砂砾岩储层复杂裂缝压裂增产技术探索

Exploration on the Fracturing Stimulation Technology for Complex Fractures in Sandstone Conglomerate Reservoir

针对大庆油田深层气砂砾岩储层直井采用常规凝胶加砂压裂技术施工,存在施工规模大、压裂后产量仍较低的问题,分析原因是其储层致密,有效渗流距离短且应力差大,压裂过程中易形成单一裂缝,导致改造体积较小。通过研究储层岩石脆性特征及水平井人工裂缝间的相互干扰,采用复杂裂缝压裂工艺,扩大裂缝改造体积,提高单井产能。通过参数对比,水平井施工规模为直井的7. 8倍,但压裂后产量是直井的17倍。现场应用情况表明,复杂裂缝压裂增产技术可行,并且为今后油田储层的高效开采提供了有力的技术支持。

The conventional gel and sand fracturing technology has been applied for vertical well in the sandstone conglomerate deep gas reservoir of Daqing Oilfield,featured with large scale of operation,while low production after fracturing.The reasons were analyzed as follows:tight reservoir,short distance of effective seepage,big stress difference,single fracture prone to be formed in the fracturing operation process,which led to the smaller volume of stimulated pay zones.By the research of the features of reservoir rock brittleness and the mutual interference of arti-ficial fractures in horizontal wells,the fracturing technology of complex fractures was adopted to enlarge the volume of stimulated fracture,and improve the single well production.Comparison of parameters showed that although the fracturing scale in horizontal wells is 7.8 times of that in vertical wells,its production is 17 times of that in vertical wells after fracturing.The application indicates that the fracturing technology of complex fractures reservoir is feasible,which will provide strong technical support for the efficient exploitation of oilfield reservoirs in the future.