The offshore Congo operator faced a challenge with a production pipeline that was restricting oil flow. Over time, the pipeline leading from offshore platforms to onshore processing facilities was becoming clogged with accumulated wax and debris from the offshore production, causing a drop in oil flow rates. Due to the speed of wax buildup, pigging was not a viable option.
To overcome the pipeline issues, the operator tried increasing pumping pressures to maintain oil production at acceptable volumes, but that technique delivered diminishing returns. The operator needed a better solution to restore the integrity of the pipeline, resume normal pumping pressures, and restore normal cash flow to the operation. Ultimately, regular cleaning of the 6.5-km (4-mi) pipeline would be required to achieve these goals.
Because pipelines often require complex maintenance, the operator partnered with SLB to deploy a specialized solution in a short time frame. A Production ExPRESS solutions package was used to heat up special solvents and pump them into the 6.5-km pipeline. The equipment deployed included a steam generator, steam heat exchanger, high-pressure high-flow-rate pump, tanks, and batch mixers.
Once the solution was deployed, the pipeline backpressure quickly reduced from 100 to 20 bar, eliminating the operator’s need to increase pumping pressures to counteract the sluggish flow. To control the chronic wax condition, the solution was reapplied every 17 months on average. Over the next 7 years, the Production ExPRESS solutions package cleaned a cumulative 32 km (20 mi) of the operator’s pipeline to keep the oil flowing and help the well realize its full potential. Without intervention, the oil flow rate would have been limited to only half the achieved rate.
