Experimental study of rheological properties of aphron based drilling Fluids and their effects on formation damage

Abstract

Abstract. Drilling uid is one of the most important and expensive aspects of any drilling process. Colloidal Gas Aphron (CGA) has been found e ective in controlling the ltration rate by bridging the pores of the reservoir rock; hence, reducing the formation damage. This work aims to synthesize the CGA in water based drilling uids to study the stability, rheology, ltration loss characteristics and formation damage properties of the resulting uid. Besides, an investigation on type of polymer, surfactant, and their concentration e ects on the characteristics of the uid, as well as optimum ratios of polymers in drilling uid was performed. Experimental results showed that Xanthan Gum (XG) provides more acceptable rheological properties (especially viscosity) in comparison to Guar Gum (GG) for preparing the base uid. Moreover, the Sodium Dodecyl Sulfate (SDS) produces more stable micro-bubbles than Hexadecyl Trimethyl Ammonium Bromide (HTAB) as a surfactant. Bubble size measurement to observe the e ect of polymer, surfactant type and concentration was performed. Through the experiments, the pH of the drilling uid was monitored which proved the CGA introduced the best performance around a pH of 9. Furthermore, a XG/GG ratio of 3:1 is suggested to reduce the cost while maintaining the uid properties.

Developments Made in the Field of Drilling Fluids by Saint Petersburg Mining University

“…When drilling wells a significant proportion of the complications can be prevented by using drilling fluid systems that ensure maximum preservation of the nominal diameter of the wellbore due to various mechanisms of interaction between drilling fluids, formation fluids and rocks. For example, when drilling wells under conditions of abnormally low reservoir pressures with low permeability, various researchers propose the use of low-density solutions, for example, aerated liquids [40][41][42][43][44][45], aphron-based solutions [46,47] and oil-based solutions [48,49], as well as the technology of drilling under balanced wells [44,45,50]. In addition, when drilling into formations with low permeability like shale the drilling process is prone to problems.…”

Problem solution analysis on finding the velocity distribution for laminar flow of a non-linear viscous flushing fluid in the annular space of a well

“…The Ostwald -de Waale power-law model takes viscosity change into account, but does not include an initial shear stress. Since modern flushing fluids have an initial shear stress and tend to change viscosity with changes in shear rate, it becomes necessary to use a modified Herschel -Bulkley power law that considers both features of a non-Newtonian medium [14][15][16]. Research in simulation of fluid motion is limited to the Shvedov -Bingham and Ostwald -de Waale models, which do not take into account real parameters of the medium in sufficient accuracy [12,17].…”