Complex sentence: Multi-stage fracturing systems are used for hydraulic fracturing, or breaking up tight rock formations to enable release of oil and gas in petroleum reservoirs allowing for segmentation of horizontal wells into sections or stages such that they can be fractured individually.
Split into simpler sentences: Multi-stage fracturing systems are used for hydraulic fracturing, or breaking up tight rock formations to enable release of oil and gas in petroleum reservoirs. Specifically, these systems allow for segmentation of horizontal wells into sections or stages such that they can be fractured individually.