Drilling Case Studies

Major Oil Storage Terminal Remediation Infrastructure Installation and Investigation – Craning the Rig into Tight Spaces        top

Aztech Technologies installed a series of two-inch and four-inch ID stainless steel remedial wells in the footprint of a four-acre petroleum product plume. The wells were installed for the purpose of free product recovery via down well pumps and soil vapor extraction. The stainless steel remedial wells were completed at depths ranging between 12 feet and 25 feet below grade in boreholes that were continuously sampled to depths as much as 32 feet below grade depending on their location. Several of these remedial wells were installed inside of the secondary containment areas of two major oil storage terminals and many of these locations were situated between aboveground tanks with working spaces tighter than 60 inches in width. Our 48” wide track-mounted drill rig was placed into locations between tanks via crane and navigated over the aboveground piping on a system of cribbing and temporary bridges that were designed and constructed by Aztech Technologies.

Landfill Site Investigation – Borings Cased through Liner        top

Aztech Technologies installed ten four-inch inside diameter (ID) protective PVC casings through an industrial landfill constructed for storage of PCB-impacted soil. The borings were advanced via 6-5/8 inch hollow stem augers. One split spoon sample was collected from the first four feet in order to verify the presence of the landfill capping material. The hollow stem augers were subsequently advanced to a depth of approximately 15 feet where continuous split spoon sampling commenced. The boreholes were continued incrementally until they were advanced two feet into the clay liner material. Four-inch ID PVC casing was subsequently installed inside of the hollow stem augers and seated into place. A cement-bentonite grout mixture was tremied into the annular space between the borehole walls and the PVC casing as the augers were withdrawn from the borehole. This technique ensures that the casing is sealed into the borehole and prevents leakage of potentially PCB-impacted liquids from the bottom of the landfill. Aztech returned to the site in the following weeks to collect 2-¼ inch diameter MacroCore samples at each cased location using direct push technology, from the native soils below the landfill liner. After completing the soil sampling, each boring was tremied with a cement-bentonite mixture to extend up into the protective casing.

Chemical Facility Supplemental Investigation – Bedrock Coring and Wells        top

Aztech Technologies installed a series of overburden monitoring wells and direct push soil borings that included collection of both continuous and depth-discrete soil and/or groundwater samples. The scope of work also included completion of monitoring wells within the bedrock/overburden interface as well as cased bedrock monitoring wells. The cased bedrock monitoring wells were completed by tremie grouting a four-inch steel casing into a “rock socket”, and obtaining bedrock cores after the grout mixture had sealed the steel casing into the rock socket. Well depths associated with this project ranged from 15 to 82 feet below grade.