Flow Assurance Engineering

PhD-Led | OLGA Expert | 18+ Years Post-Doctoral Experience

# Flow Assurance That Keeps Production Flowing.

Hydrate plugs, severe slugging, wax deposition, scale, sand transport, and water hammer - every flow assurance threat has a solution. We have built and validated those solutions on Shah Deniz 2, BP Angola Block 18, ACG Azerbaijan, and deepwater Malaysia.

Scope a Study View Scope
18+ Post-PhD Industry Years

Flow assurance from first principles to operational delivery.

Expert OLGA Practitioner

Builds, validates, and QA/QCs complex transient simulation models.

4 Major Asset Environments

Caspian deepwater, West Africa HPHT, Azerbaijan, and SE Asia gas.

Also need Process Engineering? Our Lead Process Engineer covers P&IDs, HYSYS, HAZOP, and flare systems.

View Process Engineering Services
The Production Risk

## Flow assurance failures are expensive and preventable.

Every one of these threats is predictable from the fluid properties, the pipeline geometry, and the operating envelope. That means every one of them can be designed out - if the engineering is done correctly at the right project stage.

### Hydrate Plug Events

A single hydrate blockage in a deepwater flowline stops production for weeks, demands specialist coiled tubing intervention, and carries real well-integrity risk. Safe shut-in time, cooldown analysis, MEG/methanol dosing, and restart procedures must all be validated from first steel - not first oil.

Remediation per event: $5M - $80M

### Severe Slugging

Terrain and riser slugs trip topsides separators, flare valuable gas, and erode equipment life. A separator that cannot absorb the slug volume defined by the OLGA model will trip every time. This is the most common hidden constraint on production throughput - invisible in steady-state models.

Throughput loss: 5 - 25% MMSCFD

### Cold Restart Failure

Resuming production through a cold, wax-gelled or hydrate-risk flowline without a validated restart procedure risks a well shut-in that becomes a permanent plug. Restart simulations - hot and cold - must define the safe operating envelope, the inhibitor volumes, and the ramp-up rate. Guesswork is not acceptable.

Unplanned plug: $2M - $30M

### Wax Deposition and Gelation

Below the Wax Appearance Temperature, paraffin deposits progressively restrict the flow cross-section and drive pigging frequency beyond what operations can sustain. Without a validated WAT, deposition model, and pigging strategy, wax management becomes reactive - and reactive is expensive.

Pipeline plug remediation: $2M - $30M

### Water Injection Surge

A pump trip or rapid valve closure on a high-pressure water injection system generates pressure transients that rupture pipework and collapse check valves. AFT Impulse surge analysis and correct surge vessel sizing are not optional scope - they are a fundamental pressure containment obligation.

Incident repair: $1M - $20M

### Sand Transport Failure

Wells that produce sand below the minimum transport velocity accumulate beds that progressively restrict flow, corrupt pig passages, and drive wall loss at bends. Establishing the minimum transport velocity from first principles - and designing the operating envelope around it - is the difference between a manageable system and one that fails in year one.

Pipeline failure: $10M - $50M+

## PhD-Level Governance on Every Study

Every NIQ flow assurance study is governed and quality-assured at doctoral level. We translate complex OLGA outputs, thermodynamic models, and transient simulation results into clear, auditable production KPIs for asset managers, project directors, and HSE authorities - balancing technical integrity, CAPEX/OPEX optimisation, and production availability with quantified risk. Independent peer review, design audits, and expert witness services available.

Owner's Engineering and Peer Review Risk-Based Decisions (ISO 20815) Full Traceability and Data Handover Expert Witness
Technical Scope

## Twelve scope items. Fully delivered.

These are the twelve flow assurance scope elements we deliver completely - the same items BP, TotalEnergies, Shell, and ENI require on their most demanding studies. Each is a standalone deliverable with a formal study report.

01

### Steady-State Hydraulic and Thermal Modelling

Wellhead-to-manifold sizing, temperature and pressure profiling, liquid handling capacity, gas velocity compliance (<=20 m/s), and parametric studies for additional wells and late-life water cut scenarios.

02

### Transient Cooldown and Hydrate Analysis

OLGA-based cooldown of jumpers, flowlines, and risers. Hydrate formation time determination, safe shut-in time window, insulation optimisation for active and passive thermal management systems.

03

### Slugging and Riser Dynamic Simulations

Terrain and riser slugging characterisation, slug catcher sizing, active slug control strategy assessment, and impact of additional wells on topsides separator receiving capacity.

04

### Liquid Inventory and Receiving Facility Sizing

Maximum liquid surge volume calculations, separator and slug catcher sizing, interface level control assessment, and brownfield debottlenecking for liquid handling systems.

