Reducing recurrent pipe trips offer significant time savings easily translating directly into improved well and/or project economic benefit. Utilizing a reliable multizone single trip method that reduces additional pipe trips compared to performing conventional stacked cased-hole Frac-Pack (FP) or High Rate Water Packs (HRWP) has a major impact on the overall completion costs associated with reservoirs containing multiple completion intervals. This multi-zone single trip system improves operational performance and stimulation effectiveness by incorporating an innovative service tool sealing mechanism with complete independent zonal isolation for each treatment interval. Additionally a selective zonal opening/closing tool offers an added degree of well performance control. This paper provides a summary of multizone single trip system introduction and utilization beginning in 2007 to Bekapai and Sisi Nubi field projects in Mahakam Delta offshore Indonesia for sand control in mutlilayer reservoirs. To date, a total of 74 zones with FP/HRWP's on 16 wells have been successfully installed. An average of 5.3 days completion installation time has been achieved on 13 wells with 3-6 zones at an average depth of 12,000 ft (3,657 m). This compares to a completion installation time of 20 days per typical 5 zone stacked FP/HRWP well. As a result of efficiencies gained utilizing multizone completion technology greater than 70% rig time reduction has been achieved with $US 30 million dollars savings on the project thus far. This paper will also present lessons learned, application concerns when considering multizone single trip as a completion option and challenges going forward to improve implementation of multizone completion technology.

The oilfield Tchendo, located 18 miles off the coast of the Republic of Congo, has been operated since 1991 by Total E&P Congo in depths of approximately 100 meters of water.The shallowest of the three reservoirs, the Sénonien reservoir (400 m TVD SS), involves an intercalation of carbonate layers with thicker (5 to 15 meters) but poorer quality siltstones.Various attempts to enhance productivity on existing wells were unsuccessfully carried out since initial production, including selective or extensive perforation, acid treatments on the carbonate layers, and, in recent years, hydrajetting fracture stimulation on three wells.Although the field is non-conventional, so far, it has been developed conventionally. A large amount of the original oil in place still remains in the reservoir. To make the redevelopment project viable, a step change in stimulation techniques is to be undertaken.Two workovers were performed at the end of 2012 as a "proof-of-concept". Innovative fracturing technologies, including hydrajetting, were combined to deliver a non-sleeve scenario for horizontal well multi-stage fracturing. The workovers resulted in the largest fracturing treatment executed by Total on an offshore well. This paper reports on the lessons learned in the process of fracturing this non-conventional reservoirs that will be capitalized for the future redevelopment of the project.

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