We analysed the influence of well deviation on hydraulic fracture treatments in gas bearing Bunter formations, offshore Holland. The reservoir permeability ranged from 2 to 20 mD, which was relatively high for stimulation. Analysis of the pressure records of injection tests and treatments indicated low net fracture pressure and contained fractures. Most treatments ended in wellbore screen-out, giving a high fracture conductivity, especially near the wellbore. The success of the treatments was due to by-passing of a severe skin as well as stimulation of the formation. Also, the well was connected to additional flow units, evidenced by a substantial increase of the permeability (obtained from well tests) after the treatments. In a deviated well we observed gas entry into a small section of the perforated interval. However, there was no indication for a reduced performance of wells with a large deviation compared to the performance of vertical wells.

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