Citing a BP document, the daily said the concern with the method BP chose was that if the cement around the casing pipe did not seal properly, gases could leak all the way to the wellhead, where only a single seal would serve as a barrier.
The other option under consideration would have provided two barriers in case of a gas leak, the Times said.
Rig workers and company officials have said gases were leaking through the cement hours before the explosion. .
Louisiana Governor Bobby Jindal said Wednesday some 100 kilometers of his state's coastline was now soiled, more than doubling the previous estimate. The oil is imperiling rare species of animal and plant life, and has also led to a major fishing ban in the marine rich waters.
A tour of coastal areas left the president of the local Plaquemines parish aghast at the devastation.
"The same oil that's been out there two weeks ago is still out there. And nothing is being done," Billy Nungesser told CNN Wednesday.
BP officials have also readied back-up options but some, including the drilling of relief wells to divert the flow and allow the original well to be capped, could take several months.