理想充填暂堵新方法在昆2井储层保护中的应用

A NEW TEMPORARY PLUGGING METHOD BY IDEAL PACKING APPLIED TO RESERVOIR PROTECTION IN THE WELL KUN-2

昆2井是柴达木盆地昆特依1号构造上的一口重点探井,完钻井深为5950m。为确保发现和保护油气层,按照理想充填方法对暂堵剂进行了优化设计,应用油气层保护技术领域的最新研究成果,即理想充填方法对暂堵保护方案进行了优化,并在大量实验基础上,确定出合理的保护储层钻井液配方。现场试验表明,经优化设计的第四次开钻钻井液具有显著的储层保护效果,并具有良好的流变性和润滑性能,井壁稳定性强。该油气层在使用油气层保护暂堵剂之后,油气层保护效果显著,储层渗透值恢复率高达87.5%,表皮系数小于等于1.5。井壁稳定作用明显,在同一地区首次实现无井壁失稳复杂情况,适合现场应用。

The well Kun-2,with its total depth of 5950 m,is an important exploratory well on the structure Kunteyi-1 of the Qaidam Bain.In order to discover and protect payzones,this study optimized the temporary plugging agent and the temporary plugging planning according to the ideal packing method,the newest advancement in reservoir protection studies.And through large amounts of experiment,this study determined a proper drill-in fluid system.The field tests showed that the optimized drill-in fluid used for the 4th spud-in is effective in reservoir protection,in addition having good rheological property and lubricating effect,and being helpful for wellbore stability.This new temporary plugging agent could help 87.5% of the permeability of the payzone to be recovered,with the surface coefficient of less than 1.5,which was proved to have obvious effect on reservoir protection.No wellbore instability problem occurs when this plugging agent was used in this area,which demonstrated its advantage in the wellbore stability.This paper recommends its wide use on well sites.