test •surface (or room) temperature
–The API High Temperature
–High Pressure test (HT-HP test)
•±150 degrees Celsius (300 degrees F) or bottom hole temperature Standard API Test Procedure:
•Pour the mud sample into the cell, secure the lid and make sure all valves are in the correct positions to permit the application of pressure to the sample to be filtered.
If necessary, place a fresh CO2cartridge in the holding cylinder and screw the cylinder on quickly and securely to puncture the cartridge .
Standard API Test Procedure:•Place an appropriately sized, granulated cylinder under the filtration tube.
•Using the pressure gauge as an indicator, apply 700 kPa(100 psi) pressure to the sample and begin timing the test. Standard API Test Procedure:
•Collect the filtrate in the graduated cylinder for 30 minutes. At this time, remove the graduated cylinder, turn off and relieve the pressure on the test sample.
Standard API Test Procedure:
•Report the volume of collected fluid as the fluid loss in millimeters, making sure the volume is doubled if a “half area”filter press is used. •Disassemble the test cell, discard the mud, and use extreme care to save the filter paper with minimal disturbance to the filter cake. Remove excess mud from the filter cake by light washing, or lightly sliding a finger across the filter cake. Standard API Test Procedure: •Measure the thickness of the filter cake and report in millimeters.
If desirable, the filter cake texture may also be noted as being dry to slick, and mushy to firm to provide an indication of its friction factor and compressibility.
•Wash all components thoroughly fresh water, and wipe dry with a clean cloth or paper towel High Temperature
–High Pressure Filtration Test
•The following is the standard procedure adopted by the API for testing at ±149 degrees C (300 degrees F), and 3450 kPa(500 psi) differential pressure.
•Connect the heating jacket to the correct voltage, place a thermometer in the well of the jacket, and preheat the jacket to 155 deg.
C (311 degrees F). Adjust the thermostat in order to maintain a constant temperature
High Temperature–High Pressure Filtration Test
•Take warm mud from the flowline, and preheat to 50-55 deg.
C (120 –130 degrees F) while stirring.
•Load the cell as recommended by the manufacturer.
Care should be exercised not to fill the cell closer that 15 mm from the top to allow for expansion.
High Temperature
–High Pressure Filtration Test
•Place the cell in the heating jacket with both the top and bottom valves closed.
Transfer the thermometer from the heating jacket to the well of the test cell.
•Place the pressure assembly on the top valve stem and lock into place. Place the bottom pressure receiver and lock into place.
Apply 700 kPa(100 psi) to both pressure units with the valves closed. Open the top valve, and apply 700 kPa(100 psi) while heating.
•When the temperature reached ±149 deg.c (300 deg. F), open the bottom valve and increase the pressure on the top assembly to 4150 kPa( .High Temperature
–High Pressure Filtration Test •When the temperature reached ±149 deg. C (300 deg. F), open the bottom valve and increase the pressure on the top assembly to 4150 kPa( 600 psi) to start filtration.
Collect the filtrate for 30 minutes, maintaining 149 deg.
C (300 deg F) temperature, ±2 deg. C.
•If desired, record the volume after 2 seconds.
If the back pressure rises above 700 kPa(100 psi) during the test, cautiously bleed off pressure by collecting a portion of the filtrate. Record the total volume.
.High Temperature
–High Pressure Filtration Test
•The filtrate volume should be corrected to a filter area of 4581 mm2. Double the filtrate volume and report.
•At the end of the test, close both valves.
Back the T-handle screw off the regulator, and bleed of the pressure from both regulators.
•Caution:
The filtration cell will still contain ±3500 kPa(500 psi) pressure.
Maintain the cell in a upright position and cool to room temperature. After the cell is cool, continue to hole the cell upright (cap down), and loosen the top valve to bleed off the pressure slowly. High Temperature –High Pressure Filtration Test
•After the cell has cooled and the pressure has been bled off, the cell may be inverted to loose the cap screws with an Allen wrench.
Remove the cap with a gentle rocking motion.
Carefully retain the filter cake for analysis and thoroughly clean and dry all components.
•Do not use the filtrate for chemical analysis.
High Temperature
–High Pressure Filtration Test
•If filter cake compressibility is desired, the test can be repeated using 1400 kPa(200 psi) on the top pressure unit, and 700 kPa(100 psi) for the bottom pressure unit.
•Record both temperature and pressure with the results of the filtration test at all times.
The temperature of 149 deg. C (300 deg. F) is normally selected, so as to be within the range where high temperature mud treating procedures and chemicals are required.
High Temperature –High Pressure Filtration Test Note: At any time when utilizing any HT-HP filter press, if the CO2pressure runs out in the middle of the test and a replacement cartridge has to used, remember to shut the top and bottom valves prior to replacing the CO2cartridge.
Remember the filtration cell will still contain 500 psi pressure