Stephen P. Mathis1
(1) Baker Oil Tools, Houston, TX
Abstract: Horizontal gravel packing successfully moved to the deepwater floating rig environment
This paper will use three case histories from Petrobras' Marlim field offshore Brazil to explain how horizontal gravel packing has moved successfully into deepwater floating rig environments. The three gravel packs described in this paper were the first of their kind to be placed in water depths exceeding 2,500 feet, from a floating rig. The wells are all subsea completions. Because of the premium tubulars used, extensive acid simulation must be avoided both upon initial completion and during the life of the well. Based on the experience gained from Marlim wells, the 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 as illustrated by excellent fluid loss control during the entire pumping operation. 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 remained in place during gravel packing and then was cleaned up with production in successful horizontal gravel packs in this challenging environment. Finally, we will review performance results, such as returns and initial productivity index for each well, that indicate the viability of horizontal gravel packing in all deepwater environments.
AAPG Search and Discovery Article #90914©2000 AAPG Annual Convention, New Orleans, Louisiana