Using Kaolin as Alternative for Na-Bentonite to Improve Hole Cleaning Process in Deviated Wells

Abstract

A lot of researches are proposed to improve the drilling operations to reduce the drilling cost to reach the target and to avoid a lot of drilling problems especially hole cleaning. In this research, an alternative material of bentonite was used in drilling fluid preparation to improve its ability in hole cleaning. An experimental rig was built to simulate the drilling process in the oil field. It consists of 3 m length of the outer pipe (OD 5 cm & ID 4.56 cm) and the Inner pipe with 1.25 cm OD. Na Iraqi Bentonite has been used as the main component. then kaolin was used as an alternative to the Na-Bentonite with four different concentrations (25 %, 50%, 75% &100%). it was proven that using kaolin with (25% and 50%) to water-based mud (bentonite 75% and 50%) will lead to increasing the density and decreasing the viscosities and yield point of drilling mud but within this decline in the viscosities and YP values, the percentage of cutting recovery (CR%) was improved. Especially with using drilling mud contains 50% kaolin + 50% Bentonite that leads to an increase in the capacity of drilling mud in lifting the cuttings in different inclinations. The results also showed that increasing the directional angle of the wells will reduce the quantities of cuttings lifted to the surface and increasing drill pipe rotation (120 RPM) will improve cuttings movement inside the hole and prevent them from accumulating in the bottom of the hole.