Propped Fracture Stimulation in Deviated North Sea Gas Wells

Abstract

Abstract 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.