pipeline flow assurance

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Pipeline Flow Assurance

• Flow Assurance Introduction• Flow Assurance Problems• Production Chemicals Used• HCD Multi Flow Advantage• HCD Multi Flow Case Studies

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• What is Flow Assurance?• “Transporting the fluid from well to facility with low risk.”• Flow assurance, also known as multiphase transport, involves the

transport of a mixture of oil, gas, condensates and water in the same pipeline.

• It refers to ensuring successful and economical flow of hydrocarbon stream from reservoir to the point of sale.

• Besides network modeling & transient multiphase simulation, flow assurance involves effectively handling many solid deposits, such as, gas hydrates, asphaltene, wax, scale and naphthenates.

• Flow Assurance is critical in every field development.


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• Flow Assurance is now synonymous with wide range of issues, for example:

• System Deliverability - pressure drop versus production, pipeline size & pressure boosting.

• Thermal Behavior - temperature changes, insulation options & heating requirements.

• Production Chemistry - hydrates, waxes, asphaltenes, scaling, sand, corrosivity & rheology.

• Operability Characteristics - start-up, shut down, transient behavior (e.g. slugging etc.).

• System Performance - mechanical integrity, equipment reliability, system availability etc.


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• More recently however, the Flow Assurance problems encountered in oil and gas production have become more onerous, leading to an increased overall awareness in the industry.

• This is particularly in the offshore sector, where low temperatures, remote locations & often great water depths of subsea environments conspire to exacerbate problems such ass erosion/corrosion, blockages through hydrate formation or wax deposition or topsides’ facilities shutdown due to severe slugging.

• Moreover, the ramifications of these issues can be serious incurring significant intervention costs and substantial losses in production.


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• Physical – Chemical Flow Obstruction• Multiphase flow may be obstructed by physical phenomena such as

liquid slugs or surges, or by physical- chemical phenomena. Of the latter four of the commonest are listed below:

• Asphaltenes- the heaviest components in the crude oils, which may aggregate and precipitate in response to changes in chemical composition, pressure or temperature. Precipitation or deposition may occur in reservoir rocks, wellbores and pipelines.

• Wax- a natural constituent in most petroleum fluids, this may be deposited on cold surfaces such as pipeline walls, increase the viscosity of oil until it ultimately gels and settle out at the bottom of storage tanks.


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• Emulsions - water droplets in oil, which tend to be stabilized by natural oil components and in the presence of certain solid particles. As a result, they obstruct flow and complicate separation of produced water from oil.

• Gas Hydrates – resembling snow balls or slush, these are crystalline materials comprising a framework of water molecules with their cavities filled by gas. Small clumps are easily carried along with flow but large cohesive blocks can cause a partial or complete blockage.


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• Scale in Oil Production Facilities• Oilfield scale consists mainly of inorganic salts with calcium

carbonates, barium and strontium sulphates as the commonest components.

• Scale can from brine (formation water) as it undergoes changes in pressure and temperature, or where two incompatible fluids are intermingled.

• Scale problems can arise in various circumstances: During drilling and well completion, if the drilling mud or

completion fluid is incompatible with the formation water. At the commissioning stage of new injectors, if the injection water is

incompatible with formation water.


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During production, when a well starts to produce formation water with the hydrocarbons.

During well stream processing, when significant quantities of produced water put process equipment at risk.

Commingled production, where wellstreams from various formations, reservoirs or individual wells are mixed together, can make matters worse.


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Flow Assurance

Predicting

Prevention

Monitoring

Problem Solving


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• Production Chemicals:• Pour Point Depressant• Paraffin Inhibitor/ Wax Inhibitor• Asphaltenes Dispersant• Hydrate Inhibitor• Scale Inhibitor• Drag Reducer• Defoamer/ Antifoam


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• HCD MultiFlow (Pipeline Viscosity & Drag Reduction)• HCD MultiFlow is a revolutionary conditions specific deposit

reliquification product designed specifically for oil transfer flow line deposition.

• HCD MultiFlow was developed by HCD scientists and engineers to liquefy and remove asphaltene and paraffin deposits in oil flow lines.


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• How It Works:• The reliquification is accomplished by breaking down the chemical

bonds which exist between individual carbon chains and substituting smaller carbon chains in their place carried by HCD Multi-Flow.

