冀中拗陷北部天然气成藏系统及勘探方向

对冀中拗陷北部天然气成藏地质要素研究认为，该区发育下第三系湖相泥岩和石炭—二叠系煤系地层2套烃源岩，具备雾迷山组海相碳酸盐岩、寒武系—奥陶系海相碳酸盐岩、二叠系砂岩、下第三系砾岩和下第三系砂岩等5套有利储层，上古生界—新生界发育4套区域性盖层，依据已发现天然气的成熟度、地球化学指标和构造特征划分出生物气、生物热催化气、热解气、生物改造气和煤成气等5种天然气成因类型。通过对不同类型的天然气受控的成藏组合和构造背景分析，提出了冀中拗陷北部可划分为廊固凹陷深层、浅层和霸县凹陷深层等3个天然气成藏系统，总结了8种天然气成藏模式。综合评价认为，廊固凹陷和霸县凹陷2个深层天然气成藏系统具有较大的资源潜力，指出牛东深潜山带、大兴砾岩体和苏桥—文安潜山内幕等3个领域是有利勘探方向。

On the Choice of Leading Industries in Nanchong City

The research on the natural gas reservoir-forming geologic factor of northern Hebei depression indicates that in the area，there are two sets of well developed hydrocarbon source rocks which are Lower Tertiary lacustrine mudstone and carboniferous-permian coal beds，including five sets of favorable reservoirs such as Wumishan marine carbonate rocks，Cambrian-Ordivician marine carbonate rocks，Permian Sandstone，Lower Tertiary Conglomarate and Lower Tertiary Sandstone.There are four sets of aeral cap rocks developed in from Upper paleazoic-cenozoic，such five types of natural gas genesis are grouped into biogas，biological thermal-catalytic gas，pyrolysis gas，biologic-reforming gas and coal bed methane according to the maturity，geochemical indicators and structural features of explored gas.The conditions of reservoir formation are favorable.By means of the analysis of the reservoir-forming association and tectonic settings of differenty types of gas，the three sets of gas reservoir-forming systems in northern central Hebei depression are identified，they are in deep and shallow formations of Langgu Sag and deep formation of Baxian Sag.Eight types of gas reservoir-forming models are put forward.It is indicated that two reservoir-forming systems in Langgu Sag and Baxian Sag are prospective ones.There are three favorable targets in Niudong deep buried hills，Daxin conglomerate body and Suqiao-Wen′an buried hills.