香豆胶性质的研究

A STUDY ON THE PROPERTIES OF FENUGREEK GUM AS GELLING AGENT FOR FRACTURING FLUIDS

本文介绍了香豆胶的原料、化学结构、水溶液粘度和流变性、交联及交联剂、水基冻胶性能。香豆胶水基压裂液已在116口井试用,效果明显。

Fenugreek gum is the endosperm of seeds of trigonella foenum graecum,an annual herbaceous plant of leguminosae.Chemically,it contains more than 60% galactomannus with galactose to mannose ratio 1:1.2.The galoctose main chain has branches of one mannose unit on every but one of six galactose units.Commercial fenugreek gum is read- ily soluble in water,cold or hot,to leave 6.5-8.0% solid residue and its solutions are very viscous,stable in time and tolerent to inorganic salts:1% solutions in fresh water and containing 2%KCl practically have the same viscosity of 140 mPa.s at 30℃ and 170s^(-1).Aqueous solutions of fenugreek gum may loss their viscosities owing to the biodegradation processes,to prevent these bactericides can be used.These solutions are pseudoplastic and fenugreek gum reduces friction resistance of dilute aqueous solution. Borax in 0.01-0.02% or organic titanium chelates in 0.12-0.5% crosslink fenugreek gum in solutions at proper pH range to form gels of enhanced viscosities.These gelling systems were successfully used in hydrofracturing of more than a hundred oil wells of Yumen and other two Oil Fields.