Method for recovering wet buckled pipe

A method for severing a submerged pipeline setting on the sea floor, comprising the steps of:

• lowering a deflated lift bag from the water surface to a substantially straight segment of said pipeline;
• forming a trench in said sea floor below the substantially straight segment of said pipeline;
• positioning said deflated lift bag under the substantially straight segment of said pipeline;
• inflating said deflated lift bag with liquid and raising a section of said pipeline off said sea floor;
• lowering a cutoff saw from the water surface to said raised section of said pipeline, said lowering of said cutoff saw comprises:
• lowering a buoyancy module having said cutoff saw suspended by a cutoff saw cable from said buoyancy module and a clump weight suspended by a clump weight cable from said buoyancy module, said clump weight being suspended lower than said cutoff saw so that said clump weight is first to contact said sea floor;
• setting said clump weight on said sea floor in the proximate area of said raised section of said pipeline;
• deballasting said buoyancy module so that the combined said cutoff saw and said buoyancy module achieve substantially neutral buoyancy;
• and
• positioning said cutoff saw on said raised section of said pipeline;
• clamping said cutoff saw to said raised section of said pipeline;
• severing said pipeline by means of said cutoff saw.

A method for recovering a submerged pipeline, comprising the steps of:

• lowering a deflated lift bag from the water surface to a substantially straight segment of said pipeline;
• positioning said deflated lift bag under the substantially straight segment of said pipeline;
• inflating said deflated lift bag with liquid and raising a section of said pipeline off said sea floor;
• cleanly severing said pipeline at said raised section;
• lowering a recovery head from the water surface to said raised end of said severed pipeline;
• aligning said recovery head with said raised end of said severed pipeline;
• placing said recovery head in said raised end of said severed pipeline;
• gripping said raised end of severed pipeline by activating said recovery head until said recovery head is in gripping relationship with said pipeline;
• lowering a recovery cable from the water surface to said recovery head;
• connecting said recovery cable with said recovery head;
• and
• retrieving said recovery cable to raise said recovery head and said pipeline towards the water surface.