SPECIFICATION FOR ROTARY DRILL STEM ELEMENTS 15
Annex A (informative)
Tables in US Customary units
Revise Table A.18 to Annex A to read as follows:
Table A.18 — Mechanical properties for new non-magnetic drill collars
Drill collar OD range
in. 2 3/4 through 3 7/8 4 through 6 7/8 7 through 11
Yield Strength
psi min. 120 000 110 000 100 000
TensileStrength\\
psi min. 130 000 120 000 110 000
Elongation stainless
steel collars
% min.
16 18 20
Elongationnon-ferrous collars % min.
13 13 13
Add the following new tables to Annex A:
Table A.31 — Impact energy of non-magnetic steels
Material type Non-magnetic steel Non-magnetic steel Non-magnetic steel Non-ferrous alloys
Yield strength range 100 000 – 140 000 psi 140 000 – 160 000 psi
> 160 000 psi > 100 000 psi
Minimum impact energy
60 ft-lbs 50 ft-lbs 40 ft-lbs 30 ft-lbs
Table A.32 — Sampling requirements
Maximum Diameter of forging or bar
3
All dimensions are in inches
Radius of Sampling in neck region
31
< 7 /8 1 /8
7 /8 to 9 /8 inclusive 9 /4 to 20 inclusive
>20
33
5
2 /4 3 3 /2
1
Table A.33 — Neck lengths
Location Upper Neck
Lower Neck, String stabilizer Lower Neck, Near-bit stabilizer
All dimensions are in inches
Minimum lengths 30 minimum 24 minimum 18 minimum
16 ADDENDUM 3 TO ANSI/API SPECIFICATION 7-1/ISO 10424-1
Table A.34 — Neck diameters and connections
Neck Diameter 4 /4 6 /2 6 /4 8 8
11313
All dimensions are in inches
Connection, Box x Pin
NC38 NC46 NC50
555555
Connection, NBS lower 3-/2 REG 4-/2 REG 4-/2 REG
555555111
Inside Diameter
2
13131313
Blade Diameter 5 /8 to 7 /8
1
7
1
3
2 /16 7 /2 to 7 /8 2 /16
8 to 9 /8
1
1
515
5
6-/8REG 6-/8 REG 6-/8 REG
7-/8 REG 7-/8 REG 7-/8 REG 8-/8 REG 8-/8 REG
2 /16 9 /2 to 15 /2 2 /16 15 /8 to 20 3 3 3
12 /4 to 20 15 /8 to 26 20 to 26
9 /2 7-/8 REG 9 /2 7-/8 REG 9 /2 to 11
11
1
7-/8 REG 8-/8 REG
3 >26
Table A.35 — Blade dimensions
All dimensions are in inches
Up-hole and downhole
a
blade taper angles Blade diameter (in.) +0/–1/32 Number of Blades Integral Number of Blades Welded Blade width (integral) ± .25 Blade width (welded) ± .25 Crown length min ( see note)
30 ± 5 degrees integral 30 - 45 degrees welded
/2 to 9 /25 /8 to 7 /8 7 3
3
1311
9 /8 to 12 /4 12 /8 to 14 /8 14 /4 to 20
3 or 4
3 or 4
3 or 4
51353
>20
3 3 3 3 3 3 4
2 2.5 3 3.5 4 4 1.5 2 2 2.5 3 3 12 16 18 18 20 20 NOTE The crown also may be tapered at customer’s option to form “watermelon geometry” as in Figure 4. The crown length includes the
length of this shallow taper.
a The taper angle requirement applies only for the first 1 in. radially from the blade surface. If the blade height exceeds 1 in., the taper angle for the remainder of the height may be up to 45 degrees at the manufacturer’s discretion. See Figure 14.
Table A.36 — Blade spiral definitions
Spiral Description Straight blade Open spiral Full spiral Tight Spiral
Wrap Angle (see Figure 12)
Not applicable 180 – 220 degrees 300 – 350 degrees 500 – 600 degrees
SPECIFICATION FOR ROTARY DRILL STEM ELEMENTS 17
Add the following new Annex C.
Annex C (informative)
Summary of Product Specification Level (PSL) requirements
C.1 General
Certain tools are often used in the drill stem that are not directly covered by this international standard. To help the user insure these tools will provide a minimum level of performance, this annex is provided to identify additional requirements when products are ordered to PSL – 1 which defines the material property.
