Removing scale from a wellbore

• US 10,677,021 B2
• Filed: 11/08/2019
• Issued: 06/09/2020
• Est. Priority Date: 03/07/2018
• Status: Active Grant

• Current Assignee: Saudi Arabian Oil Company (Government of Saudi Arabia)
• Original Assignee: Saudi Arabian Oil Company (Government of Saudi Arabia)
• Inventors: Bulekbay, Aslan, Attiah, Sultan, Al-Mutairi, Talal, Alsousy, Abdulrahman
• Primary Examiner(s): DiTrani Leff, Angela M
• Application Number:
  US16/678,854
• Publication Number:
  US 20200072024A1
• Time in Patent Office: 214 Days
• Field of Search: None
• CPC Class Codes: C09K 8/528 inorganic depositions, e.g. sulfates or carbonates
• CPC Class Codes: C09K 8/536 characterised by their form or by the form of their components, e.g. encapsulated material
• CPC Class Codes: E21B 33/068 having provision for introducing objects or fluids into, or removing objects from, wells cementing-heads E21B33/05
• 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 41/0078 Nozzles used in boreholes drilling by liquid or gas jets E21B7/18; drill bits with nozzles E21B10/60; perforators using direct fluid action E21B43/114; obtaining a slurry of minerals using nozzles E21B43/29

Abstract

Supercritical carbon dioxide is directed into a wellbore to a specified depth. The supercritical carbon dioxide is directed at an inner surface of the wellbore at the specified depth. Scale is removed from the wall of the wellbore with the supercritical carbon dioxide.

Claims

1. A method comprising:

pumping supercritical carbon dioxide into a wellbore to a target depth;

spraying the supercritical carbon dioxide onto a wall of the wellbore at the target depth within the wellbore, wherein the supercritical carbon dioxide changes phase to a solid phase, a liquid phase, and a gas phase of carbon dioxide;

removing scale from the wall of the wellbore with the carbon dioxide; and

sweeping the wellbore with a gel after removing the scale.

2. The method of claim 1, wherein the supercritical carbon dioxide is sprayed through an isentropic nozzle.

3. The method of claim 1, wherein the scale is a non-soluble scale.

4. The method of claim 1, further comprising flowing reservoir fluid through the wellbore in an underbalanced condition.

5. The method of claim 1, wherein spraying the supercritical carbon dioxide comprises flowing the supercritical carbon dioxide through an isentropic nozzle.

6. The method of claim 1, wherein the solid phase and liquid phase of carbon dioxide change to a gaseous phase after impacting the wall of the wellbore.