well barriers materials

International Well Control Forum

IWCF Accredited Centres are free to use and adapt this material as they see fit, for use in training. Please be aware that thispresentation is provided for general information only and it is not intended to amount to advice or guidance which you should rely

upon. It does not represent an official industry standard or recommended practice. IWCF makes no representation, warranty or guarantee that the content is accurate, complete or up-to-date. IWCF shall not be liable in any way for any claims, losses or demands

relating to your use of the presentation.

Well Barriers IWCF 2014

WELL BARRIERS

This presentation is not intended to amount to advice or guidance which you should rely upon. It does not represent an official industry standard or recommended practice. IWCF makes no representation, warranty or guarantee that the content is accurate, complete or up-

to-date. IWCF shall not be liable in any way for any claims, losses or demands relating to your use of this presentation.

IWCF 2014

WELL BARRIERSAim: To fully understand Well Barrier philosophy in Drilling,

Coring & Tripping operations.Objectives: State the Primary Barrier in normal Drilling operations. Identify Secondary Barrier elements. Describe a Barrier envelope. List what Barrier test documentation should contain.

This presentation is not intended to amount to advice or guidance which you should rely upon. It does not represent an official industry standard or recommended practice. IWCF makes no representation, warranty or guarantee that the content is accurate, complete or

up-to-date. IWCF shall not be liable in any way for any claims, losses or demands relating to your use of this presentation.

IWCF 2014

Well BarriersPrimary well barrier: This is the first object that prevents flow

from a source.

Secondary well barrier: This is the second object that prevents

flow from a source.



IWCF 2014

What are Well Barriers Well barriers are envelopes (something that

surrounds or encloses something else) of one ormore dependent WBEs (well barrier elements)to prevent fluids or gases from flowingunintentionally from a formation, into anotherformation or back to surface.

Well barrier(s) shall be defined prior tocommencement of an activity or operation bydescription of the required WBEs to be in placeand the specific acceptance criteria.



IWCF 2014

Well Barrier Element Examples1. Fluid Barriers2. Casing and Cement3. Drill string4. Drilling, Wireline, Coil Tubing, Workover BOPs5. Wellhead6. Deep set tubing plug7. Production Packer8. Stab-in Safety Valves9. Completion String10. Tubing Hanger

* Barrier elements in red denote other operations in a wellThis presentation is not intended to amount to advice or guidance which you should rely upon. It does not represent an official industry standard or recommended practice. IWCF makes no representation, warranty or guarantee that the content is accurate, complete or


IWCF 2014

Well Barriers Drilling, Coring, Tripping

Primary well barrier:This is the first object thatprevents flow from a source.

Drilling Fluid Formation Pressure

(Fluid) Barrier:The hydrostatic head of the wellbore fluid is greater than the formation pressure.

AP

SSR

UPRMPRLPR

DrillingBOP

This presentation is not intended to amount to advice or guidance which you should rely upon. It does not represent an official industry standard or recommended practice. IWCF makes no representation, warranty or guarantee that the content is accurate, complete or up-to-date. IWCF shall not be liable in any way for any claims, losses or demands relating to your use of this presentation.

IWCF 2014

Primary well barrier:This is the first object thatprevents flow from a source.

Secondary well barrier:This is the second object thatprevents flow from a source.

Well Barriers Drilling, Coring, Tripping


IWCF 2014

Formation Pressure

BOP

RamsTubulars

Casing

Safety Valves

Choke/Kill line valves

Cement

Wellhead

SOME OF THE (ELEMENTS) THAT FORM THE BARRIER ENVELOPE



IWCF 2014

BOPRams

Safety Valves

CasingChoke/Kill line valves

Wellhead

CementTubulars

SOME OF THE (ELEMENTS) THAT FORM THE BARRIER ENVELOPE



IWCF 2014

Well Barrier Acceptance Criteria.

Well barrier acceptance criteria aretechnical and operational requirements thatneed to be fulfilled in order to qualify thewell barrier or WBE for its intended use.



IWCF 2014

Acceptance CriteriaFunction and number of well barriers

The function of the well barrier and WBE shall be clearly defined.

One well barrier in place during all well activities and operations,including suspended or abandoned wells, where a pressuredifferential exists that may cause uncontrolled cross flow in thewellbore between formation zones.

Two well barriers available during all well activities and operations,including suspended or abandoned wells, where a pressuredifferential exists that may cause uncontrolled outflow from theborehole/well to the external environment.



