Feasibility of pressure shock fracturing to improve fracture height growth in shale oil formation
The physical simulation experiment of horizontal well fracturing was carried out by using layered samples prepared from reservoir outcrops of Lucaogou Formation in Jimsar.Two pressurization states were obtained by constant speed injection and rapid release of accumulated high pressure,which correspond to conventional and pressure shock conditions,respective-ly.It is found that the outcrop breakdown pressure is less than 15 MPa under the condition of constant-rate injection in hori-zontal wells,which tends to form activated laminas near the wellbore,and the fracture height is limited.Under the condition of pressure shock,the bottom hole pressure is much higher than the conventional rock breakdown pressure,and the fracture height is greatly increased.The shock pressure has a significant impact on the fracture height.Under the condition of shock pressure of about 32 MPa,the average height of fractures increased by 41.2%.Under the shock pressure of 55 MPa,the fracture height increased by 1.28 times.The increased number of times of shock can also improve fracture height growth to a certain extent.The fracture height of three shock fracturing is 50%higher than that of one shock fracturing.
万方数据
维普
