NASA Facility Gets Horizontal Well Rehabilitation Overhaul
by Seth Croy
Mineral scaling and biofouling impacted the operation of a groundwater pump and treat system at an active NASA facility in Louisiana. The horizontal groundwater extraction well that was affected had approximately 270 feet of screen and experienced a reduction in flow of over 50% of its capacity.
The horizontal well had been installed 15 years earlier by another company. Mineral scaling and encrustation happen over time due to the chemistry of the groundwater. The bio-fouling is believed to be the result of the last section of the well screen being above the water table.
Directional Technologies, Inc. performed a series of redevelopment activities, both mechanical and chemical:
• Brushing
• Jetting and flushing
• Surging
• Air-Lifting
• Acid treatments
• Dispersant treatment
Photo 1: Initial Well Returns – Black and Green Returns
Photo 2: Returns after 1st Acid Treatment
A directional drilling rig was brought in to re-enter the horizontal well with a special horizontal well rehabilitation tool. This tool, consisting of brushes with jets and rubber spacers to concentrate the flow for surging, was used for the mechanical cleaning of the well. Chemical treatments combined two acids – one to dissolve mineral scaling, and one to destroy the bio-fouling. Treatments also included a chemical to disperse clays and sediments, both within the well casing and the sand pack of the screen.
During the rehabilitation activities, positive indicators included particulates flowing back to surface, with a clarification of the water. Also, a strong sulphur odor was observed after initial acid treatments, indicating the destruction of bacteria. Reverse pump testing was performed to gauge improvement throughout the rehabilitation process. From the first to the last treatment, a 58% increase in flow was observed.
Photo 3: Entering Well with Well Cleaning Tool
Directional Technologies’ goal for each project is to ensure that your project is a success. Since Directional Technologies has installed over 1,000 horizontal wells and has kept in contact with our clients over the last 25 years, we take a more proactive approach in the beginning. We start with well placement design, include horizontal well screen design, add precision horizontal well installation and finally provide expert support and guidance for Operations and Maintenance if needed. Directional Technologies, Inc. is the only company that can provide all areas of services for Horizontal Remediation Wells. By applying a quarter century of experience and wisdom in these interworking areas, Directional Technologies can support your project from start to closure.
Photo 4: Chemicals Mixed Through a Hopper