摘要
近几年,随着我国石油天然气勘探开发力度向非常规能源井加大,页岩气井的勘探开发数量与日俱增。根据页岩气井的成藏机理,采用水平井钻井是实现高效开采页岩气的最佳方式。但是,由于页岩表面特性为水油双亲型,页岩层理和裂缝具有较强的毛细管力,同时,因为页岩地层具有倾角大、层理和裂缝发育成熟,导致在沿着最小主应力方向钻进过程中,钻井液中的液相会侵入发育成熟的层理和裂缝中,液相压力通过层理和裂缝进行传递,最终容易导致井壁失稳垮塌。因此,如何对发育成熟的页岩地层实施强化封堵以减少液相进入地层而造成的压力传递是解决井壁失稳垮塌的关键。文章针对四川长宁页岩气区块龙马溪组地层水平井长水平段钻井,根据对该区块页岩矿物成分和微观结构的分析,对高性能水基钻井液提出了相应的技术措施,建立了一套密度2. 10g/cm^3左右、抗温130℃的高性能水基钻井液体系,并对其各方面性能开展了室内评价,最终在长宁页岩气区块取得了成功的现场应用,同时取得了很好的经济效益和社会效益。
As exploration and development of unconventional resources increase,the number of shale gas wells grow rapidly.According to the reservoir accumulation mechanism of shale gas wells,the horizontal well drilling is the best way to realize highly efficient exploitation.However,there is strong capillarity on the shale surface due to the water/oil amphiphilic type.Because the shale formation has large dip,beddings and fractures developed mature,the liquid phase will invade through the beddings and fractures,leading to well collapse when drilling along the direction of the minimum principal stress.Therefore,how to plug the mature shale formation to reduce the liquid into the formation caused by the pressure transmission is the key to avoid the collapse.Based on the analysis of the mineral composition and microstructure of shale in the Longmaxi formation of Changning shale gas block in Sichuan Province,the corresponding technical measures for high performance WBM is proposed.It has a density of about 2.10g/cm^3 and a working temperature of 130℃,all its performance evaluated indoor.Finally,a successful field application is finished in Changning shale gas area,and good economic and social benefits achieved.
作者
万伟
葛炼
WAN Wei;GE Lian(CCDC Drilling Fluid Technology Service Company,Chengdu,Sichuan 610051,China)
出处
《钻采工艺》
CAS
北大核心
2019年第1期83-86,I0007,共5页
Drilling & Production Technology
基金
国家科技重大专项"非常规油气钻井关键技术与装备研究"(编号:2016ZX05022)
