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What is OCTG pipe and what it is used for

Posted on 01 November 2020 by Admin

OCTG is something that is very important and definitely needed in every oil, gas and geothermal drilling. OCTG stands for Oil Country Tubular Goods. OCTG consists of 3 products, namely Drill Pipe, Casing and Tubing Pipe.

Drill Pipe (DP) is a pipe that is used during drilling, where the pipe functions to drain the drilling mud to the bottom of the well so that the rock remains destroyed as a result of drilling can be lifted to the surface.

Casing is a pipe that is inserted into the well after the well is drilled for cementing so that the well drilled wall does not collapse and closes the well again.

Tubing is the last pipe inserted, where the well is known to contain oil that can be produced. Tubing functions as a pipe that lifts the fluid (oil / gas / steam) to the surface with the help of a pump or with natural energy due to the difference in pressure in the well with surface pressure.

The method of making the pipe is divided into:

1. A pipe made of solid steel (billet) with a certain diameter which is then heated to a very high temperature then is perforated in the middle with a certain diameter using solid iron, so that it forms a pipe without a connection or commonly called a Seamless Pipe. Usually, seamless pipes are used in wells that have high enough pressure.
2. Pipe originating from a steel plate that is bent and then welded in the middle to form a pipe. This pipe is commonly called ERW Pipe. ERW pipes are used for low pressure due to the presence of welds in the middle which can cause the pipe to break when under high pressure.

What is OCTG pipe and what is it used for?

OCTG pipes refer to Oil Tubular Goods, a collection of rolled metal products, better known as drill pipes, casings and tubing which are manufactured according to API specifications and used both onshore and offshore. In the petroleum industry.

The drill pipe is a seamless tube that rotates the drill and circulates the drilling fluid. It is hollow to allow drilling fluid to be pumped into the hole through a bit and back into the annulus. The annulus of an oil well is the distance between the piping or casing and the pipe, tube or casing immediately surrounding it. The presence of the annulus gives the ability to circulate fluids in the well. The drill pipe is subjected to high torsion by drilling, axial stress with dead weight and internal stresses by cleaning drilling fluid.

A casing is the pipe used to attach a borehole, which is the actual hole that is dug into the ground to get to the oil. Like the drill pipe, it is also subject to axial tension. However, it is different when it comes to internal pressure from the oil itself, there is also external pressure from rocks and sediments that have become bored. This is also a very tough and important task for OCTG.

The tube is the pipe that goes into the casing pipe. This is the pipe through which the oil will eventually make its way out. The simplest of the OCTG family, tubing can usually be found in a segment of approximately 9m (30 ft), with a threaded connection at each end, which can be protected with drill pipe guards during transport and storage. This shield also helps protect against corrosion that can occur during storage, which can cause major problems when tons of oil are pumped.

That's a little review about the meaning and use of OCTG. Hopefully useful and can add insight to readers.