第33卷第4期 2016年7月
钻井液与完井液
DRILLINGFLUID&COMPLETIONFLUID
doi: 10.3696/j.issn.1001-5620.2016.04.024
MCB系列微胶囊破胶剂的性能陈挺，周勋，党伟，牛增前，周凤翔，杨冀平
（海钻探工程技术研究院，天津300280）
陈英等.MCB系列微胶囊破胶剂的性能[3].钻并液与完井液，2016，33（4：114-116.
Vol.33 No.4 July2016
摘要为解决水平并分段压裂过程中前段压裂液快速破胶的间题，以过硫酸铵为破胶剂，采用乳液聚合法合成2种具有不同囊衣结构的微胶囊破胶剂。测定了微胶囊破胶剂的有效含量、包埋率、释效放速率及延破胶效果。实验结果表明，
包埋率分别为83.85%和85.89%。与替通市售包
MCB-1、MCB-2两种缴胶囊破胶剂的有效含量分别为38.56%和39.69%，
蜡胶囊破胶剂相比，该微胶囊破胶剂的释放速率较慢。延迟破胶实验表明，微胶囊破胶剂可以在4h内保持压裂液的黏度缓慢降低，最终破胶后压裂液的黏度小于10mPa·s，显示出良好的延迟破胶性能，且对地层渗透率的伤害率小于12%。
关键词微胶囊破胶剂乳液聚合；过硫酸铵；延迟破胶
中图分类号：TE357.12
文献标识码：A
文章编号：1001-5620（2016）04-0114-03
Properties of the MCB series Microcapsule Gel Breaker
CHEN Ting, ZHOU Xun, DANG Wei, NIU Zengqian, ZHOU Fengxiang, YANG Jiping
(Research Institute of Engineering,CNPC Bohai Drilling Engineering Company Limited, Dagang,Tianjin300280)
Abstract In segmented fracturing of horizontal wells, gels of the fracturing fluids are often broken too early for the fluids to function properly. To solve this problem, two micro capsule gel breakers, MCB-1 and MCB-2, with different capsule cloths have been synthesized through emulsion polymerization, using ammonium persulfate as the core. The active contents, percent of encapsulation, rates of release and gel breaking retardation have been measured in laboratory experiments. The active contents of MCB-1 and MCB-2 are 38.56% and 39.69%, respectively, and the rates of encapsulation of MCB-1 and MCB-2 are 83.85% and 85.89%, respectively. Compared with the commercially available encapsulated gel breakers, MCB-1 and MCB-2 have comparatively slow release rates. The experiments also show that MCB-1 and MCB-2 gradually reduce the viscosity of the fracturing fluid in 4 hours, and the viscosity of the fracturing fluid after gel breaking is less than 10 mPa's, indicating that the synthesized micro capsule gel breakers are effective in slowing down gel breaking, and the impairment of formation permeability caused by these gel breakers is less than 12%.
Key words Micro capsule gel breaker; Emulsion polymerization; Ammonium persulfate; Gel breaking retardation
随着技术的进步，水平井多级分段压裂技术在各油田的应用越来越广泛。该技术要求所有各段中的压裂液在施工结束后统一破胶返排出地面"。前期压裂段中的压裂液停留时间较长，在破胶剂的作用下会化水向地层中扩散，其对地层的二次污染随着时间的延长而增大。这就需要寻找一种新型的破胶剂来调控压裂液的破胶时间。目前现场施工主要是使用以过硫酸铵为破胶剂、用石蜡包覆的胶囊破胶剂国来保证压裂液的携砂性。该类型破胶剂的
释放机理是膜应力破裂，在破胶时间上不能够达到人为控制的效果3)。微胶囊破胶剂(4-5)是近些年来新的发展方向，其破胶机理是水分子通过溶胀后的高分子膜进人囊心溶解破胶剂，溶解后的破胶剂通过浓度扩散流出胶囊外，从而起到破胶作用[6]。笔者介绍的微胶囊破胶剂，采用乳液聚合的方法在过硫酸铵表面将丙烯酰胺类单体聚合，通过选取不同的单体得到不同的囊衣，从而控制水进入胶囊内部的时间，最终达到延迟定时破胶的目的。
第一作者简介：陈挺，1982年生，工程师，博士，毕业于中国石油大学（华东）油气田开发工程专业，现在从事酸
化压裂等工作。电话18202613027；E-mail:15315019827@163.com。万方数据