Views: 10 Author: Site Editor Publish Time: 2017-12-11 Origin: Site
Project Name: outer net main line(power plant to bus terminal) Daqinggou Valley directional drilling and pipe pulling project
Owner Party: Henan Shangqiu Yudong Electricity Generating Co.,Ltd
Construction Contractor: Shandong Wendeng Wantong Civil Engineering Co.,Ltd
Project Feature: the Henan Shangqiu Daqinggou Valley Φ960mm*600 heating pipeline(steel pipe +insulation layer) directional crossing project fills in the blank in the case of large rig crossing the railway.
Geological Condition: the geological condition is complicated with quicksand.
Terrain Condition: the project requires crossing through the railway turning point and most of the pipeline is under the railway.
Project Difficulties: the difficulty of the project lies in the complicated geological condition underneath the railway with heavy quicksand, which makes it hard to reaming to form the hole. With the frequent passing by of trains, the possibility of hole collapse rises.
Picture1: Daqinggou Valley Terrain
2. Construction equipment
Horizontal Directional Drilling Machine: one set of Goodeng Machine GS4000-L
Picture 2：Goodeng Machine GS4000-L rig
Picture 3：Goodeng Machine GS4000-L rig
3. Technique support
Risk precaution: seamless working procedure to reduce the construction period.
Six-level reaming: 450mm, 650mm, 850mm, 1100mm, 1300mm, 1500mm six-level reaming.
Pulling pipe: 1300mm barrel reamer for pulling.
4. Construction process
Locating: taking 3 days, the average locating speed is 1 rod/5min, thrust&pull force 5Mpa, torque 5Mpa.
First level reaming: 450mm barrel reamer, torque 12-20Mpa, thrust&pull force 6-10Mpa, mud displacement 800L/min;
Second level reaming: 650mm barrel reamer, torque 12-18Mpa, thrust&pull force 8-12Mpa, mud displacement 800L/min;
Third level reaming: 850mm barrel reamer, torque 12-20Mpa, thrust&pull force 8-12Mpa, mud displacement 1000L/min;
Fourth level reaming: 1100mm barrel reamer, torque 12-20Mpa, thrust&pull force 8-12Mpa, mud displacement 1000L/min;
Fifth level reaming: 1300mm barrel reamer, torque 15-23Mpa, thrust&pull force 8-15Mpa, mud displacement 1200L/min;
Sixth level reaming: 1500mm barrel reamer, torque 15-23Mpa, thrust&pull force 8-15Mpa, mud displacement 1500L/min;
Cleaning hole: 1300mm barrel reamer, the cleaning speed is 1 rod/20min, mud displacement 1500L/min，torque 13-20Mpa, thrust &pull force 16-18Mpa;
Pulling pipe: the pulling started at 9am on Nov.26th, 2017 with pullback force 14-23 Mpa，torque 14-25 Mpa, mud displacement 1500L/min. The process finished at 8:45 am on Nov. 27th 2017, taking 23 hours 45 minutes in total.
Picture 4: Pilot Drilling
Picture 5: Reaming
Picture 6: Preparation for Pulling
Picture 7: Pulling Accomplishment
Bentonite consumption: 450 tons;
Slurry proportion: 4% ordinary bentonite, 0.15% salt-resistance tackifier, 0.15% lubricant;
Slurry parameters: Marsh funnel viscosity 55S-65S, apparent viscosity 26mpa.s, plastic viscosity 12mpa.s, yield point 8pa.
6. Project summary
The outer net main line(power plant to bus terminal) Daqinggou Valley directional drilling and pipe pulling project of Henan Shangqiu Yudong Electricity Generating Co.,Ltd is accomplished by Goodeng-made GS4000-L directional drilling machine, the success of the project fills in the blank in crossing underneath the railway, which sets the example for crossing under complicated condition and accumulates the precious experience in working under such condition.