新型酸液解卡剂在玛湖区块的应用

Application of Novel Acid-based Sticking-releasing Solution in Mahu Block of Xinjiang Oilfield

新疆玛湖油田水平井三开造斜段克下组发育大段褐色泥岩,目的层百口泉组存在褐色泥岩夹层。该褐色泥属硬脆性泥岩,岩水敏性强、易水化分散,使用水基钻井液配合螺杆钻进滑动托压严重、粘卡风险高。针对钻井期间易发生粘卡,文章通过调整酸液及其他添加剂浓度,形成酸液解卡剂8种配方,通过溶酸性评价确定采用15%盐酸+3%氢氟酸配方,对褐色泥岩和灰色荧光砂砾岩具有最强的酸蚀溶解能力,并成功应用于处理玛湖区块2次粘卡事故。相比于传统的泡油基解卡剂,该酸液解卡剂具有用量少、现场配制简单、解卡时间短、解卡率高等优点,为处理褐色泥岩段粘卡事故提供了新的选择。

In the curve sections of horizontal wells in Mahu block Xinjiang Oilfield,there are a large number of brown mudstones in Lower Karamay Formation and inter-bedded brown mudstones in the target Baikouquan Formation.Due to the high sensitivity of the brown mudstone to the water content and the characteristics of the hydration and dispersion,it enables the WOB transferring problems with high risks of differential sticking when sliding drilling with WBM and PDM BHA.In response to the issues of differential sticking while drilling into the brown mudstones,by adjusting the concentration of acid and other additives,eight kinds of acid solution for sticking-releasing agent formulae have been formed.Through the soluble acid evaluation,15%hydrochloric acid and 3%hydrofluoric acid formula has been used,which has the strongest acid corrosion dissolution ability on brown mudstone and fluorescent gray glutenite,and successfully applied in the two sticking accidents in Mahu block.Compared with the traditional foam oil based agent,the acid sticking-releasing agent has the advantages of less dosage,simple preparation,short time and high rate of sticking release,which provides a new choice for dealing with the differential sticking issues in the brown mudstone section.