Tank dewatering sensing and valve control method and apparatus

Abstract

A system for separating water from crude oil includes a bulk-storage tank for storing unrefined crude oil, a first pipe for delivering water separated from crude oil in the bulk-storage tank to a containment system, a second pipe for delivering crude oil to a shipping system, a first valve for controlling flow in the first pipe, a second valve for controlling flow in the second pipe, and a control system for controlling operation of the first and second valves. The control system has a control device for controlling the first and second valves, an acoustic sensor array mounted on the first pipe for sensing a sound pressure level during flow of water through the first pipe, means for comparing the sensed sound pressure level with a predetermined sound pressure threshold level characterizing flow of oil-water mixture through the pipe, and a control device for closing the first valve and opening the second valve when the measured sound pressure level reaches the sound pressure threshold level.

What is claimed: 
     
         1 . A system for separating water from crude oil, comprising a bulk-storage tank for storing unrefined crude oil; a first pipe for delivering water separated from crude oil in the bulk-storage tank to a containment system; a second pipe for delivering crude oil to a shipping system; a first valve for controlling flow in the first pipe; a second valve for controlling flow in the second pipe; and a control system for controlling operation of the first and second valves, the control system having a control device for controlling the first and second valves, an acoustic sensor array mounted on the first pipe for sensing a sound pressure level during flow of water through the first pipe, means for comparing the sensed sound pressure level with a predetermined sound pressure threshold level characterizing flow of oil-water mixture through the pipe; and means for closing the first valve and opening the second valve when the measured sound pressure level reaches the sound pressure threshold level. 
     
     
         2 . A system according to  claim 1 , wherein the control system comprises a computer connectable with a control device via a local computer network for operating the control device remotely. 
     
     
         3 . A system according to  claim 3 , wherein the computer comprises manual input means for actuating the control device. 
     
     
         4 . A system according to  claim 1 , wherein the control device includes an embedded controller having a processor for operating the first and second valve and including the comparing means. 
     
     
         5 . A system according to  claim 1 , wherein the control system further includes means mounted on the first pipe for sensing the conductivity of water flowing through the pipe and means for comparing the sensed conductivity with a conductivity threshold characterizing flow of water-oil mixture in the pipe, the processor being configured to adjust weighting associated with the measurement of the sound pressure level and the conductivity based on results of operation of the separating system. 
     
     
         6 . A method of operating a system for separating water from crude oil and including a bulk-storage tank for storing unrefined crude oil, a first pipe for delivering water separated from crude oil in the bulk-storage tank to a containment system, a second pipe for delivering crude oil to a shipping system, a first valve for controlling flow in the first pipe; and a second valve for controlling flow in the second pipe, the method comprising the steps of:
 actuating the first valve for initiating flow a water from the bulk-storage tank through the first pipe to the containment system;   sensing a sound pressure level of water flowing through the first pipe;   comparing the sensed sound pressure level with a predetermined sound pressure threshold level characterizing a sound pressure level of water-crude oil mixture; and   closing the first valve and opening the second valve in response to the sensed sound pressure level reaching the sound pressure threshold level.   
     
     
         7 . A method according to  claim 6 , comprising the steps of:
 sensing conductivity of water flowing through the first pipe;   comparing the sensed conductivity with a conductivity threshold characterizing flow of water-oil mixture in the pipe;   adjusting weighing associated with the measurement of the sound pressure level and the conductivity based on results of operation of the separating system; and   closing the first valve and opening the second valve in accordance with the adjusted weighting.   
     
     
         8 . A system for separating water from crude oil, comprising a bulk-storage tank for storing unrefined crude oil; a first pipe for delivering water separated from crude oil in the bulk-storage tank to a containment system; a second pipe for delivering crude oil to a shipping system; a first valve for controlling flow in the first pipe; a second valve for controlling flow in the second pipe; and a control system for controlling operation of the first and second valves, the control system including a control device for controlling operation of the first and second valves; sensor means arranged on a first pipe for measuring at least one specific property of liquid that flows through the first pipe and connected with the control device for communicating a measured value thereto, the control device having means for comparing the measured value with a predetermined threshold value of the at least one specific property characterizing flow of oil-water mixture having a specific oil-water ratio, and the control device closing the first valve and opening the second valve when the measured value reaches the predetermined threshold value; and a computer having a display with graphical user interface and connected via a Local Area Network with the control device for remotely operating the same in accordance with displayed data of a separating process. 
     
     
         9 . A system according to  claim 8 , wherein the control device has an embedded controller and an input/output (I/O) interface that connects the first and second valves and the sensor means with the controller. 
     
     
         10 . A system according to  claim 9 , wherein the controller comprises a processor for executing an application program for water crude oil separation. 
     
     
         11 . A system according to  claim 9 , wherein the controller has an internal storage for storing the application program. 
     
     
         12 . A system according to  claim 9 , wherein the Local Area Network is internet or a private wide-area network, and the application program is communicated to the controller via the Local Area Network. 
     
     
         13 . A system according to  claim 8 , wherein the sensor means comprises an acoustic sensor array for measuring a sound pressure level of the liquid. 
     
     
         14 . A system according to  claim 8 , wherein the sensor means comprises an accelerometer for measuring vibrations in the first pipe. 
     
     
         15 . An apparatus for controlling a water-crude oil separation process in a system including a bulk-storage tank for storing unrefined crude oil, a first pipe for delivering water separated from crude oil in the bulk-storage tank to a containment system, a second pipe for delivering crude oil to a shipping system, a first valve for controlling flow in the first pipe and a second valve for controlling flow in the second pipe, the apparatus comprising at least two sensor elements arrangeable on the first pipe for measuring at least two specific properties of liquid that flows through the first pipe; and a control device for controlling operation of the first and second valves, the control device including an embedded controller and an input/output (I/O) interface that connects the first and second valves and the at least two sensor elements with the controller, the controller comprising a processor for executing an application program for water-crude oil separation. 
     
     
         16 . An apparatus according to  claim 15 , wherein the controller has an internal storage for storing the application program. 
     
     
         17 . An apparatus according to  claim 15 , wherein the application program is communicated to the controller via internet or a private wide-area network from a remote computer. 
     
     
         18 . An apparatus according to  claim 15 , wherein the at least two sensor elements are formed, respectively, as acoustic sensor array for measuring a sound pressure level of a water flow through the first pipe and a conductivity sensor for measuring conductivity of the water flow. 
     
     
         19 . An apparatus according to  claim 15 , wherein the processor is configured to adjust weighting associated with the measurement of each of the at least two specific properties based on results of operation of the separating system. 
     
     
         20 . A method of operating a system for separating water from crude oil and including a bulk-storage tank for storing unrefined crude oil, a first pipe for delivering water separated from crude oil in the bulk-storage tank to a containment system, a second pipe for delivering crude oil to a shipping system, a first valve for controlling flow in the first pipe; and a second valve for controlling flow in the second pipe, the method comprising the steps of:
 actuating the first valve for initiating flow a water from the bulk storage tank through the first pipe to the containment system;   measuring the at least two specific properties of liquid that flows through the first pipe;   comparing measurements of the at least two specific properties with respective threshold values of the two specific properties characterizing a water-crude oil mixture; and   closing the first valve and opening the second valve in response to the measurement value of the at least two specific properties exceeding the threshold values thereof.   
     
     
         21 . A method according to  claim 20 , wherein the measuring step comprises
 measuring a sound pressure level of the liquid and conductivity of the liquid.   
     
     
         22 . A method according to  claim 21 , further comprising the step of adjusting weighing associated with the measurement of the sound pressure level and the conductivity based on results of operation of the separating system.