Sigra’s knowledge of exploration drilling spans from shallow site investigation holes in civil work to exploration holes for mines that may be 2000 m deep. Much of this is advantageously based around wireline coring operations, notably the Boart Longyear HQ system which is compatible with many of Sigra’s exploration tools. Sigra has designed numerous exploration drilling operations for mines and knows how to get the most information out of these.
Sigra has used directional drilling for exploration or the production of fluids. Sigra has designed directional drilling patterns for coals seam gas and water. It has also been involved in directional drilling for the installation of utilities.
The key to the successful utilisation of directional drilling techniques is understanding how the different systems work and what controls them. Sigra has worked with downhole motors, rotary steering systems, water jetting, directional hammers and wedge deflection. Other important factors in drilling are an understanding of the drilling fluids and the mechanical behaviour of the drill string.
Sigra can design drilling fluids for particular applications. Its laboratory can test fluids to determine whether they are suitable for a particular application. They also understand how fluids may support a wellbore in weak formations and the intricacy of well control.
The mechanical behaviour of the drill string and the bottom hole assembly is governed by its structural mechanics. Sigra have their own torque and drag software to predict the behaviour of the drill string and the stresses and strains that exist within it. Using this they can design borehole trajectories.
Sigra also have a working knowledge of down the hole hammer drilling, particularly Odex or Simcas casing advance systems for use in broken ground.
Much of Sigra’s drilling capability comes from having done the job or having built tools to do the job. Sigra’s tools include:
- Well control systems
- Managed pressure drilling systems
- Borehole survey systems