NORM

NORMNORM

MOHAMMED AL-KAABIKerbala University- College of Science Physics Dep.

HOW TO DEAL WITH THE HOW TO DEAL WITH THE NORM RADIATION NORM RADIATION

AHMAD UMER ABDULLAHResearch and Development

http://www.vpaf.uni.edu/fs/healthsafety/index.shtml







Reservoir rock contains small amounts of natural uranium and thorium and their radioactive daughters. One daughter, radium, is water soluble- dissolves in the reservoir water.

Radium can precipitates with the barium and calcium ions to make any scales slightly radioactive (NORM).

Clay and fine particles can absorb the radium from the formation water.

Why NORM OccursWhy NORM Occurs

Kerbala University-Science College-Physics Kerbala University-Science College-Physics DepDep. www.uokerbala.edu.iqwww.uokerbala.edu.iq2

April 30, 2012April 30, 2012


April 30, 2012April 30, 2012

FIXED IN PLACE

U-238Th-232

Ra-226

Ra-228

Soluble & mobile

Formation water

Rn-222

Oil and gas

U-238 Th-232

Fixed in place

Scal

e

Buildup of scale containing radium

Buildup of scale containing radium

Scale & Sludgecontaining radium

Radon gasRadium will decaygiving rise to manyradioactive daughters(NORM radionuclides)

Natural gas will contain a certainamount of radon

THE ORIGINS OF NORM

Why NORM OccursWhy NORM Occurs

Hazards of NORM Scale Hazards of NORM Scale


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Because NORM scale generally contains so little activity, the external radiation field is generally low. However some old tubular, separators or pumps may give measurable radiation fields.

Because of the high alpha content, NORM scale is a significant internal hazard.

Therefore priority is to stop NORM scale particles being inhaled or ingested.

This alpha toxicity also makes safe disposal important.

Where it Appears Where it Appears

NORM scale appears within the well fluid handling system :• Tubing string (especially tailpipe)• Subsurface safety valves• Wellheads• Manifolds• Separators• Oil coolers• Produced water pipework.


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It can also appear in the service water system, in pig wax in storage cells etc.

Kerbala University-Science College-Physics Kerbala University-Science College-Physics DepDep. www.uokerbala.edu.iqwww.uokerbala.edu.iq

Miscellaneous Valves

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Pipework


Oil Cooler Plates


Oil Separators


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 – beyond bends, valves, restrictions.

Also where temperature or pressure changes occur such: tubular, chokes, separators, coolers.

Separator deposits - clays may absorb radionuclides directly from water.


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How it Gets There How it Gets There

What Scales Look LikeWhat Scales Look Like

Pure barium sulphate is hard dense white solid. Pure NORM scale can be like that (especially in tubular).

More usually thin, eggshell-like, light or dark brown.

Can be stratified, like rings in a tree trunk.

Separator sludge are granular suspensions.

Sometimes deep in the surface matrix, so not visible.

Pig waxes are black tarry materials, often with chunks of rust and scale mixed in.


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April 30, 2012April 30, 2012What Scales Look LikeWhat Scales Look Like

NORM can also be found in gas wells where no fluids are present. Here it is due to radioactive lead-210 plating out on surfaces from the gas. The gas is radioactive because of the radioactive radon gas in the formation accumulating in it. This radon then decays to the lead-210. This layer is thin and cannot always be seen.Kerbala University-Science College-Physics Kerbala University-Science College-Physics

DepDep. www.uokerbala.edu.iqwww.uokerbala.edu.iq

April 30, 2012April 30, 2012NORM in Gas WellsNORM in Gas Wells

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Worker Protection

Protection from External Exposure

Protection from Internal Exposure


Protection from External ExposureProtection from Internal Exposure


Minimize the time , you will minimize the dose. Pre-plan the experiment/procedure to

minimize exposure time.

Three Effective Strategies-Time-Three Effective Strategies-Time-



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Three Effective Strategies-Distance-Three Effective Strategies-Distance-

Doubling the distance from the NORM source can reduce your exposure intensity by 25%.

Use forceps, tongs, and trays to increase your distance from the NORM source.

Move the item being worked on away from the radiation area if possible.

Know the NORM intensity where you perform most of your work, and move to lower dose areas during work delays.



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Three Effective Strategies -Shielding-Three Effective Strategies -Shielding-

Position shielding between yourself and the NORM source at all permissible times. Take advantage of permanent shielding (i.e. equipment or existing structures).

Select appropriate shielding material during the planning stages of the experiment.

Plexiglas, plywood and lead are effective in shielding radiation exposure.

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Kerbala University-Science College-Physics Kerbala University-Science College-Physics DepDep.

Exposure risk will increase when vessels are opened for maintenance.

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www.uokerbala.edu.iqwww.uokerbala.edu.iq


Kerbala University-Science College-Physics Kerbala University-Science College-Physics DepDep.

Plexiglas

Lead

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Protection from internal Exposure

Inhalation of NORM-contaminated dust or radon.Ingestion of NORM-contaminated particulates or liquids.Absorption of NORM-contaminated particulates or liquids through the skin.

The Three Internal Exposure Pathways The Three Internal Exposure Pathways for a Worker in the Petroleum Industry for a Worker in the Petroleum Industry

are: are:

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Protection from internal Exposure

The risks from maintenance activities include:The risks from maintenance activities include: Improper safety procedures for

entering pressure vessels due to the build-up of radon gas.

Sanding, grinding or polishing activities on equipment containing NORM scales that produce airborne NORM particulates.

Handling of filters that are heavily contaminated with radon progeny, without wearing protective gloves.

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Personal ProtectiveEquipment(PPE)


Respiratory protection, including air purifying respirators (half face, with goggles, or full face), self-contained breathing apparatus (SCBA). Protective clothing, including

coveralls gloves and footwear (i.e. CSA-approved safety boots, shoe covers, etc.)22





Radiation monitoring equipment, including a radiation survey instrument, personal dosimeter or alarming dosimeter.

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Radiation Badges In any work associated with

radiation that could result in exposure above 10% of the limit, users should wear a radiation badge.

Badges are designed to be worn to measure an individuals’ exposure on a one or two-month cycle.

If lead aprons are worn, badges should be clipped to the shirt collar.



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Use of NORM Warning Signs and Barricades

Signs and barricades restrict access of unauthorized workers or members of the public to certain process areas.




Pre-Use inspections for PPEPre-Use inspections for PPE Visual inspection of the integrity of the

equipment. Pre-use review of maintenance records for

previously-used PPE, including confirmation of no contamination, general maintenance schedules and operational checks of proper PPE function, as required.Correct UseCorrect UseNORM workers must received appropriate NORM workers must received appropriate

training in the correct use of PPE, prior to its training in the correct use of PPE, prior to its issuance. issuance.

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Post-Use inspections for PPEPost-Use inspections for PPE-prior to restocking for future -prior to restocking for future

use -use -Conduct a visual check of equipment

integrity .Conduct function tests of correct PPE

operation, as applicable.Record results of function tests.



Thank you for your attention!

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