Empirical Relationship among the Parameters in HLD Equation of Block Polyether Water Clarifier

In this work, the empirical relationship among three apparent parameters in the hydrophilic–lipophilic deviation (HLD) equation was studied to provide help in using the HLD equation to design a block polyether water clarifier for treating produced water in an oilfield. Ten block polyethers (including six linear polyethers and four branched polyethers) were prepared, and their HLD equations were measured. By curve fitting, the empirical relationship among apparent hydrophobicity characteristic (K), apparent characteristic curvature (Ccn), and apparent temperature coefficient (ct) of block polyether were obtained: K = 9.32ct, Ccn = 18e–24.5K (for linear polyether), and Ccn = 3.7e–20.8K (for branched polyether). By introducing these relationships into the HLD equation and combining an empirical relationship between propylene oxide/ethylene oxide (mole ratio) in a block polyether and K/Ccn, a new block polyether was designed to treat the produced water. The treatment result confirmed the reliability of these empirical relationships. The results expand the practical application of HLD theory and are useful for the development of a block polyether water clarifier.