Field experience in gravel packing the Dourado field, offshore Brazil
This paper describes the completion operations in the Dourado field, with emphasis on four major gravel packing problems: (1) formation taking excessive gravel; (2) failure of the gravel pack screens; (3) severe well productivity decline and (4) an unusual production casing buckling. The problem occurred in a new area of the field where the main reservoir, the Calumbi sandstone, is largely intercalated with plastic, water sensitive shale streaks. Presumably, stresses developed during gravel packing set off the creepage tendency of these streaks, which might be intensified by hydration upon rock imbibition with water-based completion and gravel carrier fluids. The result was a continuous migration of shale into adjacent permeable layers, leaving behind progressive void space, which allows for the excessive pumping of gravel. As the well was flowed, check-valve effect naturally ensued as lumps of dispersed shales concentrates around the wellbore; hence the decline on well productivity. Another consequence of the shale behavior was a detrimental effect in the wellbore stability, which reflected in buckling of the casing in front of the perforated interval. Finally, the screen failure, a less conjectural problem, was attributed only to poor manufacturing quality.
- OSTI ID:
- 160652
- Report Number(s):
- CONF-950501-; TRN: IM9603%%234
- Resource Relation:
- Conference: 27. offshore technology conference, Houston, TX (United States), 1-4 May 1995; Other Information: PBD: 1995; Related Information: Is Part Of 27. Annual Offshore Technology Conference: 1995 Proceedings. Volume 4: Field drilling and development systems; PB: 688 p.
- Country of Publication:
- United States
- Language:
- English
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