the science and sense of subsea sampling

TECHNOLOGY I INTELLIGENCE I SERVICE

The Science and Sense of

Subsea Sampling

2

Proserv is a controls technology company.

Our technology and industry experience improves reliability, maximises production and enhances asset integrity. By combining technical ingenuity with our design, engineering, manufacturing and field service expertise, we can create state-of-the-art solutions that can be applied to standardised systems.

800 employees 60 operating countries 14 sites

Jake McCreless – Head of Business Development/Sales Sampling – North America

[email protected]

Richard Barr – Business Development Manager

[email protected]

Who we are

Introduction

mailto:[email protected]

mailto:[email protected]

3

Years supporting

Production Chemistry

+40

Downhole samplers

manufactured, sold &

supported worldwide

+750

Sampling & Injection

solutions engineered

+3,000

Subsea sampling

systems engineered

and manufactured

10

Sample cylinders

+40,000Manufactured, sold and

serviced

Rental Fleet

+2,500supported globally

Track record

Introduction

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Oil and Gas

Production

Chemistry

The Science of Sampling

Introduction

Sampling

• Safe capture and containment of a sample

• The action or process of taking a sample for analysis

• You cannot manage what you cannot monitor

In oil and gas, it involves

• Hazards

• Single phase / Multiphase

• Right sample - right location

.

It is about capturing the chemistry, in an engineered solution

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Oil & Gas

Production

Chemistry

Production chemistry

Introduction

“…the management of the chemical reaction of

the produced fluids from reservoir to refinery…”

Production chemistry is critical

• Sampling and lack of representative data

• Budget constraints and / or lack of priority to sample

• Lack of awareness or understanding of potential impact

Effective and efficient management

• Allows for successful optimisation of operations

• Obtains a clear understanding of the process environment

• Minimises risks that could affect personnel, environment,

assets etc.

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Sampling – the tip of the iceberg

Why sample?

Required to establish

• A value

• A concentration profile

• Determine local contamination

Supports operations from reservoir to refinery.

Is prevention better than cure or don’t cross that bridge

until you come to it?

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Subsea sampling – spend a little to save a lot

Why sample?

Sampling is hard to

justify when nothing

is apparently going

wrong

The person who stops sampling to save costs….is like

the person who stops the clock to save time

Credit: https://www.credera.com/insights/asset-reliability-maintenance-oil-gas-industry-part-1-invest-data

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Chemistry is continuous and continuously changing - 24/7/365

Sampling considerations

Sampling requirements vary, hazards vary

• Atmospheric

• Pressurised

• Single or Multiphase

It requires competence to generate value

Sampling – right sample, right location

Shipment – safe transportation

Analysis – data and interpretation

It needs to be

• adequately sampled

• free of contamination

• preserved and analysed

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Safe transportation of live fluids

Sample cylinders

Sampling cylinders:

• Maintain composition

• Used when offshore analysis not possible

• Used for long-term storage of sample long after the well has been producing

Shipment of hydrocarbons under pressure, in sample cylinders, is strictly controlled

and requires equipment to have appropriate certifications to be in place.

Sample cylinders are certified to various standards for safe shipment of hydrocarbons.

• Transport Canada

• Australian Standards

• Department of Transport (US)

• Pressure Equipment Directive (EU)

• Transportable Pressure Equipment Directive (EU)

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Why sample subsea?

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Beneficial but with challenges

Topside sampling

So what may be the cause?

Physical and chemical changes in pipeline … lack of understanding

Sampling challenges:

• Fluid velocity

• Lost production from well shut-in

• Has the flowline been suitably flushed?

• Composition change / contamination in pipeline

• Co-mingled wells lead to back-out, or lost production

The topside chemistry can be different to subsea chemistry

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What has the industry learned?

