Crude oil sampling - Jiskoot · • Our equipment handles over 60% of world crude oil • Local support ... • Automatic pipeline sampling • ISO 3171 • API 8.2 ... • Removable

Crude oil sampling

Proprietary and confidential ©

• UK and USA based

• International network of over 50 agents

• Our equipment handles over 60% of world crude oil

• Local support

• Sphere of operations• Sampling

• Custody transfer, allocation and quality

• Blending• Crude oil, bunker fuel

• Multiphase Metering

Jiskoot


What is a sample?

• “A sample is a small separated part of something that illustrates the qualities of the mass.”Oxford English Dictionary

• Small

• Separated

• Representative

• Transportable


What is a sample?

• “A sample is the basis upon which we acknowledge receipt of a crude oil cargo delivery and base our payment.” - BP Oil Refinery

• Physical evidence

• Statement of faith

• Proof of purchase

• Legal ‘document’

• Fair trade


• Determine the quality

• Reduce losses

• Measure water

• Measure quality

• Measure density

• Value the batch

• Allocation/taxation measurement

• Comply with legislation and reduce the risk of dispute

Why sample?


1 in 300,000,000,000

How should you sample?

• Hierarchy of sampling

• In ships tanks

• In shore tanks

• By manifold samplers

• By a quality in-line sampling system

• Volume analysed is 1 in 300,000,000,000


Hydrocarbon sampling standards

• Automatic pipeline sampling

• ISO 3171

• API 8.2

• IP 6.2

• Compliance with ISO will mean compliance with all others


Basic requirements

• Homogeneity of pipeline contents – (mixing)

• Extraction of a flow proportional and representative sample

• Correct sample handling and mixing

• Laboratory analysis

• Proving the system by water injection


Pipeline homogeneity (mixing)

• Where do you take the sample?

• Pipeline must be well mixed to extract a representative sample

High DensityLiquid (Water)

Low DensityLiquid (Oil)


Pipeline homogeneity

• Mixing Sources

• Natural Turbulence

• Pumps, Valves, Elbows,T's etc.

• Types of Mixers

• Static

• Variable Static

• Dynamic (Power)

• Jet Mixer


Calculation of C1/C2 ratio• (Water concentration at top of pipeline as a ratio of water concentration at the bottom. It

must be greater than 0.9 for the whole flow range )

0 1 2 3 4 5 6Flow (Thousand M3/Hr)

0

0.2

0.4

0.6

0.8

1

C1/

C2

Prof

ile R

atio

0

1

2

3

4

5

6

7

8

9

10

Dro

plet

Sze

(mm

)

StraightPipeDropletSize

For adequate Sampling C1/C2 >0.9

As flowrate falls droplets get bigger and there is poorer

mixing (stratification)

Pipeline homogeneity Standards requirement


13

6

2.2 1.8 1.5 1.3 1 0.9 0.520.510.5 0.490

2

4

6

8

10

12

14

0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150Unloading Times (Minutes)

Perc

enta

ge W

ater

(%

)

Representative sampling Of the COMPLETE batch

Water content changes during transfer


Representative sampling Sample extraction - take-off size

Relationship of the takeoff size to mixing

• Droplet Size/Takeoff Size = 0.1

Water droplet

CoJetix

In-LineFast Loop

Which is Potentially More Accurate ?


Representative sampling Of the COMPLETE batch

• Representative sampling of the batch

• Samples must be taken flow proportionally

• Repeatable sample size

• High frequency samples

• Performance monitoring


Representative Sampling Sample extraction

• Samples must be taken flow proportionally

• Sample taken from the central 1/3rd of pipeline

• Each 1ml sample grab must be repeatable (normally ±2%)• Irrespective of changes in viscosity, pressure or density

• Sampler must take high enough frequency samples to take 1-15 litres of sample• Depending on application

• Sampler performance monitoring


Representative Sampling System feedback

• Performance monitoring

• Required by standards

• Weighing and feedback systems

• Grab sensors and checkers

Performance Factor Calculations


Sample Handling & Mixing Sample Receivers

• Fixed or portable receivers

• Constant pressure receivers

• Considerations in selection

• Analysis requirements

• Volume required

• Type of analysis

• Homogeneity

• Mixing

• Pressure

• Portability


Laboratory Analysis

• Mixing systems for receivers

• Sub-sampling

• Analysis Methods

• Water

• Density

• Sediment

• Vapour Pressure

• Sample storage/retention


System Proving

• System proving by water injection

• Standards define a procedure

• Must prove the whole installed system to be valid

• Can be independently witnessed and certified


Four Basic Requirements Summary

• Pipeline Conditioning

• Representative Sampling of the Batch

• Sample Handling & Mixing

• Laboratory Analysis

Do all the steps right or don't bother !!!!!


What are your options?

• Mixing

• Power mixing is the only option because of the pressure drop across a static system

• Current manifold samplers have no mixing and will under-measure water

• Sampling

• In-line system

• Accuracy improvement - 0.033 - 0.09% (total water)

• CoJetix mixing and sampling system

• Accuracy improvement - 0.113 - 0.17% (total water)


JetMix®


• Energy input increases as flowrate decreases

• Installed without depressurising/draining

• Mixing energy added to flow rather than derived from it

• No pressure drop

• Removable for pigging

• Recycle loop

• Simple to maintain

JetMix®


In-line sampling system

• Sample Probe• Pitot entry for minimum disruption to flow

• Housing• Can change system

• Pressure relief system

• Optional purging

• Flow meter input • Flow proportional

sampling

• Controller• Performance factor

• Reports


In-line sampling system


CoJetix sampling system

• Combined JetMix & sampling system in a single package

• JetMix takeoff ‘quill’ and mixing nozzle

• 1 - 2 " line with isolation valves

• Magnetically coupled pump (sized to maintain mixing in loop)

• Housing• Cell sampler• Receivers• Weighing system• Can change system

• Flow meter

• Controller


CoJetix Sampling system


CoJetix or In-line?

High batch cross contamination

Minimal batch cross contamination

Fast Loop System In-Line System

Sample cross-contamination


CoJetix or In-line?

• Relationship of the takeoff size to mixing• Droplet Size/Takeoff Size = 0.1

Water droplet

CoJetix

In-LineFast Loop

Which is Potentially More Accurate ?


• In Line• Less components

• Install as close to the pipe as possible

• High retained volume/contamination possibility

• Harder to maintain

• Needs 4 tappings to install

• Less accurate

CoJetix or In-line?

• CoJetix• More components

• Can incorporate

• Densitometers

• Water Monitors

• Convenient location

• Minimal retained volumes

• Cheaper to maintain

• Only needs 3 tappings to install

• More accurate

• More rapid ROI

Thank youAny questions

Documents

Crude oil sampling - Jiskoot · • Our equipment handles over 60% of world crude oil • Local support ... • Automatic pipeline sampling • ISO 3171 • API 8.2 ... • Removable