NKKT Document No DSTJ-005 Rev.0 Dec.24 1996 Rev.1 Mar. 6 1997

Rev.2 Jul. 2 2007

Approved by K.Sakura Sheet 1 of 5

05 Field Inspection Recommendation Procedure DSTJ Rev2.doc

Field Inspection Recommended Procedure of NK-DSTJ Tool Joint

1. Field Inspection of the NKK DSTJ High Rotary Connectiona) DSTJ is modified API Connection and interchangeable with the same API connection.- See Appendix 1.b) The inspection of the DSTJ connection except the items described in this procedure

shall be carried out in accordance with API RP7G by experienced inspectors.

1.1. Box connection- Visual /Dimensional Inspection- See Appendix 2.

Box-External Seal Shoulder : Sealing Shoulder and Torque Stop ShoulderBox-Internal Seal Shoulder : Torque Stop Shoulder

a) The thread elements, B-ESS, bore-back and the B-ISS must be thoroughly cleaned with a rotary power wire brush in order to remove dope, dirt, rust, mud, etc. to enable a good visual inspection of all above mentioned areas.

b) The thread profile must be checked with the appropriate API profile gauge.c) Check boxes for widening (swelling)- See API RP7G Para.13.3.2d) The B-ISS is not a sealing shoulder. Light corrosion or indentations without protrusion

are acceptable.e) The depth of the box shoulder should be measured using depth micrometer.- See Appendix 3.

Measured data should be recorded.f) Field re-facing of the B-ESS and B-ISS is not be permitted.- B-ESS and B-ISS with damages within the re-facing limits shall be identified with a

green band around the box OD to be refaced in a NK- DSTJ licensed machine shop.-

B-ESSB-ISS

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1.2. Pin Connection- Visual /Dimensional inspection- See Appendix 2

Pin-External Seal Shoulder : Sealing Shoulder and Torque Stop ShoulderPin-Internal Seal Shoulder : Torque Stop Shoulder

The thread elements, P-ESS and P-ISS must be thoroughly cleaned with a rotary power wire brush in order to remove dope, dirt, rust, mud, etc to enable a good visual inspection of all above mentioned areas.

a) Check the thread profile with the appropriate API profile gauge and for pin elongation.- See API RP7G Para. 13.3.2

b) The P-ISS is not a sealing shoulder, light corrosion or indentations without protrusion are acceptable. Proud mechanical damages must be removed using a fine file.

c) The length of the pin shoulder should be measured using depth micrometer.- See Appendix.3

Measured data should be recorded.d) Field re-facing of the P-ESS and P-ISS is not permitted.- P-ESS and P-ISS with damages within the re-facing limits shall be identified with a

green band around the pin OD to be refaced in a NK-DSTJ licensed machine shop.

1.3. Generala) The external surface of widened boxes and the threaded area of elongated pins shall

be inspected by MPI Black-Light for longitudinal cracks on the box and transverse cracks in the thread roots prior to sending to a machine shop for re-cutting.

b) A red band around the box or pin tool joint is identified as the connections to be recut. All connections rejected by a inspection crew should be re-inspected by a inspection supervisor.

P-ESS

P-ISS

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c) The inspection report with serial number of the drill pipes on which repairs of connections are required shall be submitted to the machine shop for information.

d) The good connection shall be well doped with specified compound and clean thread protectors that shall be wrenched tight installed and sealed.

- Damaged or deformed thread protectors should not be installed.

Appendix 1

DSTJ Interchange abilityDSTJ NC38 with API NC38DSTJ NC40 with API NC40DSTJ NC46 with API NC46DSTJ NC50 with API NC50DSTJ NC 5-1/2FH with API NC 5-1/2FH

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Appendix 2

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Appendix 3

Connection Depth of Box Length of Pin(MM) Min. Max. Min. Max.

DSTJ NC38 111.85 112.15 111.65 111.92DSTJ NC40 124.85 125.15 124.65 124.92DSTJ NC46 124.85 125.15 124.65 124.92DSTJ NC50 124.85 125.15 124.65 124.92DSTJ 5-1/2FH 137.85 138.15 137.65 137.92DSTJ 5-3/4FH 137.85 138.15 137.65 137.92

Connection Depth of Box Length of Pin(inch) Min. Max. Min. Max.

DSTJ NC38 4.404 4.415 4.396 4.406DSTJ NC40 4.915 4.927 4.907 4.918DSTJ NC46 4.915 4.927 4.907 4.918DSTJ NC50 4.915 4.927 4.907 4.918DSTJ 5-1/2FH 5.427 5.439 5.419 5.430DSTJ 5-3/4FH 5.427 5.439 5.419 5.430