龙凤山构造北2井储层保护钻井液技术

Reservoir Protection Drilling Fluid Technology for North 2 Well in Longfengshan Structural Belt

北2井为龙凤山构造第二口探井,为该构造第一口4 000 m以上井。因此本井在钻探过程中可借鉴临井资料少,风险性大,钻井液维护处理难度大。北2井二开裸眼井段长3 571 m,根据北1井实钻情况,本井可能出现粘土矿物含量高,砂泥岩不等厚互层,井壁稳定控制难度大;储层井段存在井漏风险,储层保护难度大。针对以上情况,本井钻井液采用强抑制、封堵性钻井液体系控制粘土水化膨胀,进行快速有效的防漏堵漏措施。

North 2 well is the second well in Longfengshan structural belt, and is the first well whose depth is more than 4 000 m. So this well drilling is difficult because of lacks of drilling well data, high drilling risk, and difficult drilling fluid maintenance process. The second open hole is 3 571 m, according to the North 1 well drilling data, the well may appear high clay mineral content, sand shale different thickness interbedding, difficult borehole wall stability control; Reservoir interval has the risk of lost circulation, reservoir protection is difficult. In view of above situation, the well drilling fluid system with strong inhibition and plugging should be used to control the clay hydration expansion and carry out quick effective plugging measure.