Three years of planning and preparation bore fruit in the late winter of 2022-2023, as WellJet® mobilized personnel and equipment from California, across the fruited plain, to New England.
Specifically, New Haven, Connecticut. Birthplace of the Knights of Columbus, Yale University, and Frank Pepe’s legendary pizzeria. Founded in 1638, New Haven is also home to the South Central Connecticut Regional Water Authority (RWA), a nonprofit corporation that provides 45 million gallons a day of water and related services to 430,000 consumers in the region. Staffed by experts known for both their experience and innovation, RWA consistently pursues a Best Practices approach to operating and maintaining the wells that serve the community.
WellJet® was invited to participate in a multi-well rehabilitation project for RWA. The targets were three older wells, two of which had been drilled in the 1960s (since fitted with stainless steel liners, tending to reduce performance), and the third that was situated close to the Housatonic River and suffered from biofouling and high concentrations of manganese. All three wells had suffered significant declines in production and efficiency and were considered difficult to restore.
WellJet® (USPatent No. 8,312,930 B1) has built its global reputation as the world’s leading practitioner of high-pressure hydrojetting for water well development and rehabilitation by improving flow rates and efficiency in just such “difficult to restore” wells. Over the past decade, WellJet® has developed and rehabilitated more than a thousand wells throughout California, Arizona, Nevada, Colorado, Utah, Texas, Hawaii and the Middle East. No other tool or process is capable of matching WellJet’s ability to generate energy downhole to remove encrustation, open clogged perforations, and break down harmful deposits in the filter zone and near-wellbore formation that impede free water flow. This unique ability is especially useful in lined or sleeved wells.
The rehabilitation team consisted of RWA, SB Church (driller/pump company), HydroPressure Cleaning, Inc. (HPC/WellJet®), and WSP engineering and professional services. Groundwater Science, an independent consulting firm based in Ohio, was present to observe the process and evaluate the results.
Communication and collaboration among the team proved invaluable, as the scope of work changed based on discoveries and data collected in the field while the rehabilitations were under way.
The wells were all contained inside structures, with the difficult access addressed by the use of HPC’s purpose-built quadropod to make possible the WellJet® high-pressure hydrojetting process.
The general rehabilitation procedure involved pump removal, downhole video, sodium hypochlorite treatment, high-pressure hydrojetting by WellJet®, cleanout surge-and-airlift, additional jetting, and then physical and chemical redevelopment.
The liners in NSG-2 and NSG-1 (which had just been installed) demanded high pressure (15,000-18,000 psi) and multiple passes with the jetting tool, to generate energy beyond the screens and gravel packs, into the near-wellbore formation to break down harmful deposits impeding free water flow. Seymour #5, a more delicate well with no gravel pack below 83’, required different tooling and a single pass at lower pressure (5,000 psi).
SB Church performed the non-jetting services, under the supervision of RWA personnel, with consulting from WSP.
The WellJet® process was dramatically successful on two of the three wells (NSG #2 and Seymour #5). Results were less impressive on NSG #1, although the recent installation of the liner prevented a true apples-to-apples comparison, as all prior performance data was gathered before the liner had been installed.
When considering this positive outcome on NSG #2, Jim Hill, Director of Operations at SCCRWA, said: “If we’d known about WellJet 10 years ago, we could have saved the trouble and expense of drilling a new replacement well.”
When asked if it was worth it to bring WellJet® all the way across the country to help rehabilitate RWA wells, Jim Hill said: “Let’s do it again!”
Read more here: https://www.welljetbyhpc.com/case-studies/connecticut-rwa-case-study/
