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EDTA removes formation damage at Prudhoe Bay

Conference · · Soc. Pet. Eng. AIME, Pap.; (United States)
OSTI ID:5396237

Formation damage has been observed in some wells of the Prudhoe Bay Field. Laboratory and field testing confirmed that the primary cause of damage was the buildup of calcium carbonate scale either in the perforation tunnels or in the formation sandstone near the wellbore. Conventional acid treatments could dissolve this scale, but scale reprecipitation from the spent acid caused rapid productivity decline. A scale removal treatment using Na/sub 2/H/sub 2/EDTA has been developed that can effectively dissolve scale and chelate the dissolved metal ions. Chelation of the dissolved scale prevents scale reprecipitation. Of the 25 Prudhoe Bay wells acidized with EDTA, 19 have responded with a significant productivity increase. In 17 of these wells, productivity has been sustained after treatment.

Research Organization:
Exxon Production Research Co.
OSTI ID:
5396237
Report Number(s):
CONF-820927-
Journal Information:
Soc. Pet. Eng. AIME, Pap.; (United States), Journal Name: Soc. Pet. Eng. AIME, Pap.; (United States) Vol. SPE11188; ISSN SEAPA
Country of Publication:
United States
Language:
English