Modern drilling technology is characterized by an advanced suite of downhole tools, including PDC drill bits that are capable of drilling entire well sections in one run. The ability to balance the loading on the PDC cutter against available energy is critical to improving the drilling process and taking the industry forward in terms of efficiency.
Although quite similar to a shock absorber in appearance, Tomax’s patented AST tool is something different: it is a downhole regulator with capabilities very similar to the traction control systems used in cars. The AST uses robust mechanics to continuously control the axial force or weight on the bit. In this way, not only does the tool prevent the cutters from sticking, but it also provides an optimal balance between cut and losses to friction.
No downhole vibration mitigation solution has been analyzed and scrutinized by science to the same extent as the AST. Experts from academia in the fields of control systems and nonlinear dynamics have worked through the mathematics of the AST algorithm and published results that identify autonomous regulators as the way forward in deep drilling.
The AST is designed as a “bolt-on” solution with no need for added rig crew, and it requires minimal effort to deploy. It is typically placed above the MWD or non-magnetic portion of the BHA and is also used with under-reamer tools.
Both laboratory computer modelling and field results demonstrate the AST’s capacity to remove the same amount of rock using 40% less energy. The gain can be exploited in many ways: faster ROP, reduced bit wear and reduced tool damage from vibrations. The AST technology also enables greater efficiency through the use of more aggressive, low-friction drill bits.
New Combi-AST takes the trophy
The “C” means combi and reflects an extensive capability in terms of both radius of turn and lateral reach. This tool is the latest addition to the ast fleet.