Top Kill Shows Signs of Success

In a Thursday afternoon press briefing, BP Chief Operating Officer Doug Suttles reported that the top kill operation was going according to plan.

Drilling mud had been pumped into the riser through late Wednesday evening, and industry and government experts spent much of the day Thursday analyzing the initial pressure data. A decrease in pressure indicates that the heavy drilling mud is inhibiting the flow of oil and gas from the wellbore.

"During the job, we clearly had suppressed the amount of oil and gas coming out," said Suttles, quickly adding that the operation will only be successful if it stops the flow completely. "The operation hasn't yet achieved its objective." In the next round of pumping, which Suttles said would begin "quite soon," BP may add bridging agents to help direct the water-based, non-toxic mud into the wellbore and not out of the four leak points in the riser.

If the top kill operation continues to show signs of success, BP will continue to modify the drilling mud mixture as needed until the flow from the wellbore stops. In that event, the company would proceed to pumping cement to seal the well. Should top kill not provide the desired result, BP would then implement the lower marine riser package (LMRP) cap strategy. The engineered containment device is already on-site.

Suttles expressed cautious optimism with the current top kill approach. "I believe this can work," he said. "The analysis would suggest this would work." However, he reiterated that a cessation of flow from the wellbore is the only measure of success. Also, he pointed out that determining a time frame for the operation is a difficult exercise at this point.

"We might finish this in the next 24 hours or it may take longer," he said. "Are we surprised that it's taking this long? No."