Sparky - "...secondary extraction is a weak substitute to opening new provinces". Actually many of those old giant fields you referred to are still producing a significant amount of their reserves thanks to enhanced recovery techniques such as pressure maintenance (Mexico's Cantarell Field), water floods (most of the Permian Basin fields) and infield drilling of horizontal wells (Ghawar Field) which includes the Rockman's field that went from 12 bopd to 500 bopd thanks to such wells. Although not all technically defined as EOR methods they are utilized for the same reason. But this is also why old field production will never see a
Seneca cliff: once these fields have reached this stage their depletion rates are very, very low.
As you and others have mentioned the shales and the Deep Water GOM fields are a very different dynamic. Every individual shale well is its own
Seneca cliff. But collectively they have actually developed a
Seneca Mountain when viewing the US chart. And now that lower oil prices have cut the rig count we've started down the back side of this
Seneca Mountain. But it's important to remember that the great majority of shale wells have entered a much lower decline rate phase. As a result while we are beginning to slide down the back slope of the
Seneca Mountain there won't be a
Seneca cliff ahead for the EXISTING production. OTOH a plot of new production might look more like a
Seneca cliff.Projecting DW GOM is trickier. Here's the yearly production since 1985.
https://www.data.bsee.gov/homepg/data_c ... ummary.aspYou'll see it plateaued around 2002 around 350 million to 450 million bbls per year. But the combination of relative short COMMERCIAL lives (6 to 8 years) and long lag times between discovery and first production makes projecting difficult. As a result it wouldn't be a surprise to see increased DW GOM oil production increase the next few years despite lower oil prices. Once $billions have already been spent companies will keep on schedule. Bottom line from 1985 to 2002 the DW GOM climbed an impressive
Seneca Mountain from zero to 450+ million bbls of oil per year. Now on a plateau. Some DW projects early in their development phase could stall with the current lower oil price. But there's no detailed data available to make even a rough guess.