Influence of fracturing fracture height on productivity of horizontal wells in tight sandstone reservoir
More and more development practices show that for multi-interlayer tight sandstone gas reservoirs,it is not that the higher the effective reservoir drilling rate,the higher the productivity.In order to find out the reasons for the good fracturing effect and high productivity(initial productivity up to 7.5×104 m3/d)of horizontal wells with low drilling rate(drilling rate less than 60％,minimum only 31％)in He 8 Member of Sulige gas field in Ordos Basin,the paper combines reservoir development characteristics,rock mechanics characteristic parameters and numerical simulation methods.The effect of fracturing fracture height on the productivity of horizontal wells in tight sandstone gas reservoirs with interlayer development is discussed.The results show that for tight sandstone gas reservoirs with developed interlayers,multiple sets of vertical gas layers are connected to the wellbore through the interlayers,which is the main reason for the high production of horizontal wells with low drilling rate,and the fracturing fracture height has an important influence on the productivity of horizontal wells.For the single thick tight sandstone gas reservoir without interlayer development,the productivity of horizontal wells does not change significantly with the increase of fracturing fracture height.Therefore,for horizontal wells continuously drilled with long horizontal sections(more than 100 m)with thin interlayers,according to the development of longitudinal sand bodies and gas reservoirs in tight sandstone gas reservoirs,perforation and fracturing in non-effective reservoir sections can be considered,and multiple sets of longitudinal interlayers should be fractured as far as possible to significantly improve gas well productivity.This is of great guiding significance for the optimal design of fracturing and increase of productivity of horizontal single wells of similar tight sandstone gas reservoirs in and outside Ordos Basin.
interlayerhorizontal well fracturingeffective reservoir drilling ratefracture height expansionHe 8 Member
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NSTL
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