Sag Tester

M8500 Ultra HPHT Dynamic Sag Tester

Patented design prevents contamination of sample by pressurization fluid
Contact with pressurization fluid can compromise the integrity of sag test results. The M8500 HPHT Dynamic Sagging Tester prevents any contact between the test sample and the pressurization fluid, because the innovative design, in particular the accumulator piston, prevents the test sample from contact with any other fluid, from pressure chamber to pycnometer.

Highest pressure and temperature rating
The M8500 offers the highest pressure and temperature rating of any HPHT sagging tester available in the USA, providing the researcher with a very realistic and robust test environment. The unit is also fully compliant with API 10B and API 13B standards.

Multifunction options are available, adding many capabilities
The M8500 is available with optional Ultra HPHT Fluid Rheometer, HPHT Cement Rheometer, and/or PVT and LSM Tester modules, with more being developed. These options allow a laboratory to significantly expand the scope and variety of fluid performance testing, without having to purchase, operate and maintain multiple instruments.

The Grace Instrument M8500 High Pressure, High Temperature Dynamic Sagging Tester is designed for evaluating barite sagging and other weight material sag under simulated drilling conditions. It is also engineered for safe testing while providing ultra high pressure and high temperature sag test conditions. The M8500 features a rotating rod simulating drill pipe within the sample to provide dynamic sagging test.

U.S. Patent: 7,845,212
China Patent: CN 101614648 B
Dimensions: 30" height x 12.5" width x 25" depth (tower)
20" height x 25" width x 15.5" depth (cab)
Weight: 278 lbs.
Construction: Stainless Steel
Temperature Range: Ambient (20°F with chiller (-6°C)) to 600°F (315°C)
Pressure Range: Atm to 30,000 psi
Speed Range: 0.01 - 600 rpm continuous
Shear Rate: 0.004 to 202 S-1
Borehole Angle: 0 to 80°
Voltage: 120 VAC or 240 VAC (with transformer)
Frequency: 50 Hz or 60 Hz
Coolant Supply: Tap water or chiller
Compressed Air: 120 psi
Compliance Standards: Fully compliant with API 10B and API 13B
Computer Requirements: PC with MS Windows 9X/2000/XP/Vista/7/8/10/11

Example of M8500 Dynamic Sagging Tester Test Results (using MS Excel®):


Table 1:  M8500 Dynamic Sagging Tester Results for 11.00 lb/gal, oil-based fluid with API Barite weight material
Initial Mud Density lb/gal 11.00
Borehole Angle degrees 80
Temperature oF 300
Pressure psi 20,000
RPM rpm 100
Annulus inch 0.375
Shear Rate S-1 33.71
Sag Density after 1 hour lb/gal 13.14
Density Difference lb/gal 2.14
Relative Density Increase % 19.45
Downloads for the Lubricity Dynamic Filtration Drilling Simulator:

Read more about our instrument's technical applications within these scientific and academic publications:

  1. AGH Drilling Oil Gas 34(1):181 2017
    Wellbore Trajectory Impact on Equivalent Circulating Density
    A Grace M8500 Ultra HPHT Dynamic Sagging Tester was used to determine how in wellbore conditions of high pressure and temperature, inclination angle modifications could influence equivalent circulating density.


  2. ADIPEC 390 2013
    Innovative technology improves lubricity in high performance water base mud systems: field application in a challenging HPHT environment
    A high performance lubricant added to water based drilling fluid to improve drilling rate while using advanced drilling system. M8500 was used to conduct sagging test.