Control Line Blockage Solutions Using a SCCO2 Application Keith J - - PowerPoint PPT Presentation

Control Line Blockage Solutions Using a SCCO2 Application

Keith J Houghton – CWIE & Espen K Amundsen - MD

Agenda

• Introductions
• SCCO2 Technology
• Case study wells
• Next planned SCCO2 operation
• Economics
• Conclusion
• Q&A

SCCO2 Properties

• Low viscosity (ten times lower than water) with a tuneable

density giving the same carrying capacity as oil

• High diffusivity (gas-like) penetrates wax, corners
• No surface tension & excellent solvent solution
• Non-toxic & non flammable
• Kills bacteria

SCCO2 Technology

• Concepts:

– Laminar flow (Low velocity & pressure drop) – Turbulent flow (High velocity & pressure drop)

• Challenges with conventional flushing:

– Pressure loss over length of the line

Flow Modes

CO2 Solubility

So what are we doing to CO2:

• Changing the Electronegative Difference

– Temperature & pressure – Surfactant (soap)

SCCO2 Back-Flush Technology

Appl pplication o

• f SC

C CO CO2 – Bac Back-flushin ing and Unbl blockin ing

Back Flushing Changing fluid in one way lines Unblocking of CHC Injection line Lifting media out of one way lines

Coil Flushing Unit & Process

Case Study 1

Case Study 1 Results

Case Study 2

Control Line ID: 3.05mm

• Closed loop system with blocked control line

– Back flush method

• TRSV Depth: 1750ft
• TRSV Depth temp. 20-25degC
• Control line ID: 3.05mm
• Total CL Volume: 3750mls
• Blockage depth 560ft

Case Study 2 – Results

• Back flushing success with

down hole Sample

• Results – Way ahead

Barite Rose

Next Planned Operation

• Open loop system with a partially blocked control line

– Flushing

• TRSV Depth: 989ft
• TRSV Depth temp. 60-90degC
• Control line ID: 3.95mm
• Total CL Volume: 3700mls
• Blockage depth 400ft +/- 100ft

Control Line ID: 3.95mm

Next Planed Operation Cont.

• Downhole Camera results
• Recovered WRSSSV - SAR Results
• Non-OEM Seal design – corroded seal face

The SCCO2 should dissolve the

• rganic material seen in the

sample and carry the solids in turn clearing the blockage

Challenges

• Non Ex rated unit

– Removal of Battery & UPS – Platform mitigations in place

• Equipment functionality

– Fluid system to a gas system – Seals

Conclusion

• Where is the application most applicable?

– Flushing lines and cleaning sub sea umbilical’s – Back flushing debris – Dissolving certain contaminations – Changing oil in one way lines

• Pro Active approach preventing the blockage

– Keeping up your production

• Not in a Re Active State due to a blockage

– Intervention required – Retrofit equipment – Workover

Q&A