Top British Petroleum (BP) official said Friday that the oil company's “static kill” operation would be delayed until next week because of debris found in a relief well. “They found some debris that had settled in on itself,” retired Coast Guard Admiral Thad Allen said in a briefing, who is in charge of U.S. President Barack Obama's oversight of the spill. He said that the oil company will likely move forward with the “static kill operation” next week once the well is cleaned out. The “static kill” will pump mud and cement into the undersea Macondo well and the relief well will offer a more permanent plug for the site of the massive off-shore oil spill that devastated the Gulf of Mexico on April 20. The oil giant plans to meet the costs of the spill clean-up, damage claims, and lawsuits through a $25 billion to $30 billion global asset sale. Since April's oil rig explosion, millions of liters of oil poured into the Gulf. The explosion left both BP and U.S. President Barack Obama's administration facing huge challenges, especially since the spill has significantly slowed the already embattled Gulf Coast's economy, as well as causing the worst environmental disaster in U.S. history. “This has been a real wake-up call for the oil and gas industry,” Dudley said.