At WOS we are focused on the use of our InterrogatR, and how it provides data that allows operators to make more informed decisions at any drilling site.

During a recent job, we pulled data from a Bottom Hole Assembly (BHA), which drilled out 22 plugs using our 5 bpm 3-1/8” EaZyDrill Extended Reach Tool (ERT) and our 5 bpm 3-1/8” POWR Motor and a JZ BoreHaug Rollercone Bit.

WOS tools measured the pressure drop across the EaZyDrill and POWR Motor, as seen in the charts below.

Why is measuring the pressure drop in drilling important?

Not only are accurate measurements critical for optimizing drilling efficiency, they also help to protect equipment and people, while controlling costs.

The bit uses the pressurized flow of drilling fluid to clear cuttings and debris from the well, reducing friction and cleaning the cutting surface. Many of the basins we operate in have a high wellhead pressure (WHP) and inherently resist the flow coming from the bit. This is often one of the main detractors from an efficient operation, establishing that these wells are considered “pressure limited.” While tools need to consume pressure energy to operate, it is imperative in these “pressure limited” scenarios that the consumption of pressure of the BHA is not so high as to jeopardize the completion of the drillout operation.

These measurements also:

  • Allow for the calculation of pump power requirements
  • Manage wellbore pressure, preventing stuck pipe or blowouts
  • Ensure the equipment operates correctly
  • Clean the wellbore

Much of the pressure drop comes from the power sections consuming the pressure and converting that potential energy (pressure) into kinetic vibrational (EaZyDrill) and kinetic rotational (motor) energy. While this is intended, consuming too much energy can break tools, leading to non-productive time (NPT) and possibly expensive fishing operations.

Operations can be pressure-limited, so maintaining a high pressure at the bit is important for the success of the operation.

The InterrogatR can measure the actual pressure drop downhole in an operational environment, not just on the surface, on a dyno pre/post job.

ERTs, like the EaZyDrill, create pulsating vibrations to help the BHA during a Coiled Tubing operation. Unlike Stickpipe, weight cannot be transferred down through the coil into the lateral, and an ERT is often required to reach total depth (TD).

There are cases where an ERT can be too powerful and may lead to untimely failure of other components in the BHA, like Check Valves and Motors. This data is being used by the WOS engineering team to optimize tools for downhole conditions to provide the ideal balance between power and durability.


Flow rate is another factor affecting the BHA performance and is directly related to pressure.

Pressure is dependent on flow rate, and the two are directly proportional, meaning that the higher the flow, the higher the pressure.

Flow rate is carefully recorded on the surface; however, pressure at the bit is what clears plug parts and cleans the well which can only be recorded with the use of the InterrogatR.

Armed with this data, operators no longer have to rely on calculations alone, and critical operational decisions aren’t left to the margin of error from assumptions, but are instead made from accurate, factual information.

At WOS, we remain invested in developing top-tier tools that perform consistently, reliably and at the highest level. Reach out to our sales team at sales@wos.com or give us a call at 346-774-4433 anytime.