Method of controlling salinity of an injection water during commissioning of an injection well

Patent metadata

Field	Value
Publication number	US-11162311-B2
Application number	US-201816637285-A
Country	US
Kind code	B2
Filing date	Aug 9, 2018
Priority date	Aug 10, 2017
Publication date	Nov 2, 2021
Grant date	Nov 2, 2021

Abstract

An integrated system includesa desalination plant including a reverse osmosis (RO) array to produce an RO permeate blending stream and a nanofiltration (NF) array to produce an NF permeate blending stream.The integrated system also includes a blending system.a control unit, andan injection system for an injection well that penetrates an oil-bearing layer of a reservoir.The blending system is to blend the RO permeate blending stream and the NF permeate blending stream to produce a blended injection water stream.The control unit is to dynamically alter operation of the blending system to adjust amounts of at least one of the RO permeate blending stream and the NF permeate blending stream to alter the composition of the blended injection water stream from an initial composition to a target composition.

First claim

The invention claimed is:

1. An integrated system comprising:
a desalination plant comprised of a reverse osmosis (RO) array to produce an RO permeate blending stream and a nanofiltration (NF) array to produce an NF permeate blending stream;
a blending system;
a control unit; and
an injection system for an injection well that penetrates an oil-bearing layer of a reservoir, the injection system comprising an injection line and at least one injection pump;
wherein the blending system is configured to blend the RO permeate blending stream and the NF permeate blending stream to produce a blended injection water stream and to pass the blended injection water stream to the injection system,
wherein the control unit is configured to dynamically alter operation of the blending system to adjust amounts of at least one of the RO permeate blending stream and the NF permeate blending stream to alter the composition of the blended injection water stream from an initial composition to a target composition, and wherein the control unit is configured to dynamically alter operation of the blending system to adjust the amounts of the at least one of the RO permeate blending stream and the NF permeate blending stream by adjusting an amount of at least one of the RO permeate and NF permeate discharged from the blending system via an RO permeate dump line or an NF permeate dump line, respectively.

2. The integrated system of claim 1 wherein the blending system is further configured to blend the RO permeate blending stream and the NF permeate blending stream with a high salinity water blending stream having a salinity of from 17,500 to 50,000 mg/L to produce the blended injection water stream, and
wherein the control unit is configured to dynamically alter operation of the blending system to adjust the amounts of the at least one of the RO permeate blending stream and the NF permeate blending stream and an amount of the high salinity water blending stream to alter the composition of the blended injection water stream from the initial composition to the target composition.

3. The integrated system of claim 1 , wherein the control unit is to dynamically alter operation of the blending system to alter the composition of the blended injection water stream from the initial composition to the target composition by following a concentration profile for decreasing the salinity or ionic strength of the blended injection water stream.

4. The integrated system of claim 3 , wherein the control unit is configured to receive the concentration profile from a source external to the control unit.

5. The integrated system of claim 1 , wherein the control unit is configured to monitor a pressure in the injection well or at a wellhead of the injection well, in real time, for an increase in pressure to a value at or above a threshold value; and,
when the control unit detects an increase in pressure to a value at or above the threshold value, the control unit either ceases to dynamically alter the composition of the blended injection water stream or dynamically alters the composition of the blended injection water stream by following a recovery concentration profile for increasing the salinity or ionic strength of the blended injection water stream, until the pressure falls to below the threshold value.

6. The integrated system of claim 1 , wherein the control unit is configured to monitor a flow rate of the blended injection water stream in the injection line of the injection system downstream of the at least one injection pump, in real time, for a decrease in flow rate to at or below a threshold value; and,
if the control unit detects a decrease in flow rate to a value at or below the threshold value, the control unit either ceases to dynamically alter the composition of the blended injection water stream or dynamically alters the composition of the blended injection water stream by following a recovery concentration profile for increasing the salinity or ionic strength of the blended injection water stream, until the flow rate increases to above the threshold value.

7. The integrated system of claim 5 , wherein the control unit is configured to receive the recovery concentration profile from a source external to the control unit.

8. The integrated system of claim 1 , wherein the blending system is further configured to blend the RO permeate blending stream and the NF permeate blending stream with a fines stabilizing blending stream to produce the blended injection water stream wherein the fine stabilizing blending stream comprises an aqueous solution of at least one fines stabilizing additive, and
wherein the control unit is configured to dynamically alter operation of the blending system to adjust the amount of fines stabilizing blending stream to alter the composition of the blended injection water stream from the initial composition to the target composition.

9. The integrated system of claim 8 wherein the control unit is configured to dynamically alter operation of the blending system to adjust the amount of fines stabilizing blending stream to alter the composition of the blended injection water stream by following a concentration profile or recovery concentration profile that includes changes to the concentration of the fines stabilizing additive in the blended injection water stream.

10. A method for operating an integrated system comprising:
a desalination plant comprised of a reverse osmosis (RO) array and a nanofiltration (NF) array;
a blending system;
a control unit;
an injection system for an injection well that penetrates an oil-bearing layer of a reservoir;
the method comprising:
introducing a high salinity water feed to the desalination plant;
producing an RO permeate blending stream using the RO array of the desalination plant;
producing an NF permeate blending stream using the NF array of the desalination plant;
blending the RO permeate blending stream and the NF permeate blending stream in the blending system; and
dynamically altering operation of the blending system during commissioning of the injection well to adjust amounts of at least one of the RO permeate blending stream and the NF permeate blending stream to alter the composition of the blended injection water stream from an initial composition to a target composition for a main phase of a low salinity waterflood by following a concentration profile for decreasing the salinity or ionic strength of the blended injection water stream, wherein dynamically altering the operation of the blending system during the commissioning of the injection well to adjust the amounts of the at least one of the RO permeate blending stream and the NF permeate blending stream to alter the composition of the blended injection water stream from the initial composition to the target composition for the main phase of the low salinity waterflood by following the concentration profile for decreasing the salinity or ionic strength of the blended injection water stream includes adjusting an amount of at least one of the RO Permeate and NF permeate discharged from the blending system via an RO permeate dump line or an NF permeate dump line, respectively.

11. The method of claim 10 , wherein the desalination plant has a high salinity water by-pass line configured to pass a portion of the high salinity water feed stream as a high salinity blending stream to the blending system wherein the high salinity water feed stream has a total dissolved solids content in the range of 17,500 mg/L to 50,000 mg/L and wherein dynamically altering operation of the blending system during commissioning of the injection well further comprises adjusting an amount of the high salinity water blending st

Assignees

• Bp Exploration Operating Co Ltd

Inventors

• Collins Ian Ralph
• Couves John William
• Crouch John Henry
• Williams John Dale

Classifications

• B01D61/029

  Multistep processes comprising different kinds of membrane processes selected from reverse osmosis, hyperfiltration or nanofiltration · CPC title

• B01D61/12 Primary

  Controlling or regulating · CPC title

• E21B49/008

  by injection test; by analysing pressure variations in an injection or production test, e.g. for estimating the skin factor (measuring pressure E21B47/06) · CPC title

• B01D2311/06

  Specific process operations in the permeate stream · CPC title

• E21B43/20 Primary

  Displacing by water · CPC title