CT Extended Reach Acid Stimulation in Openhole Wells, Offshore Saudi Arabia: A 23-Well Case Study

Abstract

A new generation of ultradeep wells has significantly increased in Saudi Arabia in green and brown field developments. One ongoing complex field development is the Manifa field, which is located in northeast Saudi Arabia. Manifa is probably the largest extended reach hydrocarbon producer project globally, with more than two-thirds of its 350 wells being extended or mega reach wells. The offshore portion of the field contains 83 developed wells in 13 platforms with openhole sections within the range of 3,000 to 9,000 ft, where acid stimulation intervention is necessary to remove reservoir damage and to help improve well performance after drilling operations. Although the openhole completions provide superior deliverability, a primary challenge remains with respect to rigless intervention.The offshore platforms have limited deck load capacity and available deck space necessary for performing coiled tubing (CT) stimulation operations. To overcome these constraints, applicable CT operations from a jackup barge combined with a support pumping vessel were introduced and subsequently developed to allow well interventions using large treatment fluid volumes.This paper describes CT stimulation campaigns performed on extended reach horizontal wells in the Manifa field. A summary of the steps involved during an improved CT intervention technique successfully implemented within this field to access some of the longest openhole horizontal wells is presented. The importance of a combined application of jackup and stimulation vessel units to help ensure safe project execution on offshore platforms is reviewed.