A novel fluid for use in oil and gas well construction to prevent the oil and gas leak from the wellbore

This paper proposed a novel and efficient fluid for use in oil and gas well of deep-water weakly consolidated formation to prevent the oil and gas leak from the wellbore. The proper placement techniques are suggested to make the annulus and formation consolidated at the same time. The evaluation of compressive strength and thickening time of cementing fluid illustrated that the cementing fluid is suitable to use as oil well cement and formation curing agent. The optimal parameter of grouting pressure, grouting time, curing time, water/solid ratio and undrained shear strength of formation are proposed by depth of penetration, compressive strength and shear bonding strength tests. The reaction mechanism and solidification pattern of cementing fluid are revealed. After the operation of cementing fluid, the strength transition zone formed in the adjacent area of wellbore. Thus, the bonding strength of cement-formation interface was enhanced, and the leakage of oil and gas can be prevented. (C) 2019 Elsevier Ltd. All rights reserved.