改进的模糊-灰色综合评判方法在储层定量评价中的应用——以苏里格气田苏X井区盒8下亚段低渗透气藏为例

Application of improved fuzzy-grey comprehensive evaluation method to quantitative reservoir evaluation: A case study of the low-permeability gas reservoirs of the lower part of 8th member of the Shihezi Formation in Su X block of Sulige Gasfield

朱兆群 林承焰 张苏杰 任丽华 赵剑轩 陈仕臻 贾萧蓬 陈莉 张吉

Zhu Zhaoqun Lin Chengyan Zhang Sujie Ren Lihua Zhao Jianxuan Chen Shizhen Jia Xiaopeng Chen Li Zhang Ji

储层认识不成熟以及评价信息不完备等问题，给苏里格气田苏X井区盒8下亚段低渗透气藏早期的储层评价带来很多不确定性，进而无法精细刻画储层特征。如何充分体现储层评价过程的不确定性以及有效扩大评价结果的差异性，则成为改善储层评价效果的关键。以隶属度为纽带，按照多信息叠合思想，将不确定方法中的模糊综合评价和灰色关联评价方法有机组合，对内部算法进行差异化改进处理，建立了更加有效的模糊-灰色综合评判方法。实例应用表明，新方法在兼顾研究区储层评价模糊性和灰色性的同时，还提高了低渗透储层的区分度，提升了储层描述的精度。根据改进后的储层分类结果，将盒8下亚段划分出4类储层，其中Ⅰ和Ⅱ类为有利储层。平面上储层展布与过去的近连片认识相比刻画得更加精细，储层类别间具有较好的区分，更贴近河流沉积的发育规律和地质知识库，与已有实践成果和地质认识也大致匹配。该方法能够快速有效地指导气田勘探开发部署实践，为类似的低渗透储层评价提供了新的思路。

For the lower section of 8th member of the Shihezi Formation (Middle Permain) in the Su X block of the Sulige gasfield,significant degree of uncertainty was involved in early-stage evaluation of low-permeability gas reservoir due to immature understanding and incomplete information,which causes difficulty to a fine reservoir description.It is vital for a better reservoir evaluation to fully account for uncertainty and effectively magnify the differences of different reservoirs in evaluation results.In this paper,based on the idea of multi-information superposition,the methods of fuzzy mathematical evaluation and grey correlation analysis are linked by membership degree and are integrated to establish a more effective fuzzy-grey comprehensive evaluation model,along with differentiated and improved internal algorithm.The application of the model to reservoir evaluation in this study suggests that this method enhances the differences and precision for the low-permeability reservoir classification and characterization,with consideration of the fuzzy and grey properties of reservoir.In this case study,four types of reservoir are classified and the type Ⅰ and Ⅱ are deemed to be the favorable targets.The different reservoir categories are better separated in plane view than before.The comparison of evaluation results with the real production data and geological principles of fluvial deposition also displays good coincidence.This method may be effective and efficient for guiding the exploration and development of the gas field,and provide a new thought for similar low-permeability reservoir evaluation as well.

10.11743/ogg20170121