User login


You are here

Topic 64: Discuss the risks and challenges involved in simultanous operations or co-activities in Oil and Gas activities.

Oghenekevwe Ovbije's picture

Operations with two or more installations and simultaneous operations such as construction and production need appropriate management systems and controls for effective use of resources and to minimise risk.


Andrew Strachan's picture

The permit to work system is an effective safety management tool to control and manage risk when multiple hazardous activities are being carried out concurrently in a confined environment such as an offshore platform or any other industrial plant. The benefits include:
1) Ensures risk assessments are carried out since a permit will not be given without one.
2) Ensures good handover between shifts since the permit has to be handed in after the completion of each shift.
3) Allows management to highlight and control activities, which might clash and potentially cause harm when carried out simultaneously.

JIEFU's picture




/* Style Definitions */
{mso-style-name:"Table Normal";
mso-padding-alt:0cm 5.4pt 0cm 5.4pt;

agree with your comment about risk assessment here. Risk assessment and
temporary operation plan is essential for reducing the risks and challenges
involved in co-activities. Risk assessment should be the more specific and
comprehensive the better. Then Risk analysis can be conducted concerning these
anticipated risks in terms of the probability and the severity a specific risk
may happen. Then according to the different level of risks, the measures can be
categorized and conducted through  ‘Remove’, ’Transfer’, ‘Reduce’ and ‘Manage’. For
example, a road is under construction while it is also used by another party
for transporting goods. By removing the risks means a temporary road can be
adapted after negotiating with stakeholders. Therefore, risk assessment is
really important in managing the simultaneous activities.  

Claire Snodgrass's picture

I have been involved in combined operations where a MODU (mobile offshore drilling unit) was re-drilling and working over some existing subsea wells that were tied back to a host platform.

For this project an interface document was prepared and agreed by the MODU operator and the platform operator.  This documented which company had responsibility for various operational and health, safety and environmental aspects – everything from the work programme to waste handling to competency to emergency response.  The appropriate procedures were also identified for each topic.

Additionally, a hazard identification and risk assessment was conducted with representatives from both operators (both companies had not only onshore management representatives but also an offshore installation manager (OIM)) as well as appropriate third parties, such as the anchor handler.

As required by the Offshore 2005 regulations, a notification of the combined operations was submitted to the HSE.  The notification described the operations that were to take place, the arrangements that had been put in place to manage the safety of the combined operations (the interface document) and a summary of the risks identified at the HIRA and the mitigation measures put in place.

William J. Wilson's picture

The comments raised above are very valid at the planning stage and at a higher operations level where managers get a holistic view of all sub-activities being carried out.  For example; activities A and B affect each other in scenarios 1a, 2a, 3a, 1b, 2b, etc.   If we come down a level of hierarchy to the processing level where junior engineering supervisors are then they might be unaware of the consequences of their actions within sub activity 1a towards the needs and actions of sub-activity of 2b.  This could be something as simple as re-locating materials away from where they are needed for sub-activity 2b.  Having spent much of my career managing this I can say this happens a lot with the following consequences:
1. Miss-communication between sub-activities
2. Confusion and frustration about times and assets available
3. Loss of time
Carrying out adequate hazard identification and risk assessment that engages with all stakeholders like Claire addressed above is paramount to successful simultaneous operation but only if relevant information is passed down to everyone on the shop floor.

William Wilson
MSc Subsea Engineering

Oghenekevwe Ovbije's picture

Hi Claire, it is nice to share an experience on the blog.

Simultaneous operations or co-activities have strong implications on a project; they can either lead to the prompt completion of the project or cause a setback or delay on the project execution. The risks involved in carrying out simultaneous co-activities from the planning to completion stage can be eliminated or minimised through proper planning, communication and supervision.

