一种利用热化学解除特超稠油油藏堵塞的方法

针对特超稠油油藏热采过程中酸化解堵效果差的难题,开展了热化学剂实验、降黏实验、降黏剂与热化学剂复配实验,研究出一种利用热化学流体的升温、增能作用有效解除特超稠油近井地带堵塞的方法。室内实验表明,亚硝酸盐和铵盐的热化学体系反应可释放大量热量,提高周围温度,同时释放出大量气体。这2个特点有利于解堵,但与特超稠油也会发生混合液反相乳化,建议使用过程中采取一定破乳手段提高解堵效果。该方法在现场应用证实有效,为该类油藏的解堵提供一种新思路。

A method of thermochemical block removal for extra and super heavy oil reservoirs

Acidizing block removal is inefficient in thermal recovery of extra and super heavy oil reservoirs.Experiments on thermochemical agent,viscosity reduction,and the combination of viscosity reducer and thermochemical agent have been conducted.An effective method of removing near wellbore blocking in extra and super heavy oil reservoirs has been developed by using the temperature rise and energizing effect of thermochemical fluid.Indoor experiments indicate that the thermochemical reaction of nitrate and ammonium salt system can release a great quantity of heat,improving ambient temperature and giving off a lot of gas which are helpful for block removal.However,reversed phase emulsification may occur when mixing with extra and super heavy oil,so it is recommended to adopt some emulsion breaking methods to improve block removal result.This method has been proved effective through field applications,providing a new concept for block removal in similar oilfields.