急倾斜多煤层勘查区煤层层位测井曲线对比研究

Study on Coal Seam Horizon Logging Trace Correlation in Steeply Dipping,Multiple Coal Seam Exploration Area

急倾斜地层,特别是多煤层的急倾斜地层勘查区,由于地层倾角的变化较大,单纯依靠钻孔取心进行煤层层位对比或利用地震时间剖面同相轴进行煤层层位追踪,效果均不理想。以新疆尼勒克煤田胡吉尔台勘查区为例,在钻探施工方法各异的情况下,通过对各种勘探方法的比较,最终选择误差影响因素较小的自然伽马测井曲线进行煤层层位对比,并找出了该区煤单层、煤层组合及煤岩层组合等自然伽马测井曲线响应特征,如11煤的"上凹下峰"形态,7煤层与9煤层的"手套"形态,16、17、18煤的尖峰与直立组合形态等。根据上述标志层的典型响应特征,采用先走向后倾向的原则,对全区进行煤岩层对比,揭示了该勘查区煤层的分岔、合并、冲刷、沉缺、煤层厚度等变化规律,取得了良好的对比效果。

Since significant changes of strata dip angles in steeply dipping plus multiple coal seam exploration area, simply relying on drilling core coal seam horizon correlation or using seismic time section lineups carrying out tlorizon tracing will all have no ideal effects. Taking the Hujirtay exploration area, Nilka coalfield, Xinjiang as an example, under situations of different drilling operational methods, after comparison of various exploration methods, finally the natural gamma logging trace with lesser error impacting factors has been selected to carry out coal seam horizon correlation, find out natural gamma logging trace responding features of single coal seam, coal group and coal rock group, such as ＂concave upper and peak lower＂ configuration of No.ll coal seam, ＂glove＂ configuration of Nos.7 and 9 coal seams, ＂pinnacle and erect combination＂ configuration of Nos.16, 17 and 18 coal seams. Based on above typical responding characteristics of key beds, using a principle of strike first, dip second, to carry out coal and rock correlation in whole area, successfully reveals variation pattern of coal seam splitting, merging, scouring, absence and coal thickness, have obtained good correlation results.