Hydraulic fracturing is essential for stimulating tight-gas reservoirs, where hydrocarbon recovery is optimized by placing long and conductive fractures. It has been established in the oil and gas industry that placing hydraulic fractures in vertical wells can be achieved with a good degree of confidence; however, when the wellbore is deviated from the vertical plane, completion challenges can negatively impact the proper placement of the fracture and stimulation. Moreover, if wellbore deviation is very high (greater than 65°) and the formation to be fracture stimulated is located in the overlap of the last casing and production liner, achieving effective stimulation can be even more challenging.
Perforation, completion, and fracture stimulation of tight-gas reservoirs performed in highly deviated wellbores that are located in the overlap of the casing/liner is not common practice within the industry; when this situation is encountered, performing effective fracture stimulations is often considered impossible because of operational challenges and screenout risks.
This paper presents a case history of a successful perforation and fracture stimulation of a deep tight-gas reservoir where the wellbore was highly deviated (65°) and was located between a 7-in. casing and 4 1/2-in. liner overlap. Wellbore perforation was performed using an innovative oriented hydrajetting process, where the perforated interval was aligned to the plane of the maximum stress. Additionally, this paper documents the innovative isolation of the openhole section located below the zone to be fractured using a chemical packer.