NMR技术评价油田高温堵剂调剖效果
Evaluation the Effect of Profile Controlling Reagent SCA-II Injection at High Temperature by NMRI in Liaohe Oil Field
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摘要: 开采稠油的主要方式是注蒸汽,其中包括蒸汽驱和蒸汽吞吐。随着蒸汽吞吐的次数增加,稠油的采出量依次递减。由于油层的非均质性严重,蒸汽首先进入高渗层,高渗透地层的稠油首先被采出,低渗透率地层油采出很少。之后的蒸汽都进入高渗低层,即产生汽窜,所谓的低效蒸汽。蒸汽冷凝后形成热水,受到重力作用进入底部油层,降低了蒸汽的利用率;同时,由于蒸汽的重力超覆和沿高渗透地层窜流,使蒸汽在地层中的波及系数降低。为了克服蒸汽驱中的问题,国内外学者进行了大量的研究。通过注入一种流体-调剖剂,由于它的高粘度特点进入高渗透层后,将减少高渗通道的蒸汽的渗透率,消除“汽窜”,封堵高渗透地层,提高中低渗透油层的动用程度,提高原油产量和采收率。本文利用核磁共振成像(NMR)无损检测技术,对蒸汽驱SAD- 型高温调剖剂进行岩心动态评价实验,考察该调剖剂的热稳定性以及堵剂的封堵效果。Abstract: This paper present a new method of evaluation the injection of profile controlling reagent by NMRI at 200℃ in Liaohe Oil Filed to elimination stream flow along the high permeability layer. With the modern digital NMR SPECTROSPIN 47/40 made in BRUKE Corporation, the reagent first flow along higher permeability layer in the middle of the sample. Then, following stream flood into lower permeability area to increase oil productivity. The velocity of stream flooding into the sample affected the effect by the injection of SCA-II. The higher of velocity of stream flooding, the lager of the permeability rising by following stream. SCAII reagent can not only reduce the permeability in higher permeable area, but also increase oil productivity from lower permeable area.