Subsea Sampling on the Critical Path of Flow Assurance
Shailesh Rathood
Product Champion, Schlumberger
Hua Guan
Flow Assurance Consultant, OneSubsea
Devex 2016, 16-17 May, Aberdeen UK
2
Outline
• Flow assurance along the fluid journey
• Fluid PVT and importance of representative samples
• Subsea sampling system
• Subsea sampling demo
• Project example – subsea sampling application for scale squeeze optimization
3
Flow Assurance
4
Pressure
& Liquid
Mgmt
Wax &
AsphaltenesHydrates
Heavy
OilScale
PVT & Fluid
Behavior
Corrosion
& ErosionOperability
Integrated
Solutions
Production
Optimization
Thermo
Hydraulics
Production
System
Architecture
PVT
Sampling
Wellbore
Sim.
Production
chemicals
Fluid
Analysis &
Modelling
Steady
State MP
Flow Sim.
Riser & Flowline
Monitoring
Solids Prec.
& Depos.
Topside
Process
Sim.
Production
Operations
& Opt.
Forecasting,
Risks, and
Sensitivities
Processing
/ Boosting
The Fluid Journey
SS
Surveill.
Subsea
Archi-
tecture
Transient
MP
Flow Sim.
Interv.MP Flow
Metering
Inflow
Performance
Completion
Exploration PG1 Feasibility PG2Concept
Selection PG3 Definition PG4Execution/
Implement.PG5 Operation
The Project Development Timeline
Interacts with All Disciplines Across the Fluid Journey
5
PVT & Fluid Behavior
WaxAsphaltene
Gas Hydrate
Athabasca Bitumen r>1
Organic ScaleInorganic scale
6
PVT & Fluid Behavior
Temperature
Pre
ssu
re
Hyd
rate
Curv
e
Facility
Reservoir P&T
Start
Reservoir P&T
Long-Term
Look-a-head
7
Integrated Modeling to Diagnose and Optimize FA Problems
Schlumberger Tools Third Party
ScaleChem MultiScale
OLI Analyzer StudioProsper / GAP
PVT Analysis Scale Analysis
Corrosion Analysis Wells / Pipelines
Economic Analysis Process Simulation
HYSYS
Wells / Pipelines
Steady State
Wells / Pipelines
Dynamic
Reservoir Simulation Integrated Modeling
PVT Specialized Flow
Assurance
8
Subsea Production Trends and Sampling Drivers
9
Multiphase Representative Sampling
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• Strategically chosen, phase-rich sampling points
• Each phase is enriched and captured individually
• Isothermal and isobaric
10
Subsea Sampling Hardware
Sampling Interface–Based on blind T, flexible access / retrievable
–Dual pressure barrier philosophy
Sampling Module–Isothermal and isobaric sampling
–Phase detection and phase enrichment
–ROV deployed skid
–Remotely controlled system
–Transportable sample receptacles
Topside Equipment
Subsea Sampling Services
Subsea Sampling System
11
OneSubsea Sampling System - Demo
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12
Offshore Scale Squeeze
Procedure–Injection of inhibitors and retention
–Inhibitor flowback for protection
Sampling and Analysis–Inhibitor residual -> Re-squeeze
when < MIC
Design Requirement
Water Depth: 1100 m
P/T: 10,000 psi and 121 degC
Access: horizontal
Samples: 4 x 600 cc
Project A – Subsea Sampling for Scale Squeeze Optimization
0.1
1
10
100
1000
10000
0 1000 2000 3000 4000 5000 6000
cummulative water production (x1000 bbls)
Inh
ibit
or
co
nc
en
tra
tio
n (
pp
m)
field return concentration (ppm)
new modelled return concentration (ppm)
previous modelled return concentration (ppm)
13
Subsea Sampling
Representative Samples–Isobaric / isothermic
–Subsea units in place
Reliable Analysis–Enable accurate estimate of re-sqz time
Scale Squeeze Optimization
Integrated modelling for accurate prediction
Reliable scale control -> prevention
Reduce intervention frequency
OPEX saving and increased up-time
Project A - Benefits
14
Integrated Subsea Sampling and FA Risk Analysis
Sample extraction
QA, condition,
segregate,
restoration, and
transfer
Analysis and
reporting
Modelling, EoS,
Uncertainty, and
decisions
Chain of
Custody
Sampling interface
Production
management
workflows
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