Expert Contribution: Third-Party Well Examination

The National Hydrocarbon Commission (CNH) in Mexico require all deepwater oil and gas wells to have their design examined by an independent expert before a permit for drilling a well is approved. In the civil engineering world this would be comparable to the design of a bridge or tunnel, once the design is done by the engineers, another independent team of engineers will complete an independent design review. This independent review should cover the design and the construction as well as any required maintenance for the life of the bridge or tunnel. This process provides the bridge / tunnel owner with the assurance that the design is verified, and the construction, and the maintenance of the bridge or tunnel can all be done correctly and is all fully compliant with the current regulations.

In this article we explain in a non-technical language how this same process is done for oil and gas wells, and we show how the independence of the review is assured.

What is Well Examination?

Well examination is the engineering review of the design and construction of an oil or gas well. The examination is done by an independent party and includes a review of the design as well as the verification of the construction (drilling) of the well, this verification is done according to the approved design. This ensures both the design, and the construction of an oil or gas well is completed fully compliant with all applicable regulations, standards, and policies.

The examination of an oil or gas well is done by a senior engineer, who is nominated as the “independent well examiner.” The well examiner first reviews the design of the well and ensures this complies with all the regulatory requirements. The design is signed off and the well examiner then follows the construction process of the well being drilled. This ensures the well is drilled as it was approved in the design. The examiner is independent from the oil company. The oil company hires the well examiner to provide them with the assurance that the well is correctly designed, and the well is drilled as it was designed.

The well examiner has a solid understanding of all the regulations, standards, and policies. The examiner works closely with the oil company and will ask the engineers in the oil company for clarification as to why and how things are done. The examiner reviews the challenges and proposed solutions and provides input back to the engineers to ensure the well is designed and drilled according to the standards. The government entity, which in this case would be the National Hydrocarbon Commission, gets a well examination report from the examiner. This allows the government regulator to review and confirm the well is safely designed and constructed. A rapid approval from the government regulator allows the oil company engineers to focus on the drilling operation. This provides the value effectiveness of an independent well examination process.

Why an Independent Well Examination?

The independent well examination ensures the following:

• All aspects of the well design comply with local and international regulations and standards.
• The construction of the well is done as per the design
• All the acceptance testing for the well is completed as required in the design.
• The engineers from the oil company are fully capable of designing a well
• The oil company has considered all safety aspects of the well, including design, construction, production operations, maintenance, and final plugging.

Who is the Well Examiner?

The Well Examiner is a senior drilling engineer, or a senior petroleum engineer employed by an engineering company. The Well Examiner is knowledgeable and can effectively conduct the tasks of well examination.

An engineer appointed as a Well Examiner is a qualified engineer with many years of practical experience in design, drilling and production of oil and gas wells. The well examiner is also a good presenter, coach, and listener. The oil company who appoints the well examiner will review the expertise of the independent well examiner to ensure they are qualified. The well examiner is not alone, he is fully supported by a team of specialist engineers and other well examiners working for the same engineering company. This allows any technical challenges encountered to be quickly resolved with his support team in the office.

What is examined?

The main aspects of the well examination scheme are:

• Review of well design including all the design documents and calculations
• Interviews and discussion with well engineers responsible for the planning and construction of the well to clarify design decisions made .
• Monitoring of the actual drilling operations by reviewing daily reports and all verification reports.
• Once the well starts production the well examiner also reviews any maintenance requirements to ensure these are conducted in line with requirements.
• Detailed review of any changes required during the drilling and maintenance operations ensuring the correct actions are taken.

A balance is required between providing a Well Examiner with all the necessary information at an early stage, but not involving the examiner in the detailed operational decision-making process. The well examiner has to stay independent.

Who is Responsible for Well Examination?

The so-called RACI matrix for well examination would look like this.

What is a typical outcome?

At the end of the review, the well examiner issues a report containing the Well Examiner’s views and findings with respect to the well design and the required control measures for the drilling of the well. A formal statement is included in the report verifying the design is suitable and complies with regulations.

If the Well Examiner does not have any significant findings, the suitability statement becomes a short formal statement

A checklist is created. This checklist gives the critical program steps during drilling and lists the required tests which must be completed to ensure the well is safe and it is drilled as it was designed.

The Well Examiner participates in any reviews and assessment of changes required during the drilling of the well (management of change). The Well Examiner will then be requested to examine any material change to a notification of well operations

The agreed checklist will be signed by well examiner and by the oil company after drilling has been completed. A certificate of well examination is issued to show that the design and construction of the well has been independently verified.

Mexico, like other countries, has a regulatory requirement to have an independent well examination performed before a permit for drilling a well is approved. Currently, the regulation in Mexico only applies to all deep-water wells.

However, it is a good practice to have all drilling and well operations independently examined including any onshore wells. The Well Examiners are normally experienced professionals who not only examine a well but can also suggest better ways to achieve certain objectives.

This review provides both the oil company and the government regulators with the assurance that an oil or gas wells is correctly designed and constructed for the expected conditions. This avoids accidents and possible hydrocarbon leaks creating a safer workplace and it also reduces potential for hydrocarbon releases into the environmental.

Specialist parts of a well design can be reviewed by a well examiner as separate projects. This can be helpful in complex wells to ensure that any required design changes can be made prior to ordering big and potentially expensive equipment required for drilling of the well.

WellSpec is a well engineering and advisory company providing engineering solutions and well examination to the global drilling and well intervention industry. WellSpec is a team of highly experienced well engineers and is a part of the ModuResources Group since 2018.

Information provided by By Steve Nas, WellSpec, MR Group
Holland House would like to thank our HHM Orange Member, Modu Resources  for submitting this week´s Expert Contribution.

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