To safely carry out simultaneous co-activities, the following should be strongly adhered to:
•Do not carry out simultaneous co-activities without prior inspections and approval
•Co-ordinators should ensure the assigned task for individuals are specified
•Continuous supervision must be carried out.

victor.adukwu's picture

Interference due to simultaneous operations or co-activities can increase the risk levels in an oil and gas production platform. Simultaneous operations or co-activities entail:
• Having authorized representatives' conduct a preliminary inspection of the installations
• Performing a HAZOP study with supporting documents
• Implementing all the recommendations resulting from the HAZOP study
• Defining each person’s role and designating the person in charge of safety, vested with the appropriate authority
• Holding specific information, coordination and planning meetings
• Regularly updating approved files
• Obtaining formal authorization to proceed with the operations from the operations manager, who coordinates all the permits and instructions.
In conclusion, simultaneous operations or co-activities should be given a high safety priority in oil and gas activities to minimise any form of accident.

Savitha Haneef's picture

Simultaneous operations are defined as the potential clash of activities. It may occur as a result of clash in schedules or physical clashes,failure impacts, interference.An early risk assessment for all the operations identifying the hazards and constraints.Proper contingency plans should be in place identifying redundancy in case intended scope of work take longer than scheduled and affect other operations, or an equipment failure occur or take in to account unforeseen weather conditions.

I agree to previous posts saying successfull simultaneous operation is through communication.Communication is key in simultaneous operations.I would like to expand on the the key factors to be considered : Proper plan to switch to alternate communication system if it fails, system to be tested before the commencement of operations, proper notification arrangements incase of a failure,consent to stop the work immediately in case of an emergency. Appropriate emergency response plans should be in place.

Savitha Haneef

 MSC Safety & Reliability Engineering

JIEFU's picture

Some risks of conducting the simultaneous operations result from lack of right or enough resources when they are in need. In my opinion, to reduce this type of risks and challenges, it is essential and critical to have a precise and comprehensive assessment for all the co-activities. The assessment should be carried out from both time and quantity prospects for both resources and workforce allocation. Detailed assessing activities could include the earliest and latest date/ hour for the requirement of a certain type resource, the duration of the resources, and the earliest and latest date for dismissing these resources. With the detailed assessment, the simultaneous operations can be managed relatively smoothly by having the required resources at near hand in advance without other activities. 

Connie Shellcock's picture

Jiefu in the previous post mentions that
assessments could be carried out when a SIMOP is about to take place. The IMCA
provides guidance on for marine companies who are carrying SIMOPS. In this
document the companies are instructed carry ut SIMPOPS assessment review. This
reviews all work tat is to be carried out identifies potential risks of the
tasks. This is done soby using tools such as hazard identification and risk
assessment, clash analysis as Savitha touched upon and interdependency
analysis. Following these guidelines is one way in which the risks and challenges
could be looked at in a methodical way.

ikenna_ekekwe's picture

As we go into times when there is a lot of competition between major IOCs, more projects become highly schedule-driven. This means that in order for these projects to be successfully completed and commissioned, a lot of SIMOPS (simultaneous operations) have to be carried out. SIMOPS can also become a critical part of emergency response. As the name implies, ‘simultaneous operations’ involves the concurrent interaction of two or more work systems in close proximity. 

The major challenge facing the success of SIMOPS are command/control and clear/comprehensive communication – which imperatively, must be established from the onset and maintained daily for SIMOPS to be performed in a safe and controlled manner. To ensure that this challenge is taken care of, roles must be clearly defined, and every involved personnel must meet the training and competency requirements for effective SIMOPS.