05

### Wax Deposition and Pigging Design

WAT/WDT determination from fluid characterisation, deposition rate modelling, pigging interval optimisation, gel formation risk, and restart pressure assessment after extended shutdowns.

06

### Chemical Inhibitor Hydraulic Assessment

MEG/methanol injection rate design, distribution hydraulic modelling across multiple injection points, dosing optimisation against CAPEX/OPEX trade-offs, and storage/regeneration facility sizing.

07

### Methanol Requirements at Restart

Dosage calculation, storage volume requirements, injection ramp-up profiles, and verification of distribution to all subsea isolation points before and during restart operations.

08

### Sand Transport Velocity Analysis

Minimum transport velocity using field analogue methods, sand accumulation risk at reduced flow, erosional velocity ratio compliance, and sand monitoring strategy.

09

### Hot Restart Simulations

Slugging behaviour during designed well ramp-up sequences, thermal recovery profiles, separator surge arrival timing, and operating procedure development for controlled restart.

10

### Cold Restart Simulations

Thermal and hydraulic performance during unplanned cold restart, hydrate window analysis, depressurisation requirements, back-pressure management, and minimum restart flow conditions.

11

### Operating Philosophy Verification

Consistency check of field operating philosophy against all flow assurance findings. Operating envelope definition, alarm/trip setpoint recommendations, and operator guidance documentation.

12

### Water Injection Surge Analysis

Pump trip, valve closure, and water hammer transient analysis using AFT Impulse. Surge vessel sizing, check valve dynamics, and pipeline pressure rating verification. Full surge report.

Application Domains

## Every environment. First-hand experience.

Our flow assurance work spans every production environment - from ultra-deepwater subsea tiebacks to onshore slug catchers. We follow the fluid from reservoir to export.

Subsea systems demand the most rigorous flow assurance philosophy. Remoteness, deepwater pressures, low seabed temperatures, and the impossibility of rapid intervention mean that every failure mode must be anticipated and designed out at FEED. Shah Deniz 2 and Block 18 Angola are the benchmark - we have worked on both.

- OLGA transient cooldown of subsea jumpers, flowlines, and risers - safe shut-in time determination and insulation optimisation for both active heating and passive insulation systems
- MEG/methanol injection design - injection rate, distribution hydraulics, storage sizing for multi-well subsea developments with multiple injection points and variable production
- Hot and cold restart simulations - slugging during well ramp-up, hydrate window analysis, depressurisation requirements, and minimum restart flow conditions
- Wax management strategy - WAT profiling, deposition modelling for ultra-deepwater flowline temperatures, pigging strategy for long-distance subsea tiebacks
- Sand transport - minimum velocity verification, EVR compliance, and monitoring strategy for sandy reservoir developments

### Primary Tools

OLGA LedaFlow PVTsim Nova Multiflash PIPESIM HYSYS

### Reference Projects

Shah Deniz 2 | BP - Caspian Sea (Wood Group Kenny)

Full-scope flow assurance from FEED through commissioning. OLGA cooldown, hydrate management, subsea-to-topsides co-simulation for the South Caucasus Pipeline. Chemical injection operating guidelines for all hydrate mitigation scenarios.

Block 18 | ENI / BP - Angola (Deepwater)

HPHT wellhead conditions. Severe slugging mitigation, ultra-deepwater wax management for long-distance flowlines, FPSO topsides integration with subsea transient model.

FPSO and fixed platform flow assurance is dominated by the interface between subsea transient behaviour and topsides processing capacity. An OLGA slug model that hasn't been sized against the separator is not a flow assurance model - it is a theoretical exercise. We integrate both.

- Riser and FPSO slugging analysis - OLGA-based slug frequency, volume, and arrival timing for separator sizing and active slug control design
- Slug catcher sizing - dynamic liquid surge volumes linked to topsides separator capacity and interface level control response times
- Hydrate management for FPSO disconnection - chemical injection strategies for planned and emergency mooring disconnection and reconnection scenarios
- Pigging operations analysis - pig tracking, liquid surge arrival prediction, and receiving facilities sizing for FPSO-connected pipeline systems
- Export pipeline hydraulics - steady-state and transient modelling from FPSO to export terminal or buoy, including pigging and thermal response

### Primary Tools

OLGA PIPESIM HYSYS/UniSim LedaFlow Prosper/GAP K-Spice

### Reference Projects

Block 18 FPSO | ENI - Angola

Deepwater subsea-to-FPSO integration. Severe slugging characterisation, separator sizing, FPSO topsides transient model, wax management for ultra-deepwater flowlines.

ACG Field | BP - Azerbaijan

Azeri-Chirag-Gunashli flow assurance support. Integrated subsea and topsides transient modelling across one of the world's largest producing assets.

Topsides flow assurance covers the interface between the subsea system and the processing train - particularly slug catcher and separator sizing, active slug control, compressor stability, and chemical injection distribution. Getting this interface wrong produces a topsides that trips every time the subsea slugs.

