The CO2 School, Midland, Texas, 28 January-1 February 2007
Ever wishing to broaden his knowledge, Steve Furnival (steve.furnival@senergyltd.com) of Senergy Ltd headed west to Texas to attend ‘The CO2 School’. Here he reports on his experiences.
Organisers
If you want to learn about the business of CO2 flooding, you should consider enrolling for future sessions of ‘The CO2 School’. The course was run by the Applied Petroleum Technology Academy (APTA) and Petroleum Professional Development Center of Midland College. The lead presenter was Steve Melzer of APTA and Melzer Consulting ably supported by Bob Kiker and Bob Trentham of APTA, Hoxie Smith of APTA and Midland College and Rebecca Larkin of Kinder Morgan.
CO2 EOR
Day One of the course was largely an introduction and overview of CO2 Enhanced Oil Recovery. This included a discussion of the history and status. The first CO2 flood started at SACROC in the early 1970s and today there are around 80 floods worldwide with over 50 in the Permian Basin.
Most of the CO2 used in the Permian Basin comes from fields of high purity CO2, mostly in the Mid-West and owned by Kinder Morgan who also own much of the pipeline network used to transport the CO2 around the country. Many of the other students were excited by the idea that anthropogenic CO2 might become available in the near future – this must be one of the few areas in the world when they haven’t got enough sources of CO2!
The emphasis of Day Two was the evaluation of suitable fields for CO2 flood which included a review of screening tools. The first of these was a spreadsheet written originally by Shell and now updated and maintained by Kinder Morgan which allows the user to define the size and scale of their proposed field/flood with cost/revenue implications: the key parameters are usually the distance from the CO2 pipeline and the tax/benefit implications. A second more sophisticated screening tool discussed was the Prophet streamtube model developed in the mid-1990s by Texaco and the US Department Of Energy (DOE). If a prospect passes these tests, then and only then would you be digging out the manuals for the compositional simulator!
CO2 School students visiting the Seminole field
Field Visits
Day Three started with a short session on facilities and operations which prepared us for two field trips to see two contrasting CO2 floods. Firstly we were taken to Seminole, some 70 miles north of Midland, which is a field now operated by Amerada Hess who have a 34% interest: there are over 100 other partners in the field but only 7 have a stake greater than 1%. This was described as the ‘Cadillac’ operation in which the produced gas stream is subject to extensive processing to remove H2S and NGLs leaving high purity CO2 for re-injection. This field is also notable as one of the few where the oil in the transition zone is already being targeted using the CO2 flood. Other companies are actively investigating production from the Residual Oil Zone (ROZ).
The second visit was to Penwell, some 40 miles west of Midland in which a ‘Blood, Guts and Feathers’ operation is being conducted by the operator, Energen Resources. Using minimal facilities, the produced water and oil are recovered and all the produced gas is re-injected.
Producer and separation tanks at the Seminole field
Business Issues
Day Four concentrated on many of the business issues. There was a natural focus on US and Texan tax implications along with land and minerals rights. And yet even this was useful as we know that the way CO2 is taxed, either as a cost to the producer or a benefit to the injector will be key to making CO2 EOR or CO2 CCS become adopted more widely. The day ended with an extensive discussion of the potential of ROZ recovery. A study by Advanced Resources International has estimated that the Permian Basin prize for CO2 flooding in the main pay is around 7 billion barrels of which just over 1 billion has been recovered to date. By contrast, ARI has estimated that there maybe 12 billion barrels of technically recoverable oil in the ROZ. There was some confusion as what constitutes a ROZ and my understanding is it is a transition zone which has been subject to nature’s water flood by a tilted or active aquifer.
The class was limited to 40 attendees and there was a waiting list. Going forward, they are hoping to run the class once or twice a year and have a tentative start date of 11th June 2007 for the next course.
I found this course extremely useful, both in terms of the contributions of the lecturers and many of my fellow students who are already in the business of CO2.