US 4,994,671 A · Apparatus and method for analyzing the composition of formation fluids

Abstract

A borehole apparatus for analyzing the composition of a formation fluid is disclosed and generally comprises a testing chamber, a means for directing a sample of fluid into the chamber, a light source which emits at least near infrared rays, a spectral detector, a data base means, and a processing means. The light source is preferably an incandescent lamp and the testing chamber includes a window which is substantially optically transparent to at least one near infrared light, and preferably also the near ultraviolet and visible light of the source. The light source is directed at least partly towards the window in the chamber either via collimation or fiber optics. The spectral detector means is preferably a spectrometer which detects and measures the spectra of the light which has been transmitted through and the light which is backscattered by the fluid sample. The preferred data base means stores the spectra at different pressures and temperatures of water, gas, and a plurality of oils. A determination of the composition of the fluid sample is made by the processing means by obtaining the spectrum of the source, and at least one of the transmitted light or backscattered light spectra, and by fitting the plurality of spectra in the data base to the obtained spectral information. A determination of a transition of the obtained fluid samples from mud filtrate to formation fluids is made by monitoring the visible light and/or near ultraviolet spectrum for changes in large molecule components.

Claims34

Dependent claims

An apparatus for analyzing the composition of a fluid comprising at least one of water, oil, and gas, the apparatus comprising:

(a) a light source means for emitting at least near infrared rays towards said fluid, said light source having a spectrum;
(b) spectral detector means for detecting the spectrum of at least near infrared rays which were at least one of scattered by and transmitted through said fluid;
(c) data base means for storing near infrared absorption spectral information of at least two of said water, oil and gas expected to be analyzed;
and
(d) processing means for obtaining said spectrum of said light source means and said spectrum detected by said spectral detector means and for substantially determining therefrom and from at least said near infrared absorption spectral information of said data base means the composition of said fluid.

2 more elements

A borehole apparatus for analyzing the composition of a fluid obtained from a formation, said fluid comprised of at least one of water, oil, and gas, the apparatus comprising:

(a) a testing region;
(b) means for directing a sample of said fluid obtained from said formation into said testing region;
(c) a light source means for emitting light rays towards said fluid obtained from said formation in said testing region, said light source having a determinable spectrum;
(d) spectral detector means for detecting the spectrum of resulting rays which were emitted by said light source and which were at least one of scattered by and transmitted through said fluid, wherein said testing region, said means for directing, said light source means, and said spectral detector means, together at least partially comprise a borehole tool operating downhole in said formation such that said spectrum of resulting rays are detected downhole in said formation;
(e) data base means for storing spectral information of at least two of said water, oil and gas expected to be analyzed;
and
(f) processing means for obtaining said light source means spectrum and said detected spectrum and for substantially determining therefrom and from said spectral information of said data base means the composition of said fluid.

4 more elements

Dependencies are inferred from the claim text.

Apparatus and method for analyzing the composition of formation fluids

Life of this patent

Apparatus and method for analyzing the composition of formation fluids

Life of this patent

Abstract

Claims34