Hiya,
Just get yourself some
Tenacious Tape. Its the biz. It may not work so well when adhering to wet surfaces, so it may not be so good for 'in the field repairs' but it can fix thermarests, platypus drinking bladders and gore-tex jackets so I can confirm that it can take a bit of abuse and form a water or air tight barrier.
Its just like sellopate - cut a piece off the roll, stick it over the hole and away you go. You can forget about it as it will last for years . . . .. A lot easier than glues and potions! Just make sure you cut it on-the-round so there are no corners to catch and then lift.
Andy
PS - You'll get it from good mountaineering shops.