Cementing Practice of Easy-Leaking Formations Under Complex Geological Conditions

Jizhong buried-hill reservoir and Menggulin conglomerate heavy oil reservoir in Huabei Oilfield contain abundant residual oil and gas resources. In order to use the reserves as much as possible, CO2 injection gravity flooding and fire flooding reservoir technologies were used respectively for exploiting in the experiment. Aiming at the problems of low formation pressure, easy leakage while cementing, carbon dioxide corrosion and easy cement ring failure and casing damage under ultra-high temperature conditions, the anti-corrosion pipe, the anti-leakage plugging technology, the anti-carbon dioxide corrosion cement slurry system, the optimization of prestressed cementing, balanced pressure cementing and other cementing processes were selected. The field application effect was remarkable, and the pass rate of one interface was 100%. The qualified rate of the two interfaces is greater than 93%, and the average perfection rate is 93%, which meets the requirements of the pilot test on the integrity of the wellbore seal and provides technical support for the long-term, safe and effective operation of oil and gas wells.