Formatted Title
A Novel Multi-Branch Horizontal Well Remediation Technology for In Situ Soil and Groundwater Remediation
Background/Objectives
Soil and groundwater contamination is a key issue in many brownfield redevelopment areas and active manufacturing facilities. Due to the limited stage area in some target remediation areas, especially at the active manufacturing facilities, it is particulaly difficult to use some large remediation equipment. Horizontal wells are considered a potential useful technology as thay can remediate the contamination areas located underneath buildings and other surface/subsurfcae obstacles.
Approach/Activities
A novel multi-branch horizontal well technology was developed to resolve some challenging conditions faced during the remediation of above-mentioned circumstances. This technology integrates vertical/horizontal directional drilling, high-pressure water jetting, rotary injection, and expansion double packer sealling technologies, in addition, relevant dosing and injecting equipment were also developed. A series of bench tests, above-ground tests, and field-scale tests were conducted to test drilling tool performance, driling accuracy, and the radius of influence (ROI) for reagent injection. Additionally, CFD model FLUENT was used to optimize the injection pressure,diameter and number of nozzles, as well as the interaction between inflated packers and surrounding formation. Comsol Multiphysic model was used to facilitae the design and optimize the multi-branch horizontal well and smulate the remediation performance.
Results/Lessons Learned
In one full-scale field test site, the results showed that one multi-branch horizontal well can remediate a contaminated area of over 3000 square meters (m2), and an ROI of 5 meters was achieved in low permeability formations with hydraulic conductivity values of 10-5cm/s or lower. This is believed to be th first multi-branch horizontal well injection technology application in the remediation field.