CO2 EOR Consulting

Several high-level and seasoned consultants of A&A Consulting Team have been involved in CO₂ EOR projects since the 1970s, and during this time have worked on some of the major CO₂ EOR projects in several regions of the United States, including, but not limited to, the following:

The Permian Basin (in West Texas and Eastern New Mexico),
The Gulf Coast region (of Texas, Louisisina, Mississippi, and Alabama), and
The Rocky Mountain region
The Williston Basin

Several high-level and seasoned consultants of A&A Consulting Team have also been involved in CO₂ EOR projects in other countries, including, but not limited to, the following:

Canada
Argentina
Indonesia
Vietnam
Suriname

A&A Consulting Team's extensive CO₂ EOR project experience includes, but is not limited to, conducting:

CO₂ EOR project scoping/ feasibility studies,
Pilot-test CO₂ EOR project design, evaluation and optimization studies,

Field-wide CO₂ EOR project design, evaluation and optimization studies, and

CO₂ EOR project surreveillance.

With A&A Consulting Team's extensive experience working on all aspects of CO₂ EOR projects, around the world, A&A can truly be called the CO₂ EOR project consulting company!

The high-level and seasoned CO₂EOR consultants of A&A Consulting Team have not only worked on all aspects of CO₂ EOR projects for more than fifty years but have also provided training to professional and managerial staff of our client companies, around the world, for many years, on ‘Practical Engineering Aspects of CO₂ Injection for EOR, and CO₂ Geosequestration’. An outline of this customized training workshop, that can be conducted at our clients’ offices, around the world, whenever mutually convenient, is available on request

Our high-level and seasoned CO₂ EOR consultants, along with other CO₂ EOR industry veterans, have also been volunteering their time and effort to train next generation of engineers in CO₂ EOR technologies and practices by teaching two popular public training courses, around the world, under the auspices of the Society of Petroleum Engineers (SPE):

Since 2004, more than 600 members, and non-members, of SPE, have attended these two popular public training courses, or expanded customized versions of these courses offered by A&A, around the world.

We can put teams of our high-level and seasoned CO₂ EOR consultants, with extensive experience in conducting reservoir simulation, facilities, and related studies, for CO₂ EOR project design, evaluation and optimization, to work on our clients’ CO₂ EOR projects, around the world, whenever required.

To find out how we can help your company on its CO₂EOR project scoping/ feasibility studies, pilot-test design, evaluation and optimization, and field-wide project design, evaluation and optimization, as well as project surrveillance, around the world, please contact us.

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Reservoir Surveillance of CO₂ Floods

Surveillance of CO₂ floods is critical in establishing maximum oil recovery. Injection and production profiles are used to determine the inflow and outflow of fluids into the various layers of the reservoir. Radioactive tracer logs are often used for this purpose. A slug of radioactive tracer (typically Iodine 131) is added to the injection fluid and as the slug moves down the well, several gamma ray logs are recorded at specific time intervals. The reduction in tracer material as it moves down the wellbore indicates how much of the injected fluid goes into each zone. The position of the tracer slug is seen as a large gamma ray spike whose size is proportional to the flow rate. A reduction in the size of the peak indicates a loss of fluid into the formation. Fluid velocity can also be calculated from the time interval and the distance the peak has moved using time-slug analysis. The radioactive tracers can be used to detect channels and leaks within the casing and cement jobs. Correction of these wellbore integrity issues is critical in maximizing vertical sweep.

Tracer logs can also be used to determine inflow from the producing zones. The tool is operated in reverse mode to that of an injection profile. Capacitance sensors are installed to determine the percentage of oil and water flow from each zone. The dielectric constant of water (80) is so high relative to that of oil (1.9 to 2.3) that the capacitance is a direct indicator of the amount of water.

In addition to inflow and outflow from perforations in the wellbore, the breakthrough of CO₂ provides an indication of the sweep. Dimensionless curves can be generated for the various patterns and poorly performing patterns can be identified. This deviation from normal flow behavior provides an indication that the injector and producers should be investigated for potential mechanical integrity issues. The adjustment of injection and production flowrates can also be used to maximize areal sweep based upon the formation thickness and pattern size.

For relatively mature CO₂ floods, 3-D seismic has been used to determine areal sweep. Operators often do not consider the fact that CO₂ can move downdip toward plugged and abandoned wells. Should this occur and these wells have mechanical issues, extreme losses of CO₂ can occur. Reservoir pressure in all parts of the reservoir should therefore be monitored closely.

