The Intersection of Environment and EOR: How Carbon Capture is Changing Tertiary Recovery

Editor's Notes

• #4: By the end of my talk I hope to convince you that CO2 EOR and carbon sequestration creates significant opportunities for both Industry and the environment.
• #5: CO2 EOR can revitalize mature fields, a typical tertiary response is on the order of the secondary recovery efforts both in duration and volumes. In the past projects have been limited by chemistry, CO2 supply, and infrastructure.
• #6: Since the first CO2 project in 1972, at least 154 more have been emplaced world-wide. Projects initially depended on natural CO2 and demand has outpaced supply allowing the use of capture technology to augment natural supplies. Over 1BCF of natural CO2 is injected into the Permian basin every day, and this could be replaced with anthropogenic CO2. Anthropogenic CO2 can also add to the total available CO2 for EOR projects. Including in 2015, a pilot project by Saudi Aramco with CO2 being captured at the Hawiyah gas recovery plant and piped 85 km to the ‘Uthmaniyah field. This plot shows the number of CO2 EOR projects over time since 1972. Currently approximately 37% of projects use captured CO2. This is poised to change, with the Paris accord, a dozen countries are looking at offshore storage of carbon, EOR plays a key role in this due to in place infrastructure and economic motive.
• #7: Conventional coal plant waste streams are expensive to processes into pure CO2, both in facilities cost and required energy, but there are other facilities that provide pure CO2 streams and only require dehydration and compression. These smaller sources, fertilizer, ethanol, gas processing, cement plants, etc can be more local to a potential project. The chart on this slide shows that about 63% of project are in the Permian basin or Gulf coast and utilize predominantly natural CO2 sources. The remaining 37% use captured CO2.
• #8: The US has dominated CO2 EOR with large natural sources proximal to favorable geology. However, CO2 sources are widely distributed! Wherever there are people there are sources of CO2. Power plants, cement plants, gas processing, fertilizer plants, ethanol generation, etc. Over 80% of power used by humans is based on fossil fuels, and many chemical and industrial processes generate CO2 as a waste stream.
• #9: This map shows anthropogenic sources of CO2 and potential oilfield sinks. Existing pipelines from natural sources are in close proximity to large man-made sources. Mature basins in the region are all within a few 10’s of miles of existing sources. A large gas separation plant in Wyoming provide CO2 for 16 CO2 EOR projects in Colorado, Wyoming, and Montana, and highlights the potential to generate CO2 in proximity to mature oil development.
• #10: Regulations may impact the affordability of projects. The Arkalon Ethanol Plant in Liberal Kansas supplies 200,000 metric tonnes of CO2 per year to 3 EOR projects. Because their CO2 is “sequestered” they can sell their ethanol in California, where there are laws requiring “green energy sources”. Companies can benefit from proximity of CO2 sources to mature production, increased production and extended field life, and may potentially benefit from carbon credits, and since CO2 EOR inherently stores CO2, they can benefit from improved public perception about their projects.
• #11: Black drops show the approximate location of large scale CO2 EOR / sequestration demonstration projects in the united states. The Southwest regional partnership on carbon sequestration, signified by SWP on this map is a consortium of three universities, three national laboratories, service companies, and operating partners including Chaparral Energy who operates eight CO2 EOR projects utilizing man-made CO2. Farnsworth Unit is the location of the SWP’s large scale demonstration project.
• #12: Chaparral Energy acquired FWU, and started to convert the field to CO2 EOR in 2010 No natural CO2 available. Existing infrastructure in place from waterflood was updated
• #13: Farnsworth unit is a Carbon Capture, Utilization and Storage project. Co2 is sourced from two anthropogenic sources, the Arkalon Ethanol Plant in Liberal Kansas, and the Agrium Fertilizer plant in Borger Texas. Over 100 miles of pipeline connect the two sources to 3 currently active projects and can be extended to several more fields in the area. Grey shaded portions of the map show oil fields in the vicinity of these two point sources of CO2. Chaparral can vary delivery to fields to maintain operational flexibility. Chaparral built or partnered in compression and dehydration facilities at each site. Carbon cost is low, ~$0.60 per mcf, less than paying for natural CO2, even if it were regionally available.
• #14: This map shows current and near future pattern conversion to CO2 injection. Development uses invert 5 spot patterns with a central CO2 injector surrounded by 4 producers on approximately a 40 acre spacing. Farnsworth development is being monitored by the SWP and the sequential addition of additional patterns allows for testing and retesting of technologies to directly and indirectly observe CO2 in the reservoir. At present only the western half is being developed for CO2 EOR, though eventually as CAPex allows the eastern side will also be developed.
