The theory of "source rock control" has evolved from source-rock-control hydrocarbon accumulation, to effective source-rock-control hydrocarbon accumulation, and to high-quality source- rock-control hydrocarbon accu...The theory of "source rock control" has evolved from source-rock-control hydrocarbon accumulation, to effective source-rock-control hydrocarbon accumulation, and to high-quality source- rock-control hydrocarbon accumulation. However, there are problems, such as whether high-quality source rocks exist or not? What high-quality source rocks are, and how to identify them, are yet to be agreed upon. Aimed at this issue of concern to explorationists, and taking the Beier Sag in the Hailaer Basin as an example, this paper defines the high-quality source rocks and the lower limit for evaluation of high-quality source rocks, by using the inflection point on the relationship curve of hydrocarbon (oil) expulsion, which is calculated by the material balance principle, versus total organic carbon (TOC). The results show that when TOC is low, all source rocks have limited hydrocarbon expulsion and slow growth rate, thus they cannot be high-quality source rocks. However, when TOC rises to some threshold, hydrocarbon expulsion increases significantly with TOC. This inflection point should be the lower limit of high-quality source rocks: those with TOC greater than the inflection-point value are high-quality source rocks. In addition, the lower limit of high-quality source rocks is also related to the type and maturity of organic matters in the source rocks, as well as the mineral components of the source rocks affecting the residual hydrocarbons. Theoretically, the lower limit of high-quality source rocks depends on geological conditions rather than being a constant value. However, for the sake of simplicity and practicability, in this paper TOC=2.0% is regarded as the lower limit of high-quality source rocks. The examination of such standard in the work area indicates that the high-quality source rocks in members K^n2 and K^n~ of the Nantun formation contribute 76% and 82% to oil generation, and 96% and 91% to oil expulsion, respectively. The distribution of high-quality source rocks is also closely related to the distribution of hydrocarbon reservoirs in the region, demonstrating that high-quality source rocks control hydrocarbon accumulation.展开更多
Both HIV and EIAV belong to the retroviridae family and lentivirus genus. They share considerable simi- larity at gene structural and component level. Hotzel pro- posed that two variable regions and surrounding amino ...Both HIV and EIAV belong to the retroviridae family and lentivirus genus. They share considerable simi- larity at gene structural and component level. Hotzel pro- posed that two variable regions and surrounding amino acids of EIAV gp90 might adopt the same topology as V1, V2 and bridging sheet of HIV gp120. These regions map to V3, V4 and surrounding amino acids of EIAV gp90. Based on this proposal, we further analyzed the distribution profile of N-glycosylation site and linear epitope for EIAV gp90 and HIV gp120 at these regions. Our results demonstrated that EIAV gp90 and HIV gp120 are highly similar at these two aspects. Most likely, V3, V4 and surrounding amino acids of EIAV gp90 adopt the same topology structure as V1, V2 and bridging sheet of HIV gp120.展开更多
基金funded by the 973 Prophase Special Program of China(NO.2011CB211701)National Natural Science Foundation of China(41172134)CNPC Innovation Foundation (2011D-5006-0101)
文摘The theory of "source rock control" has evolved from source-rock-control hydrocarbon accumulation, to effective source-rock-control hydrocarbon accumulation, and to high-quality source- rock-control hydrocarbon accumulation. However, there are problems, such as whether high-quality source rocks exist or not? What high-quality source rocks are, and how to identify them, are yet to be agreed upon. Aimed at this issue of concern to explorationists, and taking the Beier Sag in the Hailaer Basin as an example, this paper defines the high-quality source rocks and the lower limit for evaluation of high-quality source rocks, by using the inflection point on the relationship curve of hydrocarbon (oil) expulsion, which is calculated by the material balance principle, versus total organic carbon (TOC). The results show that when TOC is low, all source rocks have limited hydrocarbon expulsion and slow growth rate, thus they cannot be high-quality source rocks. However, when TOC rises to some threshold, hydrocarbon expulsion increases significantly with TOC. This inflection point should be the lower limit of high-quality source rocks: those with TOC greater than the inflection-point value are high-quality source rocks. In addition, the lower limit of high-quality source rocks is also related to the type and maturity of organic matters in the source rocks, as well as the mineral components of the source rocks affecting the residual hydrocarbons. Theoretically, the lower limit of high-quality source rocks depends on geological conditions rather than being a constant value. However, for the sake of simplicity and practicability, in this paper TOC=2.0% is regarded as the lower limit of high-quality source rocks. The examination of such standard in the work area indicates that the high-quality source rocks in members K^n2 and K^n~ of the Nantun formation contribute 76% and 82% to oil generation, and 96% and 91% to oil expulsion, respectively. The distribution of high-quality source rocks is also closely related to the distribution of hydrocarbon reservoirs in the region, demonstrating that high-quality source rocks control hydrocarbon accumulation.
基金supported by Ministry of Science and Technology of China(First StageGrant No.2001 CCA00600)supported by the National Science Foundation of China(Grant No.30371319).
文摘Both HIV and EIAV belong to the retroviridae family and lentivirus genus. They share considerable simi- larity at gene structural and component level. Hotzel pro- posed that two variable regions and surrounding amino acids of EIAV gp90 might adopt the same topology as V1, V2 and bridging sheet of HIV gp120. These regions map to V3, V4 and surrounding amino acids of EIAV gp90. Based on this proposal, we further analyzed the distribution profile of N-glycosylation site and linear epitope for EIAV gp90 and HIV gp120 at these regions. Our results demonstrated that EIAV gp90 and HIV gp120 are highly similar at these two aspects. Most likely, V3, V4 and surrounding amino acids of EIAV gp90 adopt the same topology structure as V1, V2 and bridging sheet of HIV gp120.