Patent ID: 6286603
Filing Date: 2001-09-11
Classification: E21B

Abstract:
Annular packer apparatus, for packing the hollow annulus between the outwards-facing wall of a work-pipe, and the inwards-facing wall of a borehole casing, wherein:the apparatus includes a generally cylindrical, hollow, support-tube, of relatively rigid material, the support-tube having an upper end and a lower end;the apparatus includes an outer bladder, comprising an outer tube of stretchy elastomeric a material;the outer bladder is located outside the support-tube, its location being such as to create an annular outer space between the inside surface of the outer bladder and the outside surface of the support tube;the outer bladder is sealingly fastened, at its upper and lower ends, to the support tube;whereby the outer space forms a sealed outer chamber, between the outer bladder and the support tube;the apparatus includes a means for communicating pressurised fluid into the outer chamber,the apparatus includes an inner bladder, comprising an inner tube of stretchy elastomeric material;the inner bladder is located inside the support-tube, its location being such as to create an annular inner space between the outside surface of the inner bladder and the inside surface of the support tube;the inner bladder is sealingly fastened, at its upper and lower ends, to the support tube;whereby the inner space forms a sealed inner chamber, between the inner bladder and the support tube;and the apparatus includes a means for communicating vacuum to the inner chamber.