Petromac Wireline Express centralizes MRIL-D in casing, drastically reducing the magnetic drag.
Drag is the result of the friction force between the body of a tool travelling downhole and the borehole wall. It is proportional to the friction coefficient of the materials in contact, the area in contract, and the normal force maintaining the contact.
This normal force is generally related to the weight of the tools only, but the MRIL-D tool also features a large permanent magnet. When conveying the tool in the casing, the magnetic force on the casing metal is added to the usual weight force.
This additional magnetic drag drastically reduce the ability of the tool to to travel down, even at relatively low deviation.
The magnetics force between two objects is inversely proportional to the square of the distance between the two objects connected by this magnetic field. The magnetic drag is therefore maximum when the logging tool housing is in contact with the casing. The magnetic drag is minimized when the logging tool centralized in the casing.
Petromac Wireline Express perfectly positions the MRIL-D tool in the center of the 9 5/8” casing, which maximizes the distance between the magnet and the casing. This reduces the magnetic drag to a minimum, which extends the deviation limit that the tool cab be conveyed to.
CHALLENGE
Successfully descend MRIL-D in a high-angle cased section well, where the magnetic drag is significant.
SOLUTION
Centralize the MRIL-D toolstring with Petromac Wireline Express Taxis so that the magnetic drag is at its minimum.
RESULTS
The toolstring descended smoothly in casing. Highest well deviation currently recorded is 69 degrees.