Zonal isolation tools and methods of use

An apparatus comprising:

• a) a wellbore sealing member inflatable by fluid pressure to contact a wellbore over an initial contact area and compressible by an axial load, the wellbore sealing member comprising an inner sealing element and an outer sealing element;
• b) an inflation valve open during inflation of the sealing member and closed upon the fluid pressure reaching a predetermined setting;
• c) a vent between the sealing member and a wellbore annulus adapted to open after the inflation valve is closed;
• and
• d) a compression member adapted to produce the axial load on the wellbore sealing member to form a sealing point at or near a leading edge of the wellbore sealing member.

A method comprising

• a) positioning a zonal isolation tool in a wellbore between two zones, the zonal isolation tool comprising
• i) a wellbore sealing member expandable by fluid pressure to contact a wellbore over an initial contact area;
• ii) an inflation valve open during expansion of the sealing member to the initial contact area and closed upon the fluid pressure reaching a predetermined setting;
• and
• iii) a vent between the sealing member and a wellbore annulus adapted to open after the inflation valve is closed;
• b) inflating the wellbore sealing member to establish an initial sealing area;
• c) axially compressing the wellbore sealing member to achieve a final seal having a point at or near a leading edge of the sealing member.