LSA/NORM

1
LSA/NORM

• Training and Awareness Pack

2
Why Oilfield Scale Occurs

• Reservoir water is rich in calcium, barium and
  strontium ions. Injection water is rich in
  sulphate ions. When they mix, precipitation of
  calcium, barium and strontium sulphate occurs.
• Pressure and temperature drops also promote
  precipitation.
• This causes a layer of scale to form inside
  production tubing and process vessels.

3
Why it Becomes LSA

• Reservoir rock contains small amounts of natural
  uranium and thorium and daughters. One daughter,
  radium, is water soluble - dissolves in the
  reservoir water.
• Radium precipitates with the barium and calcium
  ions to make the scale slightly radioactive.
• This makes the scale a Naturally Occurring
  Radioactive Material (NORM) which is of Low
  Specific Activity (LSA).

4
Where it Appears

• LSA scale appears within the well fluid handling
  system -
• Tubing string (especially tailpipe)
• Liner, below the packer
• Subsurface Safety Valves
• Wellheads
• Manifolds
• Separators
• Oil coolers
• Produced water pipework
• It can also appear in the service water system,
  in pig wax, in storage cells etc.

5
How it Gets There

• Incompatible waters mix as they pass through
  perforations - this starts scale depositing in
  the tailpipe and tubing, then throughout the
  plant.
• Deposition is heaviest in areas of turbulence -
  bends, valves, restrictions.
• Also where temperature or pressure changes occur
  - chokes, separators, coolers.
• Separator deposits - clays may absorb
  radionuclides directly from water.
• Service water systems probably due to
  concentrating natural radioactivity from
  seawater.

6
How it Looks

• Pure barium sulphate is hard dense white solid.
  Pure LSA scale can be like that (especially in
  tubulars).
• More usually thin, eggshell-like, light or dark
  brown.
• Can be stratified, like rings in a tree trunk.
• Sometimes deep in the surface matrix, so not
  visible.
• Separator sludges are granular suspensions.
• Pig waxes are black tarry materials, often with
  chunks of rust and scale mixed in.
• See Photo.

7
An LSA Contaminated Tubular
8
Structure of the Atom

• All matter consists of atoms.
• The atom consists of a nucleus, made up of
  protons and neutrons, and a cloud of electrons
  surrounding the nucleus.
• Each sub-atomic particle has its own properties
  in terms of mass and charge-
• Proton Mass 1 Charge 1
• Neutron Mass 1 Charge 0
• Electron Mass 0.0005 Charge -1
• See picture

9
Atomic Structure
10
Types of Radiation

• Some atomic structures are unstable because the
  ratio of protons to neutrons in the nucleus is
  wrong.
• These naturally decay to a stable configuration
  by emitting radiation.
• Three types of radiation are emitted -
• Alpha 2p2n Mass 4 Charge 2
• Beta electron Mass 0.0005 Charge -1
• Gamma photon Mass 0 Charge 0

11
Hazards of Each Type

• Alphas - large and highly charged. Easily
  stopped and absorbed. Sheet of tissue, outer
  skin or centimetres of air will stop them.
• Betas - smaller and less charged, so more
  penetrating. Sheet of cardboard, metal foil or
  metres of air will stop them.
• Gammas - pure electromagnetic energy. Very
  penetrating. Require lead sheet, steel plate or
  many metres of air to stop them.
• See penetration picture.

12
Penetration of Each Radiation Type
13
External and Internal Hazard

• These properties determine effect on health.
• Gammas can penetrate body from outside and damage
  deep internal cells. This penetration makes them
  an External Hazard.
• Alphas/betas cannot penetrate far from outside.
  However if alpha emitting materials enter the
  body, particularly the lungs, the size and charge
  of the alphas makes them very damaging to the
  cells they hit. This alpha toxicity makes them
  an Internal Hazard.

14
Uranium -238 and Thorium-232 Decay Series

• Two decay series in LSA scale - U-238 and Th-232.
• Uranium-238 emits alphas, betas and gammas to
  decay through protoactinium, thorium, radium,
  radon, polonium and bismuth to stable lead-206.
• Thorium-232 emits alphas, betas and gammas to
  decay through radium, actinium, radon, bismuth,
  polonium and thallium to stable lead-208.
• Each decay step takes an approximate length of
  time (half life). Because some half lives are
  long, ratio alphas/betas/gammas is fairly
  constant.
• See decay series charts.

