API RP 13M:2004 pdf download
API RP 13M:2004 pdf download.Recommended Practice for the Measurement of Viscous Properties of Completion Fluids.
8.2.2.1.2 Operation
8.2.2.1.2.1 Preparation
Rotor and bob shall be properly aligned. AJI parts in contact with the fluid shall be at the same temperature as the fluid. Use of the standard cup provided by the manufacturer Is recommended. Other vessels may be used, however the vertical space between the bottom of the bob and bottom of the vessel shall be at least 13mm (050 in).
822.1.2.2 Procedure
The non-crosslinked fluid sample to be tested shall be representative of the fluid as a whole, and air entrainment shall be minimal. After being placed in the viscometer. the fluid is stirred for lOs to 15s at the highest shear rate for which a measurement is to be made. Viscosity measurements should be made from lowest to the highest shear rate. Record the average reading 20 s alter reading is stabilized at each shear rate.
8.2.2.1.3 Calculations
In order to convert a reading in revolutions per minute to shear rate, use the following formula:
1 r/min = 1,704s 1
Viscometric calculations shall be performed according to the manufacturers specified procedure. For rheological calculations, see Clause 9.
8.2.2.2 PressurIzed concentric-cylinder vlscometer2), to measure the viscous and theological properties of completion fluids at elevated temperatures.
Pressurization minimizes the effect of entrained air on measured parameters and allows measurements to be made at temperatures above the atmospheric boiling point of the sample. Multiple-point measurements may be suitable for determining the rheological parameters of fluids.
Any pressurized concentric-cylinder viscometer with the dimensions shown in Figure 3 may be used.
8.2.2.2.1 Calibration
Measure the temperature of the fluid being tested according to the manufacturer’s specified procedure which shall be traceable to a nationallinlemational standard such as ISO, ASTM, DIN, or equivalent.
Measure the rotor or sleeve speed according to the manufacturer’s specified tachometer calibration procedure which shall be traceable to a national!international standard such as ISO, ASTM, DIN, or equivalent.
Use one of the following calibration methods:
a) preferred method
Verify system using a standardised Newtonian calibration fluid traceable to a national,internatiorial standard such as ISO. ASTM, DIN or equivalent. A calibration oil viscosity shall be selected to encompass the shear ratelshear stress envelope to be evaluated. The calibration shall be conducted at ambient pressure.
NOTE Whde the compressibility of aqueous fluids are not significantly affected by the pressure, some calibration oils, in parilailar silicone oils, are affected by pressure.
a) Loading. pressurizing and heating the fluid
Load the fluid to be evaluated Into the viscometei- Immediately after the last component is added according to mixing procedure. Place 52 cm3 of fluid in the viscometer. This volume is sufficient to fully cover the bob. Pressurize the system with nitrogen to a minm’um of 275 MPa (400 psi) and immediately start shearing at 100 s-1 When shearing of the fluid starts, define the elapsed time as zero Ct 0) and begin heating the fluid. All actions in this paragraph shall be completed within 45 s.
Optionally, for an ambient-temperature shear ramp (described in 8.2.2.22 b)j. elapsed time is defined as zero (t 0) immediately after completing this ramp, and fluid heating is begun
At 20 mm elapsed time, the fluid temperature shall be no lower than 5 % below (base 0 C) and no higher than 3 “C (+ 5 F) above the desired test temperature, In addition, at 30 mm elapsed time, and for the remainder of the test, the fluid temperature shall be within ± 3 “C (i 5 °F) of the test temperature.
b) Application of shear rate ramps
The fluid shall be sheared at a constant 100 S mitially and between shear rate ramps.
