基于压裂效果评价的页岩气井井距优化研究

Study on the Optimization of Shale Gas Well Spacing Based on Assessment of the Fracturing Performance

王妍妍 王卫红 胡小虎 刘华 郭艳东

WANGYanyan WANGWeihong HUXiaohu LIUHua GUOYandong

中国石化石油勘探开发研究院, 北京 海淀 100083 “页岩油气富集机理与有效开发”国家重点实验室, 北京 海淀 100083

Research Institute of Petroleum Exploration and Development, SINOPEC, Haidian, Beijing 100083, China State Key Laboratory of Shale Oil and Gas Enrichment Mechanisms and Effective Development, Haidian, Beijing 100083, China

针对页岩气藏最优井距很大程度上受限于压裂效果后评估的问题，开展了多段压裂水平井改造参数解释研究，并在此基础上开展井距优化。通过建立的渗流数学模型明确页岩气井生产时地层中存在的流态，形成基于线性流识别和特征线诊断技术的压裂参数解释方法，并对参数解释的不确定性进行了分析论证。之后通过定义百米地层累产气进行均匀压裂情况下井距优化。研究表明，地层进入边界控制流后能准确确定裂缝半长，且不影响气井的产能预测；井距的决定性因素是裂缝半长，二者之间的比例关系受SRV内外区相对物性和裂缝导流能力的影响，据此可指导现场井距优化及开发技术政策制定。

Determination of the optimum shale gas well spacing is to a large extent dependent on the assessment of fracturing performance. To tackle this problem, we explored the parameters associated with the reconstruction of horizontal wells used for multi-stage fracturing. Based on this exploration, we further optimized the shale gas well spacing. By establishing a mathematical model of seepage flow, we determined the flow regime existing in the formation of a shale gas well and furthermore developed a method to rationalize the fracturing parameters based on linear flow identification and the feature line diagnostic technique. The uncertainty associated with the parameter rationalization is also analyzed and discussed in this study. Finally, the optimum well spacing under uniform fracturing condition was determined by defining the total gas production over a 100-m stratum. The results demonstrate that the half length of the crack can be accurately determined without affecting the prediction of the production capacity of the gas well once the formation is under boundary control flow. The key factor in determining the well spacing is the half length of the crack. The relationship between these two parameters is affected by the relative physical properties and flow conductivity of the fracture inside and outside the SRV. These findings can provide guidance for performing well spacing optimization and policy-making associated with the extraction techniques.

10.11885/j.issn.1674-5086.2017.10.24.03