Stabilizing clays with potassium hydroxide

Journal Article · Wed Aug 01 04:00:00 EDT 1984 · J. Pet. Technol.; (United States)

DOI:https://doi.org/10.2118/11721-PA· OSTI ID:6425773

Sydansk, R D

A newly developed potassium-hydroxide (KOH) treatment, when properly designed and applied to claysensitive sandstone formations, will effectively and permanently stabilize clays and will prevent reduced oil production caused by changes in salt compositions of oilfield brines. The KOH treatment for stabilizing clays is applicable to a wide range of formation temperatures and mineralogies. The treatment consists of slow injection of a single aqueous solution containing KOH, along with soft-water pre- and postflushes. During laboratory flooding experiments in claysensitive sandstone, the treatment effectively stabilized clays and greatly diminished the tendency of fresh water to reduce permeability. Also, during laboratory floods, the treatment generated little, and often no treatmentinduced permeability damage. Treatment fluids are clear, nonviscous, aqueous solutions. KOH is a reactive, relatively inexpensive, readily available, inorganic chemical. Treatment effectiveness depends on KOH concentration, formation temperature, and treatment-fluid/sandstone contact time. For a studied clay-sensitive sandstone at its 185/sup 0/F (85/sup 0/C) formation temperature, optimal conditions were determined to be about 15 wt% KOH and about 16 hours of contact time. KOH clay stabilization results from caustic interacting irreversibly with clays in the presence of potassium ions. KOH ''permanently'' alters the silicate chemistry of clays and renders them insensitive to fresh water for a period well beyond the commercial life of the reservoir. KOH treatments, having operational and safety considerations similar to those of acid-stimulation treatments, are compatible with most oilfield and platform operations. Our concepts and procedures for evaluating claystabilization treatments by means of laboratory flooding experiments are discussed.

• Research Organization: Marathon Oil Co.
• OSTI ID: 6425773
• Journal Information: J. Pet. Technol.; (United States), Journal Name: J. Pet. Technol.; (United States) Vol. 36:9; ISSN JPTJA
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
020300* -- Petroleum-- Drilling & Production
ALKALI METAL COMPOUNDS
CLAYS
FORMATION DAMAGE
HYDROGEN COMPOUNDS
HYDROXIDES
OIL WELLS
OXYGEN COMPOUNDS
PERMEABILITY
POTASSIUM COMPOUNDS
POTASSIUM HYDROXIDES
RESERVOIR ROCK
RESERVOIR TEMPERATURE
ROCKS
SANDSTONES
SEDIMENTARY ROCKS
SIMULATION
STIMULATION
TEMPERATURE EFFECTS
WELL SERVICING
WELL STIMULATION
WELL TEMPERATURE
WELLS