In this paper,the geomechanical impact of large-scale carbon dioxide(CO) storage in depleted Dutch gas fields is compared with the impact of COstorage in saline aquifers.The geomechanical behaviour of four potential C...In this paper,the geomechanical impact of large-scale carbon dioxide(CO) storage in depleted Dutch gas fields is compared with the impact of COstorage in saline aquifers.The geomechanical behaviour of four potential COstorage sites is examined using flow and geomechanical simulations.Many gas reservoirs in the Netherlands are found in fault blocks,one to a few kilometres wide,laterally bounded by sealing faults.Aquifer depletion or re-pressurization in the lateral direction is seldom an issue because of a lack of active aquifers.Reservoir pressure changes are therefore limited to a gas-bearing fault block,while the induced stress changes affect the gas reservoir and extend 1-3 km away into the surrounding rock.Arguments in favour of COstorage in depleted gas fields are:proven seal quality,availability of field data,no record of seal integrity failure by fault reactivation from the seismically active producing Dutch gas fields,and the potential benefits of restoring the virgin formation pressure and stress state to geomechanical stability.On the other hand,COinjection in saline aquifers causes pressure build-up that exceeds the virgin hydrostatic pressure.Stress perturbations resulting from pressure build-up affect large areas,extending tens of kilometres away from the injection wells.Induced stresses in top seals are.however,small and do not exceed a few tenths of megapascal for a pressure build-up of a few megapascals in the storage formation.Geomechanical effects on top seals are weak,but could be enhanced close to the injection zone by the thermal effects of injection.Uncertainties related to characterisation of large areas affected by pressure build-up are significant,and seal quality and continuity are more difficult to be demonstrated for aquifers than for depleted gas reservoirs that have held hydrocarbons for millions of years.展开更多
There is limited information available on CO2 concentration and flux over marsh. The objective of this work was to characterize CO2 concentration and flux within and above marsh plant (Cares lasiocarpa Ehrh. and C. ps...There is limited information available on CO2 concentration and flux over marsh. The objective of this work was to characterize CO2 concentration and flux within and above marsh plant (Cares lasiocarpa Ehrh. and C. pseudoucuaica F. Schm) canopy at heights 0. 5, 1. 0 and 1. 5 m.CO2 concentration was measured sequentially every 3 bars by using an infrared gas analyzer. Soil and air temperature, wind speed, net radiation and soil heat flux were also measured simultaneously. Extremely drily minimum and maximum CO2 concentration rangal from 250 to 754 μmd/mol for the 4-year work. The typical minimum and maximum values ranged from 314 to 464 μmol/mol at the height of marsh plant (about 0. 5 m) during the fruiting perioed and mature date. The seasonal changes in CO2 concentration show that the minimum CO2 concentration occurred in the fruiting period and mature date, and both of their minimum values were 314 μmol/mol. This illustrates that CO2 consumed by photosynthesis was stable during the period. The flux of CO2 can be thought as a turbulent diffusion phenomenon. By micrometeorological methods, the diurnal CO2 fluxes were measured in the flowering peried, fruiting period, early mature date, late mature date and yellow-ripe stage. Their values were -0. 18, 38. 15,24. 13, 10. 9 and 4. 91 μmol/mol respectively.展开更多
Allelochemicals of Chinese-fir root was extracted by technology ofsupercritical CO_2 extraction under orthogonal experiment design, and it was used to analyzeallelopathic activity of Chinese-fir through bioassay of se...Allelochemicals of Chinese-fir root was extracted by technology ofsupercritical CO_2 extraction under orthogonal experiment design, and it was used to analyzeallelopathic activity of Chinese-fir through bioassay of seed germination. The results showed thatas to the available rate of allelochemicals, the pressure and temperature of extraction were themost important factors. The allelochemicals of Chinese-fir root extracted by pure CO_2 and ethanolmixed with CO_2 have different allelopathic activities to seed germination, and the allelochemicalsextracted by ethanol mixed with CO_2 had stronger inhibitory effects on seed germination than thatextracted by pure CO_2.展开更多
文摘In this paper,the geomechanical impact of large-scale carbon dioxide(CO) storage in depleted Dutch gas fields is compared with the impact of COstorage in saline aquifers.The geomechanical behaviour of four potential COstorage sites is examined using flow and geomechanical simulations.Many gas reservoirs in the Netherlands are found in fault blocks,one to a few kilometres wide,laterally bounded by sealing faults.Aquifer depletion or re-pressurization in the lateral direction is seldom an issue because of a lack of active aquifers.Reservoir pressure changes are therefore limited to a gas-bearing fault block,while the induced stress changes affect the gas reservoir and extend 1-3 km away into the surrounding rock.Arguments in favour of COstorage in depleted gas fields are:proven seal quality,availability of field data,no record of seal integrity failure by fault reactivation from the seismically active producing Dutch gas fields,and the potential benefits of restoring the virgin formation pressure and stress state to geomechanical stability.On the other hand,COinjection in saline aquifers causes pressure build-up that exceeds the virgin hydrostatic pressure.Stress perturbations resulting from pressure build-up affect large areas,extending tens of kilometres away from the injection wells.Induced stresses in top seals are.however,small and do not exceed a few tenths of megapascal for a pressure build-up of a few megapascals in the storage formation.Geomechanical effects on top seals are weak,but could be enhanced close to the injection zone by the thermal effects of injection.Uncertainties related to characterisation of large areas affected by pressure build-up are significant,and seal quality and continuity are more difficult to be demonstrated for aquifers than for depleted gas reservoirs that have held hydrocarbons for millions of years.
文摘There is limited information available on CO2 concentration and flux over marsh. The objective of this work was to characterize CO2 concentration and flux within and above marsh plant (Cares lasiocarpa Ehrh. and C. pseudoucuaica F. Schm) canopy at heights 0. 5, 1. 0 and 1. 5 m.CO2 concentration was measured sequentially every 3 bars by using an infrared gas analyzer. Soil and air temperature, wind speed, net radiation and soil heat flux were also measured simultaneously. Extremely drily minimum and maximum CO2 concentration rangal from 250 to 754 μmd/mol for the 4-year work. The typical minimum and maximum values ranged from 314 to 464 μmol/mol at the height of marsh plant (about 0. 5 m) during the fruiting perioed and mature date. The seasonal changes in CO2 concentration show that the minimum CO2 concentration occurred in the fruiting period and mature date, and both of their minimum values were 314 μmol/mol. This illustrates that CO2 consumed by photosynthesis was stable during the period. The flux of CO2 can be thought as a turbulent diffusion phenomenon. By micrometeorological methods, the diurnal CO2 fluxes were measured in the flowering peried, fruiting period, early mature date, late mature date and yellow-ripe stage. Their values were -0. 18, 38. 15,24. 13, 10. 9 and 4. 91 μmol/mol respectively.
基金This paper was supported by Natural Science Foundation of Fujian Province (B0010020)
文摘Allelochemicals of Chinese-fir root was extracted by technology ofsupercritical CO_2 extraction under orthogonal experiment design, and it was used to analyzeallelopathic activity of Chinese-fir through bioassay of seed germination. The results showed thatas to the available rate of allelochemicals, the pressure and temperature of extraction were themost important factors. The allelochemicals of Chinese-fir root extracted by pure CO_2 and ethanolmixed with CO_2 have different allelopathic activities to seed germination, and the allelochemicalsextracted by ethanol mixed with CO_2 had stronger inhibitory effects on seed germination than thatextracted by pure CO_2.
