The standard of well integrity in production operation

The requirements and standards pertaining to well integrity and well barrier during oil production, water injection, oil pumping and other operations were firstly introduced. The production operation lasts very long in the whole life cycle of oil reservoir and well. It starts after the well drilling, completion and testing are finished, and ends when the well is worked over, shut down or abandoned. The production operation plays an important role in the whole life cycle of oil reservoir, and presents the remarkable continuity with its concatenate operations. As for production operation, it is particularly necessary to make use of the concept of well integrity and design and utilize well barrier precisely. It is of great significance to establish well barriers with various structures by using the elements of well barrier and the additional requirements and standards to ensure the safety of production operation. The oil/gas wells with inflow source and oil/gas reservoir shall be equipped with at least two independent mechanical well barriers. Then, based on 6 typical graphs of well barrier for production operation, the function, elements and usage criteria of well barrier were illustrated. In addition, the well control procedures in production operation, the wellbore handover business and the related documents were introduced, and the monitoring and testing during production operation were described. Furthermore, two barriers (i.e., Christmas tree and production wellhead) were explained and their diagrams were presented. Finally, the acceptance forms of 4 well barrier elements were listed, including Christmas tree, production packer, downhole safety valve and tubing hanger.