摘要
为防止煤层气水平井出现井壁垮塌需使用聚合物钻井液,聚合物钻井液在稳定煤层井壁的同时也对煤层造成严重污染,需采用后期破胶技术来解除污染。相对于油气井,煤层气井破胶剂具有破胶速度慢和残渣多易损害煤层的特点,基于此优选出适宜煤层的破胶剂JBK,加量1%破胶剂JBK,2 h条件下可以将聚合物钻井液完全降解掉,具有低温破胶迅速、彻底和无残渣特点。室内岩心流动实验结果表明,破胶液自身对煤层具有改善作用,能有效解除聚合物钻井液造成的煤层污染。现场施工中采用表层清洗和深部解堵相结合的破胶施工工艺,取得了较好施工效果,成功应用了6口U型井破胶作业。
Polymer drilling fluid for CBM horizontal well collapse causes serious pollution of coal seam in the stability of shaft wall,which needs to post gel breaking technology to remove pollution. Relative to the oil and gas wells,gel breaker for coalbed methane wells has the characteristics of slow gel breaking speed and more residues for easily damaging coal seam. Based on this,the selected appropriate seam breaker JBK can degrade polymer drilling fluid completely under the condition of adding 1% gel breaker in 2 hours with fast and downright gel breaking in low temperature and no residue. Indoor core flow experiment results show that the gel breaking liquid can improve coal seam and effectively remove the pollution of coal seam caused by polymer drilling fluid. In the site construction,by adopting the combinated gel breaking construction technique of surface cleaning and deep plugging and removing,we get good construction effect,which successfully applies in gel breaking operations of 6 U wells.
出处
《煤矿安全》
CAS
北大核心
2015年第10期77-79,共3页
Safety in Coal Mines
基金
大型油气田及煤层气开发国家科技重大专项资助项目(2011ZX05036-001)
国家自然科学基金资助项目(51574040)
关键词
煤层气
水平井
完井液
破胶剂
储层保护
coalbed methane
horizontal well
completion fluid
gel breaker
reservoir protection
