义123区块非常规油气藏钻井液技术

THE DRILLING FLUID TECHNOLOGY ABOUT YI 123 UNCONVENTIONAL OIL AND GAS RESERVOIRS

义123区块地质构造复杂,上部地层泥页岩水化严重,易造成起下钻遇阻;沙河街组地层层理发育,发育超压,油泥岩易水化,施工中易发生水敏性垮塌及应力性垮塌,井壁失稳严重。针对义123区块地层特点及钻井液技术难点,优选了铝胺成膜防塌钻井液体系,评价实验表明,该体系抑制性强,封堵性及润滑性好,具有良好的油层保护能力。该体系在义123区块进行了现场应用,施工中井壁稳定,井眼净化效果好,定向过程中摩阻和扭矩低,保证了工程的顺利施工。

The geologic structure was complex in Yi 123 Oilfield. Hydration of argillutite was very serious in upper formation,which led to blockage during tripping. Collapse took place easily during the course of drilling because of hydration and stress. And borehole instability was very serious. The aluminium and amine drilling fulid with high film formation sealing capability was optimized. The result of performance evaluation showed that the drilling fluid had high inhibition,high formation sealing capability and good lubrication.On the same time,the drilling fluid had good capablity of formation protection. The drilling fluid was application in Yi 123 abnormal oilfield. The borehole was stability,the effect of hole cleaning was good,and the drag and torque was low during the course of directional drilling. The application effect was very goood.