Brookfield Engineering

Oil/Gas Exploration And Drilling

Process Viscometer Application Data Sheet


Field engineers on-site at oil and gas drilling wells need to perform rapid viscosity tests which simulate pressurized process conditions for down-hole environments. Applications include fracturing fluids, drilling muds, cements and oil/water emulsions, all at elevated temperatures characteristic of down-hole conditions. The PVS Rheometer is an ideal replacement for the standard Fann Model 50 Rheometers and Nordman Rheometers which are bulky, expensive, and cumbersome to operate.

Problem Description

Field engineers in oil and gas drilling operations can make a serious financial mistake (perhaps as much as $500,000) if the viscosity specifications of fluids pumped down-hole are incorrect. This complicates testing procedures, increases the risk of costly errors and wastes time. Consequently, it's necessary to ensure fast, accurate viscosity measurement, data collection and analysis of small fluid samples (tested under pressure and elevated temperatures) before they are pumped down-hole.


The portable PVS Rheometer gives field engineers reliable viscosity measurement on-site at the well, simplifies complicated test procedures, minimizes human error and ensures quality control without delay. The Brookfield PVS bench-top Rheometer:

  • Permits easy relocation to the most remote job site due to its small size and light weight
  • Allows quick and easy viscosity measurements under pressure and elevated temperature
  • Provides complete automation of standard test procedures and conditions
  • Obtains real-time data collection and analysis at multiple shear rates
  • Utilizes coaxial cylinder geometry identical to existing standards
  • Allows easy cleaning and disassembly due to simple, straightforward design
  • Isolates torque transducer, bearings and other mechanisms from sample/test environment
  • Minimum vapor space above sample
  • More sensitive than competitive instruments

Companies Involved In Oil/Gas Exploration And Drilling

  • Major oil/gas field service companies
  • Oil/gas companies
  • Oil/gas well owners
  • Technical labs/consultants
  • Suppliers of fluids used in oil/gas well development

Qualifying Your Application

  • Do you need to measure fluid samples under multiple shear conditions and at elevated pressure and/or temperature?
  • Are you already using an expensive, large-size rheometer?
  • Or do you use atmospheric “standard” (Model Fann 35) viscometers because the large size and weight of other instruments restricts you from taking the instrument to remote well sites?
  • Do you need to rapidly move a pressurizable rheometer from one remote location to another?
  • Are you building a new mobile test van/truck where the size and weight of the instrumentation needs to be small enough to fit inside?

If you answer “yes” to any of the above questions, then the PVS is a good solution for your requirements.


  • Prevents very costly mistakes in the field by insuring that all fracturing fluids, drilling muds, and cements meet viscosity specifications before being pumped down-hole
  • Reduces the risk of procedural errors attributable to operator haste
  • Compact size, light weight and portability quickly allow the PVS Rheometer to be set up rapidly and perform real-time tests on multiple samples in virtually any location, even the most remote job site
  • Complete software package included in base price, eliminating the need for further development to make the system operational
  • Less susceptible to dust compared to other field instruments
  • Choice of cylinder geometry allows duplication of standard test methods
  • Better sensitivity allows measurement at much lower shear rates than previously available

Viscometer Specifications

  • Speed Range: 0.01 RPM to 1,000 RPM
  • Shear Rate Range: 0.01 sec-1 to 1,700 sec-1
  • Temperature Range: -40°C to 200°C
  • Pressure Range: Vacuum to 1,000 psi
  • Repeatability: ±0.2% of full scale range
  • Sample Volume: 20 to 140 ml, depending on geometry
  • Vapor Volume: 90 ml
  • Power Requirement: 115 or 230 VAC; 50 or 60 Hz
  • Computer: PC with a minimum of a Pentium II processor
  • Material of Construction: Hastelloy C-276 for wetted parts
  • Options: Optional immersion bath for temperature control of fluid samples is available


The American Petroleum Institute (API) has recommended standard procedures for three key areas in oil/gas exploration/drilling where the PVS Rheometer could be used: fracturing fluids, drilling muds and cements. These procedures require special speeds over defined time periods and temperatures. The references below include these standard procedures:

  • Recommended Practice on the Rheology and Hydraulics of Oil-Well Drilling Fluids. API Recommended Practice 13D, 3rd Edition, June 1, 1995
  • Recommended Practice Standard for Laboratory Testing Drilling Fluids. API Recommended Practice 13I, 5th Edition, June 1, 1995
  • Recommended Practice Standard Procedure for Field Testing Oil-Based Drilling Fluids. API Recommended Practice 13B-2 (RP 13B-2), 2nd Edition, December 1, 1991
  • Practice Standard Procedure for Field Testing Water-Based Drilling Fluids. API Recommended Practice 13B-1 (RP 13B-1), 1st Edition, June 1, 1990
  • Recommended Practices on Measuring the Viscous Properties of a Cross-linked Water-based Fracturing Fluid. API Recommended Practice 39 (RP 39), 3rd Edition, May 1998