Packer Retrieving assemblies are used to mill over and retrieve drillable production packers sometimes referred to as permanent type packers.
There are two assemblies that can be used, starting from the bottom up, they would be as follows:
1. Packer Retrieving Spear
Extension
Rotary shoe or Milling shoe
Top bushing with three threads
Double Pin Sub, if necessary
Two Boot Baskets
Double Box Sub, if necessary
Bumper Jars
Oil Jars
Drill Collars
Work String
2. Packer Retrieving Spear
Extension
Packer Mill
Two Boot Baskets
Double Box Sub, if necessary
Bumper Jars
Oil Jars
Drill Collars
Work String
Go in the hole and go through the packer with the Packer Retrieving Spear and begin milling on top of the packer. Always be sure the extension is long enough to put the Packer Retrieving Spear below the packer, but do not use any more than necessary for two reasons. One, as you mill over the packer, it will be going down the hole and could hit sand or other obstructions. Secondly, if too long of an extension is run, it could hit sand and other obstructions before the shoe or mill reaches the packer.
Once the shoe or mill is on the packer, start rotary and circulating, and mill the packer up or mill over it. The idea is to mill up the top slips so the packer can be removed from the well bore. I find it a lot easier to pull the packer if is milled until it moves down the hole.
When milling on the packer, the shoe or mill should be turned fast (120 to 140 R.P.M), with very little weight (1,000 to 3,000 lbs.).
There are several companies that manufacture Packer Retriever Spears (Bowen, Houston Engineers, and Baker are three of the most popular), these are all releasable, but they are not easy to release, especially in a deep hole or crooked hole. Therefore, it is best to plan the job to where you don’t have to release them.
Be sure there is enough Kelly up when the rotary shoe or mill reaches the Packer to prevent having to release the spear to make a connection. Also, be sure you do not go through the packer until you have the Kelly in the rotary, otherwise, you will have to release the spear to get a joint out and replace it with the Kelly.
It is very important to have good figures when you run a Packer Retrieving Assembly.
For more information, refer to the Bowen manual “Bowen Simplex Packer Retrievers”, manual #5/2710.