9/8/2017 1 New developments for hard rock drilling From hydraulic DTH Hammer to Laser Drilling 1 Celle Drilling, 12.9.2017 Volker Wittig International Geothermal Centre [email protected]2 2 Drilling technology in Geothermal applications Indication of a need for a novel drilling technology Deeper and harder formations Very low rate of penetration (1 m / hr. or less) Very high bit / tool wear low service life of e.g. under 50 hrs. Numerous, long and expensive round trips Indication of a need for a Novel Drilling Technology Challenge high ROP together with long tool and bit lifetime
19
Embed
New developments for hard rock drilling From … · New developments for hard rock drilling From hydraulic DTH Hammer to Laser Drilling 1 Celle Drilling, 12.9.2017 ... DTH percussion
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Drilling technology in Geothermal applicationsIndication of a need for a novel drilling technology
Deeper and harder formations
Very low rate of penetration
(1 m / hr. or less)
Very high bit / tool wear
low service life of e.g. under 50 hrs.
Numerous, long and expensive round trips
Indication of a need for a Novel Drilling Technology
Challengehigh ROPtogether with
long tool and bit lifetime
9/8/2017
2
Flow through, internal system e.g. Wassara in Sweden, Hanjin South Korea, all otherdevelopments in the past 30 + years already available
3
Hydraulic DTH mud hammers : 2 basic systems
Drill string
Mud flow Mud flow
Closed loop system (“external” tool) percussion section is being powered with hydraulic or electric energy being generated downhole via mud generator tool may be added to any BHA with enough flow e.g. TU Freiberg is working on this design
Application of thermal energy to apply stress penetrate the rock
Thermal Drilling
LaserJet supported Drilling
SpallationMain
Research topic
Plasma Drilling
meltingUnder
investigation and evaluation
9/8/2017
11
2121
Thermal (Laser) Drilling : Thermal rock softening
• Thermal rock softening may increase ROP in factor2 to 3
• Thermal rock softening +spallation maximumpotential of laser drilling
Change of the compressive strength of selected type of rocks subjected to high temperatures.(Chen, Ni, Shao, & Azzam, 2012; Keshavarz, Pellet, & Loret, 2010; Pinińska, 2007; Sygała et al., 2013)
Spallation zone10% 45% 80%
Temperature increase Reduction in E modulus
2222
Energy comparison of Laser and common drilling methods
Comparison of Laser and conventional drilling methods. Modified after (Xu et al., 2004)
Specific Power being delivered by the drilling method, kW/cm2
1. Percussive hammers
2. Rotary standard
3. Drill-and-blast tunneling
4. Tunnel-boring machines
5. Flame jets
6. Laser spallation
7. Future Laser Drilling
> 10x ROPSame Specific energy
But more specific power
Additional Challenge :
tool lifetime !!!
9/8/2017
12
2323
Thermal spallation drilling with LaserJet
J/sec=W
Laser spallation process principle. Modified after (Preston & White, 1934;Fraunhofer IPT)
water jet guided Laser transmits energy
Excessive, rapid thermal energy
Thermal stress
Rock weakening +
thermal Spallation
mechanical assistance complete rock destruction
2424
Prototype LJD test setup @ GZB + Fraunhoferwith mechanical assistance
LJD schematical setup including mechanical assistance.( Fraunhofer
IPT)
30 KW laser system
LaserJet water
Mechanical assistance + Laser cartridge housing
multi-fluid distribution swivel and four concentric pipe
system
High powerfiber optic cable
Cutting transport&
wellbore integrity
LaserJet
9/8/2017
13
08.09.2017 Fußzeiltentext: Menüband "Einfügen" -> "Kopf- und Fußzeile" 25
Rock disintegration and drilling via LASER technology combined with monitoring, logging, characterization and analysis of water jet, rock destruction and equipmentto determine final drilling parameters
Acoustic emission system
Central data
acquisition system
Laser generator
and optical system
Laser Generator
Fiber laser
Laser generator and optical system (Fraunhofer IPT)Confining
pressure
Rock sample
08.09.2017 Fußzeiltentext: Menüband "Einfügen" -> "Kopf- und Fußzeile" 26
Acoustic MWD
system
Reinforced Rock sample
Flame
Rock disintegration / spallation / drilling via FLAME + LASER technology combined with monitoring and analysis of rock destruction to determine drilling parameters
9/8/2017
14
08.09.2017 Fußzeiltentext: Menüband "Einfügen" -> "Kopf- und Fußzeile" 27
Development of a new MWD systemmonitoring + control of rock destruction
Challenges:Data processing + interpretationNeeds more experienceSpallation + melt can be clearly seen