METHOD OF OFFSHORE PROSPECTING WELL CONSTRUCTION AND ELIMINATION Russian patent published in 2016 - IPC E21B35/00 E21B33/35 

FIELD: construction.

SUBSTANCE: invention relates to development of marine licensed sections, particularly to construction and elimination of offshore prospecting and exploration wells. Method includes performance of geological engineering surveys on offshore mobile drilling rig planned installation site, offshore mobile drilling rig transportation and placement in specified point, drilling, attachment, testing and elimination of well, providing in last (smallest) casing coupled with well head, of cement plug establishment with height of not less than 50 m, offshore mobile drilling rig removal and transportation to new drilling point, bottom examination for absence of navigation hazards and well head and sea bed video recording, providing of examination protocol to corresponding hydrographic service. At that, cement bridge roof is located at 3-5 m below sea bed level. Besides, liquidated well cement bridge head is equipped with additional protection, in form of large-size concrete construction wastes, which form artificial reef on sea bed, in radius exceeding cement head for 50 %, but not less than in radius of 10 m. At that, concrete protection height ranges from 0.2 to 0.5 m.

EFFECT: technical result consists in improvement of industrial and environmental safety, longer life and reliability of offshore prospecting and exploration wells liquidation.

1 cl, 3 dwg