Luke F. Eaton, SPE, Wrandall Reinhardt, SPE, ConocoPhillips; J. Scott Bennett, SPE,
Devon Energy Corporation; Kenyon Blake, SPE and Hugo Morales, SPE, Slumberger
ConocoPhillips is developing the Magnolia field with a tension-leg platform (TLP)
in 4,674 ft of water at Garden Banks Block 783 in the Gulf of Mexico. The wells
target multiple zones, resulting in complex directional wells with 50–60° maximum
hole angles. The wells are completed using dry trees from the TLP and are produced
primarily from massive, fine-grained, Pleistocene reservoirs.
These reservoirs require sand control to prevent sand production at the expected
drawdowns planned during the life of the wells. To help ensure high-rate, long-life
completions, the producing zones are frac packed. The average perforated interval
during the initial completion program was 310 ft, with a maximum perforated interval
of 571 ft. The typical production-casing string for the wells consists of 10 3/4-in.
casing with an 8 1/16-in. production liner. Drift diameter through the tapered production
casing is 9 1/2 and 6 1/2 in., respectively. The 6 1/2-in. drift diameter allows
using common-sized screens and packers. The wells are generally completed with a
4 1/2 × 3 1/2-in. tapered-tubing string.
Premium screens with shunt tubes are used on the wells because of the long deviated
intervals. The "frac-pack" stimulation treatments are pumped at rates of27 to 40
bbl/min with a viscoelastic-surfactant (VES) carrier fluid. Washpipe-conveyed downhole-pressure
and -temperature gauges and radioactive tracers are used to help analyze the treatment
This paper will discuss screen-selection philosophy in silt/very-fine-sand reservoirs,
carrier-fluid selection, perforation strategy, and ability to frac across shale
intervals. The paper also will cover the effectiveness of achieving a frac pack
with premium screens with shunt tubes, on the basis of downhole-pressure and temperature
and radioactive-tracer information, and will discuss revised operational practices
that resulted in zero- to negative-skin completions across long, perforated intervals,
which continue to produce sand-free after extreme reservoir depletion.