Dielectric constant measurement method

Claim 1

Apparatus for measuring with greater accuracy water content of a multiphase gas stream flowing from a wellhead through a conduit such as a gather line in which the effects due to dispersion and/or water absorption in said gas stream as measurements occur, are minimized, comprising i. a capacitance probe in contact with said gas stream including first and second spaced-apart capacitive elements, said first element being an elongated sensor rod positioned within but electrically isolated relative to said conduit, ii. resonance circuit means including cooperative sensor oscillator means in circuit with said capacitance probe adapted to drive said capacitive probe at a frequency within a range of 40-300 MHz, said resonance circuit means generating a variable frequency signal whose change in frequency is indicative of the real part of the dielectric constant of said gas stream flowing between said first and second capacitive elements, iii. reference oscillator means for generating a fixed frequency signal, iv. mixing means in circuit with said circuit means and said resonance oscillator means for simultaneously comparing said generated variable frequency signal and said fixed frequency signal and thereafter generating a difference frequency signal, v. means in series with said mixing means for converting said generated frequency difference signal to an electrical signal indicative of said real part of the dielectric constant of said gas stream so as to accurately indicate said water content of said gas stream without error being introduced by said dispersion and/or absorption effects of said gas stream.

Claim 6

The method of measuring more accurately low concentrations of water in a multiphase natural gas stream flowing from a wellhead through a conduit such as a gather line by determining the real part of the complex dielectric constant of said natural gas stream by minimizing the adverse effects due to dispersion and/or water absorption as measurements occur, which comprises the steps of: i. inserting a capacitance probe into said natural gas stream, ii. driving said capAcitance probe by an alternating current circuit at a frequency within the range of from 40 to 300 MHz, iii. measuring the capacitance of said capacitance probe and iv. calculating the real part of the complex dielectric constant of said gas stream.

Claim 7

The method of measuring more accurately low concentrations of water in a multiphase natural gas stream flowing from a wellhead through a conduit such as a gather line by determining the real part of the complex dielectric constant of said natural gas stream by minimizing the adverse effects due to dispersion and/or water absorption as measurements occur, which comprises the steps of: i. inserting a capacitance probe into said natural gas stream, ii. driving said capAcitance probe by an alternating current circuit at a frequency within the range of from 40 to 300 MHz, iii. measuring the capacitance of said capacitance probe and iv. calculating the real part of the complex dielectric constant of said gas stream.