利用测井约束反演技术辨别气层与煤层

Well log constrained inversion technique used for gas reservoir and coal bed discrimination

滇黔桂石油勘探局物探公司,昆明 650233

Geophysical Prospecting Company, Dian Qian Gui Petroleum Exploration Bureau, Kunming 650233

测井约束反演是一种基于模型的反演方法, 它以测井资料丰富的高频信息和完整的低频成分补充地震资料有限带宽的不足, 用已知地质和测井资料为约束条件, 推算出高分辨率的地层波阻抗资料, 为储层深度、厚度、物性等描述提供依据。反演结果的精度除依赖于研究目标的地质背景、钻井数量、井位分布以及地震资料的品质外, 还取决于处理和解释工作的精细程度。从陆良盆地实际资料反演效果来看, 在亮点剖面上反映明显的气层, 在测井约束反演剖面上依然反应明显；而在地震剖面上也呈亮点特征的煤层, 在测井约束反演剖面上则基本没有变化, 提高了气藏识别的精度。

Well log constrained inversion is a model-based inversion method. In the method, the richhigh frequency information and complete low frequency components of well logging data complement thelimited bandwidth of seirmic data. It uses known geologic data and well log as comtraints to obtain high-resolution stratigraphic imedance data, providing basis for describing the depth, thicknes and physicalproperty of reservoir. The precision of inversion results depends on the degree of fineness of processingand interpretation work besides on geologic background, drilling hole number, well 1ocation distributionand seismic data quality. for from the effect of inversion, the gas reservoir, shown as btight spot onseismic section, is still shown clearly on the well log constrained inversion section. coal bed, which alsohas a character of bright spot on seismic section, has no showing in general. This improves the precisionof gas pool identification.