Nowadays, isotope environmental technique tends to be used as a reconnaissance tool , both qualitative and quantitative, to calculate the aquifer parameters particularly in carbonate rock aquifers. But, the hetero...Nowadays, isotope environmental technique tends to be used as a reconnaissance tool , both qualitative and quantitative, to calculate the aquifer parameters particularly in carbonate rock aquifers. But, the heterogeneous flow is still problematic when Lumped parameter Models are usually used to calculate the residence times and hydraulic parameters. However, Discrete State Compartment Model can provide a powerful model to heterogeneous medium. One such study was carried on in Dazha valley, where the environmental tritium was used as a tracer for determining hydrogeological parameters based on a discrete state compartment model展开更多
Apparent differences in sedimentation and diagenesis exist between carbonate reservoirs in different areas and affect their petrophysical and elastic properties.To elucidate the relevant mechanism,we study and analyze...Apparent differences in sedimentation and diagenesis exist between carbonate reservoirs in different areas and affect their petrophysical and elastic properties.To elucidate the relevant mechanism,we study and analyze the characteristics of rock microstructure and elastic properties of carbonates and their variation regularity using 89 carbonate samples from the different areas The results show that the overall variation regularities of the physical and elastic properties of the carbonate rocks are controlled by the microtextures of the microcrystalline calcite,whereas the traditional classification of rock-and pore-structures is no longer applicable.The micrite microtextures can be divided,with respect to their morphological features,into porous micrite,compact micrite,and tight micrite.As the micrites evolves from the first to the last type,crystal boundaries are observed with increasingly close coalescence,the micritic intercrystalline porosity and pore-throat radius gradually decrease;meanwhile,the rigidity of the calcite microcrystalline particle boundary and elastic homogeneity are enhanced.As a result,the seismic elastic characteristics,such as permeability and velocity of samples,show a general trend of decreasing with the increase of porosity.For low-porosity rock samples(φ<5%)dominated by tight micrite,the micritic pores have limited contributions to porosity and permeability and the micrite elastic properties are similar to those of the rock matrix.In such cases,the macroscopic physical and elastic properties are more susceptible to the formation of cracks and dissolution pores,but these features are controlled by the pore structure.The pore aspect ratio can be used as a good indication of pore types.The bulk modulus aspect ratio for dissolution pores is greater than 0.2,whereas that of the intergranular pores ranges from 0.1 to 0.2.The porous and compact micrites are observed to have a bulk modulus aspect ratio less than 0.1,whereas the ratio of the tight micrite approaches 0.2。展开更多
The Tahe-Lunnan hydrocarbon province is China's largest region with oil-and-gas-producing marine carbonate rocks. However, in terms of multi-source hydrocarbon generation, multi-episode reservoir adjustment and re...The Tahe-Lunnan hydrocarbon province is China's largest region with oil-and-gas-producing marine carbonate rocks. However, in terms of multi-source hydrocarbon generation, multi-episode reservoir adjustment and reconstruction, it remains unsettled how to determine the geological period of primary hydrocarbon filling of the Ordovician reservoir in this region. Based on the analysis of distribution and properties of reservoir, hydrocarbon filling of the Cambrian source rocks in the Late Caledon stage has largely been destroyed. However, hydrocarbon filling of the Middle Ordovician source rocks in the Early Carboniferous resulted in the major body of crude oil. During the charging process, the hydrocarbons were oxidatively degraded to heavy oil due to the poor closure conditions, which is corroborated by homogenization temperature of inclusions. Moreover, the capturing of hydrocarbon inclusions with high-temperature does not represent the filling of mature petroleum in the later period, but represents the result of the natural gas containing light fraction. Therefore, the Tahe-Lunnan area underwent two hydrocarbon filling processes, and the invasion of excessive dry gas led to a gas-washing fractionation upon the original Ordovician reservoirs.展开更多
文摘Nowadays, isotope environmental technique tends to be used as a reconnaissance tool , both qualitative and quantitative, to calculate the aquifer parameters particularly in carbonate rock aquifers. But, the heterogeneous flow is still problematic when Lumped parameter Models are usually used to calculate the residence times and hydraulic parameters. However, Discrete State Compartment Model can provide a powerful model to heterogeneous medium. One such study was carried on in Dazha valley, where the environmental tritium was used as a tracer for determining hydrogeological parameters based on a discrete state compartment model
基金supported by the National Natural Science Foundation of China(Nos.41774136 and 41374135)the Sichuan Science and Technology Program(No.2016ZX05004-003)
文摘Apparent differences in sedimentation and diagenesis exist between carbonate reservoirs in different areas and affect their petrophysical and elastic properties.To elucidate the relevant mechanism,we study and analyze the characteristics of rock microstructure and elastic properties of carbonates and their variation regularity using 89 carbonate samples from the different areas The results show that the overall variation regularities of the physical and elastic properties of the carbonate rocks are controlled by the microtextures of the microcrystalline calcite,whereas the traditional classification of rock-and pore-structures is no longer applicable.The micrite microtextures can be divided,with respect to their morphological features,into porous micrite,compact micrite,and tight micrite.As the micrites evolves from the first to the last type,crystal boundaries are observed with increasingly close coalescence,the micritic intercrystalline porosity and pore-throat radius gradually decrease;meanwhile,the rigidity of the calcite microcrystalline particle boundary and elastic homogeneity are enhanced.As a result,the seismic elastic characteristics,such as permeability and velocity of samples,show a general trend of decreasing with the increase of porosity.For low-porosity rock samples(φ<5%)dominated by tight micrite,the micritic pores have limited contributions to porosity and permeability and the micrite elastic properties are similar to those of the rock matrix.In such cases,the macroscopic physical and elastic properties are more susceptible to the formation of cracks and dissolution pores,but these features are controlled by the pore structure.The pore aspect ratio can be used as a good indication of pore types.The bulk modulus aspect ratio for dissolution pores is greater than 0.2,whereas that of the intergranular pores ranges from 0.1 to 0.2.The porous and compact micrites are observed to have a bulk modulus aspect ratio less than 0.1,whereas the ratio of the tight micrite approaches 0.2。
基金supported by National Natural Science Foundation of China (Grant No. 41202112)National Basic Research Program of China (Grant Nos. 2005CB422105, 2012CB214804)Open Research Foundation of Key Laboratory of Tectonics and Petroleum Resources (CUG) (Grant No. TPR-2011-36)
文摘The Tahe-Lunnan hydrocarbon province is China's largest region with oil-and-gas-producing marine carbonate rocks. However, in terms of multi-source hydrocarbon generation, multi-episode reservoir adjustment and reconstruction, it remains unsettled how to determine the geological period of primary hydrocarbon filling of the Ordovician reservoir in this region. Based on the analysis of distribution and properties of reservoir, hydrocarbon filling of the Cambrian source rocks in the Late Caledon stage has largely been destroyed. However, hydrocarbon filling of the Middle Ordovician source rocks in the Early Carboniferous resulted in the major body of crude oil. During the charging process, the hydrocarbons were oxidatively degraded to heavy oil due to the poor closure conditions, which is corroborated by homogenization temperature of inclusions. Moreover, the capturing of hydrocarbon inclusions with high-temperature does not represent the filling of mature petroleum in the later period, but represents the result of the natural gas containing light fraction. Therefore, the Tahe-Lunnan area underwent two hydrocarbon filling processes, and the invasion of excessive dry gas led to a gas-washing fractionation upon the original Ordovician reservoirs.
