油基钻井液对泥岩特性影响实验研究

Experimental Study for the Influence of Shale Characteristics in Oil-based Drilling Fluid

邱康 宫吉泽 方华良 张瑞

QIU Kang GONG Jize FANG Hualiang ZHANG Rui

中石化海洋石油工程有限公司, 上海 200120; 中海石油(中国) 有限公司上海分公司, 上海 200030

SINOPEC Offshore Oilfield Services Company, Shanghai 200120, China; CNOOC China Limited-Shanghai, Shanghai 200030, China

油基钻井液在大位移井长裸眼段钻井过程中有较好的防塌效果。针对采用油基钻井液钻井时井壁是否存在垮塌周期问题，该文利用连续刻划实验，研究了油基钻井液浸泡对泥岩单轴抗压强度、弹性模量的影响。结果表明：油基钻井液长时间浸泡会降低泥岩单轴抗压强度和弹性模量，与水基钻井液类似，油基钻井液同样存在垮塌周期，因此，在长裸眼井段施工中要考虑井壁坍塌周期。

Oil-based drilling fluid has a good effect in preventing collapse of long open hole section of large-displacement well. To determine if there is a wellbore collapse cycle when using oil-based drilling fluid, in this paper Scratch Test was conducted to study influence of oil-based drilling fluid on uniaxial compressive strength and elasticity modulus of shale. Results showed that if oil-based drilling fluid soaks for a long time, it would reduce uniaxial compressive strength and elasticity modulus of shale. Similar to waterbased drilling fluid, oil-based drilling fluid also has a collapse cycle, which should be considered in the long open hole construction.

https://doi.org/10.3969/j.issn.1008-2336.2019.04.061