Crude hydrocarbon fluids demulsification system

Abstract

An elongate, horizontally level, pipe includes a circumferential wall. The pipe flows, within the circumferential wall, process fluid that includes a first fluid and a second fluid immiscible with the first fluid. The first fluid and the second fluid are separated by an interfacial layer. Heating coils are disposed within the pipe. Each heating coil passes through an interior region of the pipe between the circumferential wall at a respective height from a bottom of the pipe. The heating coils generate heat. A controller is connected to the heating coils. The controller triggers at least one of the heating coils that is nearest to a location of the interfacial layer within the interior region to apply heat to the interfacial layer. The heat is sufficient to at least partially demulsify the interfacial layer.

What is claimed is: 
     
         1 . A flowline fluid demulsification system comprising:
 an elongate, horizontally level, pipe comprising a circumferential wall, the pipe configured to flow, within the circumferential wall, process fluid comprising a first fluid and a second fluid immiscible with the first fluid, the first fluid and the second fluid separated by an interfacial layer;   a plurality of heating coils disposed within the pipe, each heating coil passing through an interior region of the pipe between the circumferential wall at a respective height from a bottom of the pipe, the plurality of heating coils configured to generate heat; and   a controller connected to the plurality of heating coils, the controller configured to trigger at least one of the plurality of heating coils that is nearest to a location of the interfacial layer within the interior region to apply heat to the interfacial layer, the heat sufficient to at least partially demulsify the interfacial layer.   
     
     
         2 . The system of  claim 1 , wherein the plurality of heating coils passes through the interior region of the pipe between the circumferential wall at different heights along an entire axial length of the pipe. 
     
     
         3 . The system of  claim 1  wherein the plurality of heating coils comprises an electrical heating coil further comprising an electrical power supply. 
     
     
         4 . The system of  claim 1 , wherein the plurality of heating coils comprises:
 a first heating coil passing through the interior region at a first height from the bottom of the pipe that is substantially one-third of a radius of the pipe; and   a second heating coil passing through the interior region at a second height from the bottom of the pipe that is substantially one-half of the radius of the pipe.   
     
     
         5 . The system of  claim 1 , wherein each of the plurality of heating coils is encased in a protective and heat-conductive sheath configured to protect the heating coils. 
     
     
         6 . The system of  claim 1 , wherein the process fluid comprises water and hydrocarbon liquids, wherein the heat generated by the plurality of heating coils is sufficient to at least partially demulsify the water and hydrocarbon liquids. 
     
     
         7 . The system of  claim 1 , further comprising a separator comprising a separator inlet fluidically coupled to an outlet of the pipe, the separator configured to receive the fluid with a heated interfacial layer at the separator inlet. 
     
     
         8 . The system of  claim 7 , further comprising:
 a demulsifier configured to at least partially demulsify the interfacial layer; and   a demulsifier inlet configured to receive the demulsifier.   
     
     
         9 . The system of  claim 8 , wherein the demulsifier inlet is positioned on the pipe. 
     
     
         10 . A method comprising:
 receiving, in a flowline, process fluid comprising a first fluid and a second fluid immiscible with the first fluid, the first fluid and the second fluid separated by an interfacial emulsion layer, the flowline comprising a plurality of heating coils, each heating coil passing through an interior region of a pipe between a circumferential wall at a respective height from a bottom of the pipe, the plurality of heating coils configured to generate heat; and   selectively triggering at least one of the plurality of heating coils within a pre-heater to heat the interfacial layer based on a height of the interfacial layer from the bottom of the pipe.   
     
     
         11 . The method of  claim 10  wherein the process fluid comprises water and hydrocarbons. 
     
     
         12 . The method of  claim 10  further comprising at least partially demulsifying the process fluid in response to applying heat to the interface height of the process fluid. 
     
     
         13 . The method of  claim 10 , wherein each of the plurality of heating coils is positioned at a different height within the pre-heater. 
     
     
         14 . The method of  claim 10  wherein the plurality of heating coils comprises an electrical heating coil. 
     
     
         15 . The method of  claim 10  wherein the plurality of heating coils comprises two heating coils. 
     
     
         16 . The method of  claim 10  further comprising sending the process fluid from the pre-heater to a separator. 
     
     
         17 . The method of  claim 16  further comprising further demulsifying the process fluid within the separator. 
     
     
         18 . The method of  claim 17  wherein demulsifying the process fluid within the separator comprises using demulsifying chemicals, electrostatic grids, ultrasonics, or sand jetting. 
     
     
         19 . A method comprising:
 receiving a process fluid by a pre-heater;   selecting from a plurality of heating coils to power;   applying heat to an interface of the process fluid by a heating coil selected;   at least partially demulsifying the process fluid in response to applying heat to an interface height of the process fluid;   sending the process fluid from the pre-heater to a separator; and   further demulsifying the process fluid within the separator.