Manipulation of key parameters in RESS process for attapulgite particles utilizing in drilling mud and investigation on its rheological characteristics

The crucial role of drilling mud in the petroleum industry could be considered as a stimulus force to conduct profound investigation on this issue. Drilling mud can be composed of various types of clay. All the clays have their unique properties and when prepared with water, they will exhibit different viscosities, gel strengths, and most importantly, the rheological characteristics. Attapulgite clay for drilling is also known as salt water clay which does not show any significant signs of swelling. This paper presents an evaluation of the most significant parameters in the rapid expansion of supercritical solutions (RESS) process on the size and morphology of the precipitated attapulgite particles based on the Taguchi method and also investigates the rheological characteristics of drilling mud. The average particle size of unprocessed attapulgite particles was about 15 µm, while the average particle size of the ultrafine precipitated attapulgite particles was between 0.1 µm and 1.35 µm based on different experimental conditions. Regarding the rheological characteristics, findings indicate that the attapulgite particle size distribution affects yield point (YP), while it does not affect plastic viscosity (PV). This means that an excellent achievement in order to improve the carrying capacity of drilling mud during drilling operations is obtained.