- Separator and slug catcher sizing - OLGA-linked liquid surge volumes, three-phase separation capacity, interface level control response under slug loading
- Gas compression train stability - compressor suction pressure variation under slugging, anti-surge response, and train trip avoidance strategy
- Chemical injection distribution - MEG/methanol delivery to all topsides injection points, dosing under varying flow conditions, storage sizing
- Operating philosophy verification - confirming that the topsides operating philosophy is consistent with all flow assurance findings and transient simulation results
- Co-simulation digital twin - OLGA/LedaFlow linked with HYSYS/UniSim for simultaneous modelling of subsea and topsides - foundation for operator training systems

### Primary Tools

OLGA + HYSYS LedaFlow PVTsim Nova K-Spice UniSim OTS

### Co-simulation Capability

Integrated Digital Twin Approach

NIQ links OLGA/LedaFlow with HYSYS/UniSim dynamics - enabling simultaneous modelling of subsea pipelines, risers, topsides separators, and compression trains. This is the foundation for operator training systems that represent real asset behaviour under all transient scenarios.

Onshore gathering systems, trunklines, and long-distance gas pipelines present distinct flow assurance challenges - particularly around slug catchers, water injection surge, pigging strategy, and terrain slugging in hilly terrain. We have applied these studies on Nigerian, Mozambican, and UAE onshore assets.

- Long-distance multiphase pipeline flow assurance - steady-state and transient analysis for gathering networks, terrain slugging in hilly conditions, and receiving terminal sizing
- Finger-type and vessel slug catcher design - liquid surge volume calculation for onshore receiving terminals and LNG slug catcher scopes (NLNG GTS-2/4 applied reference)
- Water injection surge - AFT Impulse - pump trip, valve closure, water hammer transients, surge vessel sizing, and check valve dynamics for high-pressure injection systems
- Hydrate formation study for onshore gas pipelines - hydrate formation prediction and inhibitor strategy for onshore gas transmission and gathering systems
- Pigging strategy for long-distance pipelines - frequency optimisation, wax accumulation limits, liquid surge management at receiving terminals

### Primary Tools

PIPESIM OLGA AFT Impulse PVTsim Nova Multiflash

### Reference Projects

GTS-2/4 Slug Catcher | NLNG (Aker Kvaerner)

FEED for slug catcher and associated equipment for LNG trains 3 and 4. Hydrate formation study report. H&M balance update for OGGS and GTS-2/4. HAZOP participation.

Oso-RE Pipeline | Mobil Nigeria (WorleyParsons)

Flow assurance and slugging report for 16-inch condensate pipeline restoration. PIPESIM hydraulics, surge capacity calculation for production separator, pipeline thermo-hydraulic results.

The Engineer

## PhD flow assurance. Personally delivers.

Our Senior Flow Assurance Consultant has 18+ post-doctoral years working on some of the world's most complex deepwater assets - and personally executes every scope.

### Senior Flow Assurance Consultant

PhD | 18+ Years Post-Doctoral Industry Experience

Doctor of Philosophy - Multiphase Flow and Thermodynamics | Expert OLGA Practitioner | Versatile in HYSYS, PIPESIM, and process engineering tools

With 18+ years of post-PhD industry experience, this consultant combines deep academic rigour in multiphase flow thermodynamics with hands-on delivery on some of the world's most technically demanding assets. A recognised OLGA authority and co-simulation architect who is equally versed in process engineering tools - making him uniquely capable of integrating flow assurance findings directly into topsides process design and bridging the gap between simulation and operations.

- Full-scope flow assurance on Shah Deniz 2 (BP) - OLGA-based subsea cooldown, hydrate management for the South Caucasus Pipeline, riser dynamics, and topsides co-simulation. One of the world's most complex deepwater gas developments.
- Lead flow assurance consultant on multiple BP and ENI block developments in Angola Block 18 - HPHT deepwater wellhead conditions, severe slugging mitigation, ultra-deepwater wax management, and FPSO topsides integration
- Flow assurance support for Azeri-Chirag-Gunashli (ACG), BP Azerbaijan - integrated subsea and topsides transient modelling across one of the world's largest producing assets
- Deepwater gas flowline and riser system design for Malaysian offshore developments - OLGA modelling, MEG injection system design, operating envelope definition for deepwater gas production
- Expert OLGA user - builds, validates, and QA/QCs complex co-simulation models linking subsea to process dynamics (OLGA + HYSYS/UniSim). Digital twin capability for operator training systems
- Translates complex OLGA outputs and thermodynamic simulation results into clear production KPIs for asset managers and project directors - bridging technical simulation and commercial decision-making with full traceability

Shah Deniz 2 | BP Azerbaijan Block 18 | ENI/BP Angola ACG Field | BP Azerbaijan Offshore Malaysia | Deepwater Gas
Software - Expert / Advanced
OLGA (Expert) LedaFlow PVTsim Nova Multiflash HYSYS / UniSim PIPESIM K-Spice AFT Impulse
Software and Simulation

## The flow assurance toolchain.

All platforms below have been applied on live IOC projects, validated against field data and client reference models.

