Packer apparatus

A downhole work string having a first packer apparatus for providing an a first annular seal in a downhole well casing or an open borehole, a second packer apparatus for providing a second annular seal in the downhole well casing or the open borehole, and a ported sub positioned between the first and second packer apparatuses for performing a fracturing operation between the first and second annular seals,

• the first packer apparatus comprising:
• a first body arranged to be disposed in a the downhole well casing or the open borehole, the first body having an internal bore that is configured to receive fracturing fluid that is supplied via the downhole work string;
• a first elastomeric packer element;
• an a first activation member mounted to the first body adjacent to the first elastomeric packer element, wherein the first activation member is moveable relative to the first body to deform an the first elastomeric packer element outwardly relative to the first body to thereby cause the first elastomeric packer element to form an the first annular seal in the downhole well casing in use or the open borehole;
• and
• a first plurality of pistons arranged to move the first activation member relative to the first body, each said piston of the first plurality of pistons defining a respective pressure chamber arranged to be filled with the fracturing fluid in response to an increase in fluid pressure in the internal bore of the first body to move each of the plurality of that is caused when the fracturing fluid is supplied via the downhole work string, wherein, as the respective pressure chamber defined by each of the first plurality of pistons is filled with the fracturing fluid, the first plurality of pistons move relative to the first body and cause which causes the first activation member to move relative to the first body to thereby deform the first elastomeric packer element and form the first annular seal;
• the second packer apparatus comprising:
• a second body having an internal bore that is also configured to receive the fracturing fluid that is supplied via the downhole work string;
• a second elastomeric packer element;
• a second activation member mounted to the second body adjacent to the second elastomeric packer element;
• and
• a second plurality of pistons arranged to move the second activation member relative to the second body in response to the fracturing fluid being supplied via the downhole work string to thereby deform the second elastomeric packer element and form the second annular seal;
• and
• the ported sub comprising:
• a third body that is positioned between the first body and the second body, the third body having an internal bore that is also configured to receive the fracturing fluid that is supplied via the downhole work string;
• and
• one or more ports that provide a fluid pathway from the internal bore of the third body to the downhole well casing or the open borehole such that, as the fracturing fluid is supplied via the downhole work string, the fracturing fluid:
• (1) causes the first packer apparatus to form the first annular seal,
• (2) causes the second packer apparatus to form the second annular seal, and
• (3) ejects from the one or more ports of the ported sub to perform a fracturing operation between the first and second annular seals.