A&A Consulting Team of high-level and seasoned CO₂ EOR consultants has the expertise and extensive CO₂ EOR project experience to help our clients on all aspects of their CO₂ EOR reservoir surveillance projects in order to optimize production rates and maximize reserves, and to maximize project profitability.

To put A&A Consulting Team of high-level and seasoned CO₂ EOR consultants to work on your company's challenging CO₂ EOR reservoir surveillance projects, please contact us. We could help your company make hundreds of Millions, if not Billions!

In addition to providing state-of-the-art consulting services on your company’s challenging CO₂ EOR reservoir surveillance projects, we will be delighted to conduct customized training workshops on this topic at your company’s offices, around the world, whenever mutually convenient. For an outline of this customized training workshop, please contact us.

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Design of CO₂ Floods in Reservoirs Impacted by Strong and Limited Aquifers (in the US Gulf Coast Region, and in Many Other Parts of the World)

In the US Gulf Coast region, and in many other parts of the world, some of the largest oil reservoirs have strong waterdrive aquifers which assist in maintaining reservoir pressure during primary production. While these aquifers are somewhat infinite, they are insufficient for maintaining pressure at original 'discovery' levels and often the pressure drops below MMP (Minimum Miscibility Pressure). While good oil recoveries have been seen by conducting CO₂ floods below the MMP, it is desirable to pressure up the reservoir as high as possible (above MMP) to achieve maximum oil recovery. A&A consultants have experienced this in actual field demonstrations where reservoir pressure was raised by water injection (SPE #144961-PP- 'Large Scale CO₂ Flood Begins Along Texas Gulf Coast', Presented at 2011 SPE Enhanced Oil Recovery Conference in Kuala Lumpur, Malaysia, 19-20 July, 2011). While doing so, it was found that large volumes of water leakoff into the aquifer during the re-pressurization process, and this can go on for many years at rates as high as 200,000 - 300,000 BWPD in the applicable fields. The design was effective in raising reservoir pressure and reducing the volume of CO₂ purchase, but the cost of water injection was expensive and often required large volumes of make-up water which had to be produced from other water bearing sands. In the case described, a nearby producing offset field also experienced reduced aquifer pressure, thus compounding the problem. All this must be considered while designing CO₂ floods in reservoirs impacted by strong and limited acquifers in the US Gulf Coast region, and in many other parts of the world.

A reservoir type which is often overlooked due to its low reservoir pressure, at the time of CO₂ flood, is the depletion drive reservoir. The depletion drive reservoirs contain higher oil saturations than waterdrive reservoirs and can be pressured-up with CO₂. The salt dome fields in the US Gulf Coast region are ideal candidates for CO₂ flooding as many of the small fault blocks had limited aquifers, and therefore had low oil recoveries during primary production. These small fault blocks were also poor waterflood candidates due to the inability to establish good patterns to improve sweep. Continuous CO₂ injection, on the other hand, offers some clear advantages for maximizing oil recovery from these isolated fault blocks. The reservoir can be pressured-up with CO₂ and then the wells flowed back while recycling the CO₂ to maintain reservoir pressure. The CO₂ moves to the boundaries of the fault block and contacts more oil than what could be achieved by water injection. The key parameters for successful CO₂ flooding of these reservoirs are good fault seal, and ability to pressure-up the reservoir. Material balance is used during the re-pressurization process to determine pore volume impacted by injection, and if CO₂ leaks into the adjacent fault block this can be accounted for.

A&A consultants have screened numerous oil fields in the US Gulf Coast region for reservoirs amenable to successful CO₂ flooding, and we can assist your company with screening/ scoping/ feasibility studies, and CO₂ flood project design studies.

To put A&A Consulting Team of high-level and seasoned CO₂ EOR consultants to work on your company's CO₂ EOR screening/ scoping/ feasibility studies, and challenging CO₂ flood project design studies, of reservoirs impacted by strong and limited acquifers in the US Gulf Coast region, and in many other parts of the world, please contact us. We could help your company make hundreds of Millions, if not Billions!

In addition to providing state-of-the-art consulting services on your company’s CO₂ EOR screening/ scoping/ feasibility studies, and challenging CO₂ flood project design studies, of reservoirs impacted by strong and limited acquifers, we will be delighted to conduct customized training workshops on this topic at your company’s offices, around the world, whenever mutually convenient. For an outline of this customized training workshop, please contact us.

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