Tubing and Tubing String Design
1239
W,
=
(Wpe
x
L)
+
e,
where W,
=
calculated weight of a piece of pipe of length
L
in lb (kg)
Wpe
=
plain-end weight in lb/ft (kg/m)
L
=
length of pipe, including end finish, as defined below in ft (m)
e,
=
weight gain or loss due to end finishing in lb (kg) (for plain-
6.
Length.
Pipe shall be furnished in range lengths conforming to the following
as specified on the purchase order: When pipe is furnished with threads
and couplings, the length shall be measured to the outer face of the
coupling, or if measured without couplings, proper allowance shall be made
to include the length of the coupling. For integral joint tubing, the length
shall be measured to the outer face of the box end.
end pipe, e,
=
0)
Pipe Range Lengths
Range
1
Range
2
Total range length' 20-24 28-32
Permissible variation, max. 2 2
Permissible length, min.
20 28
Range length
for
100%
of
carload:+
'By agreement between purchaser and manufacturer, the total range length for
Range
1
tubing may
be
6.10-8.53
m.
'Carload tolerances shall not apply to orders less than a carload shipped from the
mill. For any carload of pipe shipped from the mill
to
the final destination without
transfer or removal from the car, the tolerance shall apply to each car. For any order
consisting of more than a carload and shipped from the mill by rail, but not to the
final destination in the rail cars loaded at the mill, the carload tolerances shall apply
to the total order, but not to the individual carloads.
Performance Properties
Tubing performance properties, according to API Bulletin 5C2, 18th Edition
(March 1982), are given in Table
4-167.
Formulas and procedures for calculating
the values in Table
4167
are given in API Bulletin 5C3, 3rd Edition (March
1980).
Running and Pulling Tubing
The following are excerpts from "API Recommended Practice for Care and
Use of Casing and Tubing," API RP
5C1,
12th Edition (March 1981).
Preparation and Inspection before Running
1.
New tubing is delivered free of injurious defects as defined in API Standard
5A, 5AC and 5AX, and within the practical limits of the inspection
procedures therein prescribed. Some users have found that, for a limited
number of critical well applications, these procedures do not result in
casing sufficiently free of defects to meet their needs for such critical
applications. Various nondestructive inspection services have been employed
by users to assure that the desired quality of tubing is being run. In view
of this practice, it is suggested that the individual user:
(text continued on page
1246)