三维地震约束辫状河储层的多点统计建模研究:以委内瑞拉M区块为例

Multiple-Point Geostatistical Modeling of Braided Channel Reservoir with Constraints by 3D Seismic Data: A Case Study of M Block in Venezuela

将地震信息引入多点统计地质建模之中,可以提高模型的井间预测功能.首先以委内瑞拉奥里诺科重油带一个辫状河沉积含油区块为例,结合该区辫状河储层的地质特点,利用井震信息结合的多点统计建模方法,研究了波阻抗的相标定、砂体概率生成曲线选定、训练图像分析、井震影响比等方面的技术细节及它们在辫状河储层多点统计建模中的作用.然后结合辫状河储层的沉积学特征,对研究区的心滩、河道、泛滥平原等微相空间分布的建模结果进行了分析.最后对于不同的储层建模结果进行了不确定性分析.研究表明:井震结合的多点统计建模方法,较好地降低了稀井网地区建模结果的不确定性;通过砂岩概率生成曲线,波阻抗数据转化为地震相的空间概率分布.这样就有效地建立起了地震数据与其地质意义的联系;相比仅用测井信息建模,井震结合建模结果对井间微相预测更具合理性,同时预测的河道、心滩的连续性也得到了更好的体现.

Integrating seismic information into multi-point statistical geological modeling can improve the cross well prediction function of the model. Taking a braided river sedimentary oil-bearing block in Orinoco heavy oil belt, Venezuela, as an example, combined with the geological characteristics of braided river reservoir in this area, and using the multi-point statistical modeling method integrated well with seismic data, is this paper it studies the facies calibration of seismic wave impedance, the selection of sand-body probability generation curve, training image analysis, impact ratio between well and seismic data, and their role in multi-point statistical modeling of braided river reservoir. Then, combined with the sedimentological characteristic of braided river reservoir, the modeling results of microfacies spatial distribution such as channel bar, river channel and flood plain in the study area are analyzed. Finally, the uncertainty of different reservoir modeling results is analyzed. The research shows that the multi-point statistical modeling method integrated well and seismic data can better reduce the uncertainty of modeling results in areas with sparse well pattern. Through the probability generation curve of sandstone, the wave impedance data is transformed into the spatial probability distribution of seismic facies. In this way, the relationship between seismic data and its geological significance is effectively established. Compared with modeling only with well-logging data, the method integrated well seismic data modeling result is more reasonable for inter well microfacies prediction, and the continuity of predicted river channel and channel bar is better displayed.