Cyclic Injection to Enhance Hydraulic Fracturing Efficiency: Insights from Laboratory Experiments

Table 1

Result summary for the first batch of sandstone.

Specimen no.	Injection method	Injection flowrate or injection pressure	Breakdown pressure (MPa)	Tensile strength (MPa)	Compressive strength (MPa)
1	Conventional	2.4 mL/min	43.09	9.282	172.85
2	Conventional	2.4 mL/min	38.42	8.455	150.84
3	Conventional	2.4 mL/min	47.59	11.611	152.73
4	Stepped pressure	4-8-12-16-20-24 MPa	29.03	10.010	171.02
5	Constant pressure	20 MPa	31.53	9.148	157.51
6	Constant pressure	25 MPa	42.75	10.498	164.90
7	Constant pressure	25 MPa	36.28	8.690	153.56