The industry of oil and gas exploration is widely based on drilling explorations because these natural resources are found deep in there. It is about a couple of hundred feet below the surface, and thus, accuracy is the key here. A few inches or centimeters here or there, and you are set to lose thousands of dollars.
To go this deep in the surface, the drill bits need a hell lot of strength to cope with the forces they are going to face inside the bore. We are here going to discuss the problem of a drill string getting stuck in the wellbore while in operation.
What are the Causes of This Problem
A drill string is considered to be stuck when it can no longer be used for drilling and cannot be taken be taken out of the bore without causing it any damage. It can be classified into two categories:
- Differential pressure pipe sticking
This occurs as a result of differential pressure between the formation pressure of the mud and the hydrostatic pressure of the mud. Generally, the hydrostatic pressure is higher of the two. This pushes the drill string into a filter cake of permeable formation.
Higher torque and drag is one of the common warning signs of a differential pressure pipe sticking.
- Mechanical pipe sticking
If the drilled mud is not removed adequately from the annulus, it causes the drill string to get stuck inside the hole. This is referred to as the mechanical pipe sticking. Some borehole instabilities such as hole caving, sloughing, or plastic shale are the reasons behind this issue as well.
This problem accounts for nearly half of the total well cost. Well, this is way too much. Although prevention of stuck string is far more economical, there are times when a drilling professional has to opt for freeing procedures.
This article is prepared to discuss one of the most effective treatments for this problem. This solution is known as pipe recovery.
What is Pipe Recovery
It is a wireline operation which is used to identify the location of a stuck pipe and also to separate the free pipe from the stuck pipe. To loosen up the stuck pipe down the hole, some fishing tools are deployed there.
Fishing is the process of removing the stray equipment from a bore, which in this case is the pipe that has got stuck inside the hole. Different tools used to recover the pipe are designed for a specific job. Most of them are screwed to an end of the string and are pushed into the ground.
Some of the most commonly used fishing tools are:
- Jet Cutters: These are the circular-shaped tools that can withstand very high downhole pressures. This makes them ideal for the places where the bore is hundreds of thousands of feet deep.
- Chemical Cutters:A chemical reaction is induced inside these tools, where the most commonly used chemical; Bromine Trifluoride is made to react with a catalyst. The resultant is then expelled through the serving head of the tool creating the cuts in the wall of the tube.
Bottom Line
The losses caused to the oil and gas producers due to the problem of pipe getting stuck are very high. Since all the losses and wastage impact the final cost of the product, the issue needs to be resolved as quickly as possible so that the resources can be made available for the mass at much affordable prices. To make it a reality, pipe recovery services have to be taken into account.
Hi there! I’m Sethu, your go-to guy for all things tech, travel, internet, movies, and business tips. I love sharing insights and stories that make life more interesting. Let’s explore the world together, one article at a time!
