Apparatus, System and Method for Measuring the Properties of a Corrosive Liquid

Abstract

An apparatus and method used to determine the density and other properties of a corrosive liquid, such as drilling mud. The apparatus uses at least two sensor elements with ceramic facings spaced a known vertical distance apart and inserted into the fluid. The differential pressure measurement provided by these sensors is used to calculate the density of the liquid. This density measurement is then reported in real-time to an operator.

We claim: 
     
         1 . An apparatus for measuring in situ the density of a corrosive liquid, such as drilling mud, said apparatus comprising:
 at least two corrosion-resistant pressure sensors separated by a known vertical distance on the apparatus, wherein the at least two pressure sensors comprise corrosion-resistant fluid-contacting parts.   
     
     
         2 . The apparatus of  claim 1 , wherein the corrosion-resistant fluid-contacting parts comprise a ceramic material. 
     
     
         3 . The apparatus of  claim 2 , wherein the ceramic material is selected from the group consisting of dry ceramic-capacitive CERTEC® and high purity sapphire-ceramic®. 
     
     
         4 . The apparatus of  claim 1 , wherein the apparatus, in situ, is capable of transmitting real-time, continuous pressure measurements from the sensors, which pressure measurements are convertible to a density measurement of the corrosive liquid. 
     
     
         5 . The apparatus of  claim 1 , wherein the at least two pressure sensors are fixed to at least one rigid body, said rigid body comprising a float and at least one sensor housing. 
     
     
         6 . The apparatus of  claim 5 , wherein the at least two pressure sensors are housed in at least one sensor housing. 
     
     
         7 . The apparatus of  claim 5 , wherein the at least two pressure sensors are housed in two separate sensor housings. 
     
     
         8 . The apparatus of  claim 5 , wherein said sensor housing contains at least one pressure sensor, wherein further said sensor housing is attached to said float such that when the apparatus is in situ the sensor housing is submerged in the liquid below the float. 
     
     
         9 . The apparatus of  claim 8 , wherein said sensor housing contains at least two sensors spaced a vertical distance apart in the housing such that each sensor occupies a different vertical position in the liquid when the apparatus is in situ. 
     
     
         10 . The apparatus of  claim 3 , wherein the apparatus further comprises at least one redundant pressure sensor. 
     
     
         11 . The apparatus of  claim 1 , further comprising a sensor for measuring a physical or chemical property of the liquid. 
     
     
         12 . The apparatus of  claim 1 , wherein the apparatus further comprises at least one additional sensor for measuring a fluid property selected from the group consisting of pH, viscosity, salinity, chloride content, and temperature. 
     
     
         13 . The apparatus of  claim 1 , further comprising a power supply. 
     
     
         14 . The apparatus of  claim 1 , further comprising an electronic communication with a device to convert raw data provided by the sensors. 
     
     
         15 . The apparatus of  claim 5 , wherein the rigid body comprises PVC pipe. 
     
     
         16 . The apparatus of  claim 1 , wherein the pressure sensors comprise a stainless steel casing and a ceramic pressure sensing facing. 
     
     
         17 . A system for determining in real-time the density of a drilling mud, said system comprising:
 a sensor assembly,   a power supply in electronic communication with said sensor assembly,   a computational device in electronic communication with said sensor assembly,   a user interface in electronic communication with said computational device,   wherein said sensor assembly houses at least two corrosion-resistant pressure sensors, and   wherein further each pressure sensor is located in a fixed location on the sensor assembly providing a known vertical distance between the two sensors.   
     
     
         18 . The system of  claim 17 , wherein the pressure sensors comprise a ceramic facing. 
     
     
         19 . The system of  claim 17 , wherein the computational device comprises a computer. 
     
     
         20 . The system of  claim 19 , wherein the computer comprises a CPU. 
     
     
         21 . The system of  claim 19 , wherein the computational device further comprises a programmable logic controller in electronic communication with the at least two sensors and the computer. 
     
     
         22 . The system of  claim 17 , wherein the power supply comprises a battery box in electronic communication with a solar panel. 
     
     
         23 . The system of  claim 22 , wherein the battery box comprises a power converter and a battery, wherein further the power converter is in electronic communication with the battery, the solar panel, the computer, and the programmable logic controller. 
     
     
         24 . The system of  claim 19 , wherein the at least two sensors are in wireless communication with the programmable logic controller. 
     
     
         25 . The system of  claim 19 , wherein the computational device comprises a wireless communication device in electronic communication with the user interface. 
     
     
         26 . The system of  claim 25 , wherein the user interface is a cellular device. 
     
     
         27 . A method for measuring physical properties, including at least the density, of a corrosive liquid, such as drilling mud, said method comprising the steps of:
 a) pooling a corrosive liquid;   b) inserting into the liquid an apparatus comprising at least two corrosion resistant pressure sensors that are separated by a known vertical distance on the apparatus;   c) detecting a reading from each of two said sensors corresponding to the pressure experienced by each sensor while in the liquid, said reading comprising raw data provided by each sensor;   d) transmitting said raw data to a device;   e) using the device to convert the raw data into a density value for the corrosive liquid; and   f) transmitting said density value to a user interface.   
     
     
         28 . The method of  claim 27 , wherein additional sensors are used at step b). 
     
     
         29 . The method of  claim 28 , wherein said additional sensors detect raw data used in step c) related to the pH of the liquid. 
     
     
         30 . The method of  claim 28 , wherein said additional sensors detect raw data used in step c) related to the viscosity of the liquid. 
     
     
         31 . The method of  claim 28 , wherein said additional sensors detect raw data used in step c) related to the salinity of the liquid. 
     
     
         32 . The method of  claim 27 , wherein the user interface is co-located with the device of step d). 
     
     
         33 . The method of  claim 27 , wherein the user interface is remote from the device of step d). 
     
     
         34 . The method of  claim 33 , wherein the user interface is a cellular device.