一种缓释酸型高效驱油冲洗液研究

Study on A Slow-release Acid-type Efficient Oil-displacing Flushing Fluid

油基钻井液具有耐高温、润滑性好、储层伤害小等优点,广泛应用于深井、超深井等复杂井的开发。但钻井后井壁存在含油泥饼、套管壁上黏附有油基钻井液,影响固井质量。通过对冲洗液成分性质的研究和包裹材料的优选,选择乙基纤维素作为壁材,硼酸+醋酸作为芯材,开发了一种缓释酸型驱油冲洗液。利用纳米材料包裹弱酸物质形成包封酸,加入冲洗液辅料组分,形成冲洗液配方。对形成的冲洗液进行冲洗效率评价和界面胶结强度分析,当冲洗液加量为8%时,在70℃下冲洗效率可达到95.28%,同时有效提高了第一、二界面强度,有助于提高固井质量。

Oil-based drilling fluid has the advantages of high-temperature resistance,good lubricity,low reservoir damage,etc.,and is widely used in the development of deep and ultra-deep wells and other complex wells.However,there are oil-bearing mud cakes on the wellbore and oil-based drilling fluid attached to the casing wall after drilling,which affects the cementing quality.After studying the properties of the flushing fluid components and selecting the wrapping materials,a slow-release acid-type oil-displacing flushing fluid is developed by selecting ethyl cellulose as the wall material and boric acid+acetic acid as the core material.The encapsulation acid is formed by wrapping the weak acid with nanomaterials,and the excipients of the flushing fluid are added,and then the formula of the flushing fluid is formed.For the flushing fluid,the flushing efficiency is evaluated and interfacial cementation strength is analyzed.The results show that when the volume of flushing fluid is 8%,the flushing efficiency can reach 95.28%at 70℃,and the strength of the first and second interfaces is effectively improved,which is conducive to improving the cementing quality.