甲酸盐钻井液在长北区块的应用

Application of Formate Drilling Fluid in Changbei Block

赵向阳 张小平 陈磊 张振活 孙艳

Zhao Xiangyang Zhang Xiaoping Chen Lei Zhang Zhenhuo Sun Yan

中国石油川庆钻探工程有限公司钻采工程技术研究院, 陕西西安 710021; 低渗透油气田勘探开发国家工程实验室, 陕西西安 710021; 中国石油川庆钻探工程有限公司长庆钻井分公司, 陕西西安 710021

Drilling & Production Engineering Technology Institute of CCDC, Xi’an, Shaanxi, 710021, China; National Engineering Laboratory for Low-Permeability Oil-Gas Field Exploration and Development, Xi’an, Shaanxi, 710021, China; Changqing Drilling Branch of CCDC, Xi’an, Shaanxi, 710021, China

为了防止水平分支长裸眼井段井壁失稳,长北区块应用了甲酸盐钻井液。以甲酸钠为加重剂和抑制剂,通过测试甲酸钠对基浆黏度和切力的影响、模拟地层条件进行甲酸钠对岩心的伤害试验、评价甲酸钠的抑制性及加重效果,研制出一种适合长北区块水平井的甲酸钠钻井液。现场2口井的应用表明,该钻井液具有抑制性强、滤失量小、流变性良好、固相含量低等优点,综合防塌效果好。该区块应用甲酸钠钻井液成功钻穿水平段多套泥岩段,表明甲酸钠钻井液能有效保持稳定井壁,避免井下复杂情况出现,解决了长北区块水平分支长裸眼井段的安全钻进问题。

In Changbei Block,formate drilling fluid was used to avoid shale instability in long horizontal open hole sections.Sodium formate was selected as weighting agent and inhibitor.Through experimental study on base mud viscocity and shear force,and damage on cores under simulated formation conditions,the inhibition and weighting performance of sodium formate were evaluated.On this basis,a sodium formate drilling fluid was developed for horizontal wells in Changbei.Its field application in two wells shows that this fluid has the characteristics of strong inhibition,small filtration,good rheology and less solid content,and it is effective for anti-collapse.Multiple horizontal shale sections were penetrated efficiently with the sodium formate drilling fluid,indicating that it can stabilize borehole effectively and prevent downhole complexities.Therefore,it can ensure safe drilling in long open horizontal sections in Changbei Block.

https://doi.org/10.3969/j.issn.1001-0890.2013.01.008