Commentary on CSA Z662, Oil and gas pipeline systems

1.1

• The scope statement indicates which aspects and parts of pipeline systems and which service fluids are

covered by the Standard.

• Carbon dioxide was added as a new service fluid in 1996. The definition of “gas” was changed in

1983 to accommodate the coverage of gaseous service fluids other than fuel gas and sour gas;

however, until 1996, none had been added.

• The carbon dioxide pipelines that are covered are those onshore pipelines that are for use in enhanced

oil recovery operations, involving the transportation of high-purity carbon dioxide from a suitable

source to the injection site at an oil well. These pipelines were added to the Standard because it was

considered that there had been sufficient experience with such an application to warrant their

inclusion. Pure carbon dioxide is non-toxic and non-flammable; however, it has some specific

characteristics that necessitated the addition of requirements specific to carbon dioxide pipeline

systems. It should be noted that the definition of a carbon dioxide pipeline system permits the service

fluid in such a pipeline to be other than pure carbon dioxide, so additional special requirements are in

some cases appropriate.

• It should be noted that carbon dioxide might additionally be present in conventional pipelines as a

component of a multiphase fluid or as a component of a fluid in a gas pipeline system. For such fluids,

the conventional requirements applicable to the multiphase liquid or gas pipeline system continue to

be appropriate.

1.2

The parts of pipeline systems that are included in the scope are listed here, and the pictorial

representations in Figures 1.1, 1.2, 11.1 to 11.5, and 12.1 are intended to augment the information

provided in Clauses 1.2 and 1.3. The figures are schematic and are intended to convey broad functions

rather than specific details.

1.3

The parts of pipeline systems that are not included in the scope are listed here, along with a list of some

related items that are beyond the defined limits of pipeline systems. Items that are within the defined

limits of pipeline systems but are currently outside the scope of the Standard could be included in the

scope in some future edition of the Standard, should the CSA Technical Committee on Petroleum and

Natural Gas Industry Pipeline Systems and Materials and the Strategic Steering Committee on Petroleum

and Natural Gas Industry Systems deem that such additions to the scope are appropriate.