System and Method Of Preventing Flow Blocking When Using An Automated Pig Launcher

Abstract

A flow assurance system and method includes procedures to query current valve states and determine the likely effect of new valve states on product flow when using an automated pig launcher. The system and method allows for modulating the mainline bypass valve, kicker valve, and isolation valve between fully opened and fully closed states; prevents flow blocking of the pipeline during this modulation; enables new and different, as well as a broader range of, pig launching options for an automatic pig launcher; and integrates with existing automatic pig launchers.

What is claimed: 
     
         1 . A method of enabling a product flow system of a pipeline pig launcher to launch a pipeline pig into a mainline, the method comprising:
 determining, using indicator data from a mainline bypass valve indicator, a kicker valve indicator, and an isolation valve indicator, a current state of valves, the current state being in a range of fully opened to fully closed;   sending a request over a network to a microprocessor in communication with valve controllers to change the current state of one or more of the valves to a new state, the new state being different than the current state and in a range of fully opened to fully closed;   determining, using the microprocessor and the current state of valves left unchanged and the new state of valves to be changed, an effect on product flow, the effect being one of increasing the product flow or decreasing the product flow;   the microprocessor allowing the request if the product flow associated with the valves left unchanged is outside the predetermined range;   the microprocessor denying the request if the product flow associated with the valves left unchanged is within a predetermined range;   
       wherein the microprocessor includes a set of computer executable instructions stored on non-transitory computer readable medium. 
     
     
         2 . A method according to  claim 1  wherein the request is denied if at least one of the kicker valve and the isolation valve current state is closed and the requested new state of the mainline bypass valve is closed. 
     
     
         3 . A method according to  claim 1  further comprising:
 querying over the network pressure indicators located upstream and downstream of a mainline bypass valve; 
 calculating, using the microprocessor and pressure data from the pressure indicators, a differential pressure across the mainline bypass valve; and 
 comparing, using the microprocessor the differential pressure to a predetermined differential pressure. 
 
     
     
         4 . A method according to  claim 3  further comprising stopping modulation of a valve before it reaches the new state if the differential pressure is not within a predetermined range. 
     
     
         5 . A method according to  claim 4  further comprising reversing modulation of the stopped valve back to its last current state. 
     
     
         6 . A method according to  claim 1  further comprising verifying a current state of the valves prior to the sending a request. 
     
     
         7 . A method according to  claim 1  further comprising verifying the new state of the one or more valves after allowing the request. 
     
     
         8 . A method according to  claim 1  further comprising querying said valve indicators over the network. 
     
     
         9 . A method according to  claim 1  wherein the network is an internal network, an external network, or a combination of an internal and an external network. 
     
     
         10 . A method of enabling a product flow system of a pipeline pig launcher to launch a pipeline pig into a mainline, the method comprising, the automated pig launcher including a microprocessor, valve indicators, and valve controllers in network communication with one another, the method comprising:
 querying over the network a current state of valves as indicated by the valve indicators;   sending a request over the network to one or more of the valve controllers to change a current state of one or more valves to a new state, the new state being different than a current state and in a range of fully opened to fully closed;   determining, using the microprocessor and a current state of valves left unchanged and the new state of valves to be changed, an effect on product flow, the effect being one of increasing the product flow or decreasing the product flow;   the microprocessor allowing the request if the product flow associated with the valves left unchanged is outside the predetermined range;   the microprocessor denying the request if the product flow associated with the valves left unchanged is within a predetermined range;   wherein the microprocessor includes a set of computer executable instructions stored on non-transitory computer readable medium.   
     
     
         11 . A method according to  claim 10  wherein the request is denied if at least one of a kicker valve and an isolation valve current state is closed and the requested new state of a mainline bypass valve is closed. 
     
     
         12 . A method according to  claim 10  further comprising:
 querying over the network pressure indicators located upstream and downstream of a mainline bypass valve; 
 calculating, using the microprocessor and pressure data from the pressure indicators, a differential pressure across the mainline bypass valve; and 
 comparing, using the microprocessor, the differential pressure to a predetermined differential pressure. 
 
     
     
         13 . A method according to  claim 12  further comprising sending a command over the network to stop modulation of a valve before it reaches the new state if the differential pressure is not within a predetermined range. 
     
     
         14 . A method according to  claim 13  further comprising sending a command over the network to reverse modulation of the stopped valve back to its last current state. 
     
     
         15 . A method according to  claim 10  further comprising querying over the network a current state of the valves prior to the sending a request. 
     
     
         16 . A method according to  claim 10  further comprising verifying the new state of the one or more valves after allowing the request. 
     
     
         17 . A method according to  claim 10  wherein the network is an internal network, an external network, or a combination of an internal and an external network. 
     
     
         18 . A method of enabling a product flow system of a pipeline pig launcher to launch a pipeline pig into a mainline, the automated pig launcher including a microprocessor, valve indicators, and valve controllers in network communication with one another, the method comprising:
 determining, using the microprocessor and a current state of valves left unchanged and a new state of valves to be changed, an effect on product flow of a request to change one or more valves to a new state, the effect being one of increasing the product flow or decreasing the product flow;   the microprocessor allowing a request to change a valve to the new state if the product flow associated with the valves left unchanged is outside the predetermined range; and   the microprocessor denying the request if the product flow associated with the valves left unchanged is within a predetermined range;   
       wherein the microprocessor includes a set of computer executable instructions stored on non-transitory computer readable medium. 
     
     
         19 . A method according to  claim 18  further comprising:
 querying over the network a current state of valves as indicated by the valve indicators; and 
 sending over the network the request to change one or more valves to a new state using the valve controllers. 
 
     
     
         20 . A method according to  claim 18  further comprising:
 querying over the network pressure indicators located upstream and downstream of a mainline bypass valve; 
 calculating, using the microprocessor and pressure data from the pressure indicators, a differential pressure across the mainline bypass valve; and 
 comparing, using the microprocessor, the differential pressure to a predetermined differential pressure. 
 
     
     
         21 . A method according to  claim 20  further comprising sending a command over the network to stop modulation of a valve before it reaches the new state if the differential pressure is not within a predetermined range. 
     
     
         22 . A method according to  claim 21  further comprising sending a command over the network to reverse modulation of the stopped valve back to its last current state. 
     
     
         23 . A method according to  claim 18  further comprising verifying the new state of the one or more valves after the modulating. 
     
     
         24 . A method according to  claim 18  wherein the network is an internal network, an external network, or a combination of an internal and an external network.