Increasing Well Production

February 2001

In the North Sea, an operator decided to close 5 sliding side doors to carry out an acid stimulation and subsequently open another sliding side door. The objective of the operation was to facilitate increased well production. Three runs were required:

Run 1 – The Well Tractor was rigged up on 1 ¾” coiled tubing including an accelerator, a single impact tool and a selective coiled tubing shifting tool. The string was rigged in hole and closed the 5 sliding side doors between an interval of 9,250 and 10,030 ft.

Run 2 – A conventional coiled tubing and acid stimulation run were conducted where the tool string was rigged in hole to close a sliding side door at 8,396 ft.

Run 3 – The CT Well Tractor, accelerator, single impact tool and shifting tool were rigged in hole to 7,950 ft. Subsequently, the CT Well Tractor was put out of hole to 7,902 ft to open another sliding side door.
 
The CT Well Tractor was activated each time the opening/closing tools were used and thus subjected to considerable stress. However, no problems occurred and the operator achieved its objectives.
 
A memory push tool recorded the efficiency of the CT Well Tractor during all three runs and concluded that the pulling force was between 2,000 to 3,800 lbs on average, depending on pumping rate.