复杂深井地层测试的难点及管柱结构的应对策略

Difficulties in Formation Testing of Complex Deep Wells and Strategy for String Structure

复杂深井的地层测试技术,经过多年的实践,逐渐形成了以射孔—酸化—测试联作为代表的典型管柱。但随着应用面的扩大,出现了新的问题。针对封隔器以下尾管及射孔枪卡埋、井筒承压窗口窄、测试后产层漏失严重、探井试油后转开发作业的效率低、风险大等难点,分别提出了加入尾管安全接头、投球式常开阀和投球式常闭阀分别替代OMNI阀和RDS/RD阀,加入单向关井循环阀替换RDS阀,加入脱接式封堵阀等应对策略,形成了系列管柱结构和工艺,有效完善和改进了管柱结构和配套工艺,取得了良好的实践效果。

After many years of practice,the formation testing technology of complex deep wells has gradually formed a typical string structure represented by perforation-acidification-testing combination.But with the expansion of application,new problems have emerged.In view of four special difficulties,such as liner under packer and perforating gun stuck in wellbore,narrow pressure window,serious loss of production formation after well testing,preparation for production of the exploration zones,this paper proposes such response strategies as to add liner safety joint,ball type normally open valve and ball type normally closed valve to replace the OMNI valve and RDS/RD valve respectively,add one-way shut-in circulation valve to replace RDS valve,and add tripper type plugging valve.A series of string structure and process have been formed,which effectively perfect and improve the string structure and the supporting process with good practice effect.