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Petroleum Cleanup under Busy LA Intersection

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In March 2016, DTD completed three directionally drilled horizontal Soil Vapor Extraction wells at depths up to 55 feet beneath a busy intersection in the heart of Los Angeles. The fan-shaped array of horizontal remediation wells started in a small, corner parking area at a 24-hour gas station and convenience store, extending from 275 to 350 feet into the middle of the intersection. The horizontal wells will be used to reduce the mass of petroleum contamination that has migrated off-site from historic service station operations in the area.

Compact construction footprint enabled a busy Los Angeles gas station and convenience store to remain fully open during a Horizontal SVE Well Installation.

Compact construction footprint enabled a busy gas station and convenience store to remain fully open during well installation.

DTD mobilized one of our compact Vermeer 24×40 drill rigs for this project, which had been in planning and design phases for more than two years. Logistics were a major challenge – the gas station and convenience store are very active all day long. To minimize impacts on business and traffic on the adjacent street, DTD worked closely with our client to schedule work during off hours, from 8pm to 6am. With limited space available on site, the crew mobilized to an adjacent vacant lot secured by the consultant, using that lot for staging to the drill site itself. At the site, the rig, mud system, and waste collection systems were shoehorned into a small area, approximately 25 feet by 40 feet, to keep a small construction footprint and keep all gas pumps available for customers.


Night operations at convenience store

Night operations at convenience store

Considering the well locations beneath an active intersection, and with numerous utilities running down the street right of way, careful consideration was given to the selection of an appropriate locating system. Conventional walkover systems are frequently prone to signal and accuracy degradation due to interference from traffic signal control circuits and other sources. Coming off the recent success with the DCI Digi-Trak Short Steering Tool  (SST) at the Department of Energy site in Florida, DTD again selected the SST for this project. The ability to steer with precision along a predetermined azimuth, without the necessity to close the streets while locating personnel make locates in the street greatly reduced construction impacts on traffic patterns, and more importantly, greatly increased worker safety. The SST enabled DTD to complete a well in approximately three days. In total, the project required about two weeks to install, complete, and develop the three wells.  The system is expected to be operational within the next month.