The high-speed drilling simulator, located at Curtin University?s Department of Petroleum Engineering in Perth, can replicate popular industry methods including those for the quarry and mining industries such as drilling deep boreholes.
Professor Vamegh Rasouli of Curtin?s Department of Petroleum Engineering said the research was being undertaken with the aim of improving efficiency in hard rock drilling.
The simulator is capable of performing normal, over-balanced and under-balanced drilling, as well as simulating the use of different mud types and drilling through hard rock using diamond-impregnated bits.
?Simulation of drilling practices in the laboratory will be very beneficial for field operations as we can study the effects of different parameters on drilling efficiency,? Rasouli said.
?Drill bit surfing?
The drilling simulator has been designed with a drilling lid mounted on a True Triaxial Stress Cell (TTSC), which is capable of simulating drilling at typical bottom hole conditions.
The TTSC has been successfully used in hydraulic fracturing experiments on samples as small as 50mm to understand the response of tight sandstones and gas shale formations to drilling. It can monitor the magnitude of stress and strains on the sample and measure torque and drag systems, two important drilling operation parameters.
?During testing, three independent stresses can be applied to the sample to simulate real in-situ field stress conditions,? Rasouli said. ?A significant feature of the rig is its ultra-high speed rotation which can move at up to 10,000 revolutions per minute (rpm) to simulate hard rock drilling in tight sandstones.
?A drilling fluid of any type can be circulated in the simulated borehole, similar to a field situation, to study its effect on drilling performance.?
It has been observed that drill speeds above 5000 rpm can improve the rate of penetration by using water pressure to fracture the rock, rather than direct contact. The Curtin researchers refer to this technique as ?drill bit surfing?.
Source: Curtin University Department of Petroleum