Unlocking Reserves, Fracturing Tight Gas-Condensate Bearing Sandstone: The Base History of a North African Field (Algeria)

Hydraulic fracturing technique is worldwide used to unlock reserves in tight formations. The Devonian layer, present in this field in the Berkine Basin (Algeria), is gas condensate bearing with a permeability range of 1 to 0.1 md; the zone shows also an highly tectonic stresses, and the frac gradient can rise easily values above 1.0 psi/ft. 3 previous fracturing treatments performed in 2005 and 2006 in 3 vertical wells were without success, due to the high stresses encountered, the wrong frac designs and completion limitation. Aim of this paper is describing the successful multiple propped hydraulic fracturing treatments, placed in a subhorizontal well in March 2012, listing all the actions done in terms of Completion design Materials choice and Frac schedule optimization. This paper describes also the multiple lessons learned experienced in the execution phase of the multifrac job about frac placement, frac design and completion choice, that have to be considered for the fracturing jobs already planned, in fact the good results of this treatment allowed the Operator to plan a future appraisal/development phase for the Devonian layer.