International Research Journal of Engineering and Technology (IRJET) e-ISSN: 2395-0056 Volume: 07 Issue: 04 | Apr 2020 www.irjet.net p-ISSN: 2395-0072 © 2020, IRJET | Impact Factor value: 7.34 | ISO 9001:2008 Certified Journal | Page 2048 Experimental Investigation of Rheological Properties of Drilling Fluid with Size Variation of Clay Particles Aashish Tyagi 1 , Arun T J 2 , Midhun Krishna 3 , Romith Vijay 4 , Bhairab Jyoti Gogoi 5 1 Student & Dept. of Petroleum Engineering, Presidency University, Bangalore, India 2 Student & Dept. of Petroleum Engineering, Presidency University, Bangalore, India 3 Student & Dept. of Petroleum Engineering, Presidency University, Bangalore, India 4 Student & Dept. of Petroleum Engineering, Presidency University, Bangalore, India 5 Assistant Professor, Dept. of Petroleum Engineering, Presidency University, Bangalore, India ---------------------------------------------------------------------***---------------------------------------------------------------------- Abstract - Drilling fluid is one of the major component for any drilling operation. Clays act as a reactive phase in any aqueous based fluid. In the recent times the rheological and filtration loss properties has been improved by addition of nano particles in drilling fluid system. In this study different sizes of Bentonite clay particles were used to prepare drilling fluid samples. Rheological and filtration loss properties were studied and it was found that the size of clay particles has lot to do with these properties. Significant change in drilling fluid properties has been observed and it was concluded that lesser the size of the clay particles better will be the properties. Keywords: Drilling mud, Gel strength, Rheological properties. 1. INTRODUCTION Drilling mud, or drilling fluid, represents any fluid which used during any drilling operation. Drilling fluid is the most important component for any successful drilling operations. The main properties of drilling fluids are Plastic Viscosity (PV), Apparent Viscosity (AV), Yield Point (YP) and Gel strength. These are also called as rheological properties. Along with these filtration loss properties are also plays a vital role during any drilling operation [1]. The main function of drilling fluid is to counter balance the formation pressure, carry the drilling cutting to the surface, to provide stability to the wellbore etc. [2]. If the PV is low then the drill bit will be capable of drilling rapidly because of the low viscosity of mud whereas high PV will lead to a viscous mud. The reactive phase of any aqueous based drilling fluid is the clay particle. These clay particles are the main reason for the development of the rheological properties [3]. Bentonite is the most common and widely used clay particles in oil industry. The roles that a drilling fluid has to play during drilling are like removal of the drill cuttings from subsurface to the surface, cooling and lubrication of the drill bits, maintain the hydrostatic pressure and increases the stability of the well bore [4]. The effectiveness of these functions are depending on rheological properties of the fluids as mentioned above. Most encountered problems while drilling the wells are, lost circulation and differential sticking [5]. Changing or enhancing the rheological properties without affecting the chemical composition is the best way to overcome these kind of drilling problems [6]. Currently we see a lot of application of Nano technology in oil industry [7]. Not only in drilling technology but also it has applications in enhanced oil recovery. It can also be used to stabilize water in oil emulsions in place of polymeric surfactants [8]. But getting a nano size is a complicated, costly and time consuming task. So if the size of the clay is very less like nano bentonite clay which has the size ranges from 1nm-1000nm, the use of such clay can give better quality mud cakes and the problems also could be reduced. In our work we did sieve analysis on Bentonite clay particles using readily available sieve with different mesh size. Using those different sizes of clay, we prepared drilling fluid samples and then their properties were studied. 2. MATERIALS AND METHODOLOGY 2.1 Material used The material used for this work are Bentonite clay (API Grade), weighting Barite (Industry grade), Carboxy Methyl Cellulose (CMC, Sigma Aldrich), Xanthan Gum (XC, Sigma Aldrich), Calcium Carbonate-Fine (CaCO3, Karnataka Fine Chem.), Sodium Hydroxide (NaOH, Karnataka Fine Chem.), Potassium Chloride (KCl, Karnataka Fine Chem.), Nut Plug and Mica 2.2 Equipment used The instrument used for this work are Hamilton Brach mixer, Fann VG meter (Model 35, Fann Instrument Company, Houston, Texas), Methylene Blue Test Kit (Fann Instrument Company, Houston, Texas), Fann API filter press (Model 300, Fann Instrument Company, Houston, Texas), Fourier-transform infrared spectroscopy (Shimadzu), Scanning Electron Microscope (Zeiss Sigma).