特低渗碎屑岩储层评价方法研究——以安塞油田三叠系延长组长6油层组为例

Research on Evaluation Methods for Extremely-Low-Permeability Clastic Rock Reservoir ——Taking the Chang 6 Reservoir of Yanchang Formation in Ansai District as an Example

摘要: 中国的地质演化特点决定了中国的低渗透油气资源丰富，分布广、类型多、资源量大。在我国经济快速发展但能源紧缺的情况下，大力加紧低渗透储层的评价研究，解决低渗透油层的勘探开发难题，加快增储上产的步伐，对促进国民经济持续稳定发展具有现实的和科学的意义。我国第一个规模开发的低渗透油田——长庆安塞油田，是一个特低渗透油田。本文以安塞油田三叠系延长组长6油层组为例，从沉积体系研究低渗透油气田的分布规律，通过精细的沉积微相分析，了解低孔低渗砂体纵横向分布状况；通过成岩作用分析，确定储集体的成岩演化序列、成岩相分布；通过储层评价，认清储层的孔隙结构和物性特征，建立低渗储层评价方法和分类标准，优选有利区并完成储层预测。

Abstract: The characteristics of geological evolution in china determine that low-permeability oil and gas resource is abundant, widespread and has various types. In the rapid economic development of our country with energy shortage situation, intensifying the research and evaluation of low permeability reservoir, solving the problem of exploration and development of low-permeability reservoir, accelerating the increase in oil reserve and production to promote sustained and stable development of national economy have the realistic and scientific significance. Changqing Ansai oil field, the first large-scale development of low-permeability oil field, is a low-permeability oil field. In this paper, we take the Chang 6 reservoir of Yanchang Formation in Ansai district as an example to study low-permeability oil and gas distribution rules by depositional system. We can understand horizontal and vertical distribution of low-permeability reservoirs through refined sedimentary micro-facies analysis. The diagenetic evolution sequence and diagenetic facies distribution in the reservoir can be confirmed by the method of diagenesis analysis. Finally, through reservoir evaluation, we can recognize the reservoir pore structure and physical characteristics, establish the evaluation method of low-permeability reservoir and classification standard, optimize advantageous area and complete the reservoir prediction.