The lives of 243 people the price of cost-cutting
The drive to cut corners and save money was the cause of the nation's worst industrial disaster in over 50 years.
According to the investigation headed by the State Administration for Safe Production and Supervision, the Eastern Sichuan Drilling Company not only over-drilled and removed a special blowout-prevention valve, it also failed to ignite the leaking gas in the moments after the explosion, which would have burned off the deadly hydrogen sulfide.
The company is a subsidiary of the China National Petroleum Corporation (CNPC) which operates the Chuandongbei natural gas well.
Released in January, the report is based on interviews with 260 people and thousands of documents. Four drillers have been arrested and the CNPC's deputy general manager sacked.
The report said operators failed to add the proper amounts of lubricating fluid during the drilling process, including on the day of the accident. As a result, the drilling caused the well pressure to drop below safe levels.
Workers also intentionally removed the crucial blowout-prevention valve on the drilling post. If properly attached, it could have stopped the blast. Drillers said they unlatched the part, imported from the United States at a cost of 15 million yuan, to preserve its operational life.
The report also said the devastation could have been significantly reduced if workers had immediately ignited the leaking gas. The action would have turned the poisonous fumes into innocuous water and sulfur. However, the gas was only ignited 18 hours after the blowout.
According to a mainland media report, the delay was because workers wanted authorisation from supervisors so as to avoid being held responsible for damaging the well.
The report also said workers failed to immediately notify local governments of the blast, wasting precious rescue time. It said the Kai county and Gaoqiao governments were contacted 90 minutes after the blast.