Operating Procedure for Drilling Fluid Performance Test
Determination of Clay Cake Retention Coefficient (Friction)
Oil based drilling fluid resistance 0.08-0.09, water based drilling fluid resistance 0.2-0.35. Most water based drilling fluid resistance 0.2 is considered qualified, and the horizontal well is kept within the range of 0.08-0.1.
Due to the function of the well slope and the pressure difference, the drilling tool is often close to the mud cake of the well wall. If the mud cake is thick and the adhesion coefficient is large, the friction between the mud cake and the drilling tool in the relative movement is large, and it is easy to produce the mud cake adhesion stuck drill. Therefore, the determination of mud cake adhesion coefficient is of great significance to adjust the performance of drilling fluid and reduce the mud cake adhesion stuck drill. The viscosity coefficient of mud cake can be measured by NF-1 and NF-2 mud cake.
1. Main Technical Parameters of the Instrument
1. Gas source: 6.0MPa.
2. Area and diameter of the adhesion disc: 50.7mm.
3. Capacity of drilling fluid cup: 240 mL.
4. Working output pressure: 3.5MPa.
5. Output limit pressure: 5.0MPa.
2. Testing Program
1. Put the filter paper, rubber washer and nylon cushion on the drilling fluid cup filter screen in order, and press the pressure ring on the filter paper nylon gasket with a U-shaped board hand.
2. Tighten the lower connecting valve bar into the screw hole at the bottom of the drilling fluid cup, so that the four holes at the bottom of the drilling fluid cup align with the four pins on the bracket.
3. Pour the drilling fluid sample into the engraved line in the drilling fluid cup, pass the friction disk through the cup cap, tighten the drilling fluid cup cap to the drilling fluid cup with the pressure rod and hook wrench, and tighten the other connecting valve bar on the drilling fluid cup cover.
4. Connect the air source pipe fold at the upper connecting stem, adjust the pressure to 3.5MPa, align the 20 mL cylinder with the lower connecting stem, put it on the base, and open the upper and lower valve bars respectively (rotate 90 degrees).
5-1. Open the upper and lower valve bar to start the recording time. After filtering for 30min, the NF-1 model immediately holds the pressure bar on the support beam and presses the adhesion plate down until the adhesion plate and the filter cake in the cup are stuck (about 5min).
5-2. Pressurizing begins the recording time. After filtering for 30min, NF-2 type will put the pressure cylinder into the groove of the drilling fluid cup cover and rotate about 60, rotate and tighten, then insert the gas source into the air cylinder and lock, and close the vent valve stem. Open the air source to 3.5 mPa and press the adhesive plate until the adhesive plate and the filter stick (about 3-5min). Release the thimble, remove the pressure and remove the pressure cylinder.
6. After adhesive disc after 45min, the torque move hand with the inner hexagonal sleeve into the adhesive plate hexagonal head, adjust the torque move hand dial and pointer at 0 position, then the pressure bar slot stuck in the middle of the two pillars, left or right move torque move hand, measuring adhesion disc and start to slide the maximum torque value.
7. Close the upper and lower valve stem and the air source, open the vent valve stem, and discharge the residual gas in the air source pipe sink. Remove the source fold and tee components.
8. Release the upper valve stem and release the residual air in the cup. Open the drilling fluid cup, clean the instrument, and dry dry.
Note: When releasing the residual gas in the cup, cover the valve stem with a towel and do not aim at the person.
9. Calculate the viscosity coefficient of mud cake in the following formula:
Kf = 0.95510-3 M (formula: Kf- -viscosity coefficient of mud cake; M- -maximum torque, ibf.in)
Kf = 0.84510-2 M (formula: Kf- -viscosity coefficient of mud cake; M- -maximum torque, N.m)
3. Matters Need Attention
1. Check the instrument, valve stem, washer, filter paper, etc., starting during the test.
2. The "O" sealing ring should be replaced frequently.
3. The adhesive disk used in the instrument is the main measurement part, and it should be noted not to hurt the disk surface and keep it smooth.
Qingdao Haitongda Special Instrument Co.,Ltd.
Qingdao Haitongyuanda Special Instrument Co.,Ltd.
No.320, Jiushui East Road,Licang district
Qingdao City,Shandong Province,China
No.10, Huaan Road,Chengyang district
Qingdao City,Shandong Province,China