At the recent Society of Petroleum Engineers/International Association of Drilling Contractors drilling conference in the Netherlands, Baker Hughes Inc. (NYSE: BHI) announced the release of its TerrAdapt adaptive drillbit, which can deliver dramatic improvements in drilling economics by using automation to mitigate downhole dysfunctions that cause inefficient drilling and costly tool failures. E&P spoke with Scott Schmidt, vice president of drillbits for Baker Hughes, about the new technology.

E&P: To date how much automation has been utilized in drillbits?

Schmidt: None so far. Drillbits are really the last frontier for automation. Most automation has been focused on the surface at the rig, for parameter management or vibration management, but it’s not tied to what’s happening at the bit. Downhole there are other tools that react to what’s happening in the string or to achieve a given directional plan, but TerrAdapt is the only product in the market targeting the bit—which is critical for ensuring the most efficient drilling.

E&P: What convinced you that an adaptive drillbit was required?

Schmidt: The concept was developed as part of an internal Baker Hughes innovation contest called the Wildcat Challenge. The first one was kicked off at the end of 2013, challenging participants to think of a solution to a common industry problem that is not being addressed with current R&D projects.

The idea of a bit that could be self-adjusting won the inaugural Wildcat Challenge. As a result, the inventor was given the chance to build a team to take the winning idea from a concept to a proven solution over the next 12 months. At the close of that endeavor, a formal product development effort was launched to take the solution and further develop and package it for a commercial offering. Our formal development efforts started in 2015. It has been exciting to take such a novel idea from concept to commercial offering in less than three years.

E&P: What challenges were overcome in developing the adaptive drillbit?

Schmidt: Today most wells are drilled through a variety of formations containing layers of different rock types. Current polycrystalline diamond compact (PDC) drillbit designs feature a fixed depth-of-cut (DOC) control setting that is optimized for only a single rock type. A fixed-DOC control bit will drill smoothly in some areas, but will perform erratically and inefficiently in others because of vibrations that occur when the bit transitions between different formations, causing stick/slip. During stick/slip events, the bit’s bite becomes too aggressive, causing it to stick and stop rotating, while the drillpipe behind it continues to wind up like a spring until the bit releases, or slips, and begins spinning uncontrollably.

These stick/slip events dramatically increase drilling costs by reducing ROP. They result in poor directional control and can seriously damage the bit and other expensive downhole tools such as MWD and motors. When this happens, operators must make extra trips to replace the bit, or continue to drill with diminished performance. Both of which add time and costs to the operation. TerrAdapt was developed to address this problem. In fact, testing has shown that this technology can help overcome other drilling dysfunctions such as vibrations and impact loading as well.

E&P: How would drillers have overcome the variety of different rock types prior to the TerrAdapt?

Schmidt: There are two primary ways. The first is to adjust drilling parameters when entering known transitions and/or utilizing drilling guides—basically a parameter map section by section of the well based on offset well analysis. So if anything changes well to well the parameters may not be best matched to that given hole interval. The other option, in extreme cases, is different bit types are utilized to accommodate different rock types. Some operators will designate a point to pull the bottomhole assembly and change the bit.

E&P: How does the drill bit recognize different rock types and adapt?

Schmidt: While TerrAdapt was initially developed for stick/slip mitigation, the ability for the bit to adjust to changing conditions has a broader benefit from a bit life standpoint. Every well has an element of variation—whether it’s rock type or hardness. Uncertainty exists that can limit bit life or performance.

Since the TerrAdapt bit’s elements extend outward as soon as a load change occurs, a challenging formation no longer has to mean the end of bit life. TerrAdapt optimizes how much engagement should be happening for that exact condition and is constantly adjusting throughout the run to dial in the response. Also, the only way to prove stick/slip exists is with in-bit sensing or MWD technology.

We have those capabilities, but most wells are drilled without any sort of vibration measuring technology. We believe stick/slip is a much more common dysfunction than we’ve measured to date. Especially with the increase in higher strength, higher torque motors. The loading put on bits has continued to increase, and coupled with varying rock strength, leads to a stick/slip-rich environment.

E&P: Does this drillbit require a different drilling strategy or training for operators?

Schmidt: From the runs so far, TerrAdapt complements an operator’s drilling strategy. We have not seen major modifications being necessary. From a training standpoint, the setup/makeup of the bit is identical to standard PDC drillbits. Most of the discussion with operators and rig side crews has been on the education of the product— what it can do for vibration mitigation to increase drilling efficiency.

E&P: Do you have any figures on the cost of stick/slip in drilling?

Schmidt: No, the industry recognizes it is a very large issue constraining overall drilling efficiency and adds cost to drilling operations. In fact, hundreds of papers have been authored about the subject. The difficult part with stick/slip is knowing what exactly is happening downhole, unless running MWD tools or in-bit vibration sensing. The vast majority of wells are drilled with no downhole vibration measurements, making quantification difficult.

E&P: How has the market reacted?

Schmidt: The numerous operators we’ve spoken to have been excited. Stick/slip and erratic torque are very common issues with PDC drilling today and this provides an elegant and robust solution where it counts most—at the bit. On a wider basis, the market has recognized this is a huge departure from where fixed-cutter bits have been and sees the numerous advantages a bit that can adapt downhole provides.

E&P: What further developments are in the pipeline for adaptive drillbits?

Schmidt: TerrAdapt is the first release in a line of adaptive bits. The initial release of TerrAdapt focuses on 8½-in. to 12¼-in. bits. In the next year or so we will be scoping/developing the next adaptive bit that can adjust other components on the bit to solve other downhole issues.