VISUAL THREAD IDENTIFICATION AND INSPECTION

(THE SNEPCO EXPERIENCE)

PRESENTED BY

MOGEKWU CHINYE KELVIN VENUE

HAVILAH ENERGY CONFERENCE ROOM

INTRODUCTION HEALTH AND SAFETY VISUAL IDENTIFICATION OF

CASING/TUBULARS API GRADES OF CASING VISUAL INSPECTION EQUIPMENT CHECK LIST VISUAL INSPECTION PROCESS TYPES OF CONNECTION DRIFTING VISUAL IDENTIFICATION OF THREADS THE END REFRESHMENT

OVERVIEW

API-AMERICAN PETROLEUM INSTITUTE CR-CHROME EU-EXTERNAL UPSET FGL-FIBER GLASS LINING IU-INTERNAL UPSET NU-NON UPSET SLHT-SEAL LOCK HIGH TORQUE TPI-THREAD PER INCH

COMMON ABBREVIATIONS

Oil country tubular goods form the bases of well construction, planning and budget. To that effect, the quality and efficiency of casing and Tubular has to be ascertained with a proper Identification and inspection process.

Visual Thread Inspection is the use of tools and techniques to visually check for thread damage which includes pitting, burr and galling.

INTRODUCTION

At stonewall Tech Nigeria Limited, we promote HSE culture as our core practice in operation handling and delivery.

We Observe our client company life saving rules in Health and safety.

Use of Tool Box talk as a key tool before commencement of operation.

Use of 5x5 Rules During accident or near miss.

HEALTH AND SAFETY

Casing and Tubing can be identified using the following characteristics.

Dimensions Coupling Stencil Body Stencil Colour Codes Thread pattern/profile

VISUAL IDENTIFICATION OF CASING AND TUBING

DIMENSIONCasing and Tubing come in the following range:Range 1 16-25Range 2 26-34Range 3 34+

Table source: Pan Meridian Tubular

COUPLING STENCIL This is a pictorial view of

a coupling with the following stencil:

5CT- API Specification. 3/3- Date of

manufacture. HTNO- Heat number Vam Top- Brand of

Vallorec Colour Code- Violet.

BODY STENCIL

This is a pictorial view of a Pipe Body Stencil TSD- Tenaris Sydeca 9 ⅝-Pipe Diameter 0117- API licence number Po- Purchase Order Number 44.15- pipe Length SF-Special End finish

STEEL GRADES WITH COLOUR CODES FOR TENARIS

N80.1

-Red Coupling -1 Strip Red band on Body

L80.1-Red Coupling with a brown band -Pipe Body with Red and Brown Band L80 13 CR -Red Coupling with a yellow band -pipe body with red, brown and yellow band.-13% Chromeage J55 -Bright Green coupling with white stripe -pipe body with bright green Band

THREAD PATTERN/PROFILEPremium connections comes with their own thread patterns/connection. This is because most of these patterns are patented under API license. Below are various thread profiles which comes in various patterns

API standardized several grades of steel that have different chemical content, manufacture processes, and heat treatments, and therefore different mechanical properties.

API organized these tubing grades into three groups which include:

Group 1 is for all tubing in grades H40, J55, and N80.

Group 2 is for restricted-yield tubing grades L80, C90, and T95.

Group 3 is for high-strength tubing in

seamless grade P110. The API grade letter designation was selected arbitrarily to provide a unique name for various steels. Numbers in the grade designation indicate the minimum yield strength of the steel in thousand psi. API defines the yield strength as the tensile stress required to produce a specific total elongation per unit length on a standard test specimen

API GRADES OF CASING

Table source: Heriot watt Drilling Engineering Handbook

T&C – Threaded and Coupled LT&C – Long Thread and Coupled ST&C – Short Thread and Coupled BTC – Buttress Thread

Integral Connection External Offset Internal Offset None Upset Extreme Line Connection

TYPES OF API CONNECTION

Source:API 5CT Manual

TYPES OF CONNECTIONThreaded and Coupled Integral

Connector

Integral joint tubing has external thread at on end and internal thread at the other end. This oil pipe can be connected without the use of couplings. 

The threaded and coupled has a coupling which is box by box ready for make up for two joints

EU or external upsetstrong connection, full opening, clearance problems

TYPES OF INTEGRAL CONNECTIONS

IU or internal upset – moderately strong connection, reduced opening, good external clearance

NU or non-upset – weak connection, full opening, good external clearance

PARTS OF A CONNECTION

Black Crest

Full Crest

Seal Nose

Seal Shoulder

TENARIS FGL vs HUNTLEY SLHT

SIMILARITY -Both connection have same number of black crest -They are both Designed with higher sealing capability.-They are both used in areas with sour Gas.

DIFFERENCE DIFFERENCE -The FGL has double seal nose -Seal Nose stand at Angel 90°-silent start off and silent run off -6 TPI-broader seal nose

-SLHT has a single seal nose-seal nose bevelled forward at 75°-Loud Start off and silent run off -10 TPI -Shorter seal nose

SAFETY KIT PIPE WRENCH CHAIN THONG DRIFT MANDREL MEASURING TAPE/ DIGI-TALLY WIRE BRUSH CLEANING BRUSH AIR COMPRESSOR/PRESSURE WASH MAGNIFING LENS THREAD COMB THREAD GUAGE RAGS SOLVENT TALLY SHEET DRIFT CHART THREAD COMPOUND WHITE PAINT RED PAINT PAINT BRUSH

VISUAL INSPECTION EQUIPMENT CHECK LIST

Lay Out casings

Break Thread Protectors, Box and Pin.

Run Drift from Box to Pin with API 5CT Certified Drift Mandrel.

Use compressed air to blow casing from box to pin, in other to remove scales and debris.

Wash threads with Solvent and cleaning brush, and then use wire brush for washing threads with little rust.

.

VISUAL THREAD INSPECTION PROCEDURE

Clean threads with Rag or soft foam and allow to dry.

Inspect threads, Box and Pin by running your fingers round the threads gently with special concentration on seal in other to check for any possible damage.

Take measurement of casing and record on a tally sheet.

Mark casing that pass visual test with a white paint and red paint for the ones that fail test.

Apply Thread compound on threads and close with thread protectors.

Assemble tools with your tool checklist

VISUAL INSPECTION PROCEDURE

IDENTIFYING DAMAGED THREAD

Galled thread

Pitting on thread

Flag off Damaged thread

Drifting or Rabbit involves running a drift mandrel from the box end of a casing or tubular, to check for any

1. possible restriction2. Rusty Flakes that has occurred as a result of

internal corrosionA restriction means that the original shape of pipe has

been altered and therefore will not be suitable for purpose.

In visual inspection, it is suitable to use: Full Drift End Drift

DRIFTING

DRIFT SIZES AND END DRIFT

Photo Credit: Symetec Steel

Galling in connection

Improper Make-up (misalignment, dirt, Over thronging, too little lubrication).

Fatigue Cracking

Corrosion

REASONS FOR VISUAL INSPECTION

THE END