15
Uranium -238 Decay Series
16
Thorium -232 Decay Series
17
Hazards of LSA Scale

• Because LSA scale contains so little activity,
  the external field is generally low. However
  some old tubulars, separators, Wemcos may give
  measurable fields.
• Because of the high alpha content, LSA scale is a
  significant internal hazard.
• Therefore priority is to stop LSA scale particles
  being inhaled or ingested.
• This alpha toxicity also makes safe disposal
  important.

18
Units of Radiation

• Unit of Activity - Becquerel (Bq)
• 1 Becquerel 1 disintegration per second
• This is effectively the size of the source, or
  as Bq/g, the amount of radioactivity in a
  substance
• Unit of Absorbed Dose - Gray (Gy)
• 1 Gray 1 joule per kilo absorbed
• This is the amount of radiation energy absorbed
• Unit of Corrected Absorbed Dose - Sievert (Sv)
• 1 Sievert 1 Gray x Quality Factor
• This is the harmfulness of absorbed radiation

19
Legislative Overview

• Two main pieces of legislation.
• Ionising Radiations Regulations - set standards
  for protection of workers, by requiring certain
  precautions.
• Radioactive Substances Act - set standards for
  protection of public and the environment, by
  setting conditions for holding, using, storage
  and disposal.
• Transport regulations are separate.

20
Ionising Radiations Regulations

• Set standards for protection of workers
• Risk Assessment
• Appointment of Radiation Protection Adviser
  (RPA) and Radiation Protection Supervisor (RPS)
• Local Rules
• Controlled and Supervised Areas
• Dose control
• Training and awareness
• Regulated by HSE.

21
Radioactive Substances Act

• Set standards for protection of public and
  environment
• Registrations and Authorisations set detailed
  conditions
• Contaminated equipment to specified locations
• Offshore waste to sea only
• Ground to below 1mm
• Annual total discharge activity limit
• Record of all discharges
• No transfer between platforms
• Regulated by SEPA.

22
Definition of Radioactive

• IRR brings a substance into its remit at 100
  Bq/g.
• RSA has a Schedule by radioelement - for radium
  the level is 0.37 Bq/g.
• The large difference is due to the intent of the
  legislation - protection of the public and
  bioaccumulation require lower limits.

23
Rare Earths Exemption Order

• RSA is supported by Exemption Orders - allow some
  exemptions for certain radioelements under
  certain conditions.
• Phosphatic Substances (Rare Earths) EO can be
  used for LSA scale.
• Exempts material up to 14.8 Bq/g from RSA.
• User must be able to prove EO applies.

24
Radiation Protection Adviser

• Every radiation employer must appoint a Radiation
  Protection Adviser (RPA)
• Professional radiation specialist
• Must be accredited by professional body
• Registered with HSE
• Must be consulted on radiation protection
  matters
• Carries out annual inspection of each location
• Shell RPA - Dr. Brian Heaton

25
Radiation Protection Supervisor

• At workplace level, every radiation employer must
  appoint Radiation Protection Supervisor(s) (RPS)
• Supervise radiation work directly
• Ensure Local Rules are met on the worksite
• Shell Expro 2 day course - Level 3
• Train meter users and workforce - Level 2M, 2, 1
  
• Appointed in writing - in APR and Local Rules
• Shell Competent Person is lead RPS

26
Local Rules

• Every radiation employer must make Local Rules
• Detailed and prescriptive rules
• Tailored to each location
• Written in cooperation with Business Units and
  RPSs
• Checked and approved by RPA
• In Document 3133-001
• Also contains Source Register and LSA Record of
  Work

27
Shell Expro LSA Local Rules

• In Document 3133-001
• 01 - Preparation and Interfacing Prior to Work
• 08 - Working on LSA Contaminated Equipment
• 09 - Decontamination on the Installation
• 10 - Milling on LSA Scale
• 11 - Handling of LSA Contaminated Tubulars
• 12 - Handling of LSA Contaminated Well Control
  Equipment
• 13 - Handling of LSA Contaminated Pigs and Pig
  Debris
• 14 - Entry and Cleaning of LSA Contaminated
  Vessels
• 15 - Discharge of LSA Scale to Sea
• 16 - Dispatch of LSA Contaminated Items Onshore
• 17 - Instruction to Refurbishment Contractors
• 18 - Record Keeping, Reporting and Auditing
• 19 - Radiation Training and Competence

28
Controlled and Supervised Areas

• Every radiation employer must set up Controlled
  and Supervised Areas.
• Controlled Area
• Where it is necessary to restrict significant
  exposure
• Where dose likely to exceed 6 millisievert/y
• Supervised Area
• Where risk needs to be kept under review, or
• Where dose likely to exceed 1 millisievert/y
• Shell Expro sets up an LSA Supervised Area around
  LSA work.

