It, however, said that the one-year extension from July 4, 2004 will not affect the subsequent deadline of July 4, 2006 by which time the initial exploration period would have to be started as per the PSCs on the two blocks.

In a letter to Petrobangla, the Anglo-Dutch energy giant also sought permission for decreasing the multifold seismic survey in block 10 and aeromagnetic survey in block 5.

Shell's other plea is for undertaking a 2-D seismic survey with the equivalent cost of 6,500-km of aeromagnetic survey in block 5 and an additional 2-D seismic survey in the block which is equal to the decreased amount of multifold seismic in block 10.

"... There is no change to the total net value of our commitment; however the value of information is deemed much higher," said a letter from Shell Bangladesh Managing Director Zaffar Chida.

The production sharing contracts (PSCs) for the blocks allow three years' time from the effective date to complete the specific work programme i.e. the geological work programme including geochemical soil sampling in the blocks 5 and 10.

The PSCs provisions also allow the same period for 6,500-km of aeromagnetic survey in block 5 and 1,200-km of multifold seismic survey in block 10.

Seeking the time extension and changes in the work programme, the Shell's letter said they had conducted detailed scouting trips in both blocks and found the unexpected presence of dense commercial forests over substantial areas in the blocks.

"The progress in such areas will be much slower than that in the open rice field terrain. Our approach to seismic acquisition will have to change to firstly recording and evaluating a somewhat broader regional grid followed by detailed seismic over the detected leads," it said.

As the Shell sought an early consideration of its prayer for extension, State Minister for Energy AKM Mosharraf Hossain yesterday told UNB that the government would follow the relevant provisions of the PSCs.

He, however, referred to Shell's earlier desire of engaging state-run BAPEX for conducting the 2-D seismic survey. He added that if Shell is still willing to do so, it would be beneficial to BAPEX, the exploration wing of Petrobangla.