• #15: Pennsylvanian continental assemblage at approximately 300 million years ago, the small yellow rectangle shows the location of Farnsworth during deposition of the Morrow. Waxing and waning of ice sheets in southern hemisphere caused repeat global sea level oscillations.
• #16: The SWP project examined legacy wells, drilled three new wells specifically for characterization with extensive logs nearly to the surface, and a total of 750 feet of core in the reservoir, secondary reservoir, and primary and secondary seals. Our interpretation is that deposition occurred in an incised valley. During a high stand, mudstones and marine shales were deposited. During low stands rivers carved out or “incised” valleys into the mudstones and deposited fluvial sandstones. Later high stands deposited shales over the top of the sandstones.
• #17: Interpreted geologic cross-sections hung on the top of the Morrow shale support the incised valley theory as sands thicken across the center of the reservoir and thin at the edges in all north south cross-sections
• #18: Seismic data has been an integral part of the characterization program and includes a baseline 42 mi2 3D survey over the entire field, three baseline 3d VSPS centered on injection wells, four baseline cross-well tomography segments between injector/producer pairs. In addition, a dedicated monitoring well has a 16 level 3 component passive seismic monitoring array installed within it.
• #19: From right to left, Gamma Ray log in the 13-10A injection well, cross-well tomography, 3D VSP, and surface seismic data
• #21: Faults 1, & 2 Form an anticlinal structure; Fault 3 is an oblique slip fault; Faults 3, 4, & 5 create a trough or graben structure in the NE corner of the field; and Fault 6 terminates below the Morrow
• #22: This is not unexpected. East and west portions of the field appear to have different permeability's due to changes in diagenesis. In addition, up to 8 distinct sub-facies have been identified in log studies for the Morrow B.
• #23: R35 refers to the pore throat aperture radius when core samples are 35% saturated during a mercury porisometry experiment. It is believed that above this radius pore networks become interconnected and can form continuous flow paths.
• #24: Average permeability at the Morrow B interval with interpreted faults. Faults have offsets in the reservoir and can impact fluid flow, and storage security. Typical models have millions of gridblocks and are up-scaled when simulating flow in the morrowB
• #25: Simulation is an integral part of studying CO2 injection, and is essential for making predictions of storage security, studying storage mechanisms, and understanding material balances.
• #26: Each year a new simulation model is created using increasingly detailed geologic models as a basis. The first step each year is to accurately history match Primary, secondary , and tertiary processes including Oil, water, and gas production.
• #27: Predictions can also be made of CO2 saturation and sweep efficiency. This figure shows predicted CO2 saturation in the Morrow formation through July of 2016. We also study geomechanics and rock fluid interactions with these models and results can be used to estimate the best time for repeat seismic surveys to directly image co2 in the reservoir by running synthetic seismic data through different fluid states of the simulation models.
• #28: The Purple line is purchased CO2, this is the CO2 that a government entity would be interested in for storage statistics. The Black line represents the CO2 available for recycle at any given time. The red line is a planned wag schedule. There is potential for waste if available CO2 exceeds injection needs as patterns are filled, and CO2 that ends up being flared rather than recycled is lost to storage, and lost to utilization. The operators WAG schedule is predicted to stores ~75% of the Purchased CO2 and produces about 72% of the OOIP
• #29: Optimization of WAG cycles can increase CO2 storage by 20%, cumulative oil by 5.2 million barrels and total recovery by nearly 9%! An interesting outcome from simulation studies was that optimal storage also provides for optimal incremental recovery.
• #31: How are we going to do this? We have a battery of surface and subsurface methods at our disposal to track the fate of CO2 and look for any potential leakage.
• #32: Viewing the MVA methods on a map, our efforts are generally concentrated around the primary project CO2 injection well (13-10A) and monitoring well (13-10). CO2 Soil Flux data for sites around 13-10A well, have shown that no CO2 emissions have been detected. We also monitor the water quality in the overlying Ogallalla Aquifer, studying more than a dozen characteristics. Again, no changes during the course of our monitoring program.
• #33: The figure on the left shows monthly accounting since SWP began monitoring the site in 2013, with stacked layers representing purchased CO2 (green), net stored CO2 (blue), recycled gas (yellow), and Co2 lost to flaring (red). The figure on the right shows oil production and CO2 injection rates with the field going from about 3500 BOPM to over 65,000 BOPM in only 4 years. Oil rate growth has leveled off as new patterns are not being added at this time due to low oil price.
• #34: Circle back – Mature fields around the world are the best site for storing the carbon promised by world leaders and formalized in the Paris accord – about 1000 Farnsworth fields needed to store the 4-5 Billion tonnes by 2040. This is perhaps the only way to achieve this goal in that time period due to existing transportation infrastructure, and available point source CO2 that can effectively be captured. Public perception, regulatory policy and economics of CO2 EOR are very likely to dramatically improve in coming years.