Controlling factors for gas accumulation and high production in the Shaan-151 well area,Yulin Gas Field,Ordos Basin

The reservoir rocks in the second member of Shanxi Formation occur as the major reservoir rocks favourable for gas accumulation and high production in the Shaan-151 well area,Yulin Gas Field,Ordos Basin.The controlling factors include:abundant gas-generating mother material derived from Carboniferous Permian source rocks;multiphase subaqueous distributary channel quartz sandstone and lithic quartz sandstone as effective reservoir rocks;restricted gas and water distribution constrained by slightly uplifted structural zones,and excellent seal rocks represented by shallow lacustrine mudstone at the top of the Shanxi Formation.