Drill Pipe Grades

There are four common grades of drill pipe which define the yield strength and tensile strength of the steel being used.

Grade

E

X-95

G-105

S-135

Minimum Yield Strength (psi)

75,000

95,000

105,000

135,000

Minimum Tensile Strength (psi)

100,000

105,000

115,000

145,000

Grade E, composed of a lower grade of steel, is sometimes referred to as "mild" steel, because it has the lowest yield strength per unit area. As such, mild steel is generally defined as steel with a yield strength of less than 80,000 psi. As can be seen, Grade E drill pipe has a lower yield strength in psi than the high strength drill pipe grades, however once the yield strength is exceeded, it can withstand a greater percentage of stretch or "strain" prior to parting. Lower grades of steel such as Grade E are also more resistant to corrosion and cracking. Grade E has been utilized in medium depth wells (10,000 to 15,000 feet).

In the 1980's, as horizontal drilling, high inclination extended reach wells and deep hole drilling applications increased, so has the demand for high strength drill pipe. It is common in deep hole applications for high strength drill pipe to be utilized in the upper portion of the string to keep the tension load within the capabilities of the steel. In high dogleg environments, such as those encountered in medium and short radius horizontal wells, high strength drill pipe can withstand the associated bending stresses. In high inclination and horizontal wells, high strength drill pipe is also commonly run in compression. One drawback of higher grades of steel is that they are generally less resistant to corrosion, like that caused by hydrogen sulfide (H2S). Limited availability also contributes to the higher cost.

The yield and tensile strengths are in "pounds per square inch of the cross sectional area" of the drill pipe. In order to calculate yield strength in pounds, this cross sectional area must be known. This leads to a discussion of drill pipe classes.

Was this article helpful?

+1 -1
Helping Your Child Learn To Read

Helping Your Child Learn To Read

When parents help their children learn to read, they help open the door to a new world. As a parent, you can begin an endless learning chain: You read to your children, they develop a love of stories and poems, they want to read on their own, they practice reading, and finally they read for their own information or pleasure. They become readers, and their world is forever expanded and enriched.

Get My Free Ebook


Responses

  • lavinia
    What grade of pipe is used for drilling?
    7 years ago
  • madihah
    Can drill pipe s135 to be used for g105?
    6 years ago
  • frankie white
    Do you run s135 before g105 in horizontal wells?
    5 years ago
  • emma
    Which grade of drillpipe is most resistiant to H2S?
    4 years ago
  • Santo
    How to determine grade of drill pipe?
    3 years ago
  • Jan Pyysalo
    What is meant by drill pipe grade X95?
    2 years ago
  • daniel
    What grade steel is veiwate drill pipe?
    1 year ago
  • olindo
    What is the minimum yield strength of drill?
    12 months ago
  • JUSTIN HILL
    What detremines the grade or strenght of drill pipe?
    8 months ago
  • max vogt
    What is the difference between G105 and S135 drill pipe?
    4 months ago

Post a comment