Ekekwe Ikenna


Hani Shobaki's picture

I'd like to talk about a specific type of SIMOP, diving from a dynamically positioned vessel (DP vessel). As I'm sure you know DP vessel's, use a combination of GPS and a 360-degree rotating, turret propeller. It is generally required by the HSE's accepted codes of practice, for safe diving, that if diving beneath a vessel it maintains a minimum distance if the engine is not in neutral. A DP vessel's propellor however is continuously active and it is not moored. In addition to the hazard the propeller presents, its failure would bring an additional danger. Loss of power could result in the vessel drifting from its position. Leaving the diver either separated or dragged by their umbilical.
It is therefore critical that communication between the vessel master, the dive supervisor, the DP supervisor and the client are clear and all the risks and hazards have been evaluated. It is very important that any movement to the vessel is communicated between all parties. An ROV should be available to monitor the operation at all times and the diver should have a bell to escape to should to vessel drift away.

International Marine Contractors Association. Diving Operations from Vessels Operating in Dynamically Positioned Mode. Mar 2008. (accessed 4 Dec 2012)

Agba A. Imbuo's picture

Simultaneous operations (SIMOP’s) are used to carry out two activities at the same time and location. An example can be seen when a construction project or a new equipment is being "tied-in" to an existing plant in an oil and gas production platform. The risk inherent in carrying out this operation is huge because there tend to be a kind of miscommunication and misinformation between activities. To effectively carry out a SIMOP, it is required that the involving parties will harmonise to develop a risk and hazard management plan and mitigation strategy which will serve as a guide to commencement of a project. Also, during the project lifecycle, periodic assessment and review of progress should be carried out and recorded in an interface document. These activities include communication and contingency plan, change control, authorization to proceed process (PTW) to mention but a few.


Akuromawaye Apiambo's picture

On some occasions, construction works such as heavy lifting, hot
work, anchorage, etc  need to be
performed closed to an oil/gas  installations in normal or partial operations.
 Those construction activities creates
SIMOPS, which  stands for simultaneous or
concurrent operations, thus  present
serious potential HSE and operational risks as it, combine the hazards and
risks of drilling and production or production and construction or drilling and
construction and or drilling, production and construction .

SIMOPS conditions introduce additional risk to routine
production operations and leads to downgraded situations. Thus even more
serious when work will be performed by people who may be unaware of the risk
associated with those activities.

The challenge is to  sets
good practices and standards that can be used by other offshore oil and gas
companies to reduce SIMOPS risks to as low as reasonably practicable (ALARP)

The “How “ is a key factor 
the challenges like in:

Implementation of specific precautions and compensatory measures
to reduce and control risks

Coordination of various task and works with possible

Information and communication with the different parties

The effective implementation and actions goes a long way to
address the risk and challenges faced in SIMOPS operations.


Atava, Z. (2008)
New Technique for Addressing SIMOPS Challenges During Installation of New
Offshore Platform
.[Online]. Available from: 
05 December 2012].

Apiambo, Akuro


Thomas Ighodalo's picture

in order to carry out successful SIMOPs requires three major activities to reduce the risks associated, these activities/stage gates are  Proper Planning, effective Communication and direct supervision.

(a) Planning: this involves fully defining the scope of work, understanding the projects involved, and involving key stakeholder it can be definedas the process of setting goals, developing strategies, and outlining tasks and schedules to accomplish the set goals.

(b) Effective Communication:This ensure that the parties involved from the project managers down to the roustabout (if on a rig) is well aware of his role to play, and no one is left in the dark about activities going on around the facility.

(c) Direct Supervision:  Once the plan has been concluded direct supervision of alloted task must be done in order to avoid a personnel making decisions that go against the planned schedule of activities.


a typical example, is an upgrade from an Early Production crude oil Facility to a Central Production Facility due to increase in production from the wells, the company involved would try as much as possible to minimise shutdown activities required for tie-ins, as such a detailed plan needs to be in place to identify the required tie-in points and equipment can be made available ahead of time to take full use of normal maintenance shutdowns to tie-in to the existing facility while the design of the new facility in ongoing.