IWCF 2014

Well Barrier Acceptance Criteria Example Drilling BOPFeatures Acceptance Criteria See

A.Description The element consists of the wellhead connector and drilling BOP with kill/choke line valves.

B. Function The function of wellhead connector is to prevent flow from the bore to the environment and to provide a mechanical connectionbetween drilling BOP and the wellhead. The function of the BOP is to provide capabilities to close in and seal the well bore with orwithout tools/equipment through the BOP.

C. Designconstructionselection

1. The drilling BOP shall be constructed in accordance with !!!!! standards.2. The BOP WP shall exceed the MWDP (maximum well design pressure) including a margin for kill operations.3. It shall be documented that the shear/seal ram can shear the drill pipe, tubing, wireline, CT or other specified tools, and seal the well bore thereafter. If this can not be documented by the manufacturer, a qualification test shall be performed and documented.4. When running non shearable items, there shall be minimum one pipe ram or annular preventer able to seal the actual size of the non shearable item.5. For floaters the wellhead connector shall be equipped with a secondary release feature allowing release with ROV.6. When using tapered drill pipe string there should be pipe rams to fit each pipe size. Variable bore rams should have sufficient hang off load capacity.7. There shall be an outlet below the LPR. This outlet shall be used as the last resort to regain well control in a well controlsituation.8. HTHP: The BOP shall be furnished with surface readout pressure and temperature.9. Deep water:9.1. The BOP should be furnished with surface readout pressure and temperature.9.2. The drilling BOP shall have two annular preventers. One or both of the annular preventers shall be part of the LMRP. It should be possible to bleed off gas trapped between the preventers in a controlled way.9.3. Bending loads on the BOP flanges and connector shall be verified to withstand maximum bending loads (e.g. Highest allowable riser angle and highest expected drilling fluid density.)9.4 From a DP vessel it shall be possible to shear full casing strings and seal thereafter. If this is not possible the casings should be run as liners.

API RP53

D. Initial testandverification

See Example, Table A

E. Use The drilling BOP elements shall be activated as described in the well control action procedures.

F. Monitoring See Example, Table A

G. Failuremodes

Non-fulfillment of the above mentioned requirements. See Example, Table B


IWCF 2014

Table A. Routine leak testing of drilling BOP and well control equipment

Frequency

Element

Stump

Before Drilling out Casing Before

Well Testing

Periodic

SurfaceDeeper

Casing & Liners

WeeklyEach

14 Days

Each 6 Months

BOP

AnnularsPipe RamsShear RamsFailsafe ValvesWellhead ConnectorWedge Locks

MWDP 1)MWDPMWDPMWDPMWDPFunction

FunctionFunctionFunctionFunctionMSDP

MSDP 1)MSDPMSDPMSDP 3)

TSTP 1)TSTPTSTPTSTPTSTP

FunctionFunctionFunctionFunction

MSDP 1)MSDP

MSDP 3)MSDP

WP x 0.7WPWPWPWP

Choke/Kill line and Manifold

Choke/Kill LinesManifoldValvesRemote Chokes

MWDPMWDPFunction

MSDPMSDPFunction

MSDPMSDPFunction

TSTPTSTPFunction

MSDPMSDPFunction

WPWP

Other Equipment

Kill PumpInside BOPStabbing ValvesUpper Kelly ValveLower Kelly Valve

WP 2)MWDP 2)MWDP 2)MWDP 2)MWDP 2)

MSDPMSDPMSDPMSDPMSDP

TSTPTSTP

MSDPMSDPMSDPMSDPMSDP

WPWPWPWPWP

Legend NOTE 1 All tests shall be 1,5 MPa (200 psi) to 2 MPa (300 psi) for 5 min andhigh pressure for 10 min.

NOTE 2 If the drilling BOP is disconnected/re-connected or moved betweenwells without having been disconnected from its control system, the initial leaktest of the BOP components can be omitted. The wellhead connector shall beleak tested.

NOTE 3 The BOP with associated valves and other pressure control equipmenton the facility shall be subjected to a complete overhaul and shall be recertifiedevery five years. The complete overhaul shall be documented.

