南华北盆地通许地区上古生界天然气勘探前景

南华北盆地通许地区上古生界石炭系-二叠系保存较全，天然气成藏条件与鄂尔多斯盆地类似。 运用鄂尔多斯盆地致密砂岩气藏成藏理论，分析南华北盆地通许地区上古生界基本油气地质条件、圈闭 形成期与天然气运聚成藏期的匹配关系，明确该区天然气勘探前景。 研究表明：通许地区石炭系-二 叠系发育一套良好的区域性烃源岩，煤层发育，平均有机碳的质量分数为 62.9%，平均有机质成熟度为 3.34%，有机质类型属于Ⅱ2 型；储集岩主要为大面积分布的三角洲平原分流河道砂岩，平均孔隙度为 2.7%， 平均渗透率为 2.25 mD，发育粒间孔和粒间溶孔；上、下石盒子组泥岩发育，饱和气时突破压力为 5.88～ 9.80 MPa，是良好的区域性盖层；致密砂岩岩性圈闭为该区最有利的圈闭类型；圈闭形成于烃源岩主生排 烃期以前，源-储匹配关系好，具有良好的致密砂岩气勘探前景；尉北缓坡中南部是致密砂岩岩性圈闭气 藏发育的有利区。

Gas exploration prospects of the Upper Paleozoic in Tongxu area,southern North China Basin

The Carboniferous and Permian strata in Tongxu area of southern North China Basin are relatively complete preserved. The natural gas reservoir conditions are similar to those of the Ordos Basin. Based on the theory of tight sandstone gas reservoir forming in Ordos Basin, the basic petroleum geological conditions and the relationship between trap formation period and gas migration and accumulation period of the Upper Paleozoic were analyzed, then the gas exploration prospects of this area can be explicit. The research shows that the coal of Carboniferous and Permian in Tongxu area is well developed, the average organic carbon content of coal is 62.9%, the average maturity of organic matter is 3.34%, and the organic matter of coal belongs to Ⅱ2 type, which is a good regional source rock. Reservoir rocks mainly distributed in a large area of delta plain distributary channel sandstone, and average porosity is 2.7%, the average permeability is 2.25 mD, and intergranular pore and intergranular dissolved pore are developed. Mudstone of Upper and Lower Shihezi Formation is developed. The breakthrough pressure of mudstone saturated with gas is 5.88-9.80 MPa, and it is a good regional cap rock. The tight sandstone lithologic trap is the most favorable trap type, and it formed before the hydrocarbon generation, and the matching relationship is good. The central and southernarea of the Weibei Slope is favorable for the development of tight sandstone lithologic gas reservoir.