Application of snubbing process in different pipe strings in offshore oilfields

Snubbing process and equipment present strict requirements for structures of pipe strings. In this study, analysis was made on commonly used production strings in offshore oilfields, together with suitability and forces of snubbing process. Then, tripping operations were conducted for production string with cables, pipe string with perforation guns, production string for gas-lifting operations, production string with jet pumps, pipe string for fracturing operations, pipe string for open flow development, completion pipe string with packer and other pipe strings in simulated dowehole conditions of offshore oil/gas fields. Results of simulation tests show that snubbing process can be tested and deployed in offshore oilfields. Sealing capacity of BOP system in production string with no cable shall be enhanced to ensure safety of relevant operations.