Dynamic filtration of invert-emulsion muds

Journal Article · Wed Sep 01 00:00:00 EDT 1993 · SPE Drilling Engineering (Society of Petroleum Engineers); (United States)

DOI:https://doi.org/10.2118/24759-PA· OSTI ID:6121945

Jiao, D; Sharma, M M ^[1]

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1. Univ. of Texas, Austin (United States)

Dynamic-filtration experiments conducted on oil-based muds show that the dynamic-filtration rate is much higher than API filtration rates. The use of water-wet solids results in very poor-quality external mudcakes and high fluid-loss rates. Better external mudcakes are formed by mixing equal parts organophilic clay and mud. Filtration-loss-control additives (asphalt mineral pitches) do not reduce the equilibrium filtration rate, but do reduce spurt loss and limit solids invasion. In brine-saturated rocks, the invasion rate for oil-based muds is significantly smaller than for water-based muds because capillary pressure prevents the oil phase from entering the core in oil-based muds. Oil-based mudcakes are softer and more shear-sensitive than water-based mudcakes. Scanning electron microscope (SEM) photomicrographs indicate that oil-based mudcakes consist of individual water droplets coated with clay particles. This cake structure gives rise to the low permeability and shear sensitivity of oil-based muds.

• OSTI ID: 6121945
• Journal Information: SPE Drilling Engineering (Society of Petroleum Engineers); (United States), Vol. 8:3; ISSN 0885-9744
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
03 NATURAL GAS
DRILLING FLUIDS
LOST CIRCULATION
PERFORMANCE
NATURAL GAS WELLS
WELL DRILLING
OIL WELLS
ADDITIVES
COMPARATIVE EVALUATIONS
EMULSIONS
FILTRATION
FORMATION DAMAGE
LOSSES
PERMEABILITY
SHEAR
SHEAR PROPERTIES
SOLUBILITY
COLLOIDS
DISPERSIONS
DRILLING
EVALUATION
FLUIDS
MECHANICAL PROPERTIES
SEPARATION PROCESSES
WELLS
020300* - Petroleum- Drilling & Production
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