南华北盆地太康隆起西部新区上古生界天然气成藏条件与钻探发现

Drilling achievements and gas accumulation in the Upper Paleozoic in western new area of Taikang Uplift,Southern North China Basin

南华北盆地是我国东部重要的油气远景区之一,历经多年勘探,但始终没有工业性突破。以地震和钻井等资料综合分析为基础,以上古生界油气为主要目的层,综合考虑太康隆起油气地质条件,重点考虑保存条件,同时参考烃源岩及储层条件,可将太康隆起西部地区重新划分为5个次级单元,即:北部斜坡带、中部鼻状构造带、尉氏—薛店南次凹带、通许凸起和新郑凸起。太康隆起西部上古生界残存分布面积广、厚度大,埋藏深度适中,三叠系残存较为完整,构造整体比较稳定,圈闭发育,具备早期生烃的保存和成藏条件。从中优选出庄头断鼻部署实施钻探,在上古生界发现气测异常69段,累计厚度为81.3m,气测异常全烃最大值为24.1%;测井综合解释致密气7层,累计厚度为41.6m,其中厚度超过7m的单层为4层;页岩气层9层,累计厚度为72.3m,其中最大单层厚度为28.4m,进一步展示了太康隆起西部新区天然气的勘探前景,对推进南华北地区海陆交互相天然气资源调查和评价具有重要意义。

Based on the analysis of seismic data and well data of existing drilling,and took the characteristics of fracture structure,tectonic deformation and relict strata distribution in the Mesozoic,the sub-units of west Taikang Uplift in Southern North China Basin is re-divided,and the Zhuangtou fault nose is optimized,where Well Weican-1 was deployed.The well revealed a good exploration prospect by the discovery of 69 gas logging abnormality,with an accumulated thickness of 81.29 mand a max hydrocarbon value of24.118 3%,in the Upper Paleozoic.After comprehensive analysis,it is concluded that the hydrocarbon shows of Well Weican-1 in Upper Paleozoic is closely related to residual thickness of the overlying Triassic strata,and the study area is confirmed to be relatively stable in tectonic conditions.Consider the features of petroleum geological conditions,especially the effective sealing and preservation conditions,the west Taikang Uplift,where the dominant remnants of Upper Paleozoic is widely distributed with large thickness,medium burial depth,well preserved Triassic,and relatively stable,would be an advantaged Paleozoic natural gas foreground area with good preservation conditions,and therefore further advanced the resources investigation of continental-oceanic interactive shale gas.