• HCD Multi-Flow reliquifies the hydrocarbon chain in any deposits on contact, reducing asphaltene and paraffin flow restrictions in the transfer line.

• This reduction aids in reducing under deposit corrosion, increases flow line size, increases flow rate and reduces sludge layers along pipe walls.


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• Applications: Flow line “pigging” substitute Continuous flow line injection Oil flow lines from ships and ship to shore transfer lines Oil flow lines to holding tanks.

• Benefits: Rapid line clean-up Removes the risk of a “stuck pig” incident Reduce oil viscosity/ increase flow rate Non-toxic


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Biodegradable Raises API specific gravity and reduces viscosity No hazardous product handling Reduces heating or steam line requirements.


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• The HCD Multi-Flow Additive introduces a carbon molecular blend to produced fluids that prevents like molecular aggregation of waxes, asphaltenes and resins.

• This mechanism allows HCD to provide a uniquely long lasting flow assurance solution for pipeline and storage tank crudes.

• HCD is not a Polymer, Surfactant or a conventional Flow Improver - HCD is a molecular Disaggregator.

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• HCD attacks the root cause of the paraffin networking and asphaltene aggregation by interrupting the like molecular forces (London Forces) responsible for viscosity increase and solidification- freeing the individual molecules from these structures – resulting in liquefication and flow assurance.

• HCD achieves rapid in-line separation of the water and oil phases, breaking emulsions and eliminating foam.

• HCD MULTIFLOW will also prevent deposition of Hydrocarbon solids (sludge) on the flow line walls and in the cargo tanks.

• HCD MULTIFLOW will also prevent Hydrocarbon deposition on Heat Exchangers, Hydro-Cyclones and other process equipment vulnerable to wax and asphaltene deposition.


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• HCD MultiFlow is a multi purpose additive – this single chemical additive replaces the need for:

Pour Point Depressants BS&W Control Additives De- Emulsifiers Anti- Foaming Anti- Waxing Agents (chemical ‘pigging’) Heating (Savings on Steam & Heat Exchanger Requirements)


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• HCD MultiFlow has the following advantages over alternative chemical additive regimes:

High Flash point of 97°C so it stays in the produced crude. Hydrophobic non water based – so it does not contaminate the

water phase. Organic molecular blend (does not harm the crude or affect refinery

processes) Low toxicity (HSE) Low volatility (HSE) Easy to handle fluid Prevents under deposit corrosion.


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• The International Board of Environmental Health and Safety, Inc (IBOEHS) has awarded HCD Multi-Flow the Safety Product of the Year.

• The HCD Multi-Flow was selected because it plays a vital role in reducing the need for harmful chemical additives in the extraction and transport of crude oil, as well as making oil production more efficient. Furthermore, as HCD Multi-Flow is acknowledged for being non-toxic and replacing chemicals that cause harmful exposures to workers, their communities and the environment. Chemicals that HCD replaces are highly toxic and they include conventional flow assurance additives such as Benzene, Toluene and Xylene blends (BTXs). HCD Multi-Flow also replaces certain Polymer and Monomer technologies and Pour Point Depressants – many of which are extremely toxic to the marine environment and aquatic life.


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• HCD CARBON CHEMISTRY VISCOSITY TREATMENT - Souedie Field, Syria: HCD Flow Assurance, 2010• Crude Oil Character Paraffinic & Asphaltenic Heavy Oil – API 9 – 12

High Viscosity - 200,000 cps at 20°C• Client

SPC (Syria Petroleum Company)• Introduction: Transfer line Flow Assurance for Enhanced Oil

Recovery Elimination on Paraffin and Asphaltene based Viscosity• Purpose: The purpose of the trial was to inject the HCD additive

into the flow transfer line at the well head in a way that adequately mixes the chemical product with the high viscosity crude.


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• Results: Results were measured in terms of resistance in the line, Flow rate at the Gathering Station and sample readings for wax and asphaltene were taken from the valve at the end of the 5km pipeline run.

