Chemical injection regulation mechanism

Abstract

A regulation mechanism configured to automatically close off fluid flow through a line based on flow rate exceeding a predetermined level. This mechanism may be particularly beneficial when employed in conjunction with downhole chemical injection systems that are directed at well locations prone to becoming low pressure in nature. That is, in a conventional system, once the inherent pressure at the downhole end of an injection line exceeds that of the adjacent downhole environment, the flow rate of the column of fluid in the line may naturally increase as chemical is unintentionally emptied into the well. However, use of embodiments of the flow-based regulation mechanism detailed herein may near-automatically prevent such undesirable emptying of chemical into a low pressure well.

1 . A chemical injection regulation mechanism comprising:
 a valve disposed in a chamber for exposure to a column of injection fluid; and   a biasing device coupled to said valve and configured to allow sealing of the chamber upon a flow rate of the fluid thereinto reaching a predetermined level.   
     
     
         2 . The mechanism of  claim 1  wherein said biasing device is a spring configured to collapse upon exposure to forces determined based on the flow rate reaching the predetermined level. 
     
     
         3 . The mechanism of  claim 1  wherein said valve includes a piston with a sealing head at the end thereof to provide the sealing in response to the reaching of the predetermined level. 
     
     
         4 . The mechanism of  claim 1  wherein said valve is a shuttle valve with a flow restrictor therethrough. 
     
     
         5 . The mechanism of  claim 4  wherein the predetermined level is based at least in part on dimensions of the chamber, the valve and the flow restrictor. 
     
     
         6 . The mechanism of  claim 1  wherein said biasing device is coupled to an electrical control line to direct the sealing. 
     
     
         7 . The mechanism of  claim 1  wherein said valve is a first valve for the exposure to the injection fluid, the mechanism further comprising a second valve in fluid communication with said first valve for flow control release of the injection fluid from the mechanism. 
     
     
         8 . The mechanism of  claim 7  wherein the flow control release is governed at least in part by input from an adjacent sensor configured to provide data of a variety selected from a group consisting of flow related data and viscosity related data. 
     
     
         9 . A valve assembly comprising:
 an inlet line for accommodating a column of fluid;   a fluid flow regulation mechanism disposed in a chamber for exposure to the column of fluid; and   an outlet line to receive a flow of the fluid when pressure on the mechanism from the column is below a predetermined level.   
     
     
         10 . The assembly of  claim 9  wherein the fluid is a chemical injection fluid and the assembly is configured for disposal in a well, the assembly further comprising downhole hardware in fluid communication with said outlet for obtaining the flow to minimize occlusive buildup. 
     
     
         11 . The assembly of  claim 10  wherein said hardware is selected from a group consisting of well casing, a production screen, and production tubing. 
     
     
         12 . The assembly of  claim 10  wherein the well is selected from a group consisting of an offshore well and a substantially depleted well. 
     
     
         13 . The assembly of  claim 10  configured for disposal in an isolated zone within the well. 
     
     
         14 . A chemical injection manifold assembly comprising:
 a first regulation mechanism with a valve disposed in a chamber for regulating flow therethrough from a column of fluid in communication therewith, the regulating to allow the flow therethrough when a rate thereof is below a first predetermined level; and   a second regulation mechanism with another valve disposed in another chamber for regulating flow therethrough from the column of fluid in communication therewith, the regulating to allow the flow therethrough when a rate thereof is below a second predetermined level different from the first predetermined level.   
     
     
         15 . The assembly of  claim 14  wherein the first predetermined level is substantially different from the second predetermined level to ensure sequential closure of the mechanisms as the rate is increased. 
     
     
         16 . A method of regulating injection into a well, the method comprising:
 supplying an injection line into the well with a column of fluid mix;   flowing the fluid through a regulation mechanism to a target location in the well at below a predetermined rate; and   sealing off said flowing with the mechanism upon the fluid reaching a flow rate that exceeds the predetermined rate.   
     
     
         17 . The method of  claim 16  wherein the reaching of the flow rate exceeding the predetermined rate is aided by application of positive pressure delivered by equipment positioned at an oilfield surface adjacent the well. 
     
     
         18 . The method of  claim 16  further comprising running a pressure test on the injection line supported by said sealing. 
     
     
         19 . The method of  claim 16  wherein said sealing further comprises maintaining a continuous flow of fluid through the line. 
     
     
         20 . The method of  claim 16  wherein said sealing comprises shifting a valve of the mechanism to a closed position, said shifting including overcoming a biasing force of the valve with a force determined based on the flow rate as the predetermined rate is exceeded.