【摘要】 鄂尔多斯盆地大牛地气田主要含气层位是上石炭统太原组和下二叠统山西组、下石盒子组。地层划分对比难度大,主要原因是河流沉积相变快、井网稀、工区大,使用单一的地层划分对比方法效果不好,研究之初现场存在多种认识方案。采用标志层法(引入煤层作为标志层和辅助标志层)、厚度法(相邻井地层厚度相当)、层序地层学法、密井网解剖法(从密井网解剖入手,认识地层变化规律,进而推广到稀疏井网)4种方法相互结合、闭合对比,并应用合成地震记录标定(只针对砂组)和层面建模进行校验,形成了一套沉积环境复杂地区地层划分对比的综合方法,建立了一套新的地层划分对比方案,统一了地层认识,取得了较好的应用效果。更多还原

【Abstract】 The main gas-bearing horizons in Daniudi gas field of Ordos basin is the Upper Carboniferous Taiyuan,Lower Permian Shanxim and Xiashihezi Formations.Stratigraphic division and correlation are difficult because of rapid change of fluvial facies,sparse well pattern,and large project area in the field.Single stratigraphic division and correlation method failed to work effectively.At the very beginning of the study,there were several schemes as for how to solve the problems.As a result,a composite method of stratigraphic classification and correlation suitable for complicated sedimentary environment are developed by integrating the marker bed method(introducing coal seams as markers and supplementary horizon markers),the isopach method(the same layer having similar thickness) in adjacent wells,the sequence stratigraphy method,and the dense well pattern analysis method(i.e.,applying knowledge obtained from analysis of dense well pattern to sparse well pattern).By doing that,this paper presents a new scheme of stratigraphic division and correlation,which have been used successfully in real practice and achieved a unified understanding of the formations in the study area.更多还原