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Increasing Heavy Crude Oil Flow Through a New Flow Improver Product –
A Case Study
a report by
Subsea & Pipelines
Ray L Johnston, Peter A Lauzon and Joey D Pierce
ConocoPhillips Specialty Products Inc.
Mechanism of Drag Reduction CSPI’s new heavy crude oil DRA technology, ExtremePower™ Flow
Flow improvers (also known as drag-reducing agents [DRAs]) are long- Improvers, has been proved to increase delivery of produced heavy
chain, ultra-high-molecular-weight polymers that reduce the level of crude oil to market. The successful application of ExtremePower Flow
turbulence in fluid streams. Typical molecular weights for drag- Improvers requires a transition or turbulent flow regime in a portion of
reducing polymers are >5 million. Using parts per million (ppm) the pipeline system, heavy crude oil–DRA polymer compatibility (see
concentration levels in the fluid stream, drag-reducing polymers Table 1) and a suitable pipeline system configuration.
interact with the fluid molecules that reduce the formation and
propagation of turbulent eddies. This decreases deviations in velocity Heavy Crude Oil Flow Improver – Field Test
relative to the bulk flow of the fluid, causing the hydraulic energy to be In the South American country of Colombia, ECOPETROL SA (Ecopetrol)
more focused on moving the fluid stream down the pipeline rather produces heavy crude oil. Utilising multilateral well technology to
than in a chaotic, random motion. These reduced frictional pressure increase production of Castilla heavy crude oil, Ecopetrol found its
losses enable pipeline operators to lower operating pressures or existing pipeline to be volumetrically constrained. Although plans were
increase the rate of fluid flow. The mechanism of drag reduction has in place to expand the pipeline capacity, a near-term solution was
been extensively studied and reported in the literature.
1
A summary of necessary to realise maximum value for the production asset. Ecopetrol
this phenomenon is illustrated in Figure 1. has experience with applying DRAs to light crude oil and refined
products, and therefore approached CSPI through CSPI’s regional
Flow improver technology has been used around the world in transporting distribution partner DELRIO SA (Delrio) to enquire about available
crude oil and certain refined products (gasoline and diesel) for more than technology for heavy crude oil flow improvement. Together, Ecopetrol,
25 years.
2
In field applications, DRAs are used to address flow constraints, Delrio and CSPI developed a strategy to test ExtremePower Flow
pressure limitations or energy demand reductions. In addition, system Improvers in the field. The following is a detailed report on the system,
requirements for DRA implementation are that the flow regime must be the system analysis, the commercial application of ExtremePower Flow
turbulent and there must be an effective DRA polymer–fluid interaction. Improvers and the test results.
Heavy Crude Oil Flow Improver – A Market Need The System
As worldwide heavy crude oil production increases,
3
pipelines are faced The Apiay Pipeline (Apiay) is wholly owned and operated by Ecopetrol and
with challenges in terms of the transportation of these higher-viscosity runs through rural Colombia. The pipeline delivers batches of Apiay
fluids. Historically, heavy crude oil has been a challenge for existing (‘light’, 21°API, 100cSt at 22ºC) and Castilla blend (‘heavy’, Castilla diluted
commercially available DRAs. As crude oil gravities fall below ~23°API, with naphtha, 18°API, 650cSt at 22ºC) from the Apiay, La Reforma,
existing DRAs become ineffective. ConocoPhillips Specialty Products Chichimene, Castilla and Suria reserves. It also transports deliveries that
Inc. (CSPI) has developed a new class of DRAs to address this need. come by truck to the Apiay pump station, including those from Valdivia,
Almagro, Rubiales and others, to the OCENSA pipeline at the El Porvenir
connection. The pipeline shipments are approximately 35% light (Apiay)
Ray L Johnston is Principal Engineer at
ConocoPhillips Specialty Products Inc., with a
and 65% heavy (Castilla blend). The Apiay is currently being successfully
particular focus on the science of drag reduction and
treated with CSPI’s LP™ 300 Flow Improver. The baseline flow of the
the invention of flow improvers for liquid pipelines.
untreated system yielded an approximate rate of 94,000 barrels per day
He holds eight patents involving novel work in the
science of drag reduction. Mr Johnston graduated (BPD). However, this rate is greatly affected by the cyclic operation of the
from Oklahoma State University with a BSc and MSc
pipeline and complicated by the batching of heavy and light crude oil. The
in chemical engineering.
approximate rate of the pipeline when the Apiay crude oil is treated with
E: Ray.L.Johnston@ConocoPhillips.com
LP 300 Flow Improver is 103,000BPD (a 10% flow increase).
Joey D Pierce is Director of Sales at ConocoPhillips
Specialty Products Inc. Previously, he worked in the
The Analysis
Specialty Chemicals Division, focusing on commercial
The system analysis requires knowledge of all of the factors shown in
development. Mr Pierce also has experience in plant
Figure 2. Many elements are associated with an overall system analysis,
operations, laboratory management, sales and sales
management and refinery economics and planning. but the two key requirements are crude–DRA compatibility and hydraulic
He holds a BSc in chemistry from Southwestern
modelling. With this in mind, the first step towards a field test is the
Oklahoma State University and an MSc in physical
chemistry from the University of Texas at Austin.
successful completion of the laboratory compatibility test. If the crude is
not compatible with DRA polymers, there is little chance of performance
E: Joey.D.Pierce@ConocoPhillips.com
in the pipeline. However, when the crude oil shows compatibility with the
DRA polymer, the detailed pipeline system analysis can commence. As
96
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