Fluid loss control agents for drilling fluids containing divalent cations

Patent · Tue Jul 15 04:00:00 EDT 1986

OSTI ID:5433987

Gleason, P A; Szymanski, C D

A drilling fluid is described which consists of: a. an aqueous solution containing at least 10,000 parts per million of a divalent metal cation; b. a water-in-oil emulsion copolymer of monomers consisting of acrylamide and a water-soluble salt of acrylic acid wherein the acrylamide and acrylic acid are present in a molar ratio of about 70:30 to 95:5, the copolymer having a molecular weight of at least one million; and c. at least about 0.25 pounds per barrel of a particulate bridging solid capable of forming a filter cake against an exposed permeable formation; wherein b and c are present in amounts sufficient to reduce fluid loss during drilling.

• Assignee: National Starch and Chemical Corp., Bridgewater, NJ
• Patent Number(s): US 4600515
• OSTI ID: 5433987
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
020300* -- Petroleum-- Drilling & Production
03 NATURAL GAS
030300 -- Natural Gas-- Drilling
Production
& Processing
ACRYLAMIDE
ACRYLIC ACID
AMIDES
AQUEOUS SOLUTIONS
CAKING POWER
CARBOXYLIC ACIDS
CATIONS
CHARGED PARTICLES
CHEMICAL COMPOSITION
COLLOIDS
COPOLYMERS
DISPERSIONS
DRILLING
DRILLING FLUIDS
ELEMENTS
EMULSIONS
FLUIDS
HYDROGEN COMPOUNDS
IONS
LOST CIRCULATION
METALS
MIXTURES
MOLECULAR WEIGHT
MONOCARBOXYLIC ACIDS
MONOMERS
NATURAL GAS WELLS
OIL WELLS
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANIC POLYMERS
OXYGEN COMPOUNDS
PARTICLES
PARTICULATES
PERMEABILITY
POLYMERS
QUANTITY RATIO
SOLUTIONS
WATER
WELL DRILLING
WELLS