The SABER Tool

The SABER RSS concept utilizes Bernoulli’s effect generated across the bit face. Bernoulli’s principal is a well-established Engineering effect (Bernoulli passed in 1782!). Probably the best-known example of this principal is the aircraft wing; Bernoulli’s principle explains how lift is generated as air passes over and under the aerofoil shaped wing. 

Enteq has validated the application of the Bernoulii’s effect in the SABER RSS system by 3 methods:

• Theoretical modelling of the effect as applied to the bit face, progressing onto….
• CFD analysis, both in house and with supporting bit vendors, confirmed with….
• Actual system testing in instrumented test fixtures.

All modelling and testing to date support that the approach will provide adequate sideforce for directional control in line with the existing system in the market. The final acceptance criteria will come during the scheduled downhole trials in Q4 2022.

Although SABER operates on a different principal to the existing mud activated pad / piston style RSS tools, it is still dependent on the mud system for side force generation. As such, the dogleg severity output is proportional is proportional to the flow.

One advantage SABER has is the higher the flow, the higher the dogleg output. As SABER has none of the pads / piston associated with other RSS tools it does not have an issue with washing of components at these higher flow rates.

RSS tools have traditional been categorized as either ‘Push’ or ‘Point’ system depending on how they mechanically operate. Technically, SABER is a “push’ the bit system. However, unlike existing systems the ‘Push’ systems the ‘Push’ is achieved via the created pressure differential across the bit face. Existing systems use mechanical pistons / pads in the drilling fluid which are prone to wear / failure. This makes SABER the only genuine At-Bit steering system, it literally is directly at the bit face!

RSS tools have traditionally been categorised as either ‘Push’ or ‘Point’ system depending on how they mechanically operate. Technically, SABER is a By relocating the steering mechanism to be entirely internal, the SABER Tool removes the need for pads and pistons external to the collar, which are typically subject to extreme wear and are a common point of failure. The SABER Tool’s smooth collar design removes this drawback of current RSS design.

Furthermore, the internal sonde assembly is ‘floating’ on radial bearings and as such the electronics and control system are significantly decoupled from torsional vibration.

The core principal behind SABER was developed in-house by Shell, before being licensed to Enteq for refinement and development. The system today has come a long way since those initial designs, and draws on Enteq’s stellar track record in developing effective engineering solutions for a variety of downhole environments.

SABER utilizes a full 6 axis sensor package (3mags, 3 accels) to continually calculate Magnetic and Gravity referenced toolfaces, plus inclination and azimuth. These measurements allow SABER to have standard Magnetic & Gravity Toolface modes, as well as 2-Dimensional (Inclination only) and 3 Dimensional (Inclination and Azimuth) autopilot modes.

SABER uses modulated flow-based downlinks which are interpreted by the downhole generator incorporated into the system. This is done by manually manipulating the pumps on surface. Downlinks typically take 3-5 minutes. Downlink length can be adjusted in deeper wells to counter the unavoidable signal attenuation.

If the SABER is configured for realtime communication via the MWD system, then a confirmation response will be generated to verify that the downlink has been successfully received.

Yes, SABER has continuous inclination and azimuth readings. The offset for these readings is ~4’ from the bottom of the collar.

The 500 series SABER is ~9’ long and has a collar OD of 5 1/8”. The collar has a stabilized portion ~4’ behind the lower connection shoulder. This stabilized portion is an IBS with the gauge at 1/8” under the hole diameter and designed to maintain a minimum of 25% JSA (Junk Slot Area).

Initially, the first SABER system will be the 500 series. This series will cover nominal hole sizes from 6” through to 6 ¾”. Next to be developed will be the 700 series for 8 ½” to 8 ¾” size. Then the larger holes sizes will be covered with 800 / 900 series systems.

As with all RSS systems SABER has specific bit requirements. SABER houses a valve inside the pin of the bit, and this requires a specific pin and bot box design to accommodate. This is a mandatory requirement and based on this the bit will be a SABER only design. SABER has other preference in terms of external bit design, these will maximize DLS performance but are not mandatory. 

Any SABER optimized bit will not affect the blade count, cutter size, location or orientation i.e. will not alter any parameter that will negatively impact ROP performance. Enteq are working closely with two major bit suppliers to provide the client with options. Once SABER becomes established then Enteq will work with any client request bit supplier to provide solutions.

SABER has been designed as a performance drilling system. One unique feature of SABER is that the internal sonde assembly is ‘floating’ on radial bearings and as such the electronics and control system are significantly decoupled from torsional vibration. This makes it an ideal system for motorized RSS applications – effectively the RPM has minimal impact on performance. This coupled with a solid collar design means SABER has the potential to expand the current drilling parameters.

Yes. Unlike most traditional RSS options on the market, the SABER Tool has been designed from the outset with high-temperature environments in mind, building on Enteq’s established expertise in HT drilling applications.

Yes, SABER can be readily redressed at a field location using only hand tools. This makes the system ideal for remote operation work.

Yes, Enteq can provide direct field support for the initial deployment and will provide a full training course for Directional Drillings and MWD hands. The SABER Tool user interface has been designed to be intuitive and familiar to anyone with a directional drilling discipline background.

The SABER Tool will be deployed ‘ready to go’ and as such will not require a traditional surface test. However, if the client requires a surface test the system will have a specific test option that can be enabled during programming and this will require flowing through the tool a surface and visually confirming the functionality. This should take no more than 5 mins of flowing maximum.