Influencing factors analysis of multi-stage fractured horizontal wells' initial productivity in dense reservoirs

The matrix permeability of dense reservoirs is very low and through artificial pressure cracks by volume fracturing,the stress distribution around wellbore can be effectively changed.Meanwhile through hydraulic fractures as a bridge,the natural fractures and hydraulic cracks,as well as links between the horizontal wellbore can be enhanced.And therefore the flow of dense fluid within the reservoir can be enhanced.The dense reservoir can be divided into three seepage areas,and assuming a linear stream flow as the main flow characteristics for the three areas,the initial production volume of fractured horizontal wells have been analyzed.Study results show that properly increasing the number of cracks beat water and increasing pressure fracture half-length will be helpful to activate the dual medium dense reservoir of natural micro-cracks,and then increase productivity.