应用测井方法计算泥页岩有机碳质量分数

Application of logging method for calculating TOC of mud shale

有机碳质量分数(TOC)是评价页岩气资源潜力的重要参数之一。利用测井信息的特殊响应,可以快速识别井下泥页岩地层。依据大量的实测数据,结合测井方法计算泥页岩TOC,可以有效地筛选富有机质泥页岩层段。以塔里木盆地2口井为例,探讨测井方法计算TOC的适用性。研究认为:经典的△lg R法对高—过成熟阶段的海相泥页岩TOC的计算并不适用,对中等成熟阶段的陆相泥页岩TOC的计算具有一定的适用性;对海相、陆相泥页岩利用U曲线法计算TOC具有很好的应用效果;在缺乏成熟度数据的非高—过成熟阶段的泥页岩层段,使用△lg R与U曲线组合法计算TOC,可以提高计算值的精确度。

Organic carbon mass fraction is one of the most important parameters for evaluation of the shale gas resources potential. Using the logging information, shale layer can be fast recognized. Based on large quantities of measured data,TOC of mal4ne shale is calculated by using logging method and the favorable shale layers which are rich in organic matters are screened effectively. Taking two wells in Tarim Basin as an example, the applicability for TOC calculation is discussed by using logging methods. The study shows that the classic AIgR method is not fit for TOC calculation of high-over mature marine shale and has certain applicability tbr medium mature continental shale; while TOC calculation by using uranium logging eurve has got good results for marine and continental shale. In the non high-over mature shale interval which is lack of maturity data, a combination of AIgR mettmd and uranium logging curve for TOC calculation can impruve the accuracy of calculated value.