粘弹性表面活性剂(VES)压裂液

Viscoelastic Surfactant Based Fracturing Fluids

粘弹性表面活性剂 (VES)压裂液是SchlumbergerDowell公司开发的新型无聚合物压裂液 ,商品名ClearFrac,由表面活性剂长链脂肪酸的季铵盐溶解在盐水中而成。长链季铵盐分子在盐水中形成高度缠结的蚯蚓状成刚性长棒状胶束 ,使压裂液具有了一定的粘度和弹性 ,压裂液冻胶遇到烃类 (原油、天然气 )便会破胶。VES压裂液不需要破胶剂、交联剂、杀菌剂等 ,用量少 ,对地层伤害小。本综述分章介绍VES压裂液的开发简史 ,组成及结构 ;流变性 ;滤失性 ;导流能力 ;国外国内应用概况。

Viscoelastic surfactant(VES) based fracturing fluids under trade mark Clearfrac is a new, polymer free fluid of Schlumberger Dowell, composing of surfactants quarternary ammonium salts of long chain fatty acids dissolved in salt(s) water. These surfactants form long worm like or cylinderical micelles highly entangled each with others in aqueous salt solutions which thus become viscoelastic micellar gels of network structure. These gelled fluids break down in contact with hydrocarbons(crude oil or natural gas). For VES fluids any gel breaker, crosslinker, or bactericide are not necessary. Their use level is low and the damage for reservoir formations is very slight. The article reviews the brief developmental history, composition and morphological structure, rheologic behavior, filtration loss, conductivity in fractures, and applications abroad and in China of VES fracturing fluids.