29
Dose Controls

• Every radiation employer must limit radiation
  exposure ALARP
• Engineering controls
• Systems of Work
• Personal protective equipment
• Dose limits
• Workers - 20 millisievert/y
• Public/others - 1 millisievert/y
• At 6 millisievert/y, workers must be Classified.
• Not really relevant to LSA scale work (external
  radiation limitation).

30
Philosophy of LSA Management

• Stop inhalation or ingestion of scale particles-
• Stop dust being created
• Stop dust becoming airborne
• Stop dust from entering the body
• Contain scale in one area and minimise contact
• To achieve this we -
• Adhere to Local Rules
• Keep scale wet to stop dust rising
• Wear personal protective equipment
• Set up LSA Supervised Area and restrict contact

31
LSA Workflow

• General workflow is as follows -
• Identification of work with LSA potential
• Preparation for work with LSA potential
• Detection and identification of LSA
  contamination
• Working on LSA contaminated equipment
• LSA disposal to sea
• LSA contaminated equipment to onshore cleaner
• The rest of this pack will cover each of these
  areas in detail.

32
Identification of Work with LSA Potential

• Assume all fluid bearing systems are LSA
  contaminated until proven clean.
• Use Local Maps to identify areas of known LSA
  contamination.
• External monitoring may identify very active LSA
  but not reliable.
• Test all systems at first breach, and regularly
  as new surfaces are encountered.
• Record zero readings.

33
Preparation for Work with LSA Potential

• Local Rule 01 (onshore), 08 (offshore).
• Onshore planning of work - coordination between
  Shell and contractor(s).
• LSA Procedures/Local Rules in Workpacks.
• All parties must know/understand Shell and own
  Local Rules.
• Equipment - muncher, tape, labels, tags,
  polythene, PPE etc.
• Training and awareness. Tool Box Talks etc.
• Permit to Work.

34
Detection and Measurement of LSA Scale - 1

• Shell standard LSA meter - Mini 900 with 44A
  probe
• Scintillation counter - detects high energy
  betas and gammas
• Readout in counts per second (cps)
• Fairly robust probe
• Not intrinsically safe
• See Picture.

35
Mini 900 with 44A Probe
36
Detection and Identification of LSA Scale - 2

• Special meter for confirming external
  contamination on tubulars - Mini 900 with EP15
  probe
• Geiger tube - detects alphas and low energy
  betas
• Readout in counts per second (cps)
• Fragile probe
• Not intrinsically safe
• Used by some operators and contractors as their
  standard LSA meter - Shell prefers 44A probe
• See Picture.

37
Mini 900 with EP15 Probe
38
Detection and Identification of LSA Scale - 3

• Dosemeter - ICI Gammatrol PRI 90 and 90s
• Measures external radiation field at a point
• PRI 90 readout is in millirads per hour (mrad/h)
• Converts to microsieverts per hour (µSv/h) by
  multiplying by 10 (1 mrad 10 µSv)
• PRI 90s readout is in microsieverts per hour
  (µSv/h)
• Both have three ranges - 100, 1000, 10000 µSv/h
• Use 100 µSv/h range for LSA scale fields
• Intrinsically safe
• See Picture.

39
ICI Gammatrol PRI 90
40
Selection and Use of Meters

• The Mini 900 with 44A probe is Shells standard
  meter for LSA identification.
• Measuring gammas is more reliable than
  alphas/betas in the field situation, as they are
  not attenuated by water, mud, wax etc.
• The Mini 900 with EP15 probe can be used to
  confirm external contamination on tubing.
• However the Mini 900 with EP15 probe is not
  always reliable for LSA identification in the
  field situation.
• Alphas/betas may be attenuated in dirty material
  

41
Meter Reading to Declare LSA

• Using the Mini 900 with 44A probe, a reading of
  3 cps above background is LSA.
• 3 cpsabg is the lowest statistically reliable
  reading with the meter
• Does not convert directly to Bq/g, but 3 cpsabg
  is in the range of 0.37 Bq/g (depending on
  thickness etc)
• Note - it is not possible to convert from cpsabg
  to Bq/g as you do not know the thickness and thus
  the mass of scale that the counts come from.
• We identify contamination, we do not measure
  scale activity.

