Discussion on Well Sealing Technology for Abandoned Sidetracking Wells in Buried Hill Gas Injection Gravity Drive

Some of the buried hill gas injection blocks in Huabei Oilfield were used for water injection development sidetracking in the early stages. The original vertical well bore was not sealed, which was sidetracking in the upper free casing section. The sealing of abandoned wells in gas injection gravity drive involves overall production safety. At present, in order to improve economic benefits, fully utilize the original water injection well network, and consider production safety, it is necessary to carry out sealing operations on unused wells. Due to the fact that the original vertical wellbore was not sealed, it is difficult to restore the original wellbore trajectory using existing technology. Therefore, based on the demonstration of the sealing performance of the cover layer and the analysis of wellbore integrity, and drawing on existing sealing technology, a side drilling hole sealing has been developed, in conjunction with the auxiliary control technology of the vertical wellbore. This ensures the sealing effect and production safety in terms of technology, and is economically feasible.