# US 2014/0360257 A1 · System And Method For Estimating Oil Formation Volume Factor Downhole > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0360257 A1 - Document ID: US20140360257A1 - Status: Published application - Kind: A1 - Application number: 13/913,462 - Filed: 2013-06-09 - Published: 2014-12-11 - Earliest claimed: 2013-06-09 - Assignees: Schlumberger Technology Corporation - Applicants: Schlumberger Technology Corporation - Inventors: Kentaro Indo; Kai Hsu; Julian Pop - Web page: https://patentgrep.com/patent/US20140360257A1 ## CPC - E21B 49/087: {Well testing, e.g. testing for reservoir productivity or formation parameters} - E21B 47/113: using electrical indications; using light radiations - E21B 49/088: {combined with sampling} - E21B 49/10: using side-wall fluid samplers or testers - G01N 21/274: {Calibration, base line adjustment, drift correction} - G01N 21/31: Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry {(G01N21/72 takes precedence)} - G01N 21/85: Investigating moving fluids or granular solids - G01V 8/10: Detecting, e.g. by using light barriers (by reflection from the object G01S17/00) - E21B: EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS - G01N: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES (measuring or testing apparatus or processes other than immunoassay, involving enzymes or microorganisms C12M, C12Q) - G01V: GEOPHYSICS; GRAVITATIONAL MEASUREMENTS; DETECTING MASSES OR OBJECTS; TAGS (means for indicating the location of accidentally buried, e.g. snow-buried, persons A63B29/02) ## Abstract A system includes a downhole formation fluid sampling tool and a processor. An optical spectrometer of the downhole formation fluid sampling tool is able to measure an optical characteristic of a formation fluid flowing through the downhole formation fluid sampling tool over a plurality of wavelengths. The optical spectrometer generates optical spectra data indicative of this optical characteristic. The processor is designed to receive the optical spectra data generated by the optical spectrometer and to estimate a formation volume factor of the formation fluid based on the optical spectra data. ## Claims ### Claim 1 A system, comprising: a downhole formation fluid sampling tool configured for operation in a downhole environment; an optical spectrometer of the downhole formation fluid sampling tool, wherein the optical spectrometer is configured to measure an optical characteristic of a formation fluid flowing through the downhole formation fluid sampling tool over a plurality of wavelengths and configured to generate optical spectra data indicative of the optical characteristic; and a processor, configured to execute instructions disposed on a non-transitory, computer-readable medium to monitor or control operations of the system to: receive the optical spectra data generated by the optical spectrometer; estimate a composition of the formation fluid based on the optical spectra data; remove a color effect and a spectral offset from the optical spectra data to generate de-colored optical spectra data; and estimate a formation volume factor of the formation fluid based on the estimated composition and the de-colored optical spectra data. ### Claim 2 (canceled) ### Claim 3 (depends on 1) The system of claim 1, wherein the processor is configured to execute the instructions to monitor or control operations of the system to estimate respective vapor fractions for multiple components of the formation fluid based on the estimated composition and to estimate the formation volume factor based on the estimated respective vapor fractions of the multiple components. ### Claim 4 (depends on 3) The system of claim 3, wherein the processor is configured to execute the instructions to monitor or control operations of the system to estimate the respective vapor fractions for the multiple components by applying an artificial neural network (ANN) based model to the estimated composition. ### Claim 5 (canceled) ### Claim 6 (depends on 1) The system of claim 1, wherein the processor is configured to execute the instructions to monitor or control operations of the system to identify respective absorption coefficients for multiple components of the formation fluid and to estimate the formation volume factor of the formation fluid based on the respective absorption coefficients. ### Claim 7 (depends on 6) The system of claim 6, wherein the respective absorption coefficients are predetermined constants derived by applying an optimization algorithm to a database, wherein the database comprises prior optical spectra data and corresponding formation volume factor data. ### Claim 8 (depends on 1) The system of claim 1, wherein the processor is configured to execute the instructions to monitor or control operations of the system to estimate the formation volume factor based on formation fluid parameters and predetermined coefficients corresponding to a single wavelength of the optical spectra data. ### Claim 9 (depends on 8) The system of claim 8, wherein the single wavelength is approximately 1725 nm. ### Claim 10 (depends on 1) The system of claim 1, wherein the