Study and Test of Horizontal Well Cluster Fracturing Technology

In order to improve the development benefit of tight sandstone gas reservoir,based on the engineering geological characteristics of reservoirs,single well logging data,and measurement of gamma while drilling,the overall fracture pattern,fracture parameters and treatment parameters of horizontal well cluster were optimized by combining the numerical simulations of three-dimensional two-phase reservoir model and full three-dimensional network model.As a result,He 1,Shan 1 and Tai 2 formations were optimized to a crossing fracture pattern with equal spacing(150 m),containing 7-9 fractures with half length of 150-200 m and conductivity of 30 D·cm,and other parameters including 4.0-5.0 m3/min displacement,35%-40% prepad,21%-25% average proppant concentration and 35-45 m3 sand content in single segment.Field application showed that,after fracturing,two horizontal well clusters(i.e.DP43H six-well cluster and DPT-27 four-well cluster)achieved open-flow capacity of 77.6×104 and 73.2×104 m3/d respectively,with single well open-flow capacity of 12.9×104 and 18.3×104 m3/d,which were 1.5 times and 2.2 times of that offset wells in the same formation.Moreover,the fracturing time of the two well was 11 d and 17 d less than the accumulative time of wells.It is therefore concluded that the horizontal well cluster fracturing technology is an effective solution to improve the single well production,shorten the treatment period,and reduce the cost of fracturing.