binbin, not too sure which oil & gas experts you are targetting...

binbin,

not too sure which oil & gas experts you are targetting and I guess with Elk, you have seen all of them come an go. Nonetheless, IMHO, Grieve is an excellent CO2 EOR prospect and will prove to be so if and when Denbury is prepared to give it the attention it warrants.  That will involve injecting the required volume of CO2 in the appropriate areas of the reservoir.

 

"A hybrid approach to CO2 flood is the optimal way to exploit this stratigraphically trapped resource. WAG wells are being utilised in the crest of the field and along its base.A bottom up top down line drive WAG development."

You do not need to be an oil & gas expert to know that injecting less dense (lighter) CO2 in down dip wells that are perforated above the original oil water contact (not a clearly defined depth at Grieve) is not about to provide an effective sweep of the residual oil below those perforations and above the original oil water contact.  Similarly, it is difficult to see how injecting the densest fluid ("water) into crestal wells in the reservoir will provide an effective sweep of the least dense fluids, CO2 and the CO2/oil miscible phase, to producing wells.  It would be enlightening to see either Denbury's or Elk's reservoir simulations of these gravity defying forecasts.

 "the pursuit of ROZ resource" at Grieve has yet to happen. The ROZ (residual oil zone) is recognized as the zone immediately below the original oil water contact containing immobile oil which could be in similar concentrations to the current residual oil saturations (35%?) in the Grieve oil reservoir. Grieve has no original wells drilled or at least perforated in the ROZ but Grieve's ROZ potential is real.  It is not obvious that Grieve's ROZ potential is being addressed by Denbury or Elk or that CO2 is migrating to the ROZ.  . 

binbin, the CO2 ROZ conference in Midland, Texas in December is where you will find any number of oil & gas experts discussing CO2 EOR and how  "2018 has been a very significant year. Much has occurred with the CCS, CO₂ EOR and ROZ subjects since the last conference. The economics of Carbon Capture, Utilization and Storage (CCUS) took a huge step forward with the passage of the updated 45Q (Federal) tax credits this February. The horizontal drilling with the San Andres residual oil zones (ROZs) rapidly advanced to where over 37,000 barrels of oil per day are being produced in 6 different counties. Renewed worldwide enthusiasm occurred in CO₂ flooding projects as oil settled above $50/bbl for the last 12 months and the first greenfield ROZ project is responding beautifully."

Not surprising, Denbury appears to be paying a lot more attention to its other larger 100% owned Rocky assets in Montana and North Dakota than Grieve. It could be argued that as a result, they are not performing asa reasonably prudent operator of the Grieve CO2 EOR Project.