"Everything we hear is an opinion not a fact"

Ojo Oluwayimika Joseph's picture

Simultaneous operations popularly known as SIMOPs refers to a conflict of events that could yield undesirable safety consequences such as damage to assests and environment. An example onoffshore platforms is where a drilling rig, coiled tubing unit or slickline may be in operation at the same timewhich could have an impact on safety procedures and contingency planning processes. Identifying SIMOPs could include schedule clashes, territorial clashes, failure impacts, interference between vessel operations and platform operations, environmental clashes and other conflicting activities that could jeopardize success of operation. These risks could be mitigated and controlled by effective communication between operations, effective supervision and adequate planning procedures.

Ojo Oluwayimika Joseph

Oil and Gas Engineering

Manuel Maldonado's picture

Simultaneous operations define some rules which should be used to assess the risks associated to operations to be performed in parallel or simultaneously in at defined area but not necessarily in the same place. Those activities can take place either in a single subsea installation or in situations where two vessels operate in the same area side by side or above and below (subsea operations - drilling operations etc.). Those activities also need to be performed at the same time in those places.

There are some challenges the industry needs to overcome and in particular in the new business environment where cooperation between companies have become very important for facilitating operations. It is usual now a days to see a number of companies working in the same project and on a single operation where the tasks can be performed by different parties.

In this type of operations challenges need to be sorted out by good management of simultaneous operations , because of the rules to be followed, the liability for legislation and in particular conflict of interest become important aspects to be considered. The level of safety to consider in those operations depend on the understanding if the regulation, their interpretation, the establishment of a risk scenario and the ability to operate within this environment while ensuring an effective control of risks to prevent unwanted outcomes which could impact health, environment and safety.

For these operations it is necessary to understand the responsibilities, liabilities, regarding to managing risks while performing operations. However, there would be only one leader which normally control the execution of the activities and manage the simultaneous operations. This leader (usually oil companies or duty holders) set the rules and standards and ensure consistency on safety and operational approaches.

Mohamed H. Metwally's picture


operations are one of the safety challenges that shows how the individuals
involved in these operations are professional and diplomatic.

It needs quiet dialogue between
different companies in the same worksite. The challenge here is that there
should be some sort of understanding of each other's operations and also some
skills in getting the message across to other party.

Some operators like Aramco, has a
system of priorities for its contractors, but despite this, meetings have to be
held to understand more and solve problems on case by case basis. 



Ahmed_Abdelkhalek's picture

I appreciate all the useful information provided by my colleagues above.  In my opinion, one of the biggest risks in SIMOPS is the incompetency of the party managing the interfaces.  Most of time the operator is responsible for the management of SIMOPS interfaces. According to my experience small scale operators do not have the competencies required to do so. I have seen several cases were construction contractors at the working site are hit by the fact that they are required to act simultaneously during the operation of another contractor. Much can be said about the time lost and time and quality, but the most important issue was that safety in most of the cases was jeopardized to minimize the impact on cost and schedule.
Bottom line it is important to have a competent party managing the interfaces to identify that SIMOPS exist in the first place.

SanjayVyas's picture

Safety Risk Assessment for SIMOPs for Oil and Chemical Industries is extremely critical and requires a detailed risk assessment for the following minimum scenarios;

1.    Potential hazards from existing operating facility to construction workers and temporary buildings/ camps;

2.    Potential hazards from construction and commissioning activities to Industry construction workers and existing plant buildings and temporary buildings/ camps;

3.    Potential hazards from existing operating facility to new facilities /building

4.    Potential hazards from new facilities to workers for existing and new facilities/ buildings

5.    Potential hazards from combined (existing and new) facility to society and surrounding environment.

An integrated Emergency Response Plan (ERP) with one single Incident Command System is another critical requirement to minimise risk from incident/accident event arising a simultaneous operations.

Sanjay Vyas- ID - 51234203

Subscribe to Comments for "Topic 64: Discuss the risks and challenges involved in simultanous operations or co-activities in Oil and Gas activities."

Recent comments

More comments


Subscribe to Syndicate