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Oil and Gas Discussion BB
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Re: Given the OPEC deal I think CNE's Mono Capucino well takes on new significance. Hi doom. In the late 90s I went as representative of the company I was with (with the President) to look at opportunities in the Middle Magdelena valley. On offer was all the wealth in the Western world from our stockbroker friends if we would take a significant piece of the action on some very interesting Technopetrol leases near the old Los Angeles field. At the time we were the leaders in developing the technology of underbalanced drilling technology and had used it flawlessly and successfully in a large variety of settings. The trip was driven by rumours of a huge flow test results (>9,000 bopd, >12,000 boepd) on two well legs drilled by Harken Energy nearby on an analogous pop up structure to many that were on the Technopetrol permits and leases. The play involved two laterals from a single wellbore by Harken energy - one in the La Luna one in the lower Rosa Blanca. These are fractured cretaceous carbonates with bugger all matrix porosity or storage. (The reservoir is in the fractures - maybe 0.5% of the total rock volume?) My job was to review the available data (seismic, well logs, core data, vertical well production data from well bores that had produced something from these fractures etc - and to make sure we didn't get skinned alive). After collecting all the data I needed at the Technopetrol offices and asking for whatever else in the drilling records file (there was a lot of older Taxaco data here and other secondary targets - shallower Lisama sands with heavier oil and gas plays - we did a bit of sightseeing, I bought a few small Emeralds from the Government store and then flew back to YYC (Calgary) and I spent some time thoroughly reviewing what I had. Basically there was a very good reason for the huge flow rates from the Harken well bores - huge fracture permeability and the over optimistic rates of flow during severe underbalanced flows uncorrected for these hydrodynamic effect introduced at the surface. There was also a reason they never went into commercial production - very little reservoir storage. The vertical wells producing from these fractured carbonates told the story very well with cumulative production histories typical of very limited OOIP - high recovery factors and super permeabilities. They come on gangbusters - flat line - then fall right off a cliff as the boundaries get hit very very quickly. The geometry too of these petal or pop up structures is against reservoir size. These are inverted wedges or like orange segments tipped on edge - the knife edge at the bottom (Rosa Blanca) the fat outside at the top (the La Luna). Some of the better vertical wells did better than 25,000 bbls of nice medium to light gravity oil - and again a fairly high GOR but I cannot remember exactly anymore. For my company it was obvious that this was only ever going to be a promotional scam (?) benefiting the brokers and the cheats - but the upside represented by having access to "real" and conventional oil and gas prospects in the shallower high porosity Lisama sands was worth taking a potential hit on the one in exchange for the (really good) upside on these "lesser" targets. So after much navel gazing by the BOD (of which I was not a part) - the decision was to offer a 10% paid working interest to earn in about a 5% net working interest - with the state run Ecopetrol sucking up most of the profits (if any?) after the whole thing had been de-risked. Of course the brokers told us to go forth and multiply - and we saved ourselves a lot of grief - could still look at ourselves in the mirror and focused instead on Jean Marie gas up in NE BC before it got taken out by EnCana and other more conventional to tight plays in Alberta and Saskatchewan - as well as south west Ontario where we had some interesting potential in the Ordovician plays that Talisman was the only real competition for. This is of course an anecdotal story and it involves looking for oil in fractures in geographically quite narrow and low volume pop up structures. (The regional story was - or seemed to be - one of a huge dynamic salty aquifer with a concomitant minor accompanying oil phase migration). However it is possible that somewhere in that basin there are much larger stratigraphic traps that have steadily accumulated oil such that even at ~ 0.5% or much less average fracture porosity and essentially nil matrix storage - there could be significant oil in place accumulations lurking waiting for the right time? But this stuff is a very conventional naturally fractured reservoir and remember the compression in the pop-ups puts their average fracture density and volume up hugely - the regional - more unstressed - picture would be considerably lower. (From simple theory). What is often thought of as "Oil in place" is actually organics (immature to mature kerogens) and the porosity they inhabit about as permeable as a block of styrofoam. I'm sure Chevron would not make such a mistake? Right! GS |
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