1. Cases of valve replacement under pressure in the international market:

①. TOTAL—Changqing block:

Oilfield: Total Sulige Gas Field, Changqing, China.
Well number: Tao-6#, gas well time: 2007.7.

Reason: After being put into production, the No. 3 main valve was damaged, mainly caused by medium corrosion.
Work: Complete valve replacement under pressure in 6 hours.

②. Kazakhstan:

Oil field: Kazakhstan
Well number: Ha-301, gas well
Time: 2013.10

Reason: After being put into production, the No. 1 main valve was damaged, mainly caused by medium corrosion
Work: Complete valve replacement under pressure in 6 hours

2. Domestic market application:

①. CNPC—Xinjiang:

Oilfield: Xinjiang Oilfield, China
Well number: Mo-101, oil and gas mixing well time: 2006.8

Cause: The No. 2 main valve cannot be closed, mainly because oil and gas corrode it seriously
Work: Complete valve replacement under pressure in 6 hours

②. CNPC—Changqing:

Oilfield: China Changqing Oilfield
Well number: G8-10, gas well
Time: 2009.9

Cause: No. 3 main valve disc wedge gate is damaged
Work: Complete valve replacement under pressure in 6 hours

③. CNPC—Changqing:

Oilfield: China Changqing Oilfield
Number: G43-5
Time: 2006.4

Cause: After being put into production, the No. 1 main valve could not switch due to corrosion and rust
Job: Complete valve replacement under pressure drilling

④. On April 24, 2017, well Yan920-2 in Yanchang Gas Field, Shaanxi Province, adopted multi-stage seal plugging for valve replacement operation under pressure:

2015-2017 China Changqing Oilfield Service Statistics: