基于储层潜力的水平井分段酸压设计优化与应用

OPTIMAL PLANNING AND APPLICATION OF STAGED ACID-FRACTURING IN HORIZONTAL WELLS BASED ON RESERVE EVALUATION

为了明确影响四川盆地震旦系碳酸盐岩储层水平井改造效果的关键因素,同时建立一套适合本区的强非均质储层水平井分段酸压方法,采用信息量和灰关联分析手段,对30口气井地震、成像和岩心等资料进行了评价,基于评价结果开展了设计优化相关研究。结果表明,地震资料反应出的缝洞发育情况对震旦系气井产量影响最大,其次为成像测井资料、岩心资料和钻录井显示资料,构造背景因素影响最低。基于上述认识,震旦系储层水平井可主要依据地震资料建立分段酸压优化方法,将地震剖面与井眼轨迹叠合,实现水平井合理分段,确定各段改造目标和选择每段工艺及参数。现场应用表明,相比于前期同类改造井,压后测试产量提高2～3倍,为同类型储层改造提供了有效的手段。

In order to identify the key factors affecting acid-fracturing performance in the carbonate reservoir in Sinian formation of Sichuan Basin and to establish a suitable staged acid-fracturing method for horizontal wells in highly heterogenous reservoirs, the information amount theory and gray correlative method were used to evaluate the seismic data, images and cores of thirty gas wells.The results show that the fracture-cavity development information reflected by seismic data is the most important influence factor for gas well production in Sinian formation, then the imaging logging data, the core data, the drilling/logging data, and the structural setting.So the staged acid-fracturing optimization method can be built mainly based on seismic data.The composite of seismic profiles and borehole trajectory can help to divide horizontal section reasonably and to determine the stimulation goal of each section, also help to decide the technology and parameters.Field application shows that the gas production after acid-fracturing was 2~3 times the production of previous wells in similar formation.It provides an effective way for the stimulation of same type reservoir.