| abstract |
A method of controlling the fracture location, orientation, and reduce the breakdown pressure in multistage fracturing, particularly of unconventional reservoirs. Acid etching can be used to initiate small channels (wormholes) around the horizontal well, followed by the hydraulic fracturing fluid to create the fractures. The fracture orientation can follow the same direction of the etched part of the well and in the same location of the wormholes. The breakdown pressure can be reduced by 5, 10, 15%, or more, e.g., from 2200 to 1800 psi after acid etching which can minimize the pumping requirements at the surface and break the formation with very high breakdown pressure. |