42
Use and Care of the Meter

• Local Rule 08.
• Turn on, battery check (green), read.
• With or without speaker.
• Function test - use test source before use.
• Probe and meter are matched - do not mix.
• Remove cap, replace with thin plastic bag.
• Take background, bring to surface, back away -
  look for rise and fall.
• Test all new exposed surfaces.
• Calibrate annually - Aberdeen University.

43
Work Precautions - LSA Contaminated Equipment

• Local Rule 08.
• Record the whole job on Form F/4507 as you go.
• Regular monitoring of surfaces.
• LSA Supervised Area.
• Personal protective equipment.
• Personal hygiene - shower after work.
• PA announcement before work.
• Keep scale wet during work.
• Minimise wire brushing, grinding, burning.
• If Mini 900/44A gt200 cps, check with Gammatrol
  PRI 90. If gt7.5 µSv/h, contact BU HSE team.
• Label and tag everything.

44
Work Precautions - LSA Supervised Area

• Local Rule 08.
• Barriered off and labelled as LSA Supervised
  Area.
• Deck lined with polythene to collect any loose
  scale.
• Entry controlled and logged.
• PPE donned on entry, removed at exit.
• Contamination check on exit.
• Minimise entry - need only.
• Eyewashes and showers where appropriate.
• PA announcement on setup.
• All LSA to be contained in the area.
• When work completed, area thoroughly cleaned and
  monitored.

45
Work Precautions - Personal Protective Equipment

• Local Rule 08.
• One piece slicker suit or Tyvek disposable suit.
• Impermeable gloves.
• Impermeable boots.
• Facepiece respirator to EN146FFP3 - 3M 8835 or
  Moldex 3405.
• Eye protection - safety goggles.
• All PPE to be cleaned after job and monitored as
  free from contamination. Must be reused or
  returned as normal waste.
• Contaminated PPE cannot be sent to shore.

46
Work Precautions - Personal Hygiene

• Local Rule 08.
• No eating, drinking, chewing gum, sweets,
  tobacco.
• No application of barrier cream.
• All cuts and abrasions effectively dressed.
• Wash hands and face before eating, drinking or
  smoking.
• Shower after work.

47
Work Precautions - Labelling and Tagging

• Local Rule 08.
• Tape and tag immediately after testing.
• Positive reading - yellow/black LSA Contaminated
  tape tag.
• Negative reading - green LSA Externally Clear
  tape tag.
• Mark tags with cps, Date, Name of Tester,
  Platform.
• Tubulars - tape ends 2 tubular tags
• See pictures.

48
Labelling and Tagging - LSA Contaminated
49
Labelling and Tagging - LSA Externally Clear
50
Labelling and Tagging - Tubulars
51
Work Precautions - Offshore Decontamination

• Local Rule 09.
• Mainly for repair and reinstatement on
  installation.
• Not for tubulars or very large items.
• Carried out by experienced contractor cleaning
  crew.
• Extensive decontamination requires dedicated
  habitat - preferably purpose-fitted container.
• Habitat is an LSA Supervised Area.
• Can be used for onshore refurbishment or scrap -
  Clearance Certificate required.
• Arisings must be discharged as per Authorisation.
• Work must be recorded on Form F/4507.

52
Work Precautions - Milling of LSA Scale

• Local Rule 10.
• LSA scale cleanouts in wells - usually coiled
  tubing.
• Large LSA scale particles caught in junk-sub,
  small LSA scale particles entrained in brine.
• Solids in junk-sub must be disposed to sea as per
  Authorisation. Sample and mass estimate
  required.
• Light brine discharged to sea. Sample and mass
  estimate of solids required.
• Heavy brine filtered for reuse - precoat filter.
  Sample and mass estimate of backwash solids
  required.
• After work, mud handling equipment and filter
  equipment must be decontaminated and tested.
• Work must be recorded on Form F/4507.

53
Work Precautions - LSA Contaminated Tubulars

• Local Rule 11.
• Use Mini 900 with 44A probe. Lay down tubular,
  insert probe into pin end.
• Test every fifth joint until LSA indicated, then
  every joint from then on.
• Mark clean tested joints with green tape tags.
• Mark contaminated joints with yellow/black tape
  tags. Fit end caps, segregate. Mark slings with
  tape.
• Tape and tag each joint - not bundle.
• Test for external contamination - Mini 900 with
  EP15 probe, or wipe test if meter not available.
• Work must be recorded on Form F/4507.

