Abstract: A pressure-up blow-down method for recovering oil from an underground hydrocarbon formation, comprising the steps of: injecting an injection fluid into alternatingly-spaced multiple-induced fractures which extend radially outwardly and along a horizontal portion of a wellbore in the formation; ceasing injection of said injection fluid; recovering to surface oil which flows from remaining of the multiple induced fractures into the wellbore; and successively repeating the foregoing steps one or more times. Gas preferentially is initially used as the injection fluid and after one successive iteration water is then used. A sliding sleeve or sleeves which may be selectively slid open and closed within the wellbore in accordance with the method to allow and prevent, at various time periods in the method, fluid communication with fluid injection fractures and oil production fractures.

Abstract: A method for enhancing production from multiple-fractured underground “tight” formations. Spaced upwardly-extending injection fissures are created along a horizontal injection wellbore, and upwardly-extending collection fissures, alternately spaced with the injection fissures, are created along the horizontal injection wellbore or another adjacent production wellbore. The injection wellbore is supplied with fluid under pressure, which flows into such created fissures and drives reservoir fluids within the formation to the remaining (alternately) spaced adjacent fissures along such wellbore or another parallel adjacent (production) wellbore, thereby allowing reservoir fluids to flow downwardly along such alternately spaced production fissures for collection.