Tool / Platform | Proficiency | Primary Application
--- | --- | ---
OLGA | Expert | Transient multiphase flow - cooldown, hydrate window, slugging, hot/cold restart, pigging. Shah Deniz 2, Block 18 Angola, ACG, Malaysia validated models.
LedaFlow | Advanced | 3-fluid transient simulation, riser dynamics, slug frequency and volume characterisation.
PVTsim Nova | Advanced | Fluid characterisation, EOS tuning, hydrate equilibrium curves, wax appearance temperature determination.
Multiflash | Advanced | Phase equilibria, wax, asphaltene, scale and hydrate thermodynamics - fluid property inputs to OLGA.
PIPESIM | Proficient | Steady-state hydraulic and thermal profiling, line sizing, nodal analysis, operating envelope definition.
HYSYS / UniSim | Proficient | Process simulation for topsides integration - separator sizing, compression, co-simulation with OLGA.
AFT Impulse | Proficient | Water injection surge analysis, pump trip transients, accumulator sizing, check valve dynamics.
K-Spice / UniSim OTS | Working knowledge | Control system dynamics and operator training system development integrated with OLGA.

Co-simulation capability: NIQ links OLGA/LedaFlow with HYSYS/UniSim dynamics - enabling simultaneous modelling of subsea pipelines, risers, topsides separators, and compression trains. This is the foundation for true digital twins and operator training systems that faithfully represent the real asset under all transient scenarios - including emergency shutdown, cold restart, and slug events.

Track Record

## Reference assets. Real delivery.

These are not references from a proposal template. They are assets where our engineer was the flow assurance lead - and where the work is still operational today.

Deepwater Gas | Subsea and Pipeline

### Shah Deniz 2

BP - Caspian Sea, Azerbaijan

One of the world's largest and most complex deepwater gas developments. Full-scope flow assurance from FEED through commissioning - OLGA transient cooldown, hydrate management philosophy for infield and export pipelines, riser dynamics, and subsea-to-topsides co-simulation for the South Caucasus Pipeline system. Chemical injection operating guidelines for all shutdown and restart scenarios.

OLGA Expert Hydrate Mgmt Restart Deepwater Gas BP ETP Co-simulation
Deepwater | Subsea FPSO | HPHT

### Block 18 Angola

ENI / BP - Offshore Angola

Deepwater subsea development in Block 18 offshore Angola. Flow assurance encompassing HPHT wellhead conditions, severe slugging characterisation and mitigation, ultra-deepwater wax management for long-distance flowlines where seabed temperatures drive wax deposition risk, and full FPSO topsides integration with the transient subsea model.

OLGA HPHT Deepwater Slugging Wax FPSO Integration
Large Offshore Field | Integrated Asset

### Azeri-Chirag-Gunashli (ACG)

BP - Azerbaijan, Caspian Sea

Flow assurance support for the ACG field - one of the world's largest offshore oil fields. Integrated subsea and topsides transient modelling across a complex multi-platform, multi-pipeline production system. Operational performance optimisation and production envelope verification using OLGA models validated against field production data.

OLGA Integrated Model Multi-platform Production Optimisation
Deepwater Gas | Subsea Tieback

### Deepwater Malaysia

BP / Operator - Offshore Malaysia

Flow assurance for deepwater gas field development offshore Malaysia. OLGA-based transient modelling of subsea flowlines in high water-depth conditions where thermal performance is critical to hydrate management. MEG injection system design for multi-well development. Operating envelope definition and commissioning support for first gas delivery.

OLGA Deepwater Gas MEG Design Hydrate SE Asia
Cross-Discipline Support

## Also need process engineering?

Our Lead Process Engineer covers P&IDs, HYSYS simulation, HAZOP facilitation, flare and relief system design, equipment sizing, and pre-commissioning - on Shah Deniz 2, ADNOC, Saudi Aramco, TotalEnergies, Shell, and ExxonMobil assets. Both disciplines, one team.

View Process Engineering Services
Engage NIQ

## Your flow assurance problem has a solution.

Complete field development flow assurance studies, specific transient simulations, independent peer review, operational troubleshooting - delivered by a PhD engineer who has personally worked on equivalent assets at BP, ENI, and operator level.

Request a Consultation +234 903-305-8380
Email info@niqong.com
Phone +234 903-305-8380
Web www.niqong.com
Governance PhD-Level | ISO 20815