Hydrologic detection of abandoned wells near proposed injection wells for hazardous waste disposal

Abstract

Deep saline aquifers are being used for disposal of hazardous liquid wastes. A thorough knowledge of the competency of such aquifers and their confining geologic beds in permanently isolating the hazardous substances is the key to successful disposal operations. Characterization of such systems, and in particular the detection of any conduit that may permit hydraulic communication between the host aquifer and nearby freshwater aquifers, must be carried out prior to the initiation of disposal projects. In deep, multi‐aquifer systems, leaky faults, abandonded wells, highly conductive fractures, or shear zones may all provide leakage paths. If not initially detected, such conduits may show no apparent effect until contaminants in the freshwater aquifer reach detectable levels at the discharge point. By then, of course, detection is generally too late. This paper is an attempt to address the problem of initial detection of improperly plugged or open abandoned wells. A new analytic solution has been derived to calculate the amount of leakage from an abandoned well and the corresponding drawdown at monitoring wells. A method is proposed that can be used to detect such deep abandoned wells in the area of influence of a proposed deep injection well in a multiple‐aquifer system.

Deep Injection of Waste Water in the Western Canada Sedimentary Basin

“…There is some potential for cross-formational flow (Tóth 1978) but a series of aquitards (Hendry et al 2013) will normally protect shallow groundwater resources. Attention must be given to pathways that allow for passage through these aquitards, such as improperly completed or abandoned wells (Javandel et al 1988;Gasda et al 2004) or faults, which commonly occur in association with dissolution of the Prairie Evaporite in the WCSB (Grasby and Chen 2005).…”

A harmonic pulse testing method for leakage detection in deep subsurface storage formations

“…A primary environmental concern of these practices is the potential migration of injected fluids through connected pathways (e.g., abandoned wells or geologic faults) into underground sources of drinking water. A number of previous works have focused on forward and inverse modeling of leakage from deep subsurface storage formations [e.g., Avci, 1994;Cihan et al, 2011;Javandel et al, 1988;Nordbotten et al, 2004;Sun and Nicot, 2012]. Most of these analyses assume passive monitoring, in which pressure gauges are simply used to ''listen'' for possible leak signals.…”

Hydraulic barrier design and applicability for managing the risk of CO2 leakage from deep saline aquifers

“…The idea was proposed by Javandel et al (1988), and Zeidouni & Pooladi-Darvish (2010a,b) recently developed a new analytical solution and proposed its inversion in a purpose of localization and leak characterization. One of their conclusions is that locating a leak using one single pressure signal is very unlikely.…”

“…They therefore do not focus their study on the time delay necessary for locating a leakage happening during storage operations. Zeidouni & Pooladi-Darvish (2010a,b) consider a 100 days injection and monitoring period, whereas Javandel (1988) presents recorded signals from 1 month to 1 year. We assume that the same order of magnitude -a few months-is necessary for characterizing an unexpected leak during a storage operation.…”