地震属性在延川南煤层气勘探中的应用
2012-10-21黄超平
黄超平
(中石化华东分公司物探研究院,江苏 210007)
地震属性在延川南煤层气勘探中的应用
黄超平
(中石化华东分公司物探研究院,江苏 210007)
从延川南地区地震资料中提取各种地震振幅、频率、相位等地震属性,比较分析地震属性与反射结构、煤层气储层中的煤层、含水层、含气层的关系,结果表明地震属性分析可以精细地描述煤层气储层的构造、地层和岩性特征,可以判别储层中强含水、含气层。结合钻井地质资料与测井资料,三瞬剖面解释可以进行煤层厚度估计与质量评价,为煤层气钻井设计提供依据。
地震属性 储层 煤层气 延川南
Abstract:Various seismic attributes,like amplitude,frequency,phase,etc.are drawn from seismic data of Yanchuan south area.By comparing the relationship between seismic attributes and reflection configuration,and coal seam,aquifers,gas-bearing layers in CBM reservoir,the authors found that seismic attributes could be used to describe elelaborately the tectonics,ground strata and lithologic characteristics of CBM reservoir,and they can be used to discriminate strong water-bearing and gas-bearing layers in the reservoir.Using geological data and logging data obtained in drilling,the three transient section interpretations can be used to estimate seam thickness,and to evaluate quality,so as to provide criteria for design of CBM well design.
Keywords:Seismic attribute;reservoir;CBM;Yanchuan south
1 概况
延川南煤层气勘探区块位于鄂尔多斯盆地的东南缘,是我国煤层气勘探开发的热点地区之一,现有二维测线长464km,约2km2三维面积的地震资料。地震构造解释结果表明整体构造相对简单,地层由南东向北西倾斜,局部小断层发育。地质与钻井资料研究表明从石炭系太原组到二叠系石盒子组为主要含煤地层,即煤层气储集层,总厚度超过300m,深度普遍在600~1300m之间。2#与l0#煤全区分布稳定,其余煤层横向稳定性较差,厚度变化大。2#煤层赋存于山西组下部,为全区稳定可采煤层,煤层厚度为2.09~8.65m,平均厚度5.97m。煤层在区块内总体呈东南厚西北薄的变化趋势,东南部厚度达到8m,西北部厚度2.5m。10#煤层赋存于太原组下部,煤层层位稳定,但厚度相对较薄,煤层厚0.79~6.50m,平均厚2.57m。区块煤层埋深总体由西北向东南逐渐变浅。
地震勘探的主要目的层为二叠系山西组2#煤层与石炭系太原组10#煤层。……
