摘要
为解决清水钻进带来的煤层井壁严重失稳问题,开发出可降解聚合物钻井液,其组成为:清水+0.1%纯碱+0.5%可降解聚合物DPA+1.0%润滑剂WLA。性能测试结果表明,可降解聚合物钻井液较清水具有强的防膨性,侵入煤层深度浅,对煤岩强度影响小,稳定井壁能力强;对煤层有污染,但通过氧化型破胶液可以有效解除可降解聚合物钻井液造成的煤层污染,达到保护煤层的目的。6口煤层气U型水平井应用结果表明,可降解聚合物钻井液稳定井壁能力强,配合后期破胶液技术,综合煤层保护效果好。
To solve the problem of borehole instability caused by clear water, a degradable polymer drilling fluid for coalbed methane horizontal well was developed, whose formula is: clear water+0.1% soda+0.5% degradable polymer+1.0% water-based lubricant. Performance tests show that the degradable polymer drilling fluid has a better anti-clay-swelling ability, and compared with clear water, its invasion depth is shallower. Moreover, the degradable polymer drilling fluid has little influence on the strength of coal rock, which ensures the borehole stability of coal rock. Core flow tests show the degradable polymer drilling fluid has some contamination on coal reservoir, but the pollutants can be removed by using broken fluid. The degradable polymer drilling fluid was applied successfully in six U-shape wells, which can increase the stability of CBM borehole, and effectively protect coal reservoir combined with broken fluid. © 2015, China Coal Society. All right reserved.
出处
《煤炭学报》
EI
CAS
CSCD
北大核心
2015年第S2期425-429,共5页
Journal of China Coal Society
基金
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
可降解聚合物钻井液
水平井
井壁稳定
储层保护
Boreholes
Boring
Coal
Coal bed methane
Coal deposits
Drilling fluids
Firedamp
Horizontal wells
Methane
Natural gas wells
Polymers
Reservoirs (water)
Rock drilling
Stability
