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.
Successfully descend MRIL-D in a high-angle cased section well, where the magnetic drag is significant.
Centralize the MRIL-D toolstring with Petromac Wireline Express Taxis so that the magnetic drag is at its minimum.
The toolstring descended smoothly in casing. Highest well deviation currently recorded is 69 degrees.
Holefinder system facilitates wireline logging in an ‘impossible well’ in Iraq
Near Vertical ‘Impossible Well’ Logged in Iraq
An operator in Iraq was combating major issues with wellbore ledges in a well with only 6 deg deviation. After two wireline runs which were held up at shallow depth, the operator undertook a wiper trip, only to experience similar problems again on the 3rd attempt. The decision was made to run a TLC operation, however this was also unsuccessful.
In all a total of 5 days of rig time had been lost trying to pass a 20” washout with associated ledge.
Frustrated with the lack of results from conventional wireline and TLC, the operator sought the expertise of Petromac to log this critical well. A total of 6 descents were made with Petromac Wireline Express – all seamlessly conveyed to TD.
Without a holefinder, wireline toolstrings are easily held up by ledges and washouts.
Using the Wireline Express holefinder, the toolstring does not loose any momentum as it slides over wellbore obstructions.
In ‘vertical’ wellbores large ledges will persistently holdup toolstrings, even on TLC operations.
Petromac Tool Taxis ensure that the angled holefinder is always oriented upwards, allowing the toolstring to slide seamlessly over ledges.
A well which could not be logged on TLC was subsequently logged using the Petromac holefinder system (6 successful runs in hole).