GEOSCAN Search Results: Fastlink

GEOSCAN Menu


TitlePlugging of an historic, high-flow, high-pressure, artesian flowing well, Coldstream, BC
AuthorSargent, N; Foley, J; Quail, N; Hinton, M; Ulmi, M; Hadzariga, M; Diggle, R
Source69th Canadian Water Resources Association National Conference, abstract book/69e congrès national de l'Association canadienne des ressources hydriques, livre des résumés; by Canadian Water Resources Association; 2016 p. 157-158
LinksConference
Year2016
Alt SeriesEarth Sciences Sector, Contribution Series 20160268
PublisherCWRA-ACRH
Meeting69th Canadian Water Resources Association National Conference
Documentbook
Lang.English
Mediaon-line; digital
File formatpdf
ProvinceBritish Columbia
NTS82L/03; 82L/06
AreaVernon
Lat/Long WENS-119.5000 -119.0000 50.5000 50.0000
Subjectshydrogeology; groundwater; groundwater resources; wells; artesian wells; aquifers; Coldstream Ranch Well; Water resources
ProgramCold Stream Remediation Project, GSC Pacific Division
AbstractIn 1965, the Geological Survey of Canada drilled an uncased stratigraphic bore (Coldstream Ranch Well; CRW) in the valley bottom on the Coldstream Ranch, near Vernon, BC. At approximately 60 m, a confined, flowing, artesian aquifer (the Lower Aquifer) was encountered resulting in a blow-out and uncontrolled flow estimated at 38 L/s (500 Igpm). A potential shut-in pressure of about 345 kPa (50 psi) was estimated from mud densities used to control the well. In 1965, three attempts to plug the CRW by grouting were unsuccessful despite the installation of numerous casings and pipes and two small diameter relief wells. Flow was eventually contained in 1966 by driving a 30-inch casing to a depth of approximately 46 m and by gravel backfilling and cement grouting a 9 to 10-m diameter crater formed as a consequence of erosion. By 1979, surface seepage had begun as a result of well clogging that ultimately required the installation of a 16-inch casing and well screen completed through the 30-inch casing to a total depth of 53 m. Although this configuration generally contained the water in the casings; once again, the well could not be shut-in and required continual discharge to Coldstream Creek. By 2009, well clogging and deterioration of the well resulted in variable flow and periodic turbid discharge. Options for addressing the CRW were reviewed in 2010 and included: 1) doing nothing; 2) attempting to kill the CRW down the centre of existing casings; and, 3) completing a pumped relief well (RW3) to stop the flow of the CRW and allow its grouting under non-flowing conditions. Based on risks and the potential for success, Option 3 was selected. To allow RW3 to be shut-in at the high pressures encountered in the CRW at relatively shallow depths, the design of RW3 comprised three concentric casings cemented in place using oil field pressure cementing techniques and completed with a well screen and packer system. The well was designed based on probable formation fracture pressures over the depth of interest. In 2013, RW3 was completed 5 m from the CRW. With the CRW flowing at approximately 38 L/s (500 Igpm), initial shut in pressures at RW3 were approximately 131 kPa (19 psi). Pumping tests of RW3 and a nearby municipal well in the Middle Aquifer proved that flow from the CRW could be stopped, allowing it to be grouted under quiescent conditions. In May 2015, the CRW was successfully abandoned. The compromised near surface aquitard was compaction grouted using Low Mobility Grout, placed through a total of eight holes around the CRW. The 16-inch well and well screen were pulled and the granular plug of Lower Aquifer material emplaced in the Lower Aquitard during the blowout of the CRW drilled-out to the top of the Lower Aquifer. The Lower Aquitard was then grouted up into the 30-inch casing. The 30-inch casing was perforated and filled with flowable grout. Following plugging, RW3 was shut-in with gauge pressures reaching 338 kPa (49 psi) and initial flows when RW3 was first opened up to 111 L/s (1500 Igpm).
Summary(Plain Language Summary, not published)
In 1965, the Geological Survey of Canada drilled an uncased bore hole (Coldstream Ranch Well; CRW) in a valley bottom near Vernon, BC. A buried layer of coarse gravel under high pressure was encountered resulting in uncontrolled flow at the surface. Several attempts to plug the CRW by grouting were unsuccessful. Flow was eventually contained in 1966 by driving in a 30-inch casing. By 1979, surface seepage had begun as a result of well clogging that ultimately required the installation of a 16-inch casing to restore flow. However, the well could not be shut-in and required continual discharge to Coldstream Creek. By 2009, deterioration of the well resulted in variable flow and periodic turbid discharge. Solutions to the problem were reviewed in 2010. A relief well (RW3) was constructed 5 m from the CRW in 2013. Pumping of this well along with other nearby wells in May 2015, stopped the flow in the CRW, allowing the successful abandonment of the CRW by the injection of grout in the CRW.
GEOSCAN ID299426