厚油层内部隔夹层预测建模——以Velasquez油田为例

Modeling of Inner Interlayer Prediction in Thick Oil Layer——with Velasquez Oilfield as an Example

开发后期,厚油层内部隔夹层是造成剩余油分布的主要因素之一。Velasquez油田G组厚油层内部发育泥质隔夹层和物性隔夹层,本文建立了这两种隔夹层的电性、物性识别模式,利用该模式开展全区隔夹层的识别及横向对比。结果表明,该区隔夹层可分为稳定型、次稳定型和随机型3种。在分析3种隔夹层分布规律的基础上,分别用确定性建模、物性下限值控制、条件模拟等方法预测了隔夹层的井间分布,建立研究区隔夹层三维展布模型,为油藏后期措施调整和水平井的部署提供了地质依据。

The inner interlayers are the main causes for forming multi-layer reservoirs with strong heterogeneity,which control the remaining oil distribution.Velasquez oilfield is located in the central part of Magdalenda basin in Columbia,and the paleogene group G sandstone reservoirs are of braided channel deposition.Muddy interlayer and interlayer of physical property are developed in the G reservoirs in Velasquez oilfield.Muddy interlayer consists mainly of flood argillaceous sediments,with the porosity less than 5%,and the permeability less than 1×10-3μm2.The porosity of physical interlayer is less than 11.3%,and the permeability is less than 23.3×10-3μm2.Two models for interlayers are built in order to identify interlayers in the whole area and to carry out lateral correlation.According to their planar distributions,the interlayers in the study area are divided into the steady,sub-steady and stochastic types,and then their interwell distributions are predicted by using the methods of interwell correlation,lower limit of physical property control and conditional simulation,respectively,in order to build the interlayer 3D distribution model and provide foundations for predicting remaining oil distribution.The method enjoys the necessary accuracy for the high water-cut reservoir interlining.