Aqueous-Based Fluids for Perforating and Oil-Phase Mud Removal

Conference · Tue May 01 04:00:00 EDT 1984 · Soc. Pet. Eng. AIME, Pap.; (United States)

OSTI ID:5405905

Goode, D L; Stacy, A L

Wells drilled with oil-phase muds are subject to severe damage due to loss of mud filtrate or whole mud to the reservoir matrix or hairline fractures. It is essential that this mud be removed prior to well production in order to gain maximum productivity. Because of the severity of this mud damage and the ineffectiveness of conventional treatments, a system of aqueous-based remedial treatments was developed to remove oil-phase drilling muds from damaged reservoirs. Mud solids are suspended and mud viscosity is permanently lowered by the aqueous-based system so that the mud can be flowed to the surface. Special surfactants restore the affected rock surfaces to a water-wet state. The system can also be formulated in high-density brines for spotting and perforating. The system's thermal stability enables it to be used for extended periods of time at elevated temperatures. The aqueous-based system represents an improvement over conventional hydrocarbon/mutual solvent treatments. The conventional treatments do not effectively suspend mud solids and only temporarily reduce mud viscosity, while leaving the treated rock surfaces in an oil-wet condition. In addition, hydrocarbon-based fluids require substantially higher pressures for placement in the well than the aqueous-based system. Laboratory data are presented showing the relative effects of the aqueous-based system and a conventional hydrocarbon/mutual solvent treatment on the degree and permanence of oil-phase mud viscosity reduction. The aqueous-based system more effectively and irreversibly lowers mud viscosity, as compared to the hydrocarbon/mutual solvent treatment. Cores damaged by oil-phase mud filtrate or whole mud were treated with either hydrocarbon/mutual solvent or the aqueous-based system. Regained core permeabilities following the treatments indicate that the aqueous-based system yields significantly higher permeability recoveries than the hydrocarbon/mutual solvent treatment.

• Research Organization: The Western Co. of North America
• OSTI ID: 5405905
• Report Number(s): CONF-8405166-
• Conference Information: Journal Name: Soc. Pet. Eng. AIME, Pap.; (United States) Journal Volume: SPE12901
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
020300* -- Petroleum-- Drilling & Production
AQUEOUS SOLUTIONS
BENCH-SCALE EXPERIMENTS
CHEMICAL COMPOSITION
DISPERSIONS
DRILLING FLUIDS
ENERGY SOURCES
FLUID WITHDRAWAL
FLUIDS
FORMATION DAMAGE
FOSSIL FUELS
FRACTURED RESERVOIRS
FUELS
HYDROCARBONS
LOSSES
MIXTURES
OIL WELLS
ORGANIC COMPOUNDS
PERFORATION
PETROLEUM
PHYSICAL PROPERTIES
SOLUTIONS
SOLVENTS
THERMODYNAMIC PROPERTIES
WELL SERVICING
WELLS
WORKING FLUIDS