Using laboratory flow experiments and reactive chemical transport modeling for designing waterflooding of the Agua Fria Reservoir, Poza Rica-Altamira Field, Mexico

Journal Article · Wed Oct 01 04:00:00 EDT 2008 · SPE Journal

DOI:https://doi.org/10.2118/103869-PA· OSTI ID:950846

Birkle, P; Pruess, K; Xu, T; Figueroa, R.A. Hernandez; Lopez, M Diaz; Lopez, E Contreras

Waterflooding for enhanced oil recovery requires that injected waters must be chemically compatible with connate reservoir waters, in order to avoid mineral dissolution-and-precipitation cycles that could seriously degrade formation permeability and injectivity. Formation plugging is a concern especially in reservoirs with a large content of carbonates, such as calcite and dolomite, as such minerals typically react rapidly with an aqueous phase, and have strongly temperature-dependent solubility. Clay swelling can also pose problems. During a preliminary waterflooding pilot project, the Poza Rica-Altamira oil field, bordering the Gulf coast in the eastern part of Mexico, experienced injectivity loss after five months of reinjection of formation waters into well AF-847 in 1999. Acidizing with HCl restored injectivity. We report on laboratory experiments and reactive chemistry modeling studies that were undertaken in preparation for long-term waterflooding at Agua Frma. Using analogous core plugs obtained from the same reservoir interval, laboratory coreflood experiments were conducted to examine sensitivity of mineral dissolution and precipitation effects to water composition. Native reservoir water, chemically altered waters, and distilled water were used, and temporal changes in core permeability, mineral abundances and aqueous concentrations of solutes were monitored. The experiments were simulated with the multi-phase, nonisothermal reactive transport code TOUGHREACT, and reasonable to good agreement was obtained for changes in solute concentrations. Clay swelling caused an additional impact on permeability behavior during coreflood experiments, whereas the modeled permeability depends exclusively on chemical processes. TOUGHREACT was then used for reservoir-scale simulation of injecting ambient-temperature water (30 C, 86 F) into a reservoir with initial temperature of 80 C (176 F). Untreated native reservoir water was found to cause serious porosity and permeability reduction due to calcite precipitation, which is promoted by the retrograde solubility of this mineral. Using treated water that performed well in the laboratory flow experiments was found to avoid excessive precipitation, and allowed injection to proceed.

• Research Organization: Ernest Orlando Lawrence Berkeley National Laboratory, Berkeley, CA (US)
• Sponsoring Organization: Earth Sciences Division
• DOE Contract Number: AC02-05CH11231
• OSTI ID: 950846
• Report Number(s): LBNL-1161E
• Journal Information: SPE Journal, Journal Name: SPE Journal; ISSN SPEJAC; ISSN 0036-1844
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
58 GEOSCIENCES
AMBIENT TEMPERATURE
CALCITE
CARBONATES
CLAYS
DISSOLUTION
DOLOMITE
FORMATION DAMAGE
INTERSTITIAL WATER
OIL FIELDS
PERMEABILITY
PLUGGING
POROSITY
PRECIPITATION
REINJECTION
SOLUBILITY
SOLUTES
SWELLING
TRANSPORT
US GULF COAST
WATERFLOODING
Waterflooding Agua Fria Reservoir