Downhole chemical injection method and system for use in ESP applications

Abstract

Provided is a chemical injection pump that is installed below an electric submersible pump. In general, the chemical injection pump is either driven by an electric motor that draws power from the electric submersible pump motor or from energized fluid leaving the electric submersible pump output port. The electric submersible pump provides electric or hydraulic power to run the chemical injection pump. Therefore, no surface chemical injection pump is required and hence less space is needed.

That which is claimed is: 
     
       1. A method for protecting electric submersible pumps from damages from downhole conditions comprising the steps of:
 with a damage resistant apparatus comprising:
 an electric submersible pump component, the electric submersible pump component including an electric pump having a top electric pump portion and a bottom electric pump portion, a seal having a top seal portion and bottom seal portion, an electric submersible pump motor having a top electric submersible pump motor portion and a bottom electric submersible pump motor portion, and a monitoring tool having a top monitoring tool portion and a bottom monitoring tool portion, 
 the electric pump having an electric pump intake operable to receive production fluids, the top seal portion adapted to be connected to the bottom electric pump portion and the bottom seal portion adapted to be connected to the top electric submersible pump motor portion, the bottom electric submersible pump motor portion adapted to be connected to the top monitoring tool portion, 
 the bottom monitoring tool portion adapted to be connected to a chemical injection pump component operable to be disposed in the well, the chemical injection pump component including a chemical injection pump motor having a top chemical injection pump motor portion and a bottom chemical injection pump motor portion, and a chemical pump having a top chemical pump portion and a bottom chemical pump portion, a chemical injection pump having an intake port adapted to be connected to a capillary tube operable to receive an inhibitor from a tank at a surface, 
 the bottom chemical injection pump motor portion adapted to be connected to the top chemical pump portion, and the top chemical injection pump motor portion adapted to be connected to the bottom monitoring tool portion such that the inhibitor is pumped into the well to protect the electric submersible pump component from downhole conditions, 
 
 placing the apparatus in a casing in the well, the well having a downhole portion, 
 providing the inhibitor from the surface through the capillary tube to the intake port of the chemical injection pump to reduce damage to the electric submersible pump; and 
 pumping the inhibitor into reservoir fluids in the well using the chemical injection pump such that the reservoir fluids contain the inhibitor to protect against damage from downhole conditions. 
 
     
     
       2. The method of  claim 1 , further wherein the inhibitor is provided through the capillary tube to the intake port such that the inhibitor achieves a concentration of 5 to 20 ppm in a water phase of the production fluids. 
     
     
       3. The method of  claim 1 , wherein the chemical injection pump component is a positive displacement pump. 
     
     
       4. The method of  claim 1 , wherein the chemical injection pump component is a centrifugal pump. 
     
     
       5. The method of  claim 1 , wherein the chemical injection pump is electrically driven with a power supply from the electric submersible pump motor. 
     
     
       6. The method of  claim 2 , wherein power is supplied for the apparatus by at least one electric cable. 
     
     
       7. The method of  claim 1 , wherein the inhibitor is provided continuously. 
     
     
       8. A method comprising the steps of:
 with an apparatus comprising:
 an electric submersible pump component, the electric submersible pump component including an electric pump having a top electric pump portion and a bottom electric pump portion, a seal having a top seal portion and bottom seal portion, an electric submersible pump motor having a top electric submersible pump motor portion and a bottom electric submersible pump motor portion, and a monitoring tool having a top monitoring tool portion and a bottom monitoring tool portion, 
 the electric pump having an electric pump intake being operable to receive production fluids, the top seal portion adapted to be connected to the bottom electric pump portion and the bottom seal portion adapted to be connected to the top electric submersible pump motor portion, the bottom electric submersible pump motor portion adapted to be connected to the top monitoring tool portion, 
 the bottom monitoring tool portion adapted to be connected to a chemical injection pump component, the chemical injection pump component having an intake port adapted to be connected to a capillary tube operable to receive an inhibitor, the chemical injection pump component having a top chemical injection pump portion adapted to be connected to the bottom monitoring tool portion; and 
 the electric pump further including an electric pump discharge operable to discharge the production fluids, the electric pump discharge having an output port adapted to be connected to a pressurized fluid passage, the pressurized fluid passage operable to deliver fluids from the electric pump discharge to the chemical injection pump component such that the inhibitor is pumped into the well to protect the electric submersible pump component from downhole conditions, 
 
 placing the apparatus in a casing in the well, 
 providing the inhibitor through the capillary tube to the intake port of the chemical injection pump; 
 pumping the inhibitor into reservoir fluids using the chemical injection pump component. 
 
     
     
       9. The method of  claim 8 , further wherein the inhibitor is provided through the capillary tube to the intake port such that the inhibitor achieves a concentration of 5 to 20 ppm in water produced at the surface. 
     
     
       10. The method of  claim 8 , wherein the chemical injection pump component is a turbine. 
     
     
       11. The method of  claim 8 , wherein the chemical injection pump component is a jet pump. 
     
     
       12. The method of  claim 8 , wherein the inhibitor is provided continuously.