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Offset Well Review

What is a “complex” well? It could mean a deepwater well, if you are used to shelf drilling, or multilaterals if you only drill single-leg horizontals. Regardless of what you are going to be doing, reviewing what’s been done before by your company and others is a fundamental part of the well design process. Facts are power is a phrase we repeat often in our training and it applies particularly to this exercise. Merlin’s well delivery process has been created to integrate this fact finding into a process designed to ultimately deliver reliable drilling operations.

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Feasibility Study

Complex challenges require clear definition of objectives and constraints to be successful. In the early stages of a project, undertaking a detailed feasibility study is the best way to ensure that the objectives can be achieved given the constraints applied, whether they are subsurface or project based. Merlin has a broad range of tools and experiences through our pioneering work in extended reach wells, which can be applied successfully to other complex well types.

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Problem Review

Despite our best intentions, problems during drilling and completion activities can occur on complex wells. Merlin has been involved in problem reviews since our founding in 2007. Whether it’s a twist off, side-track, drilling dysfunction affecting ROP or another problem we have the capability to get involved and make a factual, objective assessment of the situation and what needs to be done next time to avoid further reoccurrences.

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Detailed Well Design

Planning something out of the ordinary with your team? An extra set of competent eyes reviewing and challenging your well designs or operational plans is cheap insurance compared to the costs which can rack up if something slips through the net and causes a problem on location. The best organisations embrace this process, as an opportunity to validate their plans and learn from what others with similar challenges across the globe are doing to keep ahead of the game. Merlin’s competence, gained from the worlds most complex wells, allows us to facilitate this knowledge transfer.

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Complex Engineering Case Studies

Consecutive BHA failures caused by bit and underreamer interaction

Merlin performed an independent review of two incidents that occurred while drilling a recent ERD well. The objective of the investigation was to identify the root cause of the failures and to propose engineered solutions to prevent similar failures occurring in future runs.

9-5/8″ Floated Casing Installation

This case study explains how we helped a client address a casing installation challenge by combining engineering and operations support with our TDH software.

Problem Formation Overcome With ERD Operational Practices

This case study looks at a multi-well development project from six fixed offshore installations with sub-sea satellite tie-back wells. Challenging high angle hole sections in large hole sizes through unstable shales and depleted zones prone to losses. Drilling performance suffering from multiple lost Bottom Hole Assemblies (BHAs) and significant Non-Productive Time (NPT).

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Merlin Tools

AV Calculator
Annular Velocity (AV) is one of the “Three Pillars” of effective hole cleaning in high-angle wellbores, with the other two being pipe rotation and the low-end rheology of the drilling fluid.
Stuck Pipe Tool
Description about stuck pipe tool goes here.

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Better trained people make better decisions. It is really that simple. If the plan is pushing the team out of their comfort zone, time in the classroom learning about the fundamentals and talking through critical success factors will improve reliability of well delivery.


Execution is make-or-break time. Effort and energy expended during planning needs to be harnessed and directed to assure operational success. Merlin can support your field operations with people that have real expertise and experience, and have the know-how and energy to drive success within your team.


We developed TDH to leverage our industry-leading process knowledge honed on the worlds most complex wells. What was available commercially didn’t cut it for us, in the way we need to use data when on location or in the office.