WP Working Pressure

MWDP Maximum Well Design Pressure

MSDP Maximum Section Design Pressure

Function Function Testing shall be done from alternating panels/pods

TSTP Tubing String Test Pressure

1) Or Maximum 70% of WP2) Or at initial installation3) From above if restricted by BOP arrangement

IWCF 2014

Table B - Failure of drilling BOP and control systems

Barrierelement/equipment Actions to be taken when failure to test

Annular Repair immediately.

Shear ram If WBE, repair immediately.

Pipe ram (upper, middle, lower) If WBE, repair immediately if no other pipe rams is available for that pipe size.Rams that failed to test to be repaired at a convenient time.

Choke valves, inner/outerKill valves, inner/outer

If both valves in series have failed, repair immediately. If one valve in series has failed, repair after having set casing.

Marine riser choke and kill line * If one has failed, repair immediately.

Yellow and blue pod * If both have failed, repair immediately. If one has failed, repair at a convenient time.

Acoustic shear ram * Same as for shear ram.

Acoustic pipe rams * If one or more have failed, repair after having set casing if size is covered by another ram. If not, repair immediately.

Floating InstallationsNomenclature :

Immediately: Stop operation and temporary abandon well. After having set casing: Carry on with the operation and repair after having set the next casing.Convenient time: Applicable for WBEs that are not required.


IWCF 2014

Pressure direction The pressure should be applied in the flow direction.

If this is impractical, the pressure can be applied againstthe flow direction, providing that the WBE is constructedto seal in both flow directions or by reducing thepressure on the downstream side of the well barrier tothe lowest practical pressure (inflow test).



IWCF 2014

Documentation of leak and function testing of well barriers

All well integrity tests shall be documented and acceptedby an authorized person. This authorized person can bethe driller, tool-pusher, drilling and well interventionsupervisor or the equipment and service provider'srepresentative.The chart and the test documentation should contain Type of test, Test pressure, Test fluid, System or components tested, Estimated volume of system pressurized, Volume pumped



IWCF 2014

Swiss Cheese Model

What Is Human Error?Human error is an imbalance between what the situation requires, what the person intends, and what he/she actually does.

Human error happens when people:

Plan to do the right thing but with the wrong outcome (e.g., misdial a correct telephone number; give the correct instruction but to the wrong person)

Do the wrong thing for the situation (e.g. turn an alarm off)

Fail to do anything when action is required (e.g. fail to report faulty equipment)



IWCF 2014

Why do Errors Happen?

As imperfect humans, we have inherent limitations in our abilities. We willmake mistakes. To answer the question of why do errors happen? or whydid the error happen? it is necessary to look beyond the person who madethe error.

Simply put, errors happen when multiple factors come together to allowthem to happen. What we usually call human error is really system error.People are one part of a system that includes all of the other parts of theorganization or work environment equipment, technology, environment,organization, training, policies, and procedures. Human error is rooted infailure of the system or the organization to prevent the error fromhappening, and if an error happens, failure to prevent the error frombecoming a problem.

Swiss Cheese Model



IWCF 2014

Examples of defenses: Checking drilling mud weights. Challenging response procedures (being told to do something you

know is wrong). Setting alarms correctly. Following correct testing procedures.

It is when these defenses are weakened and breached that human errors can result in incidents or accidents.

These defenses can be portrayed diagrammatically, as severalslices of Swiss cheese (and hence the model has become knownas Professor Reasons Swiss cheese model)

Swiss Cheese ModelThe concept of defenses against human error



IWCF 2014

Swiss Cheese Model

Some failures are latent, meaning that they have been made atsome point in the past and lay dormant.

This may be introduced at the time a well barrier was designed ormay be associated with management decisions and policies.

Errors made by front line personnel, such as Supervisors, Drillersetc, are active failures.

The more holes in a systems defenses, the more likely it is thaterrors result in incidents or accidents.

In certain circumstances, when all holes line up, blowouts occur.



IWCF 2014

Simple Swiss Cheese Model explaining how a blowout could happen

Active failure: Fluid barrier breached when pulling pipe too fast reduced hydrostatic pressure and allowed the well to flow.

Latent failure: Inadequate mud checks failed to pick up on reduced mud weight?

Reservoir Hydrocarbons

Latent & Active failures: Delayed detection. Well monitoring not done resulting in increased kick size. Annular Fails to seal.

Latent & Active Failures. Secondary barrier element breached due to incorrect procedures (Tool joint across pipe rams).

Shear rams fail to shear pipe causing escape of hydrocarbons and explosion on rig floor.


IWCF 2014



IWCF 2014

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