CSA Group CSA Z341 Series:26 Storage of hydrocarbons in underground formations

Preface

This is the seventh edition of CSA Z341 Series, Storage of hydrocarbons in underground formations, which consists of CSA Z341.1, Reservoir storage, CSA Z341.2, Salt cavern storage, and CSA Z341.4, Salt cavern waste disposal. It supersedes the previous editions published in 2022, 2018, 2014, 2010, 2006, and 2002. It also replaces CSA Z341, published as a single Standard in 1998 and 1993.

This Series of Standards covers the storage of hydrocarbons and wastes from hydrocarbon production in naturally formed geological reservoirs and solution-mined salt caverns. This Series is intended to establish essential requirements and minimum standards for the design, construction, operation, maintenance, abandonment, and safety of underground storage systems. Users are reminded that this Series is not a design handbook; it is necessary to exercise competent engineering judgement in conjunction with its use.

Changes to this edition include the following:

a) CSA Z341.1:

i) Clause 3 (definitions);

ii) Clauses 6.3.2.2 (casing connection selection);

iii) Clause 7.8.5 (casing repair);

iv) Clause 10.1.3 (workover procedures); and

v) Clause 10.1.4 (wireline and logging procedures).

b) CSA Z341.2:

i) Clause 3 (definitions);

ii) Clauses 6.3.2.2 (casing connection selection);

iii) Clause 7.7.5 (casing repair);

iv) Clause 10.1.4.1 (workover procedures);

v) Clause 10.1.5 (wireline and logging procedures); and

vi) Clause 10.2.7.1 (10-year workover).

c) CSA Z341.4:

i) Clause 3 (definitions);

ii) Clauses 6.3.2.2 (casing connection selection);

iii) Clause 7.7.5 (casing repair);

iv) Clause 10.1.4.1 (workover procedures);

v) Clause 10.1.5 (wireline and logging procedures); and

vi) Clause 10.2.7 (10-year workover).

Annex A in each Standard provides commentary that complements and clarifies the clauses of CSA Z341.1, CSA Z341.2, and CSA Z341.4.

The requirements of this Series are adequate under conditions normally encountered in the storage industry. Requirements for abnormal or unusual conditions are not specifically addressed, and complete details of engineering and construction are not provided. It is intended that all work performed within the scope of this Series will meet or exceed the safety standards expressed or implied in the Series. It is possible that changes will have to be made based on new experience or technology, or both. When necessary, amendments will be issued by CSA.

This Series of Standards was prepared by the Technical Committee on Storage in Underground Formations, under the jurisdiction of the Strategic Steering Committee on Liquid and Gaseous Energy Systems, and has been formally approved by the Technical Committee.

Notes:

1) Use of the singular does not exclude the plural (and vice versa) when the sense allows.

2) Although the intended primary application of this Series of Standards is stated in its Scope, it is important to note that it remains the responsibility of the users of the Series to judge its suitability for their particular purpose.

3) This Series of Standards was developed by consensus, which is defined by CSA Policy governing standardization — Code of good practice for standardization as “substantial agreement. Consensus implies much more than a simple majority, but not necessarily unanimity”. It is consistent with this definition that a member may be included in the Technical Committee list and yet not be in full agreement with all clauses of this Series of Standards.

4) A request for interpretation can be submitted to clarify the meaning of a provision in this Series of Standards. To submit a request for interpretation, please refer to www.csagroup.org/request-for-interpretation. Committee interpretations are processed in accordance with the CSA Directives and guidelines governing standardization and are available on the Standards Activities page at standardsactivities.csagroup.org.

5) This Series of Standards is subject to review within five years from the date of publication. Suggestions for its improvement will be referred to the appropriate committee. To submit a proposal for change, please send the following information to [email protected] and include “Proposal for change” in the subject line:

a) Standard designation (number);

b) relevant clause, table, and/or figure number;

c) wording of the proposed change; and

d) rationale for the change.

1 Scope

1.1 Minimum requirements

This Standard sets out minimum requirements for the design, construction, operation, maintenance, abandonment, and safety of hydrocarbon storage in underground reservoir formations and associated equipment. The equipment considered includes

a) storage wellhead and Christmas tree assemblies;

b) wells and subsurface equipment; and

c) safety equipment, including monitoring, control, and emergency shutdown systems.

Hydrocarbons covered by this Standard are restricted to natural gas.

1.2 Scope diagram

The scope of this Standard is shown in Figure 1.

1.3 Exclusions

This Standard does not apply to

a) underground storage facilities for gases or fluids other than hydrocarbons, such as storage facilities used for air storage, unless these fluids are used specifically for the displacement of stored hydrocarbons;

b) underground storage facilities used for storing substances other than hydrocarbons, such as reaction chambers and waste disposal facilities;

c) underground storage in overburden materials involving the use of tanks, such as gasoline tanks;

d) the design and fabrication of pressure vessels that are covered by pressure vessel codes;

e) heat exchangers, pumps, compressors, and piping in processing plant facilities, manufacturing plants, or industrial plants that are covered by appropriate codes;

f) gathering lines, flow lines, metering, compressors, and associated surface equipment beyond the first emergency shutdown valve (ESV) or block valve; and

g) the storage of hydrocarbons containing hydrogen sulphide in concentrations greater than 10 mol/kmol.

1.4 Innovations

It is not the intent of this Standard to prevent the development of new equipment or practices, or to prescribe how such innovations should be handled.

1.5 Precedence

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 Applicability

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 Commentary

Annex A contains a commentary to some of the clauses of this Standard.

1.8 Terminology

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.