6. CO2-EOR flooding projects and case studies

Several literatures stated about implementation of CO2 and carbonated water to improve oil recovery since 1951 [45, 54, 58, 59], owing to its availability in adequate amounts from both natural and industrial sources [60]. The first field-wide application occurred in 1972 at the SACROC (Scurry Area Canyon Reef Operators Committee) unit in the Permian Basin, where the CO2 was transported via a 200-mile-long pipeline from the Delaware-Val Verde Basin [10]. Hashemi and Pouranfard [1] reported about the investigation of immiscible miscible CO2 injection southwest of Iranian oil field, which has two reservoirs: Gurpi and a shallower Asmari reservoir. Main reservoir in this field is the Asmari formation with Oligocene and Miocene ages, which is divided into seven zones. Therefore, only the Asmari formation has been producing oil at commercial scale. The Asmari formation in this field consists of fractured carbonates with a low permeability matrix. The matrix has a porosity and permeability of about 0.088% and 3.4 md, respectively [1]. They concluded that the minimum miscibility pressure (MMP) was 4630 psia, The optimum injection rates for immiscible and miscible CO2 injection scenarios were 17,000 and 30,000 Mscf/day, respectively and oil recovery factor reach 36.59% [1]. Al-Aryani and others [61] have reported on the first CO2- EOR pilot test in the Middle East where pulsed neutron logging was used to monitor the performance of a CO2 flood in one of the largest oil fields in Abu Dhabi, United Arab Emirates. The results of this test will be viewed with great interest based on the fact that it will have a significant impact on the application of CO2-EOR in many oil-rich countries in the Middle East with the potential for very large additional oil recoveries. In India, a CO2- EOR feasibility study was implemented in an oil field on the west coast, but the results are not yet publically available [62]. In China, there is ongoing research and pilot testing of CO2- EOR and carbon sequestration in the Jilin oil field with plans to expand to other fields [63]. As of 2012, there were 15 CO2-EOR projects outside of the United States—six in Canada, three in Brazil, five in Trinidad, and one in Turkey [64]. Of the six CO2-EOR miscible projects in Canada, the Weyburn project is the most significant because it was the first project with the primary objective of injecting CO2 for additional oil recovery as well as for carbon sequestration to help mitigate climate change. In recent years, there have been some serious efforts by Scottish Carbon Capture & Storage (SCCS), the Scottish Government, and other companies to investigate the possible application of CO2-EOR in the North Sea. This interest is based on the potential for additional oil recovery from depleted oil fields using CO2 captured from power plants and industry [10]. The objective is to gain a better understanding of the use of CO2 in EOR operations with the goal of extending the producing life of North Sea oil fields using CO2 captured from large emitters, such as power plants and industrial facilities, and permanently store the greenhouse gas in offshore oil reservoirs. It is estimated that there is the potential to recover 24 billion barrels of additional oil in the North Sea using the CO2-EOR process. About 60 active miscible CO2 projects were in operation in the United States in 1996, whereas in Canada, hydrocarbon miscible floods reach nearly 40 active projects [35, 65]. Most CO2-flooding projects carried out in the United States in Colorado, Louisiana, Mississippi, New Mexico, Michigan, Oklahoma, Texas, Utah, and Wyoming. During 2014, about 22 companies implemented CO2 flooding projects; where 128 projects contributed about 126 million tons of oil [66], applied through carbonate and sandstone reservoirs with a percentage of 55 and 37% respectively, while the other 6% were implemented in tripolite reservoirs [67]. The range of porosity is from 4 to 29.5% with a permeability of 100 mD. The main operators and their productions reported in Table 2. The increased implementation of CO2 flooding projects resort to its availability from natural and industrial sources in addition to its relatively low cost as a displacing agent compared to other alternatives [68]. It is observed that the outcome of these projects summarized in Table 2, where the recovery factor ranged from 0.15 to 36.37%. The reservoirs properties are summarized in Table 3.

7. Screening criteria for CO2 flooding

Table 3. Properties of reservoirs subjected to CO2 flooding.

Table 2. CO2 miscible flooding operator and production dataset [66, 69, 70].

