致密气藏复杂裂缝压裂技术

大庆油田深层致密砂砾岩储层直井采用常规凝胶加砂压裂技术施工13口井,存在施工规模大、压裂后产量低的问题。分析认为由于储层致密,有效渗流距离短且应力差大,压裂形成单一裂缝,导致改造体积较小。因此,结合储层岩石脆性高的特点,利用水平井人工裂缝的相互干扰来降低应力差,并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7.8倍,压裂后产量是直井的17倍。应用情况表明该压裂增产工艺技术可行,为致密气储层的高效勘探开发提供了有力的技术支持。

FRACTURING TECHNIQUE FOR THE COMPREHENSIVE CRACK IN THE TIGHT GAS RESERVOIR

13 vertical wells were stimulated by the conventional gel and the granulated substance fracturing technology in the deep tight conglomerate reservoir of Daqing Oilfield,the following operational problems were shown:the scale in a big way and lower production after the frac.The rather smaller fractured volume was analyzed and the reasons were due to the tight reservoir,shorter effective flow distance,rather bigger stress difference and the reduced single fracture.Therefore integrating with the high brittleness characteristic of the reservoir rock and with the help of the mutual disturbance among the artificial fractures in the horizontal well,the stress difference was reduced,and moreover by means of complex crack fracturing technology,the stimulated fracture volume was enlarged and the productivity of the individual well was enhanced.Through the parameter contrast,the operational scale of the horizontal well is 7.8 times of that of the vertical well,while the production after the frac is up to 17 times.The practice shows that the stimulating technology by the fracturing is feasible and provides the powerful technical support for the high-efficiency exploration and development of the tight gas reservoir.