OFITE, 11302 Steeplecrest Dr., Houston, TX 77065 USA / Tel: 832-320-7300 / Fax: 713-880-9886 / www.ofite.com
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The problems of gas migration after cementing operations have been well
documented. The costs associated with these problems, as well as stricter
environmental regulations, have forced gas well operators to look for
methods to minimize gas migration.
The OFITE Gas Migration Tester helps predict and overcome the potential
for gas migration after cementing. This unit evaluates both the potential and
severity of gas migration at downhole conditions with the recommended
slurry. This allows for the design of the most economical and reliable cement
slurry for a particular well.
A test cell is filled with a cement slurry and placed into a heating jacket. The
test cell is fitted with a piston above the slurry and a screen below. A back
pressure regulator below the test cell applies back flow pressure. Hydrostatic
pressure is applied to the piston and nitrogen/gas pressure is applied through
the piston tubing and onto the cement slurry. As the slurry hardens, if the
cement is sufficiently permeable, the nitrogen pressure will force the gas
through the back pressure regulator to be collected and measured. Both
filtrate and gas volume are collected.
Introduction
Description
Inlet Cap
Cell
Piston
Screen
Cement
Cement
N
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Gas - 500 PSI
(3,447.5 kPa)
To Computer
Pressure Transducer
Hydrostatic / Overburden
Pressure 1,000 PSI
(6,895 kPa)
To Computer
Pore Pressure Transducer
Back Pressure
300 PSI (2,068.5 kPa)
Back Pressure Regulator
Filtrate
