Cestoil CDR2081: Throughput gain on a port-to-refinery crude pipeline

A 63.8-km, DN500 crude pipeline linked a coastal terminal to a refinery in South China. The operator wanted greater delivery capacity using its existing pumps and pipeline, within a 5.0 MPa design-pressure limit.

The operating background in the report describes approximately 30,000 t/d at 4.5 MPa with two of four mainline pumps running. A third pump increased capacity to about 33,000 t/d at 5.0 MPa. The operator already used a domestic drag reducer and wanted to evaluate an alternative against that benchmark.

The technical agreement specified a throughput gain of at least 15% at no more than 15 ppm, with two-pump operation. Performance was to be evaluated at the pump-outlet flowmeter after the line had filled with treated crude.

Cestoil CDR2081 is a high-molecular-weight polyolefin drag reducer. It is designed to reduce turbulent friction in pipeline flow, allowing greater throughput or lower pressure for a given operating duty.

Cestoil and the operator agreed the trial conditions and monitored dose, flow, pressure and valve position. An initial attempt in August was interrupted by an injection-pump seal problem. Cestoil returned with the repaired pump, and the completed trial took place on 2 September 2010.

The operator held the pump-outlet valve at 60% and kept two mainline pumps in service. Maintaining these settings supported comparison of the operating readings; it does not establish that every other hydraulic condition was identical.

The operator recorded performance above the agreement’s ≥ 15% gain at ≤ 15 ppm target. Its report concluded that CDR2081 reduced pipeline friction and increased delivery capacity using the existing pumps and line.

The report also compares 36,500 t/d with two pumps and CDR2081 at ≤ 4.05 MPa with the historical three-pump, untreated operating point of 33,000 t/d at 5.0 MPa. This supports the operational case for evaluating DRA before adding pumping duty.

The 30,000 and 36,500 t/d figures are the operator’s daily-equivalent capacity estimates, not measured 24-hour totals: injection lasted 11 hours. These estimates are separate from the measured hourly-flow ranges. The pressure comparison uses injection-start and full-treatment readings, while the hourly-flow comparison uses the next-day untreated reference. The incumbent benchmark and historical three-pump operating point were reported separately, rather than established as simultaneous matched tests. Pump power and monetary savings were not measured in the supplied summary.

The reported capacity difference is approximately 6,500 t/d. Sustaining that additional capacity for an assumed 330 operating days would represent about 2.1 million tonnes/year of additional deliverable capacity. This is a projection, not an observed annual production or delivery result.

For a site-specific economic evaluation, compare the value of additional delivery and any avoided alternative transport with the cost of additive, injection support and measured pumping energy. At a reported rate of 36,500 t/d and 14 ppm by mass, additive use would be approximately 0.51 t/d, consistent with extending the 21.3 kg/h injection rate over 24 hours.

Operators reported a preference for CDR2081 because it lacked the irritating odour they associated with the incumbent. This is an operator observation. The source also describes CDR2081 as metal-free; it does not provide analytical or downstream-unit measurements that establish those product claims through this trial.

Confirm injection-pump readiness and receiving-tank capacity before starting the trial. Agree the pump configuration, valve setting, dosing basis and acceptance criteria with the operating team.

Log flow, outlet pressure, crude properties and cumulative injection together. Estimate treatment arrival from line volume divided by volumetric flow, converting mass flow using crude density where needed, and allow full-line treatment before evaluating performance.

Take untreated reference readings at the agreed operating settings and record any changes in crude, temperature, tank conditions or pumping duty. A useful economic trial should also record electrical power and the actual cost of alternative delivery routes.