Views: 11 Author: Site Editor Publish Time: 2016-07-26 Origin: Site
1、 Project profile
This project is CPC Corporation, Taiwan second natural gas pipeline, which reduces Taichung natural gas operation interruption risk, it mainly crosses Taichung port channel, steel pipe material, diameter Ø660mm, crossing length 1449m.
Owner party: CPC Corporation, Taiwan
Construction party: Taiwan Resources Engineering Services Inc.
Construction unit: India TESPL company.
Project characteristic: Steel pipe Ø660mm×1449m directional drilling Taichung port channel sets the history record of 350T hdd machine Taiwan area trenchless.
Soil condition: silty fine sand with thin layer of clay, part backfill crushed stone, undersea quicksand strata etc.
Terrian condition: max. depth drilling port channel reaches 60m,cross breakwater. The channel water depth is 16m, width about 300m.
Construction difficulty: silty fine sand with thin layer of clay and undersea quick sand starta makes the hole difficult, pipe self-weight is above 300t, so in the process of project, using excavator to lift, pulley bracket etc. to reduce pie and ground friction resistance.
Picture1： Taichung port channel in Taiwan
Horizontal directional drilling machine is Goodeng Machine GD3500-LS, locating system is USA ParaTrack 2 Geomagnetic guide, mud pump is Japan Mitsubishi F500(2000L/min).
Picture 2： Goodeng Machine GD3500-L(S) main rig
Picture 3： Goodeng Machine GD3500-L(S) rig operation cab
Picture 4：USA Paratrack2 locating system
Picture 5： Japan Mitsubishi F500 mud pump(2000L/min)
3、 Technique guarantee
Risk prevention: use ParaTrack 2 Geomagnetic guide, improves locating accuracy, pay attention to mud technique guarantee, increase mud input, avoid hole collapse, seamless connection process, try best to shorten construction period.
Three level reaming: 24inch （Ø610mm）, 30inch （Ø610mm）,42inch （Ø1067mm）three level reaming.
Pulling the pipe: use 36inch （Ø915mm）bucket reamer to pull back.
4、 Construction process:
Tracking: 5 days, tracking speed: 1 piece drill rod/15min, mud displacement 600L/min, torque 9-13Mpa, push-pull force: 5-9Mpa.
First level reaming: 24inch （ Ø610mm）barrel reamer, silty fine sand and thin layer of clay 1 piece drill rod/10min, mud displacement 800L/min, torque 12-16Mpa, pull force 10-15Mpa.
Second level reaming: 30 inch（Ø762mm）barrel reamer, silty fine sand and thin layer of clay, quick sand layer 1 piece drill rod/20min, mud displacement 1000L/min, torque 15-20 Mpa, pull force 15-18Mpa.
Third level reaming: 30 inch （Ø 762mm）barrel reaming+42inch （1067mm）cutter reamer, quick sand layer 1 piece drill rod/20min, mud mud displacement 1500L/min, torque 15-23Mpa, in the middle, the max. torque reaches 30-35Mpa, pull force 16-20Mpa.
Hole cleaning: 40 inch （Ø 1016mm）barrel reamer, silty fine sand and thin layer of clay, quick sand layer 1 piece drill rod/20min, mud displacement 1500L/min, torque 10-15Mpa, pull force 12-16Mpa.
Pulling the pipe: use 36inch （Ø915mm）bucket pull-pipe machine, on 9:30 June 11, 2016, pulling pipe starts, the pull-back force 12Mpa, torque 18Mpa, pull-back speed 3m/min, mud displacement 1800L/Min, in the process of pulling back, the pull-back force and torque keeps between 12-20Mpa and 18-23Mpa. On 6:30 June 12, 2016, pulling pipe succeeds, which takes 21 hours.
Picture 6： project site
Picture 7： Tracking is going on
Picture 8：30 inch(762mm) reaming is going on.
Picture 9： 42inch(1067mm) reaming is going on.
Picture 10：40inch(1016mm) hole cleaning is going on
Bentonite amount: 800ton.
Mud proportion: 4% normal bentonite, 0.15% salt resistance tackifier, 0.15% lubricant.
Mud parameter: Marsh funnel viscosity 55S-65S, apparent viscosity 26mpa.s, plastic viscosity 12mpa.s，yield value 8pa.
Picture 11： Prepare before pull the pipe
Picture 12: Pulling the pipe starts.
Picture 13: Pulling pipe going on
Picture 14: Pulling pipe succeeds-the moment out from ground
Picture 15: Owner construction unit take photos with machine
In the process of silty fine sand with thin layer of clay, part backfill crushed stone project, the mud use is very important, strong compressibility of strata can reduce reaming times, and construction continuity is very important.
This project is finished by Goodeng GD3500-LS horizontal directional drilling machine, which is the most difficult, longest crossing distance trenchless pipeline project among the same diameter in Taiwan, sets up the standard for complicated strata, long distance crossing, lays a solid foundation for mainland hdd machine into Taiwan market.