Ideal’s PipeRenew remediates a 4inch pipeline with abnormally high pressure of over 10 bbls of solids in one month
Segment No. 7943 – a 4-inch x 18,657-foot pipeline from the host platform at EI 342C to SST1 at EI 327 -- Fieldwood has experienced high pressure safety alarms on the pipeline since November 2016. The pipeline has experienced abnormally high flowline pressures for several years. The line was last flowed in April 2017 and has since been shut in. Total line volume is approximately 269 bbls.
In 2013, an attempt to remediate the line was executed by Blue Fin utilizing a product by the trade name “Inferno.” The actual chemistry behind this product was not provided by the client nor known by IES.
In 2015, a second attempt to remediate the line was performed with a lance. The lance was deployed to approximately 800 feet from 342C when a very hard obstruction was tagged. Lancing operations were aborted at that time and no further attempts have been made to remediate the line.
Details of the third remediation attempt were not provided; therefore, no details are known by IES. It is suspected a wrench may have been dropped in the line from EI 342C during construction operations carried out on the riser.
A paraffin analysis completed by Blue Fin in April 2013 and two oil analyses by Blue Fin in 2012 and 2013 were provided by Fieldwood. Both oil analyses indicated the presence of paraffin and asphaltenes. The pipeline does not have any known damage.
IDEAL'S RESPONSE
Based on the information collected and analysis of the deposition, it appeared the 4-inch oil pipeline likely contained a significant amount of deposition along the entire horizontal section of the line. As paraffin and other deposits accumulate in a line over time, the amount of pressure required to flow increases inadvertently, causing a reduction in flow across the line. To properly develop an effective project remediation plan, IES reviewed previous data for remediation treatments executed in the surrounding geographical area.
Proper pre-job planning, including a site visit, equipment selection, and proposed equipment layout allowed for a safe and effective job execution.
EI 327 Treatment Steps
Once the DP II vessel is positioned on location, the construction crew will recover the 2-inch HP hose secured to the flotation buoy and secure it to the boarding platform on the DP vessel bulwark. Connect the 2-inch HP hose from the HP pumps on the vessel main deck to the HP hose secured to the vessels boarding platform fitted to the bulwark.
Pressure test the surface treating lines utilizing sea water to 2,000 psi for three (3) minutes.
Once pressure test is completed and all surface lines are confirmed to be tight and free of leakage, blend a 6 bbl batch of PipeRenew® solution in preparation to begin injecting into the pipeline from EI 327 SST1 to EI 324C.
Establish verbal communications with EI 324C personnel and confirm all valves are aligned in the open position to receive pipeline fluids on EI 324C before any pumping begins on the DP vessel. Upon confirmation of the valve alignment, begin injecting PipeRenew® solution into the pipeline at a slow moderate rate while closely monitoring pipeline pressure not to exceed 1,440 psi while pumping across the pipeline.
IES personnel on 342C shall communicate return rate and content of returns being received during pumping operations. Pumping/blending operations from the vessel shall continue until it is confirmed the pipeline has been fluid packed with the PipeRenew® solution. At this time pumping shall be halted and the pipeline pressured to 1,440 psi, while fluid is allowed to soak for a 24-hour period in order to begin penetrating the deposition in the pipeline.
Pipeline pressure will be monitored with a chart recorder from this point for any changes in pipeline pressure or sharp drops in pressure, which would confirm penetration has been established through the blockage. In the event a substantial amount of solids are noted in the returns, pumping shall continue until solids are no longer confirmed present in the returns on 342C.
Upon completion of the 24-hour soaking period, begin pumping from the DP vessel at a slow moderate rate not exceeding 1,440 psi, while monitoring returns for solids at EI 342C. If no solids are noted in returns, continue to inject 3-5 bbls before halting pumping and soak for an additional 12 to 18 hours. Continue repeating this process until solids are being received on 342C.
As the solids are pushed down the line, communication will come and go. The PipeRenew® solution will continue to migrate down the line during this process and release any blockage or deposition. At any time during the pumping process fluid returns cease at 342C for a period greater than 24 hours, plans to reverse pump will be implemented from 342C while monitoring fluid returns to cutting boxes on the DP vessel.
Equipment Rig-Up
EI 342C – Structure
HIGH PERFORMANCE RESULTS
IES initially mobilized to EI 342C on October 9, 2017. 333 bbls of PipeRenew® was pumped from SSTI from October 14-25, 2017. IES demobilized on October 25, 2017, to allow for a two-week soak/residence time in the line. Approximately three bbls of solids were accounted for in cutting boxes. This does not include solids entrapped in oil sent to storage tanks on 342C while displacing the 4-inch pipeline with PipeRenew® from Botruc 40 at SSTI.
IES remobilized to EI 342C on November 6, 2017. Injection into pipeline from SSTI, commenced on November 7, 2017. 61 bbls of PipeRenew® were pumped, commencing at approximately 12:24 p.m. on November 7, 2017, and ending at approximately 2:26 p.m. on November 7, 2017. At 2:26 p.m. the line was shut-in with pressure placed on line at approximately 1,200 psi. Line pressure decreased to approximately 875 psi as of 7:00 a.m. on November 8, 2017. The line was opened flushed with sea water starting at 7:05 a.m. An entire line volume of 271 bbls of sea water was flushed through the line. Approximately 10 bbls of solids were recovered. Note that from 199 bbls pumped (at approximately 11:00 a.m. on November 8, 2017) until full line volume had been pumped (271 bbls), all returns on EI 342C were sea water with no trace of PipeRenew® or solids. Therefore, all solids recaptured occurred between 7:00 a.m. and approximately 10:45 a.m. Again, total solids recovered in cutting boxes totaled approximately 10 bbls.
Flushing was completed at approximately 12:25 p.m. on November 8, 2017. Subsequent to flushing with 271 bbls of sea water, Injection rates were established at 1:40 p.m. on November 8, 2017, 1.02 bpm, at 1,440 psi. A total of 6 bbls were pumped. Clean returns on 342C.
For more information about how non-hazardous, environmentally
responsible PipeRenew® remediation treatment can cost-effectively
remove paraffin and asphaltenes from your pipeline,
contact your Ideal Energy Solutions representative today.