深层致密储层人工缝网复杂程度研究及相关性分析

Complexity Study and Correlation Analysis of Artificial Fracture Networks in Deep Tight Reservoirs

摘要: 针对非常规储层的改造，常常采用体积压裂工艺，压裂后人工缝网的形态是体积压裂工艺是否成功的重要体现，针对深部储层压裂后人工缝网复杂程度评价技术难度大、成本高的问题，本文以大北区块30口井为研究对象，对压裂施工曲线的停泵段进行G函数解释，将人工缝形态总结为3种G函数图版，并将G函数的特征值与压后产能进行相关性分析。结果表明：大北区块的人工缝网形态可分为简单裂缝、少量沟通天然裂缝以及复杂缝网三类，G函数特征值与天然裂缝沟通程度呈现正相关关系。G函数特征值与压后产量相关性强，而与无阻流量相关性弱。基于现场压裂施工曲线的停泵段进行裂缝诊断，结合文中所得出的图版，为现场裂缝形态的诊断提供参考。

Abstract: For unconventional reservoir stimulation, volume fracturing technology is commonly used, and the morphology of the artificial fracture network after fracturing is a key indicator of the technique’s success. To tackle the challenges of high technical difficulty and cost associated with evaluating the complexity of hydraulic fractures in deep reservoirs, this study focuses on 30 wells in the Dabei Block. The shut-in segments of the fracturing treatment curves were analyzed using G-function analysis. The artificial fracture morphologies were classified into three G-function templates, and a correlation analysis was conducted between the characteristic values of the G-function and post-fracturing productivity. The results reveal that the artificial fracture networks in the Dabei Block can be categorized into three types: simple fractures, limited activation of natural fractures, and complex fracture networks. The characteristic values of the G-function show a positive correlation with the degree of natural fracture interaction. Furthermore, these values demonstrate a strong correlation with post-fracturing production but a weak correlation with open-flow potential. By diagnosing fracture morphology based on the shut-in segments of field fracturing curves and using the proposed templates, this study provides a practical reference for on-site fracture characterization.