Abstract:
Formation of internal cake due to the invasion of reservoir rock by drilling, completion, and fracturing fluids is known to be one of the major causes of productivity reduction. Although the causes of internal cake formation are relatively well identified, actual physical mechanisms involved in internal cake formation are yet to be understood. In particular, a quantitative means of relating physical properties of drilling, completion, and fracturing fluids to the degree of productivity reduction are not very well established. Xanthan gum (XG) and partially hydrolyzed poly-acrylamide (PHPA) are used extensively as viscosifiers in the oil industry for different applications due to their unique rheological properties. An experimental study has been conducted to investigate formation damage characteristics of XG and PHPA based fluids. Extensional and shear viscosity measurements, and API filtration tests have been conducted using fluids of three different concentrations (0.5, 1.5, and 3.0 lb/bbl). A series of core flow experiments have been conducted using XG and PHPA solutions to investigate the effects of polymer concentration, fluid extensional and shear viscosities, and filtration loss characteristics on the original permeability of the porous media. Based on this experimental study it can be concluded that the flow of polymer-based solutions through a porous media, particularly, in the case of xanthan gum, may cause significant reduction in the original permeability of the porous media. High Trouton Ratio (a ratio between extensional viscosity over shear viscosity) values result high-pressure losses and these pressure losses would act as an internal filter cake. Therefore, high Trouton Ratio of the viscoelastic fluids can be achieved to utilize in the reduction of formation damage during drilling, well completion and hydraulic fracturing operations.
Page(s):
315-327
DOI:
DOI not available
Published:
Journal: Proceedings SPE-PAPG Annual Technical Conference, Volume: 0, Issue: 0, Year: 2004