# US 8,464,790 B2 · Brine salinity from sound speed > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,464,790 B2 - Document ID: US8464790B2 - Status: Granted - Kind: B2 - Application number: 12/944,049 - Filed: 2010-11-11 - Published: 2011-05-19 - Granted: 2013-06-18 - Earliest claimed: 2009-11-17 - Assignees: Baker Hughes Incorporated - Applicants: Rocco DiFoggio - Inventors: Rocco DiFoggio - Web page: https://patentgrep.com/patent/US8464790B2 ## CPC - E21B 47/107: using acoustic means - E21B 49/005: {Testing the nature of borehole walls or the formation by using drilling mud or cutting data} - G01V 11/00: Prospecting or detecting by methods combining techniques covered by two or more of main groups G01V1/00 - G01V9/00 - E21B: EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS - 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 Temperature and pressure measurements that are made downhole are used to predict a compressional wave velocity for pure water under downhole conditions. The predicted velocity and a measured compressional velocity of a formation brine are used in a non-iterative method to estimate a value of the formation brine salinity that is between 0 and 1. ## Claims ### Claim 1 An apparatus configured to evaluate a formation fluid, the apparatus comprising: a carrier configured to be conveyed in a borehole in the formation; a sample chamber for receiving a sample of the formation fluid; a transducer on the carrier configured to receive an acoustic pulse from a sample of the formation fluid in the sample chamber; and at least one processor configured to use: (I) a travel time of the acoustic pulse over a known distance, and (II) a predicted value of a velocity of water under borehole conditions, to estimate a salinity of the formation fluid using a non-iterative method. ### Claim 2 (depends on 1) The apparatus of claim 1 wherein the at least one processor is further configured for at least one of: (i) reservoir evaluation, and (ii) reservoir development. ### Claim 3 (depends on 1) The apparatus of claim 1 wherein the transducer is part of a transducer assembly further comprising a first reflector and a second reflector and wherein the known distance further comprises a distance between the first reflector and the second reflector. ### Claim 4 (depends on 1) The apparatus of claim 1 further comprising a temperature sensor and a pressure sensor and wherein the at least one processor is further configured to obtain the predicted value as a polynomial function of an output of the pressure sensor and \an output of the temperature sensor. ### Claim 5 (depends on 1) The apparatus of claim 1 wherein the at least one processor is further configured to non-iteratively estimate the salinity of the borehole fluid solving a quartic equation. ### Claim 6 (depends on 1) The apparatus of claim 1 wherein the carrier is part of a downhole assembly selected from: (i) a bottomhole assembly conveyed on a drilling tubular, and (ii) a logging instrument conveyed on a wireline. ### Claim 7 (depends on 1) The apparatus of claim 1, wherein the transducer is configured to transmit the acoustic pulse. ### Claim 8 A method of evaluating a formation fluid, the method comprising: conveying a carrier into a borehole; using a transducer on the carrier to receive an acoustic pulse from a sample of the formation fluid in a sample chamber; and using at least one processor for estimating a salinity of the formation fluid using a non-iterative method from a travel time of the acoustic pulse over a known distance in the sample of the formation fluid and a predicted value of a velocity of water under borehole conditions. ### Claim 9 (depends on 8) The method of claim 8 further comprising using the at least one processor for at least one of: (i) reservoir evaluation, and (ii) reservoir development. ### Claim 10 (depends on 8) The method of claim 8 wherein the transducer is part of a transducer assembly further including a first reflector and a second reflector and wherein using the traveltime of the acoustic pulse over the known distance further comprises using a distance between the first reflector and the second reflector. ### Claim 11 (depends on 8) The method of claim 8 further obtaining the predicted value as a polynomial function of an output of a pressure sensor and an output of a temperature sensor. ### Claim 12 (depends on 8) The method of claim 8 further comprising non--iteratively estimating the salinity of the borehole fluid solving a quartic equation. ### Claim 13 (depends on 8) The method of claim 8 further comprising using, for the carrier, one of: (i) a bottomhole assembly conveyed on a drilling tubular, and (ii) a logging instrument conveyed on a wireline. ### Claim 14 (depends on 8) The method of claim 8, further comprising generating the acoustic pulse. ### Claim 15 An apparatus configured to evaluate a formation fluid, the apparatus comprising: a carrier configured to be conveyed in a borehole in the formation; a transducer on the carrier configured to receive an acoustic pulse from a sample of the formation fluid; and at least one processor configured to use: (I) a travel time of the acoustic pulse over a known distance, and (II) a predicted value of a velocity of water under borehole conditions, to estimate a salinity of the formation fluid using a non-iterative method; wherein the transducer is part of a transducer assembly further comprising a first reflector and a second reflector, and wherein the known distance further comprises a distance between the first reflector and the second reflector.