This animation, provided by Baker Hughes International, shows a cross section view of a spaced perforation methodology applied to horizontal drilling and multi-stage hydraulic fracturing in a shale formation. Follow the descriptions below for information about the different stages of the animation.

1. A vertical hole is drilled and then deviated horizontally to follow the shale facies of interest.

2. A string of spaced sleeves with internal ball valve mechanisms are inserted into the complete length of the hole instead of wellbore casing.

3. Towards the heel of the well, the ball valve size for each sleeve unit increases, such that the ball for the first stage at the toe of the well can be inserted through all the sleeves but the first. When the balls seat at their given sleeve, they form a seal that allows the heelward side of the hole to be pressurized, causing the sleeve to slide toeward, which opens hydraulic access to the formation.

4. Step 3 is repeated moving down towards the heel of the well, such that each interval corresponding to a sleeve unit within the string can be hydraulically fractured and produced independently.

свернуть