C.2 Large cross section specialty tools
These tools have a major diameter greater than 280 mm (11 in.) or tools with a change of 75 mm (3 in.) or more in outside diameter over the length of the tool and are not covered elsewhere in this international standard.
C.3 Material heat treatment
C.3.1 Low alloy steel
Tools manufactured from low-alloy steels shall be quenched and tempered. The heat treating process may be either batch or continuous. All testing shall be performed after final heat treatment.
If the starting material is bar stock that has been heat treated full length and has been tested at a depth equal to or greater than the depth at the critical location (see sub-clause C.4) and meets the required mechanical properties, the material may be used without further heat treating.
If the material does not meet the required mechanical properties at the critical location, the material shall be heat treated and tested after final heat treatment. The mechanical test specimens shall be removed from a prolongation, a sacrificial part or a qualification test coupon (QTC) as described below to verify the tensile, yield, impact and hardness properties at the critical location. Material may be rough machined prior to heat treating.
C.3.2 Non-magnetic materials
Non-magnetic materials shall be solution annealed and cold or warm worked. All testing shall be performed after solution annealing and cold or warm working.
C.4 Critical locations
Critical locations are areas on the part where the stresses from service loads are the highest. These locations are the most likely locations for in-service failures. The product designer shall be responsible for identifying the critical location in the product design. The manufacturer shall be responsible for verifying that the mechanical properties are met at the critical location.
C.5 Mechanical test specimens
For heat treated material, either batch or continuous, the mechanical test specimen shall be removed from a sacrificial production part, or from a prolongation removed from a production part, or from a Quality Test Coupon (QTC) from the same heat.
18 ADDENDUM 3 TO ANSI/API SPECIFICATION 7-1/ISO 10424-1
When required, the product designer may specify that the test specimen shall come from a sacrificial production part, or from a prolongation removed from a production part, or if a Quality Test Coupon (QTC) is to be used. If not specified by the product designer, the choice shall be at the discretion of the manufacturer.
C.5.1 Sacrificial production part
If a sacrificial production part is used to obtain the test specimens, it shall only be used to qualify parts that have the same dimensions at the time of heat treating and are of the same heat of material. The specimens shall be removed from the critical location identified in the part design.
C.5.2 Prolongation
If the test specimens are to be taken from a prolongation of a production part, the prolongation shall have the same dimensions as the critical location identified in the part design and shall be long enough so the test specimens are located no closer than one-half radius to a heat treated end.
C.5.3 Qualification test coupon (QTC)
A QTC is a separate test coupon from the same heat of material as the production part and shall be heat treated in the same lot as the production part. The purpose of the QTC is to provide representative mechanical properties of the part being qualified. The geometry of the QTC shall be selected so that the heat treat response of the QTC simulates the heat treat response of the critical location of the part it qualifies. This is accomplished using the ER method described in sub-clause C.5.3.1. A hollow QTC shall only be used if the production part is hollow at the time of heat treatment.
Depending on the hardenability of a given material, the QTC results may not always correspond with the properties of the actual components at all locations throughout their cross-sections. C.5.3.1 ER Method
Most available data on heat treatment refers to round sections. If the production parts are not round at the critical location, the geometry at the critical location can be visualized as simple shapes such as squares, hexagons, plates or tubes that can be equated to an equivalent round (ER). The equivalent round has essentially the same cooling rate as the simple shape and the same response to heat treatment, so a QTC based on the ER of the critical location can be used to verify the mechanical properties.
The method used to determine the diameter of the equivalent round shall be in accordance with the technique outlined in SAE-AMS H-6875.
The ER of a part shall be determined using the actual dimensions of the part at the critical location and in the “as heat treated” condition.
The ER of a part has the same cross sectional area as the simple shape it replaces when the dimension “T” is the thickness of the part.
The ER of the QTC shall be equal to or greater than the dimensions of the part it qualifies. The ER is the diameter of the equivalent round that replaced the simple shape. The length of the QTC shall not be less than the calculated diameter of the ER.
The QTC shall only qualify production parts whose critical sections have the same or a smaller ER.
The total hot work ratio for the QTC shall not exceed the total hot work ratio of the part(s) it qualifies. The hot work ratio is the area ratio of the cast diameter and the pre-machined finished diameter. Figure B.1 illustrates the basic models for determining the ER of simple solid shapes.