CLEANING SAGD EQUIPMENT WITH SUPERCRITICAL CO2

• US 20180328156A1
• Filed: 05/14/2018
• Published: 11/15/2018
• Est. Priority Date: 05/12/2017
• Status: Active Grant

• Current Assignee: Conocophillips Company (ConocoPhillips)
• Original Assignee: Conocophillips Company (ConocoPhillips)
• Inventors: SLATER, Peter N.
• Granted Patent: US 10,760,393 B2
• Time in Patent Office: Days
• CPC Class Codes: E21B 37/06 using chemical means for preventing or limiting , e.g. eliminating, the deposition of paraffins or like substances
• CPC Class Codes: E21B 43/2408 SAGD in combination with other methods
• CPC Class Codes: E21B 43/34 Arrangements for separating materials produced by the well

Abstract

SAGD equipment including steam generating equipment may be cleaned using supercritical carbon dioxide. Supercritical carbon dioxide is a fluid state of carbon dioxide where it is held at or above its critical temperature and critical pressure. Supercritical carbon dioxide has exceptional solvent qualities that can dissolve, soften, or dislodge the refractory fouling deposits in the SAGD equipment.

Claims

1. ) A steam generation system for producing heavy oil with steam, comprising:

a) a steam generator system having a feedwater inlet for receiving a feedwater to be converted to steam;

b) said steam generator system having an outlet fluidly connected to an injection well for injecting steam into a reservoir;

c) said steam generator system having a second inlet for receiving a supercritical CO2 (sCO2) from a sCO2 generator; and

d) said steam generator system having a second outlet fluidly connected to a container for receiving foulants and spent sCO2 existing from said steam generator system.

2. ) The system of claim 1, wherein said injection well and said production well are horizontal well pairs and the injection well is 3-10 m above said production well and steam assisted gravity drainage (SAGD) is used to produce said heavy oil.

3. ) The system of claim 1, wherein said injection well and said production well are horizontal well pairs and where SAGD or a SAGD variation is used to produce said heavy oil.

4. ) The system of claim 1, wherein said injection well and said production well are vertical wells and cyclic steam stimulation is used to produce said heavy oil.

5. ) A system for producing heavy oil with steam, comprising:

a) a steam generator having first fluidic circuit from a water treatment system for receiving a boiler feedwater from said water treatment system and to an injection well for injecting steam into a reservoir;

b) said steam generator having a second fluidic circuit from a supercritical CO2 generator (sCO2) for injecting sCO2 into said steam generator and to a flash drum for accepting spent sCO2 and foulants after said sCO2 has traversed said steam generator;

c) a production well in said reservoir and in fluid communication with said injection well, said production well fluidly connected to a separator for separating produced fluids into a heavy oil and a produced water; and

d) said separator fluidly connected to said water treatment system for cleaning said produced water to make boiler feedwater, said boiler feedwater feeding into said first fluidic circuit.

6. ) The system of claim 5, wherein said flash drum is also fluidly connected to said sCO2 generator for recycling used CO2.

7. ) The system of claim 5, wherein said injection well and said production well are horizontal well pairs and the injection well is 3-10 m above said production well and steam assisted gravity drainage (SAGD) is used to produce said heavy oil.

8. ) The system of claim 5, wherein said injection well and said production well are horizontal well pairs and where SAGD or a SAGD variation is used to produce said heavy oil.

9. ) The system of claim 5, wherein said injection well and said production well are vertical wells and cyclic steam stimulation is used to produce said heavy oil.

10. ) A improved steam generating system for steam-based enhanced oil recovery, said steam generating system comprising a steam generator fluidly connected to one or more wells for a steam based enhanced oil recovery, said improvement comprising adding a second fluidic circuit to said steam generator for injecting sCO2 into said steam generator and for collecting removed foulants and spent sCO2 on exiting said steam generator.

11. ) A improved once through steam generating (OTSG) system for SAGD, said OTSG system comprising an OTSG fluidly connected to one or more injection wells for SAGD, each injection well above and parallel to a lower production well, said improvement comprising an added inlet to said OTSG system for receiving injecting sCO2 from a sCO2 generator and an added outlet fluidly connected to a container for accepting for foulants and spent sCO2 exiting said OTSG system.