Subsea pipelines

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Having good data helps production and pipeline management

Know your system

Determine if blending is a help or hindrance

• Sulphur content and acid number blend linearly

• Viscosity, pour point and WAT do not blend linearly

Calculate if there is a need to pig or scale squeeze etc.

• Too early, expenditure earlier than needed

• Too late, potential for intervention work required

Know the impact of production rates and fluid properties on flow regime

• Slug, Wavy, Bubble, Stratified

Understand the impact of sand production, erosion and dropout in pipeline,

preventing:

• Costly production downtime

• Catastrophic equipment failure

• Environmental discharge excursions

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Productive subsea sampling

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Sampling is critical in understanding exactly what is produced

Subsea sampling

Is it now time to change the way we think, the way we act?

Effective and efficient sampling subsea can offer:

• Minimal CAPEX

• No production losses

• Improved knowledge / modelling

• Chemical free / upstream of deposit

• Undiluted / no back-out calculations

• Reduced risk of contamination / interference

A topside sample does not confirm what is entering the

pipeline, only what leaves.

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The importance of subsea sampling

Subsea sampling

Subsea sampling provides solutions that support:

• Integrity

• Metering

• Decommissioning

• Chemical free samples

• Flow assurance issues

• Production and operating efficiency

Subsea sampling helps to maximise economic recovery

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There are numerous HSE considerations from an operational perspective

Considerations

Over 500 samples safely captured and contained in our subsea systems

Systems can include the following HSE features:

• Closed system

• Proven technology

• In-situ integrity test

• Double isolation valving

• Non-return / check valves

• Dual fail-safe connection

• Subsea qualified cylinders

• Back-flush cleaning of lines

• Designed for extreme conditions

• Tested and certified transportation cylinders

• DOT, PED / TPED, AS, Transport Canada

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Industry design considerations

Considerations

Specification

Matrix

Industry

Specification

Subsea gate valve function NORSOK R004,

API 17D, SAE AS 4059

Subsea coating

specification

NORSOK M-501

Material selection corrosion

/ erosion

NACE MR 0175

Prevention of cracking

failure subsea

NORSOK M-WA-01

Structural steel fabrication DN 2.7-1, 2.7-3

Specification for control and

chemical small-bore tubing

ASME B31.3, ISO 15590,

DNV RP B401

ROV interfaces ISO 13628-8

Qualification Matrix Industry

Specification

Qualification

Pipework ASME B31.3 Pressure

Subsea valve

production fluids

API 6A PSL 3G,

API 17D

Pressure, temperature,

hyperbaric

Subsea valve non-

production fluids

API 6A PSL 1,

API 17D

Pressure, hyperbaric

Structural frame DNV2.7-1, 2.7-3 Load test x 2

Production jumper

hose

API 17E (selected

sections)

Bend at pressure,

temperature, hyperbaric

Production fluid

cylinder

API 6A, 17D Pressure, cycle,

hyperbaric

Test pressure 1.5 x working pressure

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The following parameters should be considered alongside actual requirements

Considerations

• System deployment

• System connection

• System disconnection

• Sample collection cylinders

• Slops handling

• Isothermal sampling

• Isobaric sampling

• System control

• System sensors

• Phase biased sampling

• Phase enrichment

• Hydrate remediation

Increasing complexity means potentially reduced reliability, and increased cost

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The sample point

• The sample point dictates what is captured and contained

• Ideally, vertical up-flow with a quill

• Typically, female hotstab port

• ISO/CD 13628-8

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The choice of system will depend on subsea requirements

Technologies

Wired

• Isobaric

• Large volumes

• Multi-sample capability

• Back-flush line cleaning

• Seabed / manifold mounted

Underslung

• Limited volumes

• Rapid response

• Isobaric / isothermal

• Multi-sample capability

• Back-flush line cleaning

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The choice of system will depend on subsea requirements

