This paper presents results related to the use of the ball sealer diversion technique to fracture long and multiple Triassic sand intervals in the Alwyn Field. It also focuses on the methodology adopted to design and prepare the treatment.

This technique was applied on a well producing from a gross pay zone thickness of 350 m with a perforated length of 98 meters. The production decreased drastically after condensate deposition in all reservoir intervals induced high skin levels. Due to low permeability, matrix treatments were discarded as a solution. Instead, a proppant fracture treatment was planned to by-pass the skin, using ball sealer diversion to treat the entire perforated interval.

The treatment was performed successfully in several stages including gel pad, proppant and ball sealers. Good indications of diversion showed that most of the intervals were fractured. However, performing such a treatment requires sophisticated engineering to determine the optimum number of stages, number of ball sealers per stage, gel and proppant volumes per stage and pumping rate.

The success of this operation will allow the technique to be considered for wider application such as fracturing long intervals in deviated or horizontal perforated wells at moderate cost.

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