Drill Pipe Grades

Drill pipe grades include standard API grades (E-75, X-95, G-105, & S-135), as well as proprietary grades.

API Grade Drill Pipe

API SPEC 5DP specifies the technical delivery conditions for steel drill-pipes with upset pipe-body ends and weld-on tool joints for use in drilling and production operations in petroleum and natural gas industries for three product specification levels (PSL-1, PSL-2 and PSL-3). PS-1 specifies wall thickness, impact strength, and yield strength requirements specific to the material grade. Specification levels PL-2 / PL-3 have additional mandatory requirements.

Grade E drill pipe, referred to as "mild" steel, exhibits the lowest yield strength per unit area with a yield strength of less than 80,000 psi. It is able to withstand a greater percentage of stretch or "strain" prior to fracture than higher strength drill pipe grades. It is also more resistant to corrosion and cracking. Grade E is utilized in medium depth wells from 10,000 to 15,000 feet.

Grades X-95, G-105, and S-135 are considered high strength grades. They exhibit increased yield strength which is required to service deeper wells.

Proprietary Grades

Proprietary grades often exceed the specifications set forth by API SPEC 5DP. Their enhanced performance properties are developed for sour service, critical service, and other user-defined requirements.

Sour service grades resist sulphide stress corrosion (SSC). SSC can occur when hydrogen sulfide is present. Ingress of hydrogen coupled with higher stresses, low temperatures, low pH, and high chloride content decreases the ductility of steel grades leaving them susceptible to crack propagation and failure.

Critical service grades resist corrosion when sweet gas or high concentrations of carbon dioxide are present. They are a cost effective alternative that is used in water injection applications.

Sizing

Drill pipe is manufactured according to standard specifications and is offered in nominal sizes. The two most important dimensional specifications are length and diameter.

Length

The drill string is made up of several sections of drill pipe. The term "stand" refers to two or three sections of drill pipe that are fed into the well bore to complete 60 to 90 feet of drilling. Each segment of pipe, referred to as a "single", is classified by API into three distinct length ranges; R1, R2, and R3.

Range 1 (R1) is shortest in length, more common for sizing production tubing or casing, and ranges from 18 to 22 ft.

Range 2 (R2) is considered the standard length for drill pipe and ranges from 27 to 31 ft.

Range 3 (R3) is common in casing and also deployed in deep water drilling applications. The increased length decreases the number of tool joints in each stand of drill pipe. The fall back being that the load exerted on each tool joint is greater increasing wear and reducing the expected life of the drill pipe. R3 ranges from 38 to 45 ft.

Diameter

The outer diameter (OD) of the drill pipe is offered in nominal sizes ranging from 2 3/8" to 6 5/8". The diameter of pipe is selected based on the borehole diameter. In order to effectively circulate drilling mud and minimize pressure losses, the ratio of drill pipe outside diameter to borehole diameter should be about 0.6.

As one of the most professional drill pipe manufacturers, Vigor will always adhere to the quality and service to empower customers, provide customers with high-quality products at the same time, provide our customers with the most intimate and high-quality technical services and inspection services, so that the products can arrive at the customer site in the best state and use. If you are interested in Vigor's drilling and completion tools and field services, please do not hesitate to contact us for the best quality products and services.

For more information, you can write to our mailbox info@vigorpetroleum.com & mail@vigorpetroleum.com