非均质恶性漏失气藏调剖封堵剂体系的研究与应用

DEVELOPMENT OF PROFILE-CONTROL BLOCKING AGENT FOR NON-HOMOGENEOUS GAS RESERVOIR WITH MALIGNANT LOST CIRCULATION AND ITS APPLICATION

随着普光气田套变井套管变形程度的逐年加剧,套变井含硫天然气窜漏的安全隐患也在不断增大,部分套变井亟需永久封井处理。由于采用一体化完井管柱,在套变加剧的情况下,封井时先起管柱再挤堵气层的工艺难以实施,只能先不动管柱封堵气层、再打捞原井管柱。为保障不动管柱安全封堵气层、提高气层封堵效果,针对普光长井段、非均质、恶性漏失气层封堵存在的水泥浆易漏失、沿高渗层指进等问题,通过优化ZND调剖堵漏剂、耐腐蚀超细水泥浆性能,设计了调剖封堵剂体系,配套了不动管柱调剖封堵工艺,并于2017年5月成功在普光D405-3井应用,实现了D405-3井不动管柱安全封堵气层。现场应用表明,调剖封堵剂体系能有效降低漏失、提高中低渗气层的封堵效果,对于非均质、恶性漏失气层的长效封堵,具有借鉴和指导意义。

With the casing deformation increased at Puguang gasfield,the sour gas escape risk is also increased,even demanding permanent well abandonment job in some wells. For wells with integral completion string,it is hard to plug the well by cement plugging after pipe string tripped out of the hole. The gas zone will have to be plugged while the pipe string remained down hole. In order to ensure a safe well P & A in such wells,by optimizing the ZND profile control agent and the superfine corrosion resistant slurry,a profile control and plugging system is developed to overcome the challenges of heterogeneity,malignant slurry loss,slurry fingering into the high permeability layer in long well intervals at Puguang. In May 2017 this system has been successfully applied in Well D405-3 at Puguang. The results say the profile control and plugging system can effectively reduce loss,improve the plugging of low permeability gas reservoirs.