NexTitan FAQ: downhole weight on bit for hard rock wells

NexTitan at a glance

What is NexTitan?

NexTitan is an autonomous downhole drive unit that applies and controls force directly at the bit, built for hard rock sections in oil, gas and geothermal wells. Think of it as taking 90% of the top drive functionality to the bottom of the well. Instead of transferring weight through kilometers of drill string, the tool generates controlled thrust right where the rock is. In simple terms, NexTitan brings downhole drilling automation directly to the BHA. It is built for drilling oil & gas and geothermal wells, where conventional weight transfer struggles most.

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How does NexTitan apply weight on bit downhole?

The tool grips against the wellbore just above the drilling assembly and an electrohydraulic actuator applies controlled axial thrust to the bit. A closed-loop control system running at 100 Hz holds that force steady as the formation changes, which delivers stick-slip mitigation at the source instead of damping it downstream. The tool is powered hydraulically by the drilling fluid itself, diverting a small share of flow through its valve system.

How it performs: comparison, testing and evidence

How is NexTitan different from thrusters and vibration tools already on the market?

Every commercially deployed downhole tool today is passive or reactive: it absorbs vibration, damps stick-slip after it starts, or delivers thrust without control. Surface automation platforms are active but sit at the rig floor, kilometers from the problem which delays their reaction time. NexTitan is the only tool that actively applies and controls force at the bit, downhole, in a closed loop.

How is NexTitan being tested?

At NORCE Ullrigg in Stavanger, NexTitan delivered up to 32,000 lbf of open-hole thrust in hard rock, with simultaneous string rotation and no sticking. Earlier multi-unit field testing demonstrated 7.5 hours of continuous drilling. The current test program focuses on continuous drilling length and operating endurance in vertical wells, ahead of the first commercial pilots.

What performance gains can operators expect?

With NexTitan, operators can expect a higher rate of penetration (ROP), longer laterals, longer bit and BHA runs, and fewer trips. That adds up to cost per foot savings, fewer rig days, and less non-productive time (NPT).Operators can also expect less repair maintenance and less risk. The precise multipliers are exactly what the upcoming field test and pilot program is designed to quantify. We'll share results as they come in.

Risk, failure and compatibility

What happens if NexTitan fails downhole?

NexTitan is designed with three independent failsafe mechanisms. If it loses function, mechanical retraction elements collapse it to a neutral position. In essence, it behaves like an expensive stabilizer. The tool trips out with the string like any other BHA component.

Will it get stuck in the well?

The gripping elements are pistons and their geometry is designed to prevent debris from accumulating behind them. In hard rock testing at NORCE Ullrigg, the tool operated in open hole with simultaneous string rotation and moved along both cased and open hole sections with no gripper-induced sticking. If anything does go wrong, the failsafe design returns the tool to neutral.

Does NexTitan change how the driller works?

The driller keeps full control, the same way a self-driving car still has a wheel and brakes. NexTitan manages force delivery downhole and responds to dysfunction faster than any surface correction could, while the driller keeps doing what they would always do. It assists expertise instead of replacing it.

Is it compatible with my BHA, bits, and downhole tools?

Yes. NexTitan sits in the bottom hole assembly (BHA) and applies force axially to whatever is below it, so standard polycrystalline diamond compact (PDC) bits work without modification. Measuring while drilling (MWD) and logging while drilling (LWD) tools run above or below it without signal interference, and for directional sections it pairs with a mud motor or rotary steerable system (RSS). The motor or RSS handles trajectory while NexTitan manages force delivery. Connections are standard API.

Fit, cost and availability

Where is NexTitan the right fit, and where is it not?

NexTitan is built for oil & gas and geothermal wells where drilling dominates the cost line. It’s ideal for deep, hot hard rock, and long laterals where slow penetration, tool damage, and trips add up. It is not the right tool for very shallow wells or very short runs, where it would add complexity without payback.

Does NexTitan work for geothermal wells specifically?

Geothermal is one of the two verticals NexTitan was designed for.

Geothermal wells are drilled through hard crystalline basement rock, which is exactly the formation type where surface weight transfer breaks down and where drilling cost dominates project economics. The NORCE Ullrigg testing was carried out in hard phyllite for that reason. Temperature is the binding constraint rather than the rock.

Can NexTitan handle geothermal drilling temperatures?

The tool is rated to 175°C circulating temperature at the bit. That covers most current geothermal targets, because circulating temperature during drilling runs well below the static reservoir temperature. Pre-job data from active geothermal projects shows circulating temperatures of 100 to 163°C in reservoirs that are far hotter at rest. For hotter wells, active mud cooling extends the reach further, and higher temperature ratings are on the development roadmap.

Does NexTitan make coiled tubing drilling viable?

Coiled tubing cannot transfer weight to the bit the way jointed pipe can, which is the main reason CT drilling has stayed confined to a narrow set of applications. If weight is generated downhole instead of transferred from surface, that constraint changes.

