瓜胶压裂液对储层的伤害特性

Characteristics of Formation Damage by Guar-Gum Fracturing Fluids

刘平礼 张 璐 邢希金 兰夕堂 李年银 罗志峰

LIU Ping-Li ZHANG Lu XING Xi-Jin LAN Xi-Tang LI Nian-Yin LUO Zhi-Feng

压裂液破胶后残渣是造成基质渗流率伤害和支撑剂充填层导流能力伤害的重要原因。为研究其伤害特性，从而减小对储层的伤害，在不同破胶剂加量下对两种瓜胶压裂液破胶后的性能进行测试并结合测得的破胶液黏度分析瓜胶相对分子质量大小，同时应用激光粒度仪测量两种压裂液破胶过程中的分子尺寸，对破胶液残渣进行离心并测量残渣含量，结合岩心流动实验对不同类型压裂液的破胶液进行伤害评价。研究表明：破胶时间过长会使破胶液的分子尺寸变大，出现絮凝现象，并造成更大的储层伤害；同时通常认为破胶液黏度越小，分子尺寸越小，对储层伤害越小的观点并不全面，其存在一定的局限性。

After gel-breaking, the residue is the main causes of damaging the conductivity of proppant bed deposition and the permeability of matrix. In order to research the damage characteristics and reduce the formation damage, in the study, the performance of the gel-breaking fluids of two kinds of guar-gum fracturing fluids at different dosages of gel breaker was investigated and the molecular weight of guar-gum after gel-breaking was analyzed by combining with the measurement of the viscosity of the gel-breaking fluids. The molecular size during the gel-breaking process was measured using a laser particle size analyzer and the residue content measured by centrifugating the gel-breaking fluids. Finally, the reservoir damage of different types of fracturing fluid was evaluated by the core flow experiment. The results showed that when the gel-breaking time was too long, the liquid molecular size would be bigger, and the flocculation phenomena would appear, which would cause more damage; meanwhile, the view that the smaller the viscosity of the gel-breaking fluids, the smaller molecular size, the smaller the damage to the reservoir was not comprehensive, and existed some limitations.