ISO 10427-1:2001 pdf download

ISO 10427-1:2001 pdf download.Petroleum and natural gas industries一
Equipment for well cementing一 Part 1: Casing bow-spring centralizers.
This pert of ISO 10427 provides minimum performance requirements, lest procedures and marking requirements for casing bow-spring cenb-zers for the petroleum and natural gas industries. Th. procedures provide venficabon lestmg for the manufacture?s design. materlale and process speafications. and periodic testing to confirm the consistency of product performance.
This part of ISO 10427 is not applicable to rigid or positive centralizers.
2 NormatIve reference
The following nonnatrve document contains provisions which, through reference In tis text constitute provisions of this part of ISO 10427, For dated references, subsequent amendments to. or revisions of, any of these publications do not apply, However, parties to agreements based on this part of ISO 10427 are encotaged to investigate the possibility of applying the most recent editions of the normative documents indicated below. For undated references, the latest edition of the normative document referred to applies. Members of ISO and IEC maintain registers of cisrently valid International Standards.
ISO 11960, Petroleum and natural gas industries — Steel pipes for use as casing or tubing for iveUs
3 Terms and definitions
For the purposes of this part of ISO 10427, the following terms and definitions apply
3.1
flexed
condition of a bow spring when a force three times the spedlied minimum restoring force (±5 %) has been applied ID It
3.2
holding device
device employed to b the stop collar or centralizer to the casing
EXAMPLES Set screws. i. mechanical dogs and epoxy resins.
3.3
holding forc.
maxmum force requfred to initiate slippage of a stop collar on the casing
3.4
hole size
diameter of the welbore
3.5
restoring force
force exerted by a centralizer against the casing to keep it away from the welibore wall
NOTE Restoring force values can vary based on Installation methods.
3.6
rigid centralizer
centralizer manufactured with bows that do not flex
3.7
running force
maximum force required to move a centralizer through a specified welibore diameter
NOTE Running-force values can vary depending on the installation methods.
3.8
standoff
smallest distance between the outside diameter of the casing and the weilbore
3.9
standoff ratio
ratio of standoff to annular clearance
NOTE it 1S expressed as a percentage.
3.10
starting force
maximum force required to insert a centralizer into a specified weilbore diameter
NOTE Starting-force values can vary depending on the installation methods.
3.11
stop collar
device attached to the casing to prevent movement of a casing centralizer
NOTE A stop collar can be either an independent piece of equipment or integral with the centralizer.
4 Requirements
4.1 Functions of a centralizer
The purpose of a casing centralizer is to facilitate running casing to the desired depth and to assist in centring the casing in the wellbore. One of the main objectives of centralizing a casing string is to facilitate a good cementing, thereby isolating fluids from different zones. A bow-spring centralizer can be constructed in various ways, using various types, shapes and quantities of bow spring.
4.2 Starting force
The maximum starting force shall be less than the weight of 12,19 m (40 ft) of casing of medium linear mass as defined in Table 1. The maximum starting force shall be determined for a centralizer in new, fully assembled condition.
4.3 RestorIng force
The minimum restoring force for a 67 % standoff ratio shall not be less than the values shown in Table 1. See A.2 for the derivation of the requirements.