A Review of Completions and Gravel-Pack Techniques of the Xijiang Development

Abstract

The first gravel-packed completions have been run in the Pearl River mouth basin of the South China Sea in the Xijiang fields. The reservoirs in these fields are characterized by unconsolidated, friable, high-permeability sandstones, and, as such, presented many challenges. This paper addresses the development of these fields and how reservoir characteristics and parameters and unexpected deviations were experienced by the operator, as well as the impact these deviations had on completion designs. Important considerations included the need for sand control, zonal isolation, high-rate production, and reduced completion durations. Finally, the practical application and evaluation of pregravelpack stimulation techniques, gravel-pack carrier consideration, fluid-loss controls, and general completion procedures are presented, along with the innovative completion designs developed to manage these needs.

Single-Trip Multiple-Zone Completion Technology Has Come of Age and Meets the Challenging Completion Needs of the Gulf of Mexico's Deepwater Lower Tertiary Play

“…(Rogers et al, 1997) Once the formation is treated, and the service tool is removed from the completion string, there is no mechanical device in place to prevent fluid loss to the formation.…”

“…(1) Run the entire screen and liner assembly with a snap latch on bottom, a liner packer on top, isolation packers in between, and the operating string inside the screen liner (3) Set the liner hanger packer and release the setting tool and operating string (4) Set all isolation packers (5) Run a concentric 1.90-inch Hydrill CS by 2-3/8 inch EUE tapered string inside the drill pipe and operating string (6) Sequentially gravel pack all zones through their port collars (7) Return to lower zone and repack, if required. Additional features are that downhole rotation during the gravel-packing operation was eliminated, a full column of sandladen slurry could be reversed out after sand out without pressuring other intervals, each interval could be repacked during the life of the completion, and by installing production sealing units with sliding-sleeve circulating devices inside the screen and liner assemblies, any combination of isolated intervals could be produced or selected for water injection.…”

Screenless Single Trip Multizone Sand Control Tool System Saves Rig Time

“…Other tool systems similar to the complex systems tried at Milne Point have been used successfully elsewhere, but they were considered unsuitable for the fracturing applications needed here. 1,2 It is typical for the wells in Milne Point to encounter three economically producing sands. Treating each of those sands individually with gravel packs or frac packs consumed from 7 to 21 days of rig time, depending on unforeseen delays such as weather and hole conditions, in an expensive operational environment.…”

Evolution of Single-Trip Multiple-Zone Completion Technology: How State-of-the-Art New Developments Can Meet Today's Ultra Deepwater Needs

“…These fields are comprised of multiple-layered reservoirs characterized by unconsolidated, friable and high-permeability sandstones (1700 to 30,000 md) that had to be commingled to be produced economically. 4,5,6 The STMZ differed from the "BETA" system in that the STMZ eliminated the need to run an inner concentric string from surface (Figure 2). It also eliminated the handling at surface of the inner and outer string when moving the service string to the next interval.…”