This paper demonstrates the successful application of horizontal gravel packing in the deepwater, subsea, floating-rig environment of Petrobras' Marlim field, offshore Brazil. The three gravel packs described in this paper were the first of their kind to be placed in water depths exceeding 2,500 ft (760 m) from a floating rig. The use of 13 chrome material screens require all acid treatments performed upon intial completion and during the life of the well to be well planned. Based on the experience gained from the Marlim wells, this paper will present guidelines for drilling the reservoir section, preparing the open hole and placing the gravel. Since one of these wells is an injector, we will also present guidelines for preparing a horizontal gravel pack for water injection. Among specific operational parameters and results we will discuss are precise gravel placement with close control over the pumping process. In addition, the gravel volumes placed demonstrate complete annular packing even in the presence of borehole washouts. As extensive in-house and industry-wide testing confirms, the use of extended-longevity well screens provided mechanical robustness and plugging resistance. We will also address the drill-in fluid and its role in preventing formation damage while depositing a filter cake that remains in place during gravel packing and then cleans up with production. Finally, we will review performance results (such as returns and initial productivity index for each well) indicating the viability of horizontal gravel packing in all deepwater environments.
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