摘要
四川盆地二叠系火山岩分布面积广,岩性为火山角砾岩、凝灰岩、玄武岩,夹薄层泥晶灰岩,缝洞发育,埋藏深度超过6 000 m,地层研磨性强,井漏、井壁稳定问题突出且储层保护困难。通过对前期探井实钻资料的工程地质力学特征分析,明确了钻井技术难点,提出了适用于四川盆地二叠系火山岩钻井提速和储层保护技术。结果表明:①采用目的层专层专打的井身结构保证了储层的安全快速钻达;②火山岩井段采用旋冲工具或等壁厚螺杆复合钻进,创下单只钻头进尺最多和机械钻速最高2项新指标,提高机械钻速的同时有效缩短了钻井周期;③"以防为主、防堵结合"的技术思路下,优化形成了强抑制强封堵聚磺防漏钻井液,并通过多种抑制剂和封堵剂相结合的办法确保了储层保护效果和井壁稳定能力。
Massively in Sichuan Basin, the Permian volcanic rocks, which are composed of volcanic breccia, tuff, and basalt interbedded with thin micrite, are often more than 6000 m in burial depth with developed fractures and pores. Moreover, they have stronger abrasive property, bringing about many prominent problems of circulation loss, wellbore instability, and difficult reservoir protection. So, some drilling challenges were figured out by analyzing geomechanical characteristics of drilling data on exploration wells. Then, corresponding solutions of ROP improvement and reservoir protection suitable for the Permian volcanic rocks were put forward. Results show that(1) a casing program special for target layers may ensure safe and fast drilling to reservoirs;(2) these volcanic rocks are drilled using rotary impacting tool or equal-wall-thickness screw compound drilling. And two new records are set up, i.e., the longest single-bit drilling footage and the highest ROP. ROP is improved while drilling cycle is shortened effectively. and(3) based on one technical idea of "prevention dominant and prevention-plugging combination", a kind of drilling fluid of circulation-loss polysulfonate with strong inhibition and plugging property was optimally prepared, and one approach combining multiple inhibitors to plugging agent may guarantee effective reservoir protection and wellbore stability.
作者
谭玮
罗成波
齐从丽
彭红利
Tan Wei;Luo Chengbo;Qi Congli;Peng Hongli(Petroleum Engineering Technology Institute,Sinopec Southwest Oil&Gas Company,Deyang,Sichuan 618000,China)
出处
《天然气勘探与开发》
2019年第4期102-108,共7页
Natural Gas Exploration and Development
关键词
四川盆地
火山岩
深井钻井
井身结构
提速工艺
防漏堵漏
Sichuan Basin
Volcanic rock
Deeper drilling
Casing program
ROP improvement technology
Lost circulation control