• The well produces at a rate of 10m³ of liquid per day with a water cut of 20%. The API gravity of this crude is 9.0 to 12.0 (well data records)


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Pipeline Flow AssuranceDAY Feed Rate

PPM Oil only (on 8m3 o/w)

Pressure ATMs

Flow Rate Increase from 10 m3

(wc 20%) (oc 80%)

Paraffins as %

Asphaltenes as %

Control 0 22 +0% 24 3.75 Sep 27th 2010

200 ppm

28.09.10 200ppm 21 -15% 23 4 29.09.10 200ppm 20 -10% 22 4.5 30.09.10 200ppm 18-19 +12% 22 4 01.10.10 250ppm 16 +18% 22 3.2 02.10.10 250ppm 11 +30% 15 3.7 03.10.10 250ppm 9.4 +37% 10.5 2 04.10.10 450ppm 9.0 +54% 9 1.7 05.10.10 450ppm 8.2 +72% 7 1.5 06.10.10 450ppm 8.0 +70% 6 1.2 07.10.10 600ppm 7 +89% 5 1.1 08.10.10 600ppm 5 +97% 3 0.8 09.10.10 750ppm 3.8 +98% 3 0.8 10.10.10 750ppm 2 +102% 2 0.5 11.10.10 250ppm 3 +96% 5 0.55 12.10.10 240ppm 6 +80% 6 0.95 13.10.10 240ppm 6.5 +65% 5 1.1 14.10.10 240ppm 6.4 +71% 6 1.35 15.10.10 0 7.2 +40% 12 2.1 16.10.10 0 9.0 +42% 18 3.2 17.10.10 0 9.8 +37% 22 3.75

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• Summary of Results:• The HCD Molecular blend worked on the heavy paraffinic and

asphaltic crude: • An initial drop in flow rates was due to the deposition on the walls

of the pipeline being freed into suspension.• After three days pipeline flow size and flow rate had increased.• Even at temperatures averaging 12 deg C – some 53 degrees below

the Pour Point - the additive reduced wax levels and ensured flow.• Asphaltenes were reduced with similar effectiveness• An API lift was observable in the treated crude from 11 to around

13.7 (600ppm) and around 15.2 (1000ppm)• Optimal cost effectiveness seemed to recommend dosages of

around 600 PPM


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• HCD PPE - Trial of HCD MultiFLow (PPE) for wax, asphaltene, BS&W control at Puteri platform and pipeline (PMO)

• Puteri Crude has a very high pour point due to its high wax content. Pour point of Puteri crude – 47 – 49 °C• Client: NEWFIELD (NFX)

PETRONAS CARIGALI SDN BHD (PCSB – PMO)• Site:

Oil wells (from -1300m to Well Head) and 14 km long Pipeline from Puteri Platform to BUK FPSO (PMO)


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Observations & Key Findings:• Flow Assurance:• HCD Multi-Flow outperformed Roemex at the same dosages.• Injection at the chemical mandrels proved to be very advantageous

– optimizing the mixing of the HCD PPE additive.• The additional injection at the well-head made some impact but

lacked the mixing the chemical mandrel injection points offer.• At higher dosages the Pour Point and the Remelt Temperature

seemed to diverge. This may be partly due to the testing conditions and slower heating would provide more accurate analysis.


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• The thermodynamics of Puteri crude need to be assessed and applied to the analysis of the cooling times between different temperatures. For example, it may take longer to cool from 34 deg C to 32 deg C than it does from 36 deg C to 34 deg C. This will have strategic significance for the 3rd mode of production.

• These results are on the co-mingled (Penara & Puteri) crude. If HCD PPE was being injected at both Platforms the Pour Point Readings at the Turret would be lower


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• BS&W:• The effect of HCD Multi-Flow on the Shake-Out tests – freeing the

trapped water as the crude rises has major economic benefits.• The effect of HCD Multi-Flow in reducing BS&W readings after the

third separator on the FPSO (by 3.5 times) has major economic implications, particularly in view of:

• A) discounts incurred for off-spec crude.• B) Savings on the FPSO Water Separation Line (Savings on

Surfactants; Demulsifiers; and Time & Energy)• These results are on the co-mingled (Penara & Puteri) crude. If HCD

PPE was being injected at both Platforms the• BS&W readings could be on-spec even before the crude is processed

at BUK FPSO


pipeline flow assurance

Documents

gas production

gas hydrates

pipeline walls

mixture of oil

viscosity of oil

pipeline size pressure

natural oil components

wax deposition