COIL TUBING PLUG RETRIEVAL FISHING OPERATIONS ON DEEP, HIGH-PRESSURE SOUR WELLS

This paper discusses coil tubing operations performed on three sour ga s wells in which coil tubing was used to retrieve plugs where conventi onal wireline methods proved ineffective. All three wells are located in the Obed Field of Alberta, which produces high pressure sour gas. T he field was suspended in March 1992 with wireline plugs set to isolat e the downhole formation. All of the wells had severe corrosion proble ms prior to suspension, making plug setting and retrieval difficult. C oil tubing offered the versatility of jetting and circulating, allowin g access to the downhole plugs in a sloughing scale environment. On th e first two reactivations, coil tubing was used for descaling tubing a nd washing onto plugs. During the third reactivation, the coil tubing was parted, leaving 3,000 m of 31.8 mm coil tubing (CT) downhole. The 31.8 mm CT was successfully retrieved using 50.8 mm CT in conjunction with wireline chemical cutters.