Automated directional drilling system outperforms human directional driller
Huisman Well Technology (HWT) developed a Rotary Steerable System (RSS) based on some unique features of the Enhanced Casing Installation (ECI) system.
ECI is an innovative retrievable casing installation system that allows directional drilling and installing casing simultaneously while keeping the freedom to change BHA components mid-section if needed or at TD. The system uses compact drilling BHA’s that can be retrieved by cable resulting in large times savings besides the typical risk elimnations that come with casing drilling.
Opposed to a conventional RSS on drill pipe that requires continuous downhole position measurements, an electronic control and power system to steer the full-mechanical ECI-RSS uses the MWD’s ToolFace data-points and a laptop a surface to steer resulting in an extremely reliable directional drilling tool. The point-the-bit type ECI-RSS has the characteristic small stick-out that eliminates the need of ‘over-washing’ once desired depth is reached and that minimizes shocks & vibrations while drilling. The combination of ECI and the proprietary rotary steerable technology results in a low risk and predictable drilling system that requires a minimum of expertise to operate. The unique and continuous steering method allows reliable automated directional drilling what has been demonstrated by HWT while drilling two open hole sidetracks.
The first of the two sidetracks was drilled from a cement plug but the second was drilled without any cement or other medium to kick—off from. Both sidetracks were ‘time-drilled’ from an inclination around 8 degrees what shows the predictable steering behavior of the system and how little the steering is affected by the formation. The time drilling of the second sidetrack was performed full-automatic with a laptop at surface steering in the desired direction and the rig continuously but very slowly lowering the topdrive.
Parts of the laterals were drilled by human control and other parts by the computer. A comparison showed the continuous good performance in automatic mode while occasional the human would match the computers performance although also large spikes of poor performance were registered. This comparison shows the strength of automation which has become in reach for many directional drilling operations thanks to the ECI-RSS system.