SIMOPS: A Simple Definition and then a Further Explanation

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Jason Lavis
Jason Lavis
Serial Energy Entrepreneur. Webmaster at Founder of Out of the Box Innovations Ltd. Co-Founder of Natural Resource Professionals Ltd. Traveller and Outdoorsman, Husband, Father. Technology/Internet Geek.

SIMOPS is an abbreviation of ‘simultaneous operations’.

Obviously, on any well site there will be many different tasks to be done, often at the same time. The distinction here relates to major work events, such as having two different well heads in close proximity. They could be at any stage of production, one might be abandoned, and one might be being freshly spudded.

To a lesser degree, some might refer to any important events on the same rig as SIMOPS, even if there is only one well bore. A rig crew needs to focus on each job at hand, be that deploying the drill string, casing or cement. Any other major task in the background that might counteract, distract, or impact in any way could be described as a SIMOP situation. An expert in this area will see the bigger picture, with data points from both operations. From a higher view point, risk and performance can be properly assessed and contingencies can be prepared.

This brings us on to a more common accurate definition:

A SIMOP describes two or more well bore operations that are close enough to interfere with each other, and transfer risk or performance implications.

This is a HSE and well integrity concept that’s mostly used in the well completions stage of the drilling process. Both well bores might be drilled concurrently, but it’s more likely that one has been in production for a period of time.

Here are some examples of SIMOP situations:

  • A well is being hydraulically fractured, and the reservoir is shared with other nearby leases that are being conventionally drilled. (Or vice versa).
  • On an offshore rig, a drilling, slickline and coiled tubing unit might be working at the same time.
  • On a multi platform land rig, separate wells will affect the reservoir pressure, and hydrocarbon flow.
  • A crane lift positioned close to another work area.

What types of interference might occur during a SIMOP?

The considerations for a SIMOPS expert to factor in are numerous, and there will be those that might not immediately come to mind. For a safe and efficient well operation, there are many things to consider, when there are simultaneous operations, this number multiplies.

Someone planning or overseeing a SIMOP will consider the more obvious things such as:

  1. Well integrity factors
  2. Environmental factors
  3. Reservoir pressure
  4. National rules and regulations
  5. International rules and regulations
  6. Operator rules and regulations

Also, there will be extra considerations, that are different to those of individual operations:

  1. Clashes between decision makers at the same hierarchy, on each operation
  2. Cultural differences if the different operations are done by different companies
  3. Schedule clashes
  4. Physical clashes between equipment or third party interfaces
  5. Issues with maintenance access.
  6. Contractual implications, on all affected contracts.

It’s important that a SIMOP is identified as early as possible in the planning stage, and then bought into the well plan. The priority is to avoid accidents, and down time. In some situations, a potential clash or safety concern might be so serious as to render one or more operation non-viable. That’s something that you’d want to discover at the very earliest opportunity.

Practical steps when a SIMOP is identified:

The SIMOP should be planned as if it were a separate drilling operation. A workshop must be organised where all of the important data can be examined. The workshop will include managers, geologists, engineers, safety specialists, construction teams, fluid specialists, and anyone else who would be involved in a DWOP or similar process. Representatives from all companies and organisations with vested interests need to be present so that everyone ends up on the same page.

During the workshop, brainstorming with a list of previous findings and incidents can help identify potential issues. preemptive risk assessments, and the collective knowledge and experience of everyone in the room can ensure that every potential hazard is covered. This process focuses on hazard identification (HAZID) as its main priority. (Another common term in this area is HIRA which means hazard identification and risk assessment).

The result of the workshop will be a planning blueprint with a full risk assessment and action points. After the initial plan, ongoing meetings and interaction need to take place for successful progress monitoring and interaction.

There will be a list of action points including a MOPO (Matrix of Permitted Operations) that can be done at any time. Risks that can be eliminated or mitigated will be, others will be monitored.

Typical action steps might include:

  1. The substitution of fluid, equipment or personnel for more compatible solutions.
  2. The physical location of the operations can be moved away from each other.
  3. Permits, contracts, schedules and procedures can be adjusted to avid a simop altogether.
  4. Additional equipment, controls or safety measures can be implemented.
  5. The creation of a list of operations that CAN be done simultaneously, and a list that CAN’T.

SIMOPS represent additional risks and challenges, so experienced managers and consultants need to be deployed. Any drilling operation holds dangers and these must never be underestimated. Operators and contractors have experiences based on previous SIMOP issues, and have developed procedures and programs. On an individual level, professional teams on each operation that will be conducted simultaneously will cognizant of the need for full respect, communication and disclosure.



  1. Interesting article which establishes the basic principles of SIMOPS.
    There are of course Project SIMOPS which can span onshore decision making, thereafter influence the offshore phase of the project re MOPO and primacy of operation. By way of example for entering the pay zone in relation to a production commissioning phase, rig moves to the side of the two WHP’s which had HP/HT wells producing, rig moves across pipelines etc are some of the challenges for primacy we met and successfully managed to ALARP. Whilst also having to factor the shutdown impact and UK Gov reaction.
    Writing and applying the SIMOPS Procedure for the Total E&P Elgin, Franklin HP/HT Field development, thereafter the Otter and Nuggets sub-sea developments was both a learning curve and a professional privilege to pioneer, what at the time was unique in the North sea at the time.


  3. Thanks Jason for such an expressive article on SIMOPs. I find it quite helpful.

    However, I am looking for a SIMOPs for an Onshore Brownfield drilling within proximity of myriad of other activities to help me plan for a SIMOPs workshop.

  4. Can anybody please help me understand if SIMOPS and COMOPS are different or is it the same principle but just different contexts – former being about wells and latter about everything else?

    • Hi Mohammed

      In the context in which we work (Technical Facilitation and Coaching), they are pretty much the same.

      SIMOPS Assessment Workshop takes a close look at activities that are taking place in close proximity to one another, that have the potential to cause a negative PEAR (Personnel-Environment-Asset-Reputation) impact on one another.

      If you’d like to know more, drop me an email on [email protected] and I’ll share you some examples.

      Typically for things like:
      * Jack-up working over a LIVE platform
      * MODU working over subsea infrastructure

  5. Interesting article which establishes the basic principles of SIMOPS.
    I would like if anyone share some examples or situation for onshore drilling.


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