酸化在酸敏性砂岩储层中的可行性分析

Feasibility Analysis of Acidification in Acid-sensitive Sandstone Reservoirs

酸化是油气田开发中常用的增产技术手段,其目的是解除近井地带堵塞,改善地层渗流能力。但如果酸液体系选择不当,将给酸敏性砂岩储层带来伤害。在措施前通常进行酸敏评价实验,判断储层是否适合酸化处理,但酸敏评价标准存在局限性,不能全面准确指导酸敏性砂岩储层的酸化可行性。通过向酸液体系中加入有机弱酸、铁离子稳定剂、助排剂等措施,可减轻或避免酸敏效应对储层的伤害,使酸敏性砂岩储层的酸化收到较好的增产增注效果。

Acidizing is a common production enhancement technique used in oil and gas field development to unblock near-well zones and improve formation permeability. However if the acid system is not selected properly, it will cause harm to acid-sensitive sandstone reservoirs. Acid-sensitive evaluation experiments are usually carried out prior to the measure to determine the suitability of the reservoir for acid treatment, but there are limitations in the acid-sensitive evaluation criteria that do not provide a comprehensive and accurate guide to the feasibility of acidizing acid-sensitive sandstone reservoirs. By adding organic weak acids, iron ion stabilizers and drainage aids to the acid system, the acid-sensitive effect on the reservoir can be mitigated or avoided, so that the acidification of acid-sensitive sandstone reservoirs receives better effect of increasing production and injection.