The Explosive Train & Perforating Gun Types || Production Engineering || Petroleum Engineering

The Explosive Train

Explosive train is a series connection of explosives.It used in petroleum industry for perforation job. If you not aware of what is perforation and  overview of perforation in petroleum industry then click this link ......

When initiated high explosives reacts supersonic in a process called detonation, By comparison, low explosives reacts sub-sonically in a process called deflagration.  

Component of The Explosive Train   

1.  An initiator or detonator that is used to start process.
2. A detonating cord which is used to transmit detonation.
3. Shaped Charge ( Used to perforate up to the formation )

Perforating Gun Types

• Retrievable Hollow steel career Guns 
• Semi Expandable
• Fully Expandable 

Advantages and disadvantages of perforating gun types

1. Retrievable Hollow Steel and Career Guns

Advantage of Retrievable HSCG  

1. High Reliability because all component are pro acted within the carrier.
2. Heavier and Stronger which permit rough treatment handling running procedure.
3. Generally high pressure and temperature rating,
4. Very little debris left in the well after perforation.
5. Explosive force is retained within the carrier to eliminating casing deformation.
6. Port Plug provides positive medication of five.

Disadvantages of Retrievable HSCG

1. Many have trouble running in and out through tubing retrievable guns in buckle tubing.(Buckle Casing :- In deviated wells)
2. Many have smaller charge components (Space required for retrievable)
3. Due to more weight, manpower is needed while lowering. Example-

Small Standoff	More Charge
Large Standoff	Less Charge

         

2. Semi Expandable

Advantages of Semi expandable -

1.  High reliability( Not as much as RHSCG )
2. After Detonation, Metal Strip and some component can be retrieved  which is turn reduced the debris in the well.
3. With a metal strip or wire carrier, Ceramic or Glass Charge cases can be used reduces the debris particle size and decreasing the chemical reaction rate.

Disadvantage of Semi Expandable

1.  More Debris remains inside the well.
2. Metal Strip Jumps. In the well fishing operation is used because difficult to put up.
3. Deeper penetration , more amount of charge.

3. Fully Expandable

Advantage of Fully Expandable of perforating gun

1.  Generally cheaper, easier to assemble at the well site.
2. Lighter and more flexible.
3. It offers more penetration compared to the retrievable Guns.
4. We can not Large sized shape charge as it is open.

Dis Advantages of Fully Expandable.

1. Can or may be deform casing of well when detonation.
2. It leaves, substandard amount of debris in the well.
3. Less reliability because component are directly exposed to the well fluid condition.
4. It sometimes doesn't detonate because it is wetted  by the reservoir due to leak in casing.
5. There is no positive indication of perforation from the surface (Only seen after removable)

Notes:- Data is collected from different university class notes and E&P company. Article is usefull for student and industry person

Article Written By:-

Ritu Raj Medhi

Founder & President 

Chief Technical & Editorial Officers

Petroleumbuddy websites and initiatives

  

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