Technologies

Diver

• Restricted to 200m

• Isobaric and isothermal

Weeps and seeps

• Leak rate

• Compositional data

Cleanliness

• Non-hydrocarbon

• MEG / hydraulic / chemical

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Cylinders

Subsea sampling

• Removable buffer chamber

• Valves qualified to API 6A-PR2

• High pressure and temperatures

• ANSI / NACE MRO175 / ISO 15156

• Certified to global transportation standards

• Hyperbaric pressures up to 530 bar, and where required, API17D

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CASE STUDY

Pipeline restriction

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Pipeline restriction – The Challenge

Case study

North Sea operator issue – 75%

loss in production due to wax

Options

• Review existing samples

• Well intervention

• Sample subsea

Several thousand barrels per day

lost production from well

Skid requirements

• Closed loop

• 2 x 2 litre slops cylinders

• 6 x 2 litre sample cylinders

• Water depth of ~100 metres

• Pressure rating of 1,000 psi

minimum

• Compact design to interface close

to tree

• Isothermal sampling - circulation of

hot water within skid

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Pipeline restriction – The Solution

Case study

• Cost effective sample upstream of pipeline restriction

• Representative fluid chemistry

• Optimise future chemical supply

• Improved understanding of flow assurance

• Saves money: removed potential of working the wrong solution

• Improved safety: reduced risks utilising subsea qualified sample cylinder

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Pipeline restriction – The Lessons Learned

Case study

The sampling stage is critical in understanding exactly what is being produced.

• A topside sample does not equate to a subsea sample

• Nearby fields' chemistry can differ

• Tomorrow – yesterday – today

Subsea sampling is

• Low risk – core technology

• Low cost – rental solutions

• Routinely performed within certain fields

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CASE STUDY

Production allocation

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Production allocation – The Challenge

Case study

Operator issue – metering

calibration, leading to allocation

errors

Options

• Shut-in wells - flush pipelines

• Rely on back-out calculations

• Subsea sample

Lost production, test flowline and

separator all costing $millions

Skid requirements

• 2,500 metres water depth

• Corrosion resistant alloy

• 2 x 12 litre slops cylinders

• 2 x 12 litre sample cylinders

• Design temperature to 88 deg C

• Design pressure of 510 bar absolute

30

Production allocation – The Solution

Case study

• Large volume sample system

• Subsea sample for compositional data and

confidence

• Improved understanding of reservoir

management, no production impact

• Large volumes offset small water-cut,

additional benefits of crude composition

• Removed potential of calibration / allocation

error, reservoir mis-management

• Improved safety, reduced risks utilising

subsea qualified sample cylinder

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Production allocation – The Lessons Learned

Case study


• Accurate data, save time

• Small change – big difference


Subsea sampling is




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CASE STUDY

Decommissioning

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Decommissioning – The Challenge

Case study

Operator issue – Gas leaking into

well bore from reservoir, and up

through subsea wellhead

Options

• Too high, excessive cost

• Too low, gas leak continues

• Subsea sample

Understanding where to set up the

plug to ensure gas leak is isolated

Skid requirements

• Portable

• ROV operated

• 300 metres water depth

• Transportable cylinders

• Hydrate prevention option

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Decommissioning – The Solution

Case study

• Portable gas capture subsea sample system

• Incorporating the ability to reduce hydrate

formation across inlet valve

• Samples improve understanding of source of

gas leak, through isotope analysis

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Decommissioning – The Lessons Learned

Case study


• Right equipment – right result

• Accurate data, save time and costs


Subsea sampling is




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Why choose Proserv?

It is more important to know what sort of sample has a result…. than to know what sort of result a sample has

Proserv offers a unique position for subsea sampling:

• Equipment – rent and purchase options

• Experience – 2,200m, 100’s of samples, +15 years

• Engineering – design, manufacture, build and service

• Capabilities – engineering, sampling and chemistry support

• Independent – work with companies to offer freedom of choice

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TECHNOLOGY I INTELLIGENCE I SERVICE

the science and sense of subsea sampling

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