多参数联合反演在火成岩储集体预测中的应用

Application of multi-parameter joint inversion in prediction of igneous reservoir

苏北盆地海安凹陷四灶地区勘探主要目的层阜宁组火成岩发育,已在阜宁组二段和三段玄武岩及辉绿岩中获得商业油流。但该区火成岩分布复杂,受火成岩影响地震资料品质较差,依据地震资料准确地识别火成岩有较大难度。本文通过分析研究区火成岩储层的地震剖面特征和测井响应特征,应用伽马和深侧向电阻率曲线构建拟声波曲线,并以高分辨率波阻抗、伽马拟阻抗和深侧向电阻率拟阻抗反演为载体,进行了高分辨率参数反演。在此基础上,利用贝叶斯多参数综合识别方法进行多参数信息融合,形成融合数据体,预测出火成岩的平面及空间展布特征。经实际资料应用表明,多参数融合技术可有效地利用波阻抗反演和参数反演的结果,能较为准确地反映出火成岩的变化特征。

Igneous rocks were developed in Funing Formation that is main target of exploration in Sizau area of Hai'an sag, Subei basin. The commercial oil flow was acquired in basal of E1f2 and diabase of E1f3. The igneous distribution in the region is complex and the quality of seismic data is poorer because of igneous influence, which makes accurate identification of igneous rock difficult if only by using seismic data. Through analysis of the feature of seismic sections and logging response of igneous reservoir in studied region, the paper uses gamma and deep lateral resistivity log curves to create pseudo acoustic curves and carries out high-resolution parameters inversion on the basis of taking the inversion of high-resolution wave impedance, gamma pseudo impedance and pseudo impedance of deep lateral resistivity as carriers. On that basis, using Bayes multi-parameter comprehensive identification method to carry out multi-parameter information combination, forming combining data volume and predicting igneous planar and special distribution feature. It is shown by practical data that multi-parameter combining technique can effectively use the results of wave impedance inversion and parameter inversion and more accurately reflect the igneous variation feature.