Hydroxyethyl Cellulose (HEC) is a water-soluble polymer that is widely used in the oil drilling industry as a rheology modifier and fluid loss control agent. It is a non-ionic cellulose ether that is derived from natural cellulose, and its properties make it suitable for a variety of applications in drilling operations. This article will provide an overview of the use of HEC in oil drilling, including its properties, benefits, and potential drawbacks.
Properties of Hydroxyethyl Cellulose
HEC is a high molecular weight polymer that is derived from cellulose, a natural polymer found in plant cell walls. It is created by reacting cellulose with ethylene oxide, which results in the formation of hydroxyethyl groups along the cellulose chain. The degree of substitution (DS) of HEC refers to the number of hydroxyethyl groups per anhydroglucose unit (AGU) in the cellulose chain. The DS can be adjusted during the manufacturing process, allowing for the production of HEC with a range of properties.
HEC is a water-soluble polymer that can be used in both aqueous and non-aqueous drilling fluids. It is highly shear-thinning, which means that it can be easily pumped at low shear rates but will thicken and gel at high shear rates. This property makes HEC an effective rheology modifier, as it can help to maintain stable flow properties in drilling fluids.