What is perforation in oil well drilling?
A perforation in the context of oil wells refers to a hole punched in the casing or liner of an oil well to connect it to the reservoir. The final stage of the completion will involve running in perforating guns, a string of shaped charges, down to the desired depth and firing them to perforate the casing or liner.
What are the main types of perforation fluids?
Perforating Methods
- Bullet Gun Perforating. Projectiles from these guns (bullets) must penetrate the casing, cement, and formation.
- Abrasive Perforating Methods.
- Water Jets.
- Shaped Charges.
What are the types of perforation?
Types of Perforations
- Round Hole Perforation.
- Square Hole Perforation.
- Slot Hole Perforation. Staggered Row Perforation. Straight Row Perforation.
Why do we need to perform perforation in a production well?
Perforation is a special operation to crease an efficient communication path between a wellbore and a reservoir by creating tunnels. The effective paths allow reservoir fluid to flow into the well with minimum pressure loss (less skin as much as possible).
What is perforation fluid?
1. n. [Perforating, Well Completions] A specially prepared fluid placed in the wellbore over the interval to be perforated. The ideal fluid is clean and solids-free (filtered), and will not react to cause damaging by-products on contact with the reservoir formation.
Why are oil wells perforated?
Perforation operation is an elemental key step in the process of well completion. It involves creating a flow path between the reservoir and the wellbore for the inflow of the reservoir fluid into the wellbore. During perforation a flow path is created with help of high energy detonation by special shaped charges.
What are completion fluids?
Completion fluid is a solids-free liquid used to “complete” an oil or gas well. Completion fluids are typically brines [chlorides, bromides, and formats (salt of formic acid)], but in theory could be any fluid of proper density and flow characteristics.
What causes perforation?
Common causes of perforation include trauma, instrumentation, inflammation, infection, malignancy, ischemia, and obstruction.
What is perforation line?
Perforated paper is a sheet of paper or card stock that has perforated lines of very small holes punched into the paper. This perforation allows parts of the sheet to be separated simply by folding and tearing along the dotted line. Macro perforation, also called stub perforation, contains 12 perforations per inch.
What types of perforation methods are used in well testing?
A well can be perforated three different ways:
- Overbalanced using a casing gun.
- Underbalanced using a tubing-conveyed gun.
- Underbalanced using a thru-tubing gun.
What is a perforated wound?
A perforated wound is a hole or break that can occur to the body, its organs or organ membrane. Perforated wounds may be the result of blunt trauma, infection, puncture or erosion.
What’s the next step after we have perforated our well?
The next step in well completion involves cementing the well. This includes pumping cement slurry into the well to displace the existing drilling fluids and fill in the space between the casing and the actual sides of the drilled well.
