Page 270 - Well Control for Completions and Interventions

264 Well Control for Completions and Interventions

Table 7.5 Well data
SITP 2750 psi
Tubing gas oil contact 3500 ft. MD
Gas gravity 0.65 sg
Oil gradient 0.35 psi/ft.
Original packer (annulus) fluid Inhibited water 0.433 psi/ft. 8.33 ppg
3
Casing 1 (upper) 10/4 in. 65.7 lb/ft. 9.560 in. ID
5
Casing 2 (lower) 9/8 in. 53.5 lb/ft. 8.958 in. ID
1
5/2 in. 3 4/2 in. cross-over 4800 ft. MD
1
SSD 13,060 ft. MD
Packer 13,100 ft. MD
Plug (in tail-pipe) 13,115 ft. MD
Reservoir datum (top reservoir) 13,520 ft. MD
TD 14,000 ft. MD

• Density (weight) of fluid is required to give a 200 psi overbalance at
the SSD.
• Pressure differential at the SSD before it is opened.

7.3.10.1 Obtaining measured versus vertical depth data
For most wells, detailed trajectory data is easy to obtain (or at least it
should be). Data may be obtained as a hard copy in the form of a spread-
sheet. Multiple data points list MD in feet or meters, inclination (in
degrees), azimuth (in degrees) and TVD in feet or meters.
More commonly, trajectory data is stored and manipulated using pro-
prietary software such as Halliburton’s “Compass.” The use of software
simplifies and speeds up the process of converting MD to TVD (and vice
versa)(Fig. 7.8).
Completion schematics should list the MD of the key components
and features in the well. Some, but not all, schematics will list the corre-
sponding TVDs. If vertical depth is unknown, it can be obtained using
software or from a deviation survey. If survey data is used, interpolation
between two survey points is required unless known depth falls exactly
on one of the data points. A deviation survey for this example is provided
in Table 7.6.
For this example, the TVDs for each of the relevant points in the
completion are provided in Table 7.7.