6- Stimpac

STIMPAC*

1 EA * Mark of Schlumberger

Completion Skin is a Problem
Many references document presence of high skins with cased

hole gravel packs. – – – – –

Shell (SPE 26564, 1993) BP (SPE 26562, 1994 Pennzoil (SPE 30470) ARCO (SPE 27899, 1994) Petrobras (SPE 27360, 1994)


Skin present at time zero
Skin increases with time

2 EA * Mark of Schlumberger

What Causes High Skin?









Pre-existing formation damage LCM / Kill pills Low conductivity gravel/proppant Fines migration / plugged perforation tunnels Depositions Multi-phase flow Incomplete perforation packing Fluid Losses – Filter cake deposits on sand face – Deep bed filtration

3 EA * Mark of Schlumberger

Gravel Placement in the Field
Gravel volume required to fill perf tunnels is small

(~0.01 - 0.02 ft3/ft)
During most gravel packs an order of magnitude more

gravel is usually placed outside casing (~0.25 ft3/ft or more)
This implies at least one of the following:

– Voids are present outside cement sheath – A fracture is created during prepacking stage 4 EA * Mark of Schlumberger

Benefits of Hydraulic Fracturing
Higher injection rates and pressures coupled with high

proppant loadings significantly increase probability of packing a large portion of total pay interval.
True reservoir stimulation achievable.

– Undamaged well – Damaged well

5 EA * Mark of Schlumberger

Gravel Placement Methods
HRWP - High Rate Water Pack

– 5 to 15 BPM - pumping completion fluid with low concentration gravel. Typically (1 to 2 PPA)
Frac Pack

– 5 to 20 BPM - pumping gel with “ramped” concentration gravel. Typically (.5 - 15 PPA)

6 EA * Mark of Schlumberger

Optimization of the Treatment
Minimize Fluid Loss to Formation – After Perforating (Frac Past Damage) – Running Production (Mechanical Fluid Loss Control)
High Conductivity Flow Path – Adequate Prop Placement


Through Entire Interval

– High Conductivity Proppant – Fluid Selection – Optimized Pump Schedule
Large Inflow Area – Reduced Sand Face Velocity and Fines Migration 7 EA * Mark of Schlumberger

STIMPAC Annular Pack Fracture Pack

8 EA * Mark of Schlumberger

Field Results: 152 Completions Completion Skins for Frac-Packs (FP), High Rate Water Packs (HRWP), and Slurry Packs (SP)

Percentage of Completions

60 50 40 30

FP HRWP SP

20 10 0