Caloosahatchee ASR PIlot Project - EXBRY-1 well 2004-2008

The purpose of this project is to provide site-specific hydrogeologic information to
address storage zone selection and well capacity, and to obtain information concerning
confinement, hydraulic properties, lithology, and stratigraphic information about the
Floridan Aquifer System at the Berry Groves Site, in Hendry County, Florida. Data
collected from the testing and monitoring of the constructed exploratory well, coupled
with additional information from the other wells completed on site, will be instrumental in
the development of this project.
This report primarily describes the drilling, construction, and testing of the 24-inch Class
V exploratory well identified as EXBRY-1. Well EXBRY-1 is the designation assigned
by the Florida Department of Environmental Protection (FDEP) under permit number
201247-001-UC. The ASR pilot project site is on SFWMD-owned land referred to as
“Berry Groves”, adjacent to State Road 80 and just east of the Townsend Canal. The
site is accessible through Berry Groves citrus farm.
The scope of the investigation included drilling the test hole to a maximum depth of
1,398 feet, performing a geophysical logging program, setting 24-inch, 0.5-inch wall mild
steel casing to a depth of 634 feet, and performing reverse air drilling and testing to total
depth to identify an appropriate ASR storage interval. Significant drilling difficulties were
encountered between 650 and 900 feet below land surface (bls) due to unconsolidated
sediments and high sand production associated with caving of the wellbore. In the end,
the total depth of the well remained slightly deeper than 650 feet bls due to continued
sloughing of very fine “sugar” sand into the wellbore.
The main findings from this exploratory well include:
• The top of the FAS was identified at a depth of 520 feet bls based on log
interpretation and correlation with nearby wells.
04792RGG.B0105.doc
• Lithologic descriptions and geophysical logs were not sufficient to identify the
boundary of the flow zone intercepted in the subsurface near 634 feet bls, but the
geophysical logs were especially useful in identifying the troublesome sand
producing intervals encountered when drilling by reverse-air circulation.
• Specific capacity testing performed during reverse-air drilling indicated the existence
of a good flow zone that appears to be below 634 feet bls. Specific capacity values
ranged up to 35 gpm/ft for the interval between the base of casing and 900 feet bls.
The final value of specific capacity for the interval immediately below the casing, 634
to 658 feet bls, measured 23 gpm/ft.
• Analysis of the data developed from an Aquifer Performance Test (APT) performed
at the end of well construction indicated that a flow zone was intercepted near the
base of the casing. The transmissivity of the flow zone, from the hydraulic analysis,
was determined to be approximately 20,000 gpd/ft (2,700 ft
2
/d).
• Water quality data indicate that the potential storage interval has a TDS value near
2,000 mg/l and a chloride level near 900 mg/l. This water quality is excellent for
highly efficient recovery if other formation attributes are good.