Frictional behavior of sliding shale rock-silica contacts under guar gum aqueous solution lubrication in hydraulic fracturing

Over the past decades, hydraulic fracturing has been adopted extensively in the petroleum field to stimulate the growth of shale gas production. To better understand hydraulic fracturing, the frictional behavior of shale rock-silica contacts was investigated. Data from experiments show that friction coefficient of the contact gradually increases from 0.2 to somewhere in the range of 0.3-0.4, and then reaches steady state with increasing load, which is directly related to the transformation from the mixed to the boundary lubrication regime of guar gum aqueous solutions. Moreover, the friction coefficient of the contact has no trend with the increasing concentration of guar gum aqueous solution, which is attributed to rheological performances of guar gum in contacts.