FRACTURE OPENING/ PROPAGATION BEHAVIOR AND THEIR SIGNIFICANCE ON PRESSURELTIMX RECORDS DURING HYDRAULIC l?RACTURING

Hydraulic fracturing with constant fluid injection r a t e was numer ica l ly model led for a p a i r of rectangular longitudinal fractures intersecting a wellbore i n a n i m p e r m e a b l e rock m a s s , a n d numerical calculations have been performed to investigate the relations among the form of pressuretime curves, fracture opening/propagation behavior a n d permeabi l i ty of t h e mechan ica l ly closed fractures . The r e su l t s have shown t h a t both permeability of the fractures and fluid injection rate significantly 'influence the form of the pressure-time relations on the early stage of fracture opening. Fur thermore i t h a s been shown t h a t wellbore pressure during fracture propagation is affected by the pre-existing fracture length.