| Oil / Gas Well Drilling Fluids
Application
Drilling for oil and gas requires sensitive viscosity instrumentation,
especially at low-shear rates, to insure that production is optimized.
Field viscosity measurements on drilling and fracturing fluids are required
to predict flow performance under the extremely low shear conditions applicable
to solids transport down hole. Grace Instrument Company's Programmable
M3500 and M5500 Viscometer
provides sensitive, low-shear rate viscosity (LSRV) measurements and is
rapidly becoming the instrument of choice when Oil/Gas service companies
need to verify performance of expensive fracturing fluids and drilling
muds immediately prior to use.
Required Equipment
For analyzing drilling fluid rheological properties in the field,
Grace Instrument Company's M3500 Viscometer used with the API
standard rotors and bobs provides the complete solution for LSRV measurement
under a variety of tough field conditions.
Test Method
Having chosen one of the rotor and bob geometries mentioned above in Required
Equipment, the procedure involves running a test at two or more different
rotational speeds. The objective is to run at a very low speed between
0.01 and 0.1 rpm and a second rotational speed between 1.0 and 6.0 rpm.
These speeds would generally equate to shear rates below 0.1 sec-1 and
10 sec-1 respectively. If the instrument has sufficient viscosity measurement
range, a higher speed test at 600 rpm can also be considered.
On tests run by a field service company on three different fracturing
fluids, the following values were obtained:
Shear Rate Fluid A (cP) Fluid B (cP) Fluid C (cP)
5.11 sec-1 800 780 900
1,400 27,000 2,500
The above values show that the three different fluids would exhibit very
similar viscosity behavior at shear rates around 3254 sec-1 and higher,
but drastically different viscosity values at the lower shear rate of
0.0027 sec-1. In order to suspend particles down hole, the higher viscosity
value at very low shear rate is important; therefore, Fluid B is a much
better solution for the application.
Options
A more detailed test can be created using Grace Instrument Company's WingatherTM software
which provides automatic data collection. In addition, the software will
calculate yield point and plastic viscosity by using the appropriate mathematical
model which is included in the software.
Higher shear rate measurements can be made if appropriate. The Grace Instrument Company
M3500 Viscometer is capable of measuring shear
rates up to 3254 sec-1. The Grace Instrument Company M5500 viscometer
can measure up to
and beyond 1870 sec-1 with the sample pressurized up to 1000
psi. For making
measurements at low shear rates under pressurized conditions, please refer
to Grace Instrument Company Application, "Oil/Gas Exploration and Drilling".
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Oil / Gas Exploration And Drilling
Application
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 M5500 viscometer is an ideal replacement for
the standard Fann® Model 50 viscometers and Nordman viscometers 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.
Solution
The portable M5500 viscometer 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 Grace Instrument Company
M5500 bench-top viscometer:
- 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 viscometer?
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 viscometer 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 M5500
is a good solution for your requirements.
Benefits
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 M5500 viscometer
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
Model 5500 HTHP Viscometer Specifications
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Dimensions:
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8.5" x 12.5" x 24" (with bath)
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Weight:
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37 lbs (with bath)
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Construction:
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316 Stainless Steel (Hastelloy C available)
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Pressure Range:
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Vacuum to 1000 psi
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Temperature Range:
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32~500 degree Fahrenheit (°F)
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Speed Range:
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0.0001~1100 rpm continuous
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Sample Size:
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13~43 ml
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Shear Rate Range:
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0.00004~1870 sec-1
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Resolution:
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0.01% of full scale range or better
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Repeatability:
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±0.05% of full scale range
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Computer:
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PC with Pentium processor
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Voltage:
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115V or 230V (with transformer)
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Frequency:
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50 Hz or 60 Hz
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References
The American Petroleum Institute (API) has recommended standard procedures
for three key areas in Oil/Gas exploration/drilling where the M5500 viscometer
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
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