马深1 井超深井钻井液技术

马深1 井是中石化部署在川东北地区的一口重点预探直井，完钻井深8 418 m。本井四开、五开井段6 225.4~8 418.0 m，井底温度高达175 ℃，存在高温污染、泥页岩井壁失稳、酸根污染以及携砂问题，常规钻井液性能已无法满足正常施工要求。鉴于以上技术难点，通过材料优选、配方优化，成功研制了KCl 聚胺磺化钻井液体系和抗高温聚磺钻井液体系。经过体系验证: KCl 聚胺磺化钻井液具有良好的抑制能力；抗高温聚磺钻井液体系抗温达200 ℃。同时，在应用过程中形成了成熟的超深井钻井液处理技术。现场应用表明，四开平均井径扩大率3.1%，五开平均井径扩大率5.1%，有效地解决了该区块超深井钻井液技术难题，具有一定的推广价值。

Drilling fluid for the super-deep Well Mashen-1

Well Mashen-1 is a key vertical well deployed in northeastern Sichuan by SINOPEC for preliminary exploration. Boasting of a TD of 8 418 m, it is the deepest land well drilled in Asia. The fourth and fifth spud-in intervals were drilled at depth of 6 225.4 ~8 418 m with bottom-hole temperature up to 175 ℃. Accordingly, these intervals have problems related to high-temperature pollution, sidewall instability in mud shale, acidic pollution and sand-carrying. Generally speaking, properties of conventional drilling fluid may not satisfy demands for routine operation. With consideration of these technical challenges, optimized materials and formula were deployed to develop KCl polyamine sulfonated drilling fluid system and temperature -resistant polysulfonate drilling fluid system. Test results indicate that KCl polyamine sulfonated drilling fluid has outstanding inhibition capabilities and can endure temperature up to 200 ℃. In addition, highly matured processing technologies for drilling fluids in super deep well have been developed. Field application results show that the well diameter has been enlarged by approximately 3.1% during the fourth spud-in and 5.1% in the fifth spud-in. Since these technologies can effectively cope with the challenges in drilling fluid for super deep wells, they can be promoted for more extensive application.