CSA Z341.4-14

1.1 This Standard sets out the minimum requirements for the design, construction, operation, maintenance, abandonment, and safety of wells and associated equipment used to inject waste into underground salt caverns in a slurry form. The equipment considered includes (a) wellhead and Christmas tree assemblies; (b) wells and subsurface equipment; and (c) safety equipment, including monitoring, control, and emergency shutdown systems. Note: The scope of this Standard is illustrated in Figure 1. 1.2 Wastes within the scope of this Standard are substances generated from the exploration, production, drilling, completion, abandonment, processing, refining, transmission, or use of petroleum or petroleum products. Note: Examples include (a) drilling mud; (b) drill cuttings; (c) completion and stimulation waste; (d) produced sands; (e) tank bottoms; (f) crude oil-contaminated soil; (g) salt-contaminated soil; (h) brine pond bottoms; (i) water treatment sludge; and (j) blowdown from water coolers or steam generators. 1.3 This Standard does not apply to (a) underground disposal in overburden materials involving the use of tanks or membranes, such as landfills; (b) design and fabrication of pressure vessels that are covered by pressure vessel codes; (c) heat exchangers, pumps, compressors, and piping in processing plant facilities, manufacturing plants, or industrial plants that are covered by appropriate codes; (d) gathering lines, flow lines, metering, compressors, and associated surface equipment beyond the first emergency shutdown valve (ESV) or block valve; (e) radioactive fuel wastes; (f) biological wastes; (g) wastes that have a pH less than 4.5 or greater than 12.5; (h) wastes that have a flash point less than 60.5 °C; and (i) wastes containing hydrogen sulphide in concentrations greater than 10 mol/kmol. 1.4 It is not the intent of this Standard to prevent the development of new equipment or practices, nor to prescribe how such innovations should be handled. 1.5 Where the requirements of this Standard differ from the requirements of other Standards or Codes referenced herein, the requirements of this Standard take precedence. 1.6 The requirements of this Standard do not apply retroactively to existing installations and installations under construction at the time of publication, but they do apply to the extension, replacement, maintenance, and upgrading of such installations. 1.7 In this Standard, “shall” is used to express a requirement, i.e., a provision that the user is obliged to satisfy in order to comply with the standard; “should” is used to express a recommendation or that which is advised but not required; and “may” is used to express an option or that which is permissible within the limits of the Standard. Notes accompanying clauses do not include requirements or alternative requirements; the purpose of a note accompanying a clause is to separate from the text explanatory or informative material. Notes to tables and figures are considered part of the table or figure and may be written as requirements. Annexes are designated normative (mandatory) or informative (non-mandatory) to define their application.