This is the application Greg Leveille singles out as the larger prize: drilling with stands of pipe becomes more efficient, but coiled tubing drilling becomes viable across a much wider range of applications than it is today. The industry has wanted that for decades.

How does NexTitan affect cost per foot?

Cost per foot moves through four mechanisms: faster penetration, fewer bit and BHA trips, fewer rig days, and less non-productive time from downhole dysfunction. Which of the four dominates depends on the section, the formation, and the day rate.

The exact multipliers come out of the pilot program. In the meantime, the drilling cost calculator lets you model the effect on your own well using your own day rate and section lengths, rather than against a generic case.

Is NexTitan commercially available today?

NexTitan is available for pre-order and is being deployed with partners through structured drilling programs, ahead of general commercial release.

How do I evaluate NexTitan for my well program?

Send us the section you are trying to improve: formation, hole size, depth, temperature, and what is currently limiting you, whether that is penetration rate, bit life, or trip count. We'll tell you whether NexTitan fits that section, or not.

Hard rock drilling explained

What is the best drilling tool for hard rock in oil, gas and geothermal wells?

There is no single best tool for hard rock, because the right choice depends on what is limiting the section. What hard rock consistently demands is the same four things, and they are a fair test to hold any tool against.

• Weight delivery. The bit needs consistent, sufficient force to fracture the rock rather than ride over it. Surface-set weight arrives uneven through a long drill string.
• Response time. Stick-slip and bit bounce start and escalate downhole in fractions of a second. A correction sent from the rig floor arrives after the damage.
• Cutter survival. Every uncontrolled oscillation costs cutter life, and trips to change bits are the largest avoidable cost in a hard rock section.
• Temperature. Geothermal and deep oil and gas wells put electronics and elastomers near their limits. A tool that cannot survive circulating temperature is not in the category.

Most tools address one of these. Dampers and agitators improve response time and cutter survival, but only once a problem has started. Bit design improves cutter survival. Surface automation works on weight delivery and response time, from the wrong end of the drill string.

NexTitan generates and controls weight on bit at the bit, rather than transferring it through the drill string. As far as we know, it is the only tool that does this downhole in a closed loop, and it has delivered up to 32,000 lbf of open-hole thrust in hard crystalline rock at NORCE Ullrigg. Because that control runs downhole with no round trip to surface, response time is a matter of milliseconds rather than the time it takes a correction to travel several kilometers and back.

On cutter survival, steadier weight on bit reduces the oscillation that destroys cutters, but we do not yet have the numbers. Vibration reduction and bit life are both unquantified, and the next test campaign is designed to produce them. On temperature, the tool is rated to 175 °C circulating temperature at the bit, which covers most current geothermal targets.

What is weight on bit, and why is it hard to control in deep wells?

Weight on bit (WOB) is the downward force pressing the cutting structure into the rock. It is the main lever on rate of penetration: too little and the bit skates, too much and it damages cutters or stalls the motor.

In a vertical shallow well, setting WOB at surface works. The deeper and more deviated the well, the less of the surface setting arrives at the bit. Drill pipe is slender and elastic over kilometers. It buckles, drags against the wellbore wall, and winds up torsionally before it releases. By the time weight reaches the bit it is neither the value the driller set nor steady. In hard rock, where the bit needs consistent force to cut rather than skate, that inconsistency is what limits performance.

What is stick-slip, and how is it normally handled?

Stick-slip is a torsional oscillation: the bit stalls against the rock while the string above keeps turning and winds up, then the stored torque releases and the bit spins far faster than the surface speed. It destroys cutters, shortens BHA life, and wastes drilling time.

The industry handles it three ways today. Surface systems detect it from rig floor measurements and adjust RPM and WOB, with the correction delayed by the time it takes to travel down and back. Downhole dampers and agitators absorb or redistribute the energy after the oscillation has started. Bit and cutter design reduces how readily it starts. All three manage the symptom.

Controlling weight on bit at the bit addresses the condition that produces it.

Why hasn't the way weight reaches the drill bit changed since the top drive?

Drilling has had three step changes in how force reaches the rock. Cable tool rigs dropped a weighted bit on a line. Rotary drilling turned the string from surface and set weight through the pipe above the bit. Top drives, introduced in the early 1980s, moved the rotation to the derrick and brought large gains in performance and rig floor safety. All three deliver weight from surface, through the drill string, to a bit that may be several kilometers away.

That is the part that has not changed. Greg Leveille, GA Drilling board member and former CTO of ConocoPhillips, puts it this way: in all that time, "little has changed in how weight is delivered to the drill bit."

In soft formations the drill string transfers weight well enough. In hard rock it does not. The string stores and releases energy, weight on bit arrives late and uneven, and the result is stick-slip, bit damage, and slow penetration. Every correction the driller makes has to travel back down the same string that caused the problem.

NexTitan moves weight delivery downhole, to a tool a few tens of feet behind the bit. The force is generated where the rock is, not transmitted to it.

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