Wellscreen having helical support surface

A filtering material for disposal around a base pipe, the filtering material comprising:

• at least two sections including:
• a first section with an upper and lower edge;
• a second section with an upper and lower edge, whereby the lower edge of the first section is attached to the upper edge of the second section and, wherein the first and second sections are of a different filter type and each of the at least two sections is constructed and arranged to cover a periphery of the base pipe as the filtering material is rolled onto the base pipe;
• and
• a third section with an upper and lower edge, whereby the upper edge of the third section is attached to the lower edge of the second section, wherein the first and third sections comprise a non-sintered porous material and the second section comprises a sintered material.

A filtering material for disposal around a base pipe, the filtering material comprising:

• at least two sections including:
• a first section with an upper and lower edge;
• a second section with an upper and lower edge, whereby the lower edge of the first section is attached to the upper edge of the second section and, wherein the first and second sections are of a different filter type and each of the at least two sections is constructed and arranged to cover a periphery of the base pipe as the filtering material is rolled onto the base pipe;
• and
• a third section with an upper and lower edge, whereby the upper edge of the third section is attached to the lower edge of the second section, wherein the filtering material has a progressively tapered width, whereby the width at the lower edge of the third section is greater than the width at the upper edge of the first section.