Coiled tubing becomes the key enabler for successful multilateral well development campaign offshore Brazil

To develop the mature Pampo Field offshore Brazil, Schlumberger used CT in perforating, logging for cement evaluation, stimulation and stiffline operations.

S. Trummer, D. Silva, V. Cano and M. Guzman, Schlumberger; N. Siqueira, C. Peixoto, and V. Nazareth, Petrobras

Pampo, produced through a fixed platform, was among the first producing fields offshore in Brazil. The maturation of the field and consequent decrease in oil production required a different completion strategy for the operator. The key reservoir, the Macaé/Quissamã, is the prime target for exploitation because it still has substantial oil in place, with good total recovery and actual recovery factors. The development of this reservoir was vital to the survival of the field. Several technical issues exist for developing this reservoir, especially during drilling, because of the high density of wells in the area. Each new well had to be carefully planned to avoid collision with existing wells and also to optimize the reservoir drainage.

Several depleted wells have been evaluated to determine whether they should be abandoned and/or substituted. There were limited options for replacing these depleted wells. With collision problems at shallow depth looming as a huge risk, the number of new wells that could be drilled was low. Furthermore, the lack of rigs available for production drilling and the high slot utilization on these platforms provided additional complications. Ultimately, the development of multilateral wells was identified as the most viable solution. From the main bore, once past the critical collision zone, several legs could be drilled to increase the drainage area.

Multilateral construction in this scenario is a nontrivial task. It requires the well junction to be placed at an area of high deviation, adding complexity for any intervention work. Nonetheless, the use of coiled tubing for most of the well completion operations proved to be the key enabler in this successful multilateral well development campaign. The versatility of CT technology significantly decreased the time needed for well completions and its other applications.