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TDH-Jar
Cloud-based jar optimization with impact, impulse, limits, and reporting.
TDH-Core
Comprehensive torque, drag & hydraulics modelling with cloud-based flexibility.
TDH-Plus
Advanced modelling, additional casing wear, cementing & design modules.
TDH-Custom
Customised TDH solutions tailored to your exact specification.
What is TDH?
TDH is a fully featured well engineering software platform for drilling engineers working across exploration, appraisal and development wells in oil, gas, geothermal and CCS.
At its core, TDH enables engineers to understand and manage system loads versus limits, building models to define the loading envelope created by the well and comparing these directly against the capability of the rig and rocks being drilled.
Proven on the world’s most complex wells, TDH combines advanced modelling capability with engineering insight, supporting a holistic approach to well construction based on a clear understanding of risk and the margins available to push performance.
Built from the ground up to meet Merlin’s exacting technical requirements, TDH is used daily in both office and field environments. It requires no local installation and is designed to be flexible, scalable and simple to adapt.
TDH is designed to give engineers speed, simplicity and consistency where it matters, building models quickly and focusing time on understanding results, not wrestling with software. Whether used daily or intermittently, TDH provides a consistent, intuitive environment that reduces rework and keeps the focus on engineering decisions.
Beyond core torque, drag and hydraulics analysis, TDH brings together a comprehensive set of modelling and analysis capabilities within a single platform. Engineers can define trajectories, wellbore architecture, strings and fluids, and apply detailed analysis across torque and drag, hydraulics, casing wear, cementing and casing design, all within a consistent, integrated workflow.
TDH supports advanced engineering workflows, including upcoming real-time data integration, data hindcasting, LAS data viewing, scenario comparison and sensitivity analysis, enabling direct comparison of models against system limits and measured field data. This allows engineers to move beyond standalone calculations and build a clear, continuous understanding of well behaviour from design through execution.
Built-in functionality supports detailed modelling of real-world conditions, including friction modifiers for centralisers and swivels, flotation effects, tortuosity, PVT-corrected hydraulics and complex fluid behaviour – without the need for workarounds or external tools. Results can be visualised, compared and reported quickly, supporting clear communication and consistent engineering alignment across teams.
Package Options
TDH-Jar
Optimized jar placement using the TDH platform’s best-in-class reporting functionality.
✔️ Impact
✔️ Impulse
✔️ Weight-on-bit operating ranges
✔️ Pull and slack-off limits vs latch settings.
✔️ Flexible output charts
✔️ Cloud Based
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TDH-Core
Comprehensive torque, drag & hydraulics modelling with cloud-based flexibility.
✔️ Jar placement functionality
✔️ Torque, drag and buckling
✔️ Hydraulics (P&T corrected)
✔️ LAS file view and hindcasting
✔️ Flexible output charts
✔️ Cloud Based
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TDH-Plus
Advanced modelling, additional casing wear, cementing & design modules.
✔️ Jar placement functionality
✔️ Torque, drag and buckling
✔️ Hydraulics (P&T corrected)
✔️ Casing wear
✔️ Cementing
✔️ Casing design
✔️ Flexible output charts
✔️ Cloud based
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TDH-Custom
Customised TDH solutions tailored to your exact specification. Example projects for real clients shown below.
TDH-Custom Example #1:
A client wanted to optimize placement of their innovative tools in the drill-string with one-click functionality. The brief tasked Merlin to develop a digital model of the tool operating mechanism from first principles, which would be used to define torque and drag roadmaps based on placement position and number of tools in the string. These models were then validated against actual measurements and observations in the field.
Following a successful validation process, TDH was modified to include a custom tool library and data inputs as well as new output reports, which streamline the tool placement process and make presentations of data to the client’s own customers simple and effective. This approach reduced the amount of time our client’s engineers spent optimizing tool placement and reduced the amount of time necessary to prepare technical reports and proposals for new opportunities.
TDH-Custom Example #2:
An independent tool provider wanted to incorporate their tool operating characteristics into TDH in order to streamline their modelling and customer proposal generation process. Custom tools were added as “drop down” options in the BHA input section, where individual tools could be specified as being part of the BHA, and their operating characteristics incorporated automatically.
TDH outputs were modified to replace spreadsheets which were used to collate data from different sources into one single location. TDH’s flexible output capability was used to generate a similar report automatically, without manual manipulation, allowing engineers to spend more time solving client problems.
Why Choose Merlin’s TDH Software
- Runs in-browser, no installation required, with full functionality available across office and field environments, including offline mode.
- Integrated well engineering platform combining torque, drag, hydraulics, casing wear, cementing and casing design, supporting drilling, tripping, reaming, casing and completions workflows in a single system.
- Advanced hydraulics modelling with PVT-corrected rheology and temperature effects, supporting accurate ECD, surge/swab and pressure analysis.
- Comprehensive casing and well integrity analysis, including wear prediction, cementing simulation and multi-axial casing design – enabling engineers to understand system limits alongside applied loads.
- Define trajectories, wellbore, strings and fluids within a consistent workflow, supporting complete well engineering models from planning through execution.
- Rapid scenario comparison and sensitivity analysis for optimisation against system limits and operational constraints.
- Integration of measured data for real-time comparison or hindcasting, including LAS data, enabling continuous model calibration and refinement.
- Built-in modelling of real-world effects including tortuosity, friction modifiers, flotation and complex fluid behaviour — without external tools or workarounds.
- Flexible reporting and visualisation with built-in templates, enabling clear communication and consistent engineering alignment across teams.
- Highly customisable platform, with features tailored to specific tools, workflows and user requirements.
- Used by operators, service companies and tool vendors across a range of applications and environments.
- Flexible licensing model with configurable duration and user requirements.
- Ongoing software updates and direct support from experienced drilling engineers.
Book a Demo with a Merlin Engineer
Allow one of Merlin’s Senior ERD Engineers to show you around the software, demonstrating how TDH can help you optimize your wells.
TDH Clients
TDH is used by operators, multinational and domestic service companies and tool vendors.
