温度扰动对井壁稳定和油田开发的影响

INFLUENCE OF TEMPERATURE PERTURBATION ON BOREHOLE WALL STABILIZATION AND OIL FIELD DEVELOPMENT

文章在连续介质力学井壁稳定性分析的基础上 ,系统地计算分析了温度扰动对直井井周应力分布和井壁稳定性的影响。结果表明 ,当地层温度低于井筒内流体温度 ,地层受井筒内流体加热作用时 ,随着温差的增大 ,井壁所受井周周向应力和轴向应力也随之增大 ,井壁压性破坏的可能性增大 ;当地层温度高于井筒内流体温度 ,地层受井筒内流体冷却作用时 ,随着温差的增大 ,井壁所受井周周向应力和轴向应力也随之减小 ,周向应力和轴向应力逐渐由压应力变为张应力 。

The influence of temperature perturbation on the stress distribution around borehole and the borehole wall stability are systematically calculated and analyzed in the paper on the basis of continuous media mechanics,It is indicated that when formation temperature is lower than fluid temperature inside the borehole,the formation will be heated by the fluid and along with the increase in temperature difference,the hoop stress and axial stress acting upon sidewall will be enlarged,thus increasing the possibility of wall's being compressively damaged;and when formation temperature is higher than fluid temperature inside the borehole,the formation will be cooled by the fluid inside the borehole and along with the increase in temperature difference,the hoop stress and axial stress acting upon sidewall will be reduced and gradually changed from compressive stress to tension stress,thus increasing the possibility of wall's being extensively damaged.