34-Well Integrity and Intervention

8/13/2019 34-Well Integrity and Intervention

1/16


2/16

Well integrity

Application of technical, operational and

organizational solutions to reduce risk of

uncontrolled release of formation fluids

throughout the life cycle of a well.

There are various facets to well integrity,

including accountability/responsibility, well

operating processes, well serviceprocesses, tubing/annulus integrity,

tree/wellhead integrity and testing of

safety systems.


3/16

Accountability/responsibility

Accountabilityis the position that

ensures a particular task is being done.

They typically control the budget and

organizational chartstructure.

Responsibilityis the position that actually

does the task. There are a variety of tasks

associated with well integrity andresponsibility can reside with a fields

well operations engineer, operators, well

service technicians, etc.
http://en.wikipedia.org/wiki/Organizational_charthttp://en.wikipedia.org/wiki/Well_serviceshttp://en.wikipedia.org/wiki/Well_serviceshttp://en.wikipedia.org/wiki/Organizational_chart


4/16

Well operating processes

This includes processes such as personnel

competency, well startup!operating!

shutdown procedures, process to report

anomalies, corrosion/erosion control, etc.

Well service processes

This includes processes such as personnel

competency, intervention procedures, etc.


5/16

Tubing/annulus integrity

This refers to the integrity of the

production tubing. "ommon threats to

tubing integrity are erosion and corrosion

by production fluids, which remove the

steel. The other threat is pressure

differential between the tubing and the A

annulus. #f it e$ceeds the rated pressureof the tubing, there is a risk of tubing burst

or tubing collapse
http://en.wikipedia.org/wiki/Production_tubinghttp://en.wikipedia.org/wiki/Production_tubing


6/16

This refers to the integrity of the

casing strings, which bound the annuli. Allannuli will naturally be filled to some level

with brine or other fluids from the

completion, though the A annulus mayhave gas down to the lowest gas lift valve

if the well is gas lifted.

The ma%or integrity issues comes from thedifferential pressure across the casings

due to the weight of brine on either side.

To protect well integrity, each annulus will

have a
http://en.wikipedia.org/wiki/Casing_(oil_well)http://en.wikipedia.org/wiki/Annulus_(oil_well)http://en.wikipedia.org/wiki/Gas_lifthttp://en.wikipedia.org/wiki/Gas_lifthttp://en.wikipedia.org/wiki/Annulus_(oil_well)http://en.wikipedia.org/wiki/Casing_(oil_well)


7/16

Tree and wellhead integrity

This refers to the integrity of the surface

)or subsea* e+uipment. Thewellheadand

the treeare typically suitably engineered

to be able to withstand the normal

operating pressures. The ma%or integrity

issues for these components surround the

operation of the valves, which are prone toleaking. or this reason, valves must be

routinely maintained.
http://en.wikipedia.org/wiki/Subseahttp://en.wikipedia.org/wiki/Wellheadhttp://en.wikipedia.org/wiki/Christmas_tree_(oil_well)http://en.wikipedia.org/wiki/Christmas_tree_(oil_well)http://en.wikipedia.org/wiki/Wellheadhttp://en.wikipedia.org/wiki/Subsea


8/16

Testing of safety systems

This refers to testing of surface and

subsurface safety systems.


9/16

Tubing hanger modified to prevent direct

impingement


10/16

Well intervention

-uring, or at the end of its productive life,that alters the state of the well and or well

geometry, provides well diagnostics or

manages the production of the well. Pumping

This is the simplest form of intervention as

it does not involve putting hardware intothe well itself. re+uently it simply involves

rigging up to the kill wing valve on the

"hristmas treeand pumping the

chemicals into the well.
http://en.wikipedia.org/wiki/Christmas_tree_(oil_well)http://en.wikipedia.org/wiki/Christmas_tree_(oil_well)


11/16

Wellhead and Christmas tree

maintenance

The comple$ity of this operation can vary

depending on the condition of the

wellheads. 'cheduled annual

maintenance may simply involve greasing

and pressure testing the valve on the

hardware. 'ometimes the downhole safety

valve is pressure tested as well.


12/16

Slickline

'lickline operations may be used for

fishing, gauge cutting, setting or removing

plugs, deploying or removing wireline

retrievable valves and memory logging.


13/16

Coiled tubing

"oiled tubing is used when it is desired to

pump chemicals directly to the bottom of

the well, such as in a circulating operation

or a chemical wash. #t can also be used

for tasks normally done by wireline if the

deviation in the well is too severe for

gravity to lower the tool string andcircumstances prevent the use of a

wireline tractor.


14/16

Snubbing

Also known as hydraulic workover, this

involves forcing a string of pipe into the

well against wellbore pressure to perform

the re+uired tasks. The rig up is largerthan for coiled tubing and the pipe more

rigid.


15/16

Subsea well ntervention

'ubsea well interventions offer up many

challenges and re+uires much advanced

planning. The cost of subsea intervention

has in the past inhibited the interventionbut in the current climate is much more

viable. These interventions are commonly

e$ecuted from ight/medium interventionvessels or &obile ffshore -rilling 0nits

)&-0* for the heavier interventions such

as 'nubbing and 1orkover drilling rigs.


16/16

34-Well Integrity and Intervention

Documents

Transcript of 34-Well Integrity and Intervention