Experimental investigation of the influence of perforating on gravel-pack impairment

Conference · Tue Dec 31 04:00:00 EST 1996

OSTI ID:457343

Blok, R H.J.; Welling, R W.F.; Venkitaraman, A ^[1]

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1. and others

Analysis of the performance of perforated, gravel-packed wells compared with openhole gravel-packed wells has indicated that the perforation could be responsible for the low productivity of internally gravel-packed wells. A series of laboratory experiments on weak rock (UCS = 1200 psi) was conducted to quantify this. Castlegate sandstone rock samples, 7 in. in diameter and 18 in. long, were perforated with shaped charges under downhole conditions. The perforations were gravel packed by circulating a gravel slurry past the tunnel entrance while applying a differential pressure. The preperforation, post-perforation and post-gravel-pack productivities of the core samples were monitored at different flow rates (5 to 20 b/d/perf). Sectional photographs of the core samples were taken at post-gravel-pack conditions for qualitative analysis. Performance evaluation of gravel-packed {open_quotes}realistic perforations{close_quotes} (debris and loose sand in the tunnel removed by drawdown-induced flow) versus {open_quotes}ideal perforations{close_quotes} (debris and loose sand removed by external means) showed the post-gravel-pack productivities of realistic perforations to be much lower than ideal perforations in oil-phase as well as water-phase experiments. Injection of fluid after gravel packing only temporarily unplugged the perforation tunnel. The study shows the importance of fines-and debris-free perforation tunnels in maintaining the productivities; of gravel-packed completions.

• OSTI ID: 457343
• Report Number(s): CONF-961003--
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
DRILL CORES
FLUID FLOW
MATERIALS TESTING
OIL FIELDS
OIL WELLS
RESERVOIR ENGINEERING
WELL COMPLETION