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With this down turn in our industry are multilaterals a useful well construction technique to reduce costs?
02 April 2015
Do we think that multilaterals are a worthwhile well construction technique to help reduce well costs or are they perceived to be too scary to contemplate in the current climate?

Is the perceived risk of constructing a multilateral well justified and if so what needs to be done to alleviate this?

7 answer(s)
Multilateral Specialist
Multilateral Solutions
Total Posts: 32
Join Date: 30/09/13

Hi there Guido.

I would fully agree with your comments about candidate selection.  I typically sit down with clients and fill in a detailed shopping list of wants and needs for the application in mind.  I also review starting with L-1 junctions and figure out what we can have both as a junction and a completions interface.

L6 junctions are pretty much off the radar nowadays.  I have been asking the vendors if they still exist in their portfolio on another forum but still awaiting a conclusive response. 

The best places to get information on ML junctions is on the vendor´s web page.  TAML as an organisation exists only in name.

The main thing for anyone considering constructing a multilateral well is to realise that they will have to compromise somewhere in the construction.  This may be hole size, liner weights or completion sizes as you mentioned.

Two of the main things to take into consideration today are the second life cycle of the well and how to abandon it in the future.

Drilling Manager
Total Posts: 1
Join Date: 18/03/15
Hi there,
while I agree to what was mentioned about the potential of ML tech and the perception of risks, I would add a couple of points for candidate selection:
- Junction ID and re-entry capabilities vs. completion/production requirements over the well life-cycle;
- Junction mech/hydro ratings vs. formation stability and gradients vs. well plans.

These criteria used to cross a lot of candidates off the list.
I recall that Level 6 offers full bore and the fastest installation but used to be very limited by formation stability and gradients. Given the expandable CSG improvmeents in ratings, I presume progress has been made in ML junctions as well? If you have information on enhanced junctions or installation methods please share some links!

I worked with MOG on the installation and re-entry of a ML Level 5 junction in 2007, North Sea, no real problems were encountered it almost felt like we had gained another slot.
Multilateral Specialist
Multilateral Solutions
Total Posts: 32
Join Date: 30/09/13

Thank you all for taking the time to pass on your thoughts and feedback.

It seems to me that the recurring theme is proper planning, the right people, taking time to educate and team communication.  Does this sound familiar Dave Taylor?

Iain, it is clear to me that planning an ERD or HPHT well has the same challenges as a multilateral project yet it appears to me that these technologies are more readily accepted by the industry certainly in the UK sector. 

Peter, I remember the WOS well you mention.  You are also correct that many multilaterals have been constructed in the past 20 years, again just not in the UK sector.

Sarah, you highlight some great statistics and make the point again about the interdisciplinary approach.  An ML well demands a team approach, exceptional team communication and extreme focus on the details. 

Education will for sure help a great deal and I for one have been offering lunch and learns and workshops for this very reason.  However sometimes the audience are there more for the sandwiches and to get a copy of the slides than to participate and engage.

Howard, you are of course correct about MOG.  They have constructed some exceptional wells and are for sure open to technology uptake.

So what I´m reading especially from Sarah and Howard's comments and from my own experience is that there is a much higher uptake of ML technology anywhere other than in the UK sector.

So why is this? Geology, Tax incentives, Demographics, Culture, Cost, Geography?

Total Posts: 7
Join Date: 13/11/07
If you have any contacts with Maersk Oil and Gas in Copenhagen would be good. They pioneered the skills of long horizontal mother bores with 2-3 lateral off in the Danish Gas fields back in the 80s. Very clever jewelry, sliding sleeve technology , coil tubing and massive frac programs, Dowel Big Orange and Halliburton Red stimulation boats attending each well back to back just to cover the volumes. They then took that experience to their new joint ventures in the Middle East with massive success.
From memory the succes I would say is down to your reservoir formation, drillability and hole stability.
So MOG in Copenhagen might be a good place to pick some brains. Nowing how MOG was run I am sure the economics of drilling multi laterals vs.improved production (sustained profit) will have been the big part of the assessment
Senior Development Engineer
Whalsay Energy Ltd.
Total Posts: 2
Join Date: 02/04/15

Hi all,

I'm not sure that the perceived risk surrounding multilaterals is necessarily justified. 

Multilateral wells, in my opinion require an interdisciplinary approach.  I think that the disciplines of drilling, completions, reservoir and subsurface, must have open communications and understand the overall context.  Developing a strategy early in the planning process is key; taking into account the well design from the bottom up, identification of key personnel and the strategy of how to engage and retain them. 

I think that what is required is a thorough understanding of the application - i.e. the potential challenges that can be faced from a particular well; hole stability problems, completion interface and tolerance, sand potential, pressure and temperature etc. 

There are some very interesting presentations which can be obtained via the SPE website, following an SPE meeting in March focussing on multilateral technology implementation.  In these documents, the standout points for me were as follows:

  • The perception of MLT to be risky is wrong

    • Less downtime on MLT operations than on standard drilling operations

  • Worst case experience: lost mainbore or lateral

    • Never happened with the 230 well experience base

  • The development of TAML5 junctions decreased junction construction times from 14.7 days to 3 days within a year´s period which is incredible.

What can we do to change perceptions?  Well, education is the key thing here I guess.  I think most of us are relatively cynical when it comes to new technology until we can see real benefits in terms of case histories and demonstrable cost savings alongside operators and service companies working together to demonstrate that the success stories are not just service sector spin. 

With the Wood Review getting the government hot under the collar, operators will no longer be granted approvals to access the low hanging fruit.  Boundaries will need to be pushed to achieve maximum economic recovery and I think multilateral developments will become a more regular feature of the UKCS sector.

Drilling Specialist/Well Engineer/Training Consultant
Kingdom Drilling
Total Posts: 352
Join Date: 10/01/05

It surely depends on the context of the multilateral.
The incremental cost.
the technical, people, change, issues.
Predicted hazards / risks.
Extent of the unknowns. 
The potential prize/ payback.
is there a fallback / recovery plan. 

E.g. I remember we attempted an industry first multilateral offshore west of Shetland on a development well, I.e. 19 years ago in the 90's. The main objective being not to compromise on the main well bore. We had problems orienting and some issues with the exit window so we stuck to plan b and still had a well. 

However i imagine thousands of multi laterals have now been sucessfully run so my introduction and the technical issues we had are now far better understood and resolved? 

So decision to increase productivity by 2x for an incremental cost of 1.2x knowing and understanding the risks using a tried and tested technology application (even offshore) is something people should be considering in current climes but in many climes will not simply result because it's far harder to change people's attitudes, or change what's been done before.

Note: Change brings pain and this is generally what people do not want.
Director Engineering
Merlin ERD Limited
Total Posts: 40
Join Date: 20/02/09
Yes. With fit for purpose detailed planning and risk mitigation they will be less scary. Technical risks are part of the challenge, one wrong action during implementation can wreck a project. Complex well projects such as ERD and HPHT have found that investing time to up-skill the Ops team (rig) provides 40 people improved awareness of the key focus areas. Supporting the team with onsite technical expert until practices are embedded provides further risk control and delivery assurance. Simple, not easy.
We wouldn't accept a pilot telling us "we need to cut costs, so I don't have time to check the aircraft", but frequently we start a drilling journey under prepared.
 So my view is yes, technology such as multi-laterals can add huge value, but it has to be done properly with a value focus.
Posted by

Ken Horne

Multilateral Specialist

Multilateral Solutions

Total Posts: 32
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