Conditioning of formation for sandstone acidizing

Patent · Tue Mar 31 04:00:00 EST 1992

OSTI ID:5310122

Gidley, J L

This patent describes a method of matrix acidizing a sandstone oil-bearing formation surrounding a wellbore. It comprises: injecting through the wellbore and into the formation a conditioning fluid having solvency for, or in, oil contained within the zone to be treated to miscibly displace the oil outwardly from the wellbore, the conditioning fluid including a solvent selected from the group consisting of carbon dioxide and mixtures of carbon dioxide and another solvent; injecting an aqueous acid preflush solution into the formation to displace the conditioning fluid outwardly from wellbore; injecting an acid solution containing HF into the formation to react with clays in the formation and to displace the acid preflush outwardly from the wellbore; and injecting an afterflush solution into the formation to water wet the formation and to displace the preceding fluids radially outwardly from the wellbore.

• Assignee: NOV; NOV-92-029042; EDB-92-106140
• Patent Number(s): US 5099924; A
• Application Number: PPN: US 7-631325
• OSTI ID: 5310122
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
020300* -- Petroleum-- Drilling & Production
ACIDIZATION
CARBON DIOXIDE INJECTION
CHEMICAL REACTION KINETICS
CLAYS
DRILLING FLUIDS
ENHANCED RECOVERY
EXTRACTION
FLUID INJECTION
FLUIDS
FLUORINE COMPOUNDS
HALOGEN COMPOUNDS
HYDROFLUORIC ACID
HYDROGEN COMPOUNDS
INJECTION WELLS
INORGANIC ACIDS
KINETICS
MISCIBLE-PHASE DISPLACEMENT
OIL WELLS
PH VALUE
REACTION KINETICS
SEPARATION PROCESSES
SOLVENT EXTRACTION
STIMULATION
WELL STIMULATION
WELLS