54
Work Precautions - LSA Contaminated Pigs

• Local Rule 13.
• Only on installations which receive interfield
  pigs.
• Use Mini 900 with 44A probe. Pig and pig wax.
• LSA precautions apply for handling and cleaning.
• If pig is to be reused directly, visually clean
  and send back to launch installation.
• Wrap pig in polythene, tape, label as visually
  but not radiologically clean.
• Send sample(s) of pig wax to UESP to determine if
  Rare Earths exemption applies.
• If exemption applies, send wax onshore for
  disposal.
• Work must be recorded on Form F/4507.

55
Work Precautions - LSA Contaminated Vessels

• Local Rule 14.
• Carried out by experienced contractor cleaning
  crew.
• Vessel entry precautions apply.
• External radiation check with PRI 90 dosemeter.
  If gt7.5 microsievert/h - vessel is Controlled
  Area. Otherwise LSA Supervised Area.
• Prior to entry, flush vessel as much as possible.
• Arisings must be discharged as per Authorisation.
• Sampling and mass estimate very important as
  these discharges are usually large.
• Sampling is a Shell Expro responsibility.
• Work must be recorded on Form F/4507.

56
Discharge of LSA Scale to Sea

• Local Rule 15.
• Conditions set by Authorisation, must be strictly
  met.
• All free scale, sludges must be discharged to
  sea.
• Dedicated hose below sea surface.
• Ground to below 1 mm (confirm).
• Suspend diving.
• Authorisations contain discharge limit - 3-10
  GBq/y
• Must sample discharges and estimate mass.
  Samples sent to UESP for radiological analysis.
  Tracked in spreadsheet.
• Discharges must be recorded on Form F/4507.

57
Sampling of LSA Discharges

• Local Rule 15 Appendix.
• Sample grinder output to check particle size.
• Sample discharge solids for radiological
  analysis.
• Samples must be representative of total
  discharge.
• Samples about 100 g (50 ml).
• For discharges lt100 kg, single sample sufficient.
• For larger discharges, eg separators, several
  samples probably required.
• If scale differs markedly in places, sample each
  type.
• Samples must be recorded on Form F/4507.

58
Dispatch of LSA Contaminated Items Onshore

• Local Rule 16.
• Must be properly sealed, labelled, taped, tagged.
• Proper documentation - manifest LSA
  Contaminated, Dangerous Goods Declaration.
• Must go to AEAT Dounreay for decontamination.
• LSA1 package, Group 2912.
• Items must be recorded on Form F/4507.

59
LSA Record Keeping

• Local Rule 18.
• Complete LSA job recorded on Form F/4507.
• Contains eight boxes -
• A - LSA Job Number
• B - Job Details
• C - Monitoring Details
• D - Sand/Scale Discharged to Sea
• E - LSA Scaled Equipment Backloaded
• F - Discharge Analysis
• G - Comments
• H - Supervised Area Log
• All boxes must be completed. Maximum
  information.
• In addition to contractor records - Shells
  overview.

60
LSA Record Keeping - Form F/4507 A-C
61
LSA Record Keeping - Form F/4507 D-G
62
Inspection and Audit

• Local Rule 18.
• HSE and SEPA have the right to inspect any
  authorised premises at any time.
• To confirm terms of IRR, RSA, registrations and
  authorisations are being met.
• Sanctions include Warning Letter, Enforcement
  Notice, Prosecution (fine, imprisonment).
• SEPA will compare their application/records with
  offshore work records to ensure consistency.
• Shell Expro carries out annual audit of each
  platform
• RPA audit of radiation protection arrangements
• Record keeping audit

63
Training and Awareness

• Local Rule 19.
• Shell Expro has produced a Competence Matrix
• Five levels - 5 - Expert - RPA
• 4 - Senior Specialist
• 3 - Shell RPS
• 2 - Working with LSA hardware
• (2M - LSA Meter user)
• 1 - General workforce
• Also approved training for each level.

64
Summary

• LSA scale represents two types of risk to Shell
  Expro
• A HSE risk
• A legal, reputation and business risk
• Both are real and important risks and must be
  taken seriously.
• We have an LSA management system to protect us -
  described in Local Rules
• Understand it
• Use it (precisely)
• Record everything
• Protect yourself, your colleagues and the Company.

65
Keep Us Out of the Headlines!
66
The Solid Gold Tubulars Return From Italy