As a kind of abnormal natural gas formed with special mechanism, the deep-basin gas, accumulated in the lower parts of a basin or syncline and trapped by a tight reservoir, has such characteristics as gas-water invers...As a kind of abnormal natural gas formed with special mechanism, the deep-basin gas, accumulated in the lower parts of a basin or syncline and trapped by a tight reservoir, has such characteristics as gas-water inversion, abnormal pressure, continuous distribution and tremendous reserves. Being a geological product of the evolution of petroliferous basins by the end of the middle-late stages, the formation of a deep-basin gas accumulation must meet four conditions, i.e., continuous and sufficient gas supply, tight reservoirs in continuous distribution, good sealing caps and stable structures. The areas, where the expansion force of natural gas is smaller than the sum of the capillary force and the hydrostatic pressure within tight reservoirs, are favorable for forming deep-basin gas pools. The range delineated by the above two forces corresponds to that of the deep-basin gas trap. Within the scope of the deep-basin gas trap, the balance relationship between the amounts of ingoing and overflowing gases determines the gas-bearing area of the deep-basin gas pool. The gas volume in regions with high porosity and high permeability is worth exploring under current technical conditions and it is equivalent to the practical resources (about 10%-20% of the deep-basin gas). Based on studies of deep-basin gas formation conditions, the theory of force balance and the equation of material balance, the favorable areas and gas-containing ranges, as well as possible gas-rich regions are preliminarily predicted in the deep-basin gas pools in the Upper Paleozoic He-8 segment of the Ordos basin.展开更多
东卡罗琳海盆(East Caroline Basin,ECB)是太平洋经向翻转环流深层流上分支(upper deep branch of the Pacific Meridional Overturning Circulation,U-PMOC)进出西太平洋的关键通道,其深层环流特征与动力机制对理解太平洋深层环流结构...东卡罗琳海盆(East Caroline Basin,ECB)是太平洋经向翻转环流深层流上分支(upper deep branch of the Pacific Meridional Overturning Circulation,U-PMOC)进出西太平洋的关键通道,其深层环流特征与动力机制对理解太平洋深层环流结构、变化及气候效应具有重要意义。基于1993~2022年OFES高分辨率模式数据,分析了ECB深层环流(>2500 m)的气候态平均输运、空间结构及季节变化特征。研究发现,ECB深层水体主要经西南深水通道流入(年均流量2.12 Sv),沿海盆西侧北向输运形成深层西边界流,随后转向东流,最终由东北深水通道流出(年均流量-2.35 Sv,负值表示流出)。海盆内部净输运接近平衡(-0.10 Sv),整体呈现顺时针(反气旋式)环流结构。深层环流具有明显季节变化:北半球冬春季(12~6月)以输入为主,夏秋季(7~11月)以输出为主,且流出过程相对流入存在滞后,表明ECB在年周期中充当深层水团的临时储存区。从动力机制看,水体自西南向东北输运过程中,β效应使行星涡度增加,为维持位涡守恒,相对涡度相应减小,驱动形成顺时针环流;深层西边界流则通过侧向摩擦耗散负涡度异常,维持系统动力平衡。本研究系统揭示了ECB深层环流结构、季节变化与动力机制,深化了对西太平洋深层环流的认识,为全球经向翻转环流模拟与深海生物地球化学循环研究提供了科学依据。展开更多
基金This study is part of the National Key Basic Research Project(973)of the"Formation and Distribution of Oil and Gas in Typical Superimposed Basins in China(G19990433)"supported by the Ministry of Science and Technology of China.
文摘As a kind of abnormal natural gas formed with special mechanism, the deep-basin gas, accumulated in the lower parts of a basin or syncline and trapped by a tight reservoir, has such characteristics as gas-water inversion, abnormal pressure, continuous distribution and tremendous reserves. Being a geological product of the evolution of petroliferous basins by the end of the middle-late stages, the formation of a deep-basin gas accumulation must meet four conditions, i.e., continuous and sufficient gas supply, tight reservoirs in continuous distribution, good sealing caps and stable structures. The areas, where the expansion force of natural gas is smaller than the sum of the capillary force and the hydrostatic pressure within tight reservoirs, are favorable for forming deep-basin gas pools. The range delineated by the above two forces corresponds to that of the deep-basin gas trap. Within the scope of the deep-basin gas trap, the balance relationship between the amounts of ingoing and overflowing gases determines the gas-bearing area of the deep-basin gas pool. The gas volume in regions with high porosity and high permeability is worth exploring under current technical conditions and it is equivalent to the practical resources (about 10%-20% of the deep-basin gas). Based on studies of deep-basin gas formation conditions, the theory of force balance and the equation of material balance, the favorable areas and gas-containing ranges, as well as possible gas-rich regions are preliminarily predicted in the deep-basin gas pools in the Upper Paleozoic He-8 segment of the Ordos basin.
文摘东卡罗琳海盆(East Caroline Basin,ECB)是太平洋经向翻转环流深层流上分支(upper deep branch of the Pacific Meridional Overturning Circulation,U-PMOC)进出西太平洋的关键通道,其深层环流特征与动力机制对理解太平洋深层环流结构、变化及气候效应具有重要意义。基于1993~2022年OFES高分辨率模式数据,分析了ECB深层环流(>2500 m)的气候态平均输运、空间结构及季节变化特征。研究发现,ECB深层水体主要经西南深水通道流入(年均流量2.12 Sv),沿海盆西侧北向输运形成深层西边界流,随后转向东流,最终由东北深水通道流出(年均流量-2.35 Sv,负值表示流出)。海盆内部净输运接近平衡(-0.10 Sv),整体呈现顺时针(反气旋式)环流结构。深层环流具有明显季节变化:北半球冬春季(12~6月)以输入为主,夏秋季(7~11月)以输出为主,且流出过程相对流入存在滞后,表明ECB在年周期中充当深层水团的临时储存区。从动力机制看,水体自西南向东北输运过程中,β效应使行星涡度增加,为维持位涡守恒,相对涡度相应减小,驱动形成顺时针环流;深层西边界流则通过侧向摩擦耗散负涡度异常,维持系统动力平衡。本研究系统揭示了ECB深层环流结构、季节变化与动力机制,深化了对西太平洋深层环流的认识,为全球经向翻转环流模拟与深海生物地球化学循环研究提供了科学依据。