Screening criteria for miscible CO2 flooding comprise reservoir depth, pressure and temperature, minimum miscibility pressure (MMP), residual oil saturation, net pay thickness, crude oil gravity, and viscosity in addition to permeability, porosity, and reservoir heterogeneity [40]. In

Property Minimum Maximum Median Mean Porosity 4 29.5 12 14.25 Permeability, mD 2 700 14 44.35 API gravity 27 45 38 37 Viscosity, cp 0.4 6 1.8 1.3 Temperature, F 83 260 108.5 133.9 Depth, ft 1150 11,950 5500 6107.3 Oil saturation (% PV) 26.3 89 46 49.6 Net thickness, ft 15 268 90 110 Minimum miscibility pressure (MMP), psia 1020 3452 1987.5 2058.4

Operator No. of projects Improved production (<sup>10</sup><sup>4</sup> tons) Recovered oil (%)

CO2 Miscible Flooding for Enhanced Oil Recovery http://dx.doi.org/10.5772/intechopen.79082 85

Occidental 33 459.63 36.37 Kinder Morgan 3 138.34 10.94 Chevron 7 126.30 9.99 Hess 4 106.89 8.46 Denbury Resources 18 86.82 6.87 Merit Energy 7 71.12 5.63 Anadarko 6 55.79 4.41 ExxonMobil 1 45.36 3.59 Breitburn Energy 5 36.87 2.92 ConocoPhillips 2 28.42 2.25 Whiting Petroleum 1 24.51 1.94 Apache 5 23.88 1.89 XTO Energy Inc. 4 13.43 1.06 Chaparral Energy 8 9.18 0.73 Fasken 5 4.30 0.34 Core Energy 9 1.90 0.15 Others 12 31.19 2.47


Table 2. CO2 miscible flooding operator and production dataset [66, 69, 70].

[10]. Hashemi and Pouranfard [1] reported about the investigation of immiscible miscible CO2 injection southwest of Iranian oil field, which has two reservoirs: Gurpi and a shallower Asmari reservoir. Main reservoir in this field is the Asmari formation with Oligocene and Miocene ages, which is divided into seven zones. Therefore, only the Asmari formation has been producing oil at commercial scale. The Asmari formation in this field consists of fractured carbonates with a low permeability matrix. The matrix has a porosity and permeability of about 0.088% and 3.4 md, respectively [1]. They concluded that the minimum miscibility pressure (MMP) was 4630 psia, The optimum injection rates for immiscible and miscible CO2 injection scenarios were 17,000 and 30,000 Mscf/day, respectively and oil recovery factor reach 36.59% [1]. Al-Aryani and others [61] have reported on the first CO2- EOR pilot test in the Middle East where pulsed neutron logging was used to monitor the performance of a CO2 flood in one of the largest oil fields in Abu Dhabi, United Arab Emirates. The results of this test will be viewed with great interest based on the fact that it will have a significant impact on the application of CO2-EOR in many oil-rich countries in the Middle East with the potential for very large additional oil recoveries. In India, a CO2- EOR feasibility study was implemented in an oil field on the west coast, but the results are not yet publically available [62]. In China, there is ongoing research and pilot testing of CO2- EOR and carbon sequestration in the Jilin oil field with plans to expand to other fields [63]. As of 2012, there were 15 CO2-EOR projects outside of the United States—six in Canada, three in Brazil, five in Trinidad, and one in Turkey [64]. Of the six CO2-EOR miscible projects in Canada, the Weyburn project is the most significant because it was the first project with the primary objective of injecting CO2 for additional oil recovery as well as for carbon sequestration to help mitigate climate change. In recent years, there have been some serious efforts by Scottish Carbon Capture & Storage (SCCS), the Scottish Government, and other companies to investigate the possible application of CO2-EOR in the North Sea. This interest is based on the potential for additional oil recovery from depleted oil fields using CO2 captured from power plants and industry [10]. The objective is to gain a better understanding of the use of CO2 in EOR operations with the goal of extending the producing life of North Sea oil fields using CO2 captured from large emitters, such as power plants and industrial facilities, and permanently store the greenhouse gas in offshore oil reservoirs. It is estimated that there is the potential to recover 24 billion barrels of additional oil in the North Sea using the CO2-EOR process. About 60 active miscible CO2 projects were in operation in the United States in 1996, whereas in Canada, hydrocarbon miscible floods reach nearly 40 active projects [35, 65]. Most CO2-flooding projects carried out in the United States in Colorado, Louisiana, Mississippi, New Mexico, Michigan, Oklahoma, Texas, Utah, and Wyoming. During 2014, about 22 companies implemented CO2 flooding projects; where 128 projects contributed about 126 million tons of oil [66], applied through carbonate and sandstone reservoirs with a percentage of 55 and 37% respectively, while the other 6% were implemented in tripolite reservoirs [67]. The range of porosity is from 4 to 29.5% with a permeability of 100 mD. The main operators and their productions reported in Table 2. The increased implementation of CO2 flooding projects resort to its availability from natural and industrial sources in addition to its relatively low cost as a displacing agent compared to other alternatives [68]. It is observed that the outcome of these projects summarized in Table 2, where the recovery factor ranged from 0.15 to 36.37%. The reservoirs properties are

84 Carbon Capture, Utilization and Sequestration

summarized in Table 3.


Table 3. Properties of reservoirs subjected to CO2 flooding.
