Mylar is a transparent film supplied in sheet form that fits inside the core barrel inner tube, to form a temporary liner to accept the core.
The advantages of using mylar are much the same as using rigid PVC Coreliner Tubes – to provide an improved handling system for rapid extrusion of sticky, broken and soft formation cores.
Mylar can be supplied to fit most types and sizes of core barrel – metric, DCDMA and wireline. It is supplied in rolls, approximately 200 metres long, which can be cut into appropriate lengths to suit the core barrel inner tube. The mylar is curled over on itself to form a loose tube within the core barrel inner tube. The lower end of the mylar tube is retained in the inner tube by means of a circular steel “mylar clip”.
To use the mylar lining system a modified Core Bit and Corelifter is required with reduced internal diameter (see Table for details). This is to ensure that there is adequate clearance for the core to fit into the mylar lining. Such “mylar set” bits and corelifters are available on request.
|Core Barrel Designation||Standard I.D. of Core Bit(mm)||Reduced I.D. of Mylar Bit (mm)|
|T2 T6 & W/L series||see data tables||3 mm smaller than standard|