Patent ID: 6507401
Filing Date: 2003-01-14
Classification: E21B,G01N

Abstract:
A method of determining the concentration of at least one predetermined constituent in a fluid flowing through a downhole portion a well, comprising the steps of:a) generating a beam of light; b) directing said beam of light into said fluid flowing through said downhole portion of said well so as to cause one portion of said light to be absorbed by said fluid and another portion of said light to travel through said fluid and emerge from said fluid, said emerging light having been scattered by said fluid and comprised of a plurality components each of which has a different wavelength; c) transmitting at least a portion of said light that traveled through said fluid and emerged therefrom to a location proximate to the surface of the earth; d) measuring the intensity of each of at least a portion of said components of said transmitted light, each of said light components in said portion of light components having a wavelength falling within a predetermined range of wavelengths, said light component intensity measurements being conducted at said location proximate said surface; e) normalizing at least those of said measured light component intensities having selected wavelengths by dividing said intensities by a characteristic derived from said measured component intensities so as to reduce the effect of said scattering of said light components; f) raising each of said normalized light component intensities at said selected wavelengths by a respective exponent, said exponents being any non-zero numbers; g) multiplying each of said exponentially raised normalized light component intensities at said selected wavelengths by a predetermined weighting factor based upon its respective wavelength so as to obtain a weighted and normalized light component intensity at each of said selected wavelengths; and h) combining said weighted and normalized light component intensities at said selected wavelengths so as to calculate said concentration of said constituent.