Technology

The Canopus Directional Steel Shot Drilling Technology is visualized in the graphic below. The DSSD Technology was published in and presented at the European Geothermal Congress 2022 and can be downloaded here.

Canopus drill bit

The DSSD drill bit is a modified PDC bit with nozzles positioned such that the steel shot erosion and the PDC cutters cooperate in the hole making. The flow rate is selected for good hole cleaning and the bit nozzle are selected for optimum bit pressure drop at that flow rate. Read more..

Steel shot

Steel shot drilling removes rock by exposing the hole bottom to a high pressure jet containing steel shot particles. It requires minimal weight on the bit and uses conventional flow rates that ensures good solids transport and well control and drills through any rock type. Read more..

Steel shot Retrieval system and the Injection Unit

The steel shot is injected into the fluid by the Steel shot Injection system (SIU). The surface system retrieves the steel shot particles from the solids-separation by the shale shaker and returns them to the SIU. The steel shot return system separates the steel shot from the cutting by a magnetic drum separator and transports them back to the SIU by means of a venturi pump. The SIU is fully automatic and remotely monitored out of a control cabin. Read more..

Steering sub

The Canopus Directional Steel Shot Drilling (DSSD) technology is effectively a Rotary Steerable system. The Canopus’ system steers by increasing the intensity of the erosion in the steering direction. The concept of the directional control is that the steering sub ensures that more steel shot particles arrive at the bit when the erosive jets are oriented in the direction of the steering action. Read more..

Steel shot

Steel shot drilling removes rock by exposing the hole bottom to a high pressure jet containing steel shot particles. It requires minimal weight on the bit – just contact between bit and hole bottom – and uses conventional flow rates that ensures good solids transport and well control and drills through any rock type. This has already been demonstrated by Gulf Research and Development in the 1970s (Ref article J.C.Fair).

The steel shot particles are spherical and therefore are not abrasive to ductile material like the steel drill pipes and casing. The size of the particles is 0.5 to 1 mm, small enough to be transported through the well at conventional flow rates and mud rheology.

Canopus drill bit

The DSSD drill bit is a modified PDC bit with nozzles positioned such that the steel shot erosion and the PDC cutters cooperate in the hole making. In the case a PDC cutter is damaged less rock is removed by that cutter but then the exposure to the erosive jet is automatically increased. The bit can be optimized for ROP optimization, directional capability, and open hole kick-off capability. The flow rate is selected for good hole cleaning and the bit nozzle are selected for optimum bit pressure drop at that flow rate. The bit pressure drop is typically between 100 and 300 bar.

The combination of the erosive jets and the PDC cutting gives that the conventional bit-rock interaction changes. Canopus developed a specific bit-rock interaction model for the Canopus bit.

Steel shot Retrieval system and the Injection Unit

The surface system retrieves the steel shot particles from the solids-separation by the shale shaker and returns them to Steel shot Injection system (SIU). The steel shot return system separates the steel shot from the cutting by a magnetic drum separator and transports them back to the SIU by means of a venturi pump.

No particles pass through the high-pressure pump – the SIU is positioned downstream that pump. The unit contains two vessels that inject steel shot alternatingly into the drilling fluid to facilitate continuous injection.  The injected volumetric percentage is controlled within the 0.2% to 1.0% of the mud flow rate.

The SIU is set up parallel to the mud line from pump to rig – the SIU can be isolated from the conduit pump-to-rig without having to stop the rig pump operation.

The SIU is fully automatic and remotely monitored out of a control cabin. Both the SIU data as well as the rig and pump data are acquired in the control system such that the operator is constantly aware of how much steel shot is circulated through the well and whether the surface pressures are consistent with the circulation model.

Steering sub

The Canopus Directional Steel Shot Drilling (DSSD) technology is effectively a Rotary Steerable system, i.e. the complete drill string rotates while steering. The Canopus’ system steers by increasing the intensity of the erosion in the steering direction. The intensity of the erosion is controlled by  the steel shot concentration in the eroding jets. The concept of the directional control is that the steering sub ensures that more steel shot particles arrive at the bit when the erosive jets are oriented in the direction of the steering action.