Application of Fast Permanent Abandoned Wells on Offshore Temporarily Abandoned Wells

When the offshore oil fields with subsea wellheads to be decommissioned, it is required to permanently abandon the exploration subsea wells which have been temporarily abandoned by setting abandonment cement plugs for reservoirs. The conventional abandonment method is to utilize a semi-submersible drilling rig to cut production casing, and set a shallow environmental cement plug, then cut surface casing and conductor 4 m below seabed. The abandonment cost is quite high from a semi-submersible drilling rig, the cost should be reduced dramatically by utilizing an offshore engineering vessel to set shallow environmental abandonment plug and cut casing strings 4 m below seabed. The perforation and cement setting combination tool allows running the tool in one trip to set environmental abandonment cement plug across 2 annuli by using perforation guns and 2 retrievable packers. High pressure hydraulic jetting abrasive casing cutting tool converts the fluid pressure energy to the kinetic energy to cut several casing strings in one go. By using the perforation and cement setting combination tool, and the high pressure hydraulic jetting abrasive casing cutting tool, the temporarily abandoned exploration wells can be permanently abandoned from an offshore engineering vessel. This abandonment method is much cheaper than abandoning from a semi-submersible drilling rig. The successful abandonment method in Well Chanter-15 provided a new cost reduction and synergy method for the operator to abandon the well construction.