Potential Evaluation of CO₂ Sequestration and Enhanced Oil Recovery of Low Permeability Reservoir in the Junggar Basin, China

Abstract

The Chinese government is seeking CO2 gas emission reduction measures. CO2 capture and geological sequestration is one of the main measures. Injecting CO2 into oil reservoirs can not only achieve the environmental protection purpose of CO2 geological sequestration but also improve oil recovery and realize economic benefits, which helps to offset the cost of CO2 sequestration. Therefore, the oil reservoir is one of the best sites for CO2 sequestration. As for the reservoir of CO2 flooding after water flooding, there are two methods for evaluating the potential of CO2 enhanced oil recovery (EOR) and sequestration capacity, which are the mass balance method and analogy method. Through a combination of these two methods, this paper presents a new method, which can be reasonably used to evaluate these potentials. Besides, the screening criteria of CO2 sequestration and EOR in the Junggar Basin are also proposed. On the basis of the guidelines of CO2 source matching, reservoir characteristics, and fluid characteristic, four typical low permeability reservoirs (Caiman oil reservoir, Karamay oil reservoir, Beisantai oil reservoir, and Luliang oil reservoir) of the Junggar Basin are selected to study their potential of CO2 EOR and sequestration. And then the potential of CO2 EOR and sequestration capacity for the Junggar Basin oil reservoirs of CO2 flooding after water flooding is studied by applying the method mentioned above. For 275 development blocks of 24 oil fields in the Junggar Basin, 139 development blocks are suitable for CO2 miscible flooding EOR and sequestration, whereas 136 development blocks are suitable for CO2 immiscible flooding EOR and sequestration. The total EOR potential could be 18 407.76 × 104 t and the CO2 sequestration potential could amount to 47 486.0 × 104 t. The evaluation results show that the Junggar Basin’s oil reservoirs are suitable sites for CO2 EOR and sequestration and have great potentials. It can provide the decision basis for the future implementation of CO2 emission reduction projects in Western China.

Effect of permeability and fractures on oil mobilization of unconventional resources during CO2 EOR using nuclear magnetic resonance

“…So it is urgent to find ways to enhance tight oil reservoirs recovery 4 . CO 2 EOR has been recognized as a potential way to enhance tight oil reservoirs recovery and to reduce CO 2 emissions and greenhouse gas effects 5 , 6 .…”

Study on Proppant Transport in Fractures of Supercritical Carbon Dioxide Fracturing

“…With the aggravation of global warming, the emission and management of greenhouse gases have drawn more attention in recent years. − It is necessary to find good approaches to dispose of CO 2 effectively and turn the greenhouse gas into a treasure in the production. Supercritical carbon dioxide (SC-CO 2 ) fracturing may give a good solution in the oil and gas production industry, which combines the utilization of greenhouse gas and the development of energy resources. − As is known to all, with the consumption of conventional resources, the emphasis and difficulty in the oil and gas industry are the unconventional reservoirs. − However, the unconventional reservoirs need to use the fracturing technology during development on account of its low porosity, low permeability, low pore-throat radius, and high gas-flow resistances. − Hydraulic fracturing has been widely used and has achieved good performance in the exploitation of oil and gas resources nowadays, while the huge water consumption and formation pollution bring a lot of limitations to the technology .…”

Feasibility Study of Applying Modified Nano-SiO2 Hyperbranched Copolymers for Enhanced Oil Recovery in Low-Mid Permeability Reservoirs

“…The exploration and exploitation of unconventional resources is an inevitability due to the pace and trend of the development of the economy. Low-mid permeability reservoirs are one of the most important unconventional resources with both an enormous economic value and an abundant quantity of reserves [1,2,3]. The classification of reservoirs is shown in Table 1 [4].…”