Techniques for hydraulic fracturing a subsurface formation can include using a deterministic model to simulate a deviated well comprising a casing and at least one perforation tunnel. The techniques can include determining a different statistical distribution for each of one or more parameters to the deterministic model. The statistical distributions can be determined from the log data along the measured depth within the wellbore. The techniques can include probabilistically solving the deterministic model to determine a mean and a standard deviation of breakdown pressures along the measured depth within the wellbore. The techniques can include processing the mean and the standard deviation of breakdown pressures to determine an upper bound breakdown pressure based on a level of confidence. The techniques can include drilling and completing a deviated well based on the determined upper bound breakdown pressure and injecting hydraulic fluid to cause hydraulic fracturing of the subsurface formation.