METHOD FOR HYDRAULICALLY FRACTURING SPACED FORMATION ZONES

摘要

Two spaced apart zones (12, 14) of a formation are simultaneously hydraulically fractured. A lower density fracturing fluid is injected into an upper zone (12) of the formation via an annulus (20) of a perforated wellbore (10, 16) communicating with the upper zone (12) thereby causing a fracture (26) to propagate. Simultaneously therewith, a higher density fracturing fluid is injected into a lower spaced apart zone (14) via a tube (24) within the wellbore (10) which fluidly communicates with the lower zone (14) thereby causing simultaneously the propagation of a second fracture (28). Neither fracture (26, 28) contacts the other although complete fracture growth is obtained.