optical characteristic comprises an optical density of the formation fluid over a plurality of wavelengths. ### Claim 11 (depends on 1) The system of claim 1, wherein the downhole formation fluid sampling tool is disposed within a wellbore extending into a formation, via a wireline or a string of tubulars. ### Claim 12 (depends on 1) The system of claim 1, wherein the processor is configured to execute the instructions to monitor or control operations of the system to estimate the formation volume factor while the formation fluid is flowing through the downhole formation fluid sampling tool. ### Claim 13 A method, comprising: receiving optical spectra data into a processor, the optical spectra data being representative of optical characteristics of a formation fluid flowing through a downhole formation fluid sampling tool; estimating, via the processor, a composition of the formation fluid based on the optical spectra data; removing, via the processor, a color effect and a spectral offset from the optical spectra data to generate de-colored and de-scattered optical spectra data; and estimating, via the processor, a formation volume factor of the formation fluid based on the estimated composition and the de-colored and de-scattered optical spectra data. ### Claim 14 (depends on 13) The method of claim 13, comprising determining, via the processor, a fluid type corresponding to the formation fluid based on the optical spectra data, and estimating, via the processor, the formation volume factor of the formation fluid when the formation fluid is determined to be a crude oil. ### Claim 15 (canceled) ### Claim 16 (depends on 13) The method of claim 13, comprising estimating, via the processor, respective vapor fractions of multiple components of the formation fluid based on the estimated composition, and estimating, via the processor, the formation volume factor based on the estimated vapor fractions. ### Claim 17 (depends on 13) The method of claim 13, comprising: estimating, via the processor, a de-colored and de-scattered stock tank oil spectrum of the formation fluid by determining a spectral offset and coloring present in stock tank optical spectra data, and removing the spectral offset and the coloring from the stock tank optical spectra data to generate the de-colored and de-scattered stock tank oil spectrum; and estimating, via the processor, the formation volume factor based on the estimated stock tank oil spectrum. ### Claim 18 (depends on 17) The method of claim 17, wherein estimating the de-colored and de-scattered stock tank oil spectrum of the formation fluid comprises averaging predetermined stock tank oil spectra corresponding to prior samples of the formation fluid at a stock tank oil condition. ### Claim 19 A method, comprising: receiving formation fluid data into a processor, the formation fluid data being representative of characteristics of a formation fluid flowing through a downhole formation fluid sampling tool; and estimating, via the processor, a volume ratio of the formation fluid at formation conditions to the formation fluid at standard conditions based on the formation fluid data while the downhole formation fluid sampling tool is disposed within a wellbore extending into a formation. ### Claim 20 (depends on 19) The method of claim 19, wherein the formation fluid data comprises optical spectra data representative of an optical characteristic of the formation fluid, the optical characteristic being measured via a spectrometer onboard the downhole formation fluid sampling tool. ### Claim 21 (depends on 13) The method of claim 13, wherein estimating the formation volume factor of the formation fluid comprises using a mathematical relationship of the form B o = Ω STO Ω L . O . · ( 1 + ɛ ~ C   1  ρ ~ C   1 + ɛ ~ C   2  ρ ~ C   2 + ɛ ~  C   3  -  5  μ C   3  -  5  ρ ~ C   3  -  5 + ɛ ~ C   6 +  μ C   6 + ( 1 - μ C   3  -  5 )  ρ ~ C   3  -  5 - μ C   6 + + 1 ) where Bo is the formation volume factor, ΩSTO is an optical spectra of the formation fluid at standard conditions, ΩLO is an optical spectra of the formation fluid at formation conditions, {tilde over (ε)}C1 is an absorption coefficient of a methane component of the formation fluid, {tilde over (ε)}C2 is an absorption coefficient of an ethane component of the formation fluid, {tilde over (ε)}C3-5 is an absorption coefficient of propane to pentane components of the formation fluid, {tilde over (ε)}C6+ is an absorption coefficient of hexane and heavier components of the formation fluid, {tilde over (ρ)}C1 is a weight fraction of the methane component of the formation fluid to the hexane and heavier components of the formation fluid, {tilde over (ρ)}C2 is a weight fraction of the ethane component of the formation fluid to the hexane and heavier components of the formation fluid, {tilde over (ρ)}C3-5 is a weight fraction of the propane to pentane components of the formation fluid to the hexane and heavier components of the formation fluid, μC3-5 is a vapor fraction of propane to pentane components of the formation fluid, and μC6+ is a vapor fraction of hexane and heavier components of the formation fluid.