Both types of rotary steerable systems provide directional control while allowing continuous drillstring rotation from surface, eliminating the need to alternate between sliding and rotating as required with bent-housing motor assemblies. Continuous rotation improves drilling efficiency, hole quality, and overall performance.
Point-the-Bit Systems
In point-the-bit design, the drill bit axis is tilted relative to the drillstring axis, typically by deflecting an internal flexible shaft or using an offset mandrel with fixed or variable offset.
The primary challenge with point-the-bit systems is their mechanical and hydraulic complexity. These designs often require large volumes of hydraulic oil, universal joints, and fluid interface seals, which can lead to reduced reliability, higher repair costs, and longer maintenance turnaround times.
Some point-the-bit systems rely on non-rotating external housings to maintain toolface orientation. These designs can increase the risk of sticking because the stabilizer cannot effectively transmit torque during reaming, allows cuttings to settle, and may hang up on wellbore ledges. Systems using fully rotating offset mandrels also require significant electrical power, increasing heat generation and electrical stress that can reduce reliability in demanding environments.
Push-the-Bit Systems
In push-the-bit systems, directional control is achieved by applying a controlled side force against the borehole wall to steer the well along the desired trajectory. This force is generated hydraulically using drilling fluid pressure.
Push-the-bit systems are widely valued for their mechanical simplicity, continuous rotation capability, and reliable directional control across a range of drilling conditions.
The D-Tech OmniSteer RST builds on these advantages with a design focused on reliability, efficiency, and serviceability. In the OmniSteer system, side force is generated using the pressure drop across the bit nozzles, diverting only a small portion of mud flow to power hydraulic pistons. This approach reduces power demand and minimizes internal wear.
Key advantages of the D-Tech push-the-bit design include:
• Lower electrical power requirements, reducing heat buildup and improving reliability
• Reduced internal wear, supporting longer tool life
• Scalable control electronics across multiple tool sizes
• Faster turnaround between runs, improving asset availability and operational efficiency
Unlike some competing systems, the OmniSteer design does not require mounting holes in the collar housing to support control electronics, a common source of fatigue cracking in high stick-slip or high-frequency torque environments, improving structural integrity and long-term durability.
