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Title: DILUTE SURFACTANT METHODS FOR CARBONATE FORMATIONS

Abstract

There are many carbonate reservoirs in US (and the world) with light oil and fracture pressure below its minimum miscibility pressure (or reservoir may be naturally fractured). Many carbonate reservoirs are naturally fractured. Waterflooding is effective in fractured reservoirs, if the formation is water-wet. Many fractured carbonate reservoirs, however, are mixed-wet and recoveries with conventional methods are low (less than 10%). Thermal and miscible tertiary recovery techniques are not effective in these reservoirs. Surfactant flooding (or huff-n-puff) is the only hope, yet it was developed for sandstone reservoirs in the past. The goal of this research is to evaluate dilute (hence relatively inexpensive) surfactant methods for carbonate formations and identify conditions under which they can be effective. Anionic surfactants (SS-6656, Alfoterra 35, 38, 63,65,68) have been identified which can change the wettability of the calcite surface to intermediate/water-wet condition as well or better than the cationic surfactant DTAB with a West Texas crude oil in the presence of Na{sub 2}CO{sub 3}. All the carbonate surfaces (Lithographic Limestone, Marble, Dolomite and Calcite) show similar behavior with respect to wettability alteration with surfactant 4-22. Anionic surfactants (5-166, Alfoterra-33 and Alfoterra-38 and Alfoterra-68), which lower the interfacial tension with a West Texas crudemore » oil to very low values (<10{sup -2} nM/m), have also been identified. Plans for the next quarter include conducting wettability, mobilization, and imbibition studies.« less

Authors:
Publication Date:
Research Org.:
University of Houston (US)
Sponsoring Org.:
(US)
OSTI Identifier:
823035
DOE Contract Number:  
FC26-02NT15322
Resource Type:
Technical Report
Resource Relation:
Other Information: PBD: 1 Jan 2004
Country of Publication:
United States
Language:
English
Subject:
02 PETROLEUM; CALCITE; CARBONATES; DOLOMITE; ENHANCED RECOVERY; FRACTURED RESERVOIRS; FRACTURES; LIMESTONE; MARBLE; PETROLEUM; SANDSTONES; SOLUBILITY; SURFACTANTS; TEXAS; WATERFLOODING; WETTABILITY

Citation Formats

Mohanty, Kishore K. DILUTE SURFACTANT METHODS FOR CARBONATE FORMATIONS. United States: N. p., 2004. Web. doi:10.2172/823035.
Mohanty, Kishore K. DILUTE SURFACTANT METHODS FOR CARBONATE FORMATIONS. United States. doi:10.2172/823035.
Mohanty, Kishore K. Thu . "DILUTE SURFACTANT METHODS FOR CARBONATE FORMATIONS". United States. doi:10.2172/823035. https://www.osti.gov/servlets/purl/823035.
@article{osti_823035,
title = {DILUTE SURFACTANT METHODS FOR CARBONATE FORMATIONS},
author = {Mohanty, Kishore K},
abstractNote = {There are many carbonate reservoirs in US (and the world) with light oil and fracture pressure below its minimum miscibility pressure (or reservoir may be naturally fractured). Many carbonate reservoirs are naturally fractured. Waterflooding is effective in fractured reservoirs, if the formation is water-wet. Many fractured carbonate reservoirs, however, are mixed-wet and recoveries with conventional methods are low (less than 10%). Thermal and miscible tertiary recovery techniques are not effective in these reservoirs. Surfactant flooding (or huff-n-puff) is the only hope, yet it was developed for sandstone reservoirs in the past. The goal of this research is to evaluate dilute (hence relatively inexpensive) surfactant methods for carbonate formations and identify conditions under which they can be effective. Anionic surfactants (SS-6656, Alfoterra 35, 38, 63,65,68) have been identified which can change the wettability of the calcite surface to intermediate/water-wet condition as well or better than the cationic surfactant DTAB with a West Texas crude oil in the presence of Na{sub 2}CO{sub 3}. All the carbonate surfaces (Lithographic Limestone, Marble, Dolomite and Calcite) show similar behavior with respect to wettability alteration with surfactant 4-22. Anionic surfactants (5-166, Alfoterra-33 and Alfoterra-38 and Alfoterra-68), which lower the interfacial tension with a West Texas crude oil to very low values (<10{sup -2} nM/m), have also been identified. Plans for the next quarter include conducting wettability, mobilization, and imbibition studies.},
doi = {10.2172/823035},
journal = {},
number = ,
volume = ,
place = {United States},
year = {2004},
month = {1}
}