Freeze and Hot Tap Case History #27
Objective: Hot tap and mill out a damaged gate valve 90% closed and freewheeling.
Well Information: 4,200kpa sweet gas well on an offshore platform with damaged gate valve not allowing access into tubing. Top gate valve functioning.
Procedure: Assemble hot tap equipment and function. Bleed off gas pressure above top valve and remove wireline flange install hot tap equipment pressure test.Equalize pressure and open top operating gate valve hot tap a ¾ inch hole in bottom valve pull above top valve close bleed off well gas remove drill bit. Install mill and reconnect flange equalize with well gas and open top valve mill out damaged bottom valve pull above top valve and close bleed off well gas and remove mill. Install reamer to open bore to 3 1/8 reconnect flanges and equalize with well gas and open top valve ream bottom gate valve to full drift. Pull above top valve and bleed off well gas remove reamer. Install wire brush reconnect flange equalize with well gas open top valve clean tubing hanger threads with wire brush pull up above top valve and close. Bleed off well gas and remove hot tap equipment.
Time on location: 33 hrs over three days