西南石油大学学报(自然科学版)

• 油气化学工程 • 上一篇    下一篇

酸预处理在水力压裂中降低伤害机理研究

刘平礼1 *,兰夕堂2,李年银1,罗志锋1,刘书杰3   

  1. 1.“油气藏地质及开发工程”国家重点实验室·西南石油大学,四川成都610500
    2. 中海石油(中国)有限公司天津分公司,天津塘沽300450
    3. 中海石油研究总院,北京朝阳100028
  • 出版日期:2016-06-01 发布日期:2016-06-01
  • 通讯作者: 刘平礼,E-mail:liupingli@swpu.edu.cn
  • 基金资助:

    国家科技重大专项(2011ZX05030 005 08)。

A Study on Damage Reduction Mechanism of Acid Preflushing During#br# Hydraulic Fracturing

LIU Pingli1*, LAN Xitang2, LI Nianyin1, LUO Zhifeng1, LIU Shujie3   

  1. 1. State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation,Southwest petroleum University,Chengdu,Sichuan 610500,China
    2. Tianjin Branch Company,CNOOC,Tanggu,Tianjin 300450,China
    3. Research Center of CNOOC,Chaoyang,Beijing 100028,China
  • Online:2016-06-01 Published:2016-06-01

摘要:

低渗透储层进行常规加砂压裂常常由于压裂液破胶不彻底、残渣和滤液伤害等问题而影响压裂改造效果。压
裂前的酸预处理技术可降低压裂过程中伤害,改善压裂效果。利用激光粒度仪对常规压裂液破胶与酸性环境下压裂
液破胶过程中瓜胶分子尺寸进行定量观测,研究不同破胶环境下岩石基质伤害的主要因素;通过电镜扫描对注入破胶
液与酸液后伤害的岩芯进行微观分析。研究表明,在酸液存在条件下压裂液破胶后瓜胶分子尺寸大幅度降低,瓜胶分
子尺寸的降低比酸性环境对降低岩石渗透率伤害贡献更大,酸液能够很好地解除压裂液伤害,提高岩芯渗透率,同时
由于酸溶蚀可形成较为明显的溶蚀孔道,进一步提高基质渗流能力。

关键词: 酸液, 预处理, 水力压裂, 压裂液, 瓜胶尺寸, 伤害

Abstract:

Hydraulic fracturing is an effective way to develop low permeability reservoir. However,halfway gelout,fracturing
fluid residue and filtrate damage often reduce stimulation effect. On-site application of acid pretreatment fracturing technology
has been proved to be able to reduce damage during fracturing,but the damage reduction mechanism of acid pretreatment
remains unclear. In this paper,molecular dimensions of guar gum under both conventional and acidic conditions are quantitatively
observed by using laser particle analyzer(LPSA). Principle factors affecting the damage of gelout fluid to matrix in
acidic environment are also researched here. In addition,microanalysis of damaged core edge after injecting gelout fluid and
acid fluid is conducted by means of scanning electron microscope(SEM). We can draw conclusions from the results:molecular
dimension of guar gum after gelout is significantly reduced under acidic condition,and the reduction of molecular dimension
plays more important role than acidic environment in decreasing damage;acid fluid is able to effectively remove damage caused
by fracturing fluid,increase core permeability,and form corrosion channels.

Key words: acid fluid, preflushing, hydraulic fracturing, fracturing fluid, guar gum molecular dimensions, damage

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