DNV GL Tackles Corrosion and Integrity of Aging Wells
Posted: 2015-1-24
The global oil and gas industry is now facing the reality that many of its on and
offshore wells are being used beyond the original lifespan. This presents
significant uncertainty around the integrity, safety and productivity of the
remaining service life. DNV GL has established a Joint Industry Project (JIP) to
develop guidelines for a decision support framework for corrosion assessment
and integrity management of ageing wells.
Many wells are reaching an age of upwards of 30 or 40 years, and operators are
facing a growing challenge to predict output, mitigate against risk and ultimately
decide whether to retire or rejuvenate ageing wells. Life extension of ageing
wells is moving up the agenda for oil and gas operators in many regions. Factors
driving this include, high oil prices, technology advances and regulatory
requirements.
"As well as dealing with the operational changes in the well’s lifetime, such as
long-term degradation effects, there can also be difficulties caused by
uncertainty over the integrity of the well and access to design documentation.
Corrosion in particular poses a major threat to these wells," says Shamik
Chowdhury, Project Manager at DNV GL. "The JIP aims to close the existing gap
in well integrity management and introduce proper corrosion assessments, as
well as provide estimates on the remaining life of individual wells. The outcome
will help operators squeeze the remaining life out of their wells safely and cost
effectively, as well as to plan for decommissioning."
"The proposed guideline resulting from the JIP will provide a clear method to
evaluate and manage corrosion for wells. This can be used on a field or
company-wide level to ensure the HSE and economical performance is balanced
and that corrosion risks are sufficiently managed," he continues.
DNV GL is inviting participants to take part in the JIP which will deliver a
corrosion threat and integrity well screening assessment method as well as
guidelines for a decision-making tool on corrosion evalution, monitoring,
maintenance and inspection.
"There are many risks to consider at the well level. External casings deteriorate
over time at different depths for a variety of different corrosion mechanisms, and
can result in loss of structural integrity," added Chowdhury. "The risk of well
collapse is therefore higher. Ageing wells also tend to have more aggressive
conditions, normally being higher water cut, and potentially with H2S arising
from reservoir changes or microbial activity, which may accelerate
attack or introduce corrosion damage where it was considered ‘not to happen’
before. The JIP will involve the review of corrosion inspection techniques,
prediction and modeling tools as well as the impact from other interfacing
aspects such as pipelines and process equipment. Investigative data will be
gathered from participants’ own experiences in this field and the operational
history of selected operators’ wells. The project will also carry out a pilot study
to test the methodology on selected wells.
The JIP will kick off later this year and will commence through to the end of 2015
with the development of a guideline for corrosion management in wells.
"DNV GL leads many joint industry projects annually, combining our expertise
with that of the sector to identify and find solutions to its most complex
technical challenges. We set the benchmark in oil and gas industry best practice,
offering open access to more than 170 oil and gas industry standards and
recommended practices, which support the industry to improve safety, reliability
and performance," says Elisabeth Tørstad, CEO DNV GL Oil & Gas.
offshore wells are being used beyond the original lifespan. This presents
significant uncertainty around the integrity, safety and productivity of the
remaining service life. DNV GL has established a Joint Industry Project (JIP) to
develop guidelines for a decision support framework for corrosion assessment
and integrity management of ageing wells.
Many wells are reaching an age of upwards of 30 or 40 years, and operators are
facing a growing challenge to predict output, mitigate against risk and ultimately
decide whether to retire or rejuvenate ageing wells. Life extension of ageing
wells is moving up the agenda for oil and gas operators in many regions. Factors
driving this include, high oil prices, technology advances and regulatory
requirements.
"As well as dealing with the operational changes in the well’s lifetime, such as
long-term degradation effects, there can also be difficulties caused by
uncertainty over the integrity of the well and access to design documentation.
Corrosion in particular poses a major threat to these wells," says Shamik
Chowdhury, Project Manager at DNV GL. "The JIP aims to close the existing gap
in well integrity management and introduce proper corrosion assessments, as
well as provide estimates on the remaining life of individual wells. The outcome
will help operators squeeze the remaining life out of their wells safely and cost
effectively, as well as to plan for decommissioning."
"The proposed guideline resulting from the JIP will provide a clear method to
evaluate and manage corrosion for wells. This can be used on a field or
company-wide level to ensure the HSE and economical performance is balanced
and that corrosion risks are sufficiently managed," he continues.
DNV GL is inviting participants to take part in the JIP which will deliver a
corrosion threat and integrity well screening assessment method as well as
guidelines for a decision-making tool on corrosion evalution, monitoring,
maintenance and inspection.
"There are many risks to consider at the well level. External casings deteriorate
over time at different depths for a variety of different corrosion mechanisms, and
can result in loss of structural integrity," added Chowdhury. "The risk of well
collapse is therefore higher. Ageing wells also tend to have more aggressive
conditions, normally being higher water cut, and potentially with H2S arising
from reservoir changes or microbial activity, which may accelerate
attack or introduce corrosion damage where it was considered ‘not to happen’
before. The JIP will involve the review of corrosion inspection techniques,
prediction and modeling tools as well as the impact from other interfacing
aspects such as pipelines and process equipment. Investigative data will be
gathered from participants’ own experiences in this field and the operational
history of selected operators’ wells. The project will also carry out a pilot study
to test the methodology on selected wells.
The JIP will kick off later this year and will commence through to the end of 2015
with the development of a guideline for corrosion management in wells.
"DNV GL leads many joint industry projects annually, combining our expertise
with that of the sector to identify and find solutions to its most complex
technical challenges. We set the benchmark in oil and gas industry best practice,
offering open access to more than 170 oil and gas industry standards and
recommended practices, which support the industry to improve safety, reliability
and performance," says Elisabeth Tørstad, CEO DNV GL Oil & Gas.
