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

Flow Modes • Concepts: – Laminar flow (Low velocity & pressure drop) – Turbulent flow (High velocity & pressure drop) • Challenges with conventional flushing: – Pressure loss over length of the line

CO2 Solubility So what are we doing to CO2: • Changing the Electronegative Difference – Temperature & pressure – Surfactant (soap)

SCCO2 Back-Flush Technology Appl pplication o of 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 • 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 Control Line ID: 3.05mm

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 organic 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