摘要
裂缝导流能力主要是通过实验方式获取,只有较少的理论计算模型计算填砂裂缝导流能力,对于未填砂水力裂缝导流能力的理论计算模型几乎没有。为此,根据未填砂水力裂缝闭合后的特点,并结合Carman-Kozeny公式和Walsh模型,建立了砂岩储层无填砂水力裂缝导流能力计算模型;通过考虑颗粒剥离充填,并利用Hardin颗粒破碎模型,建立了考虑颗粒支撑和颗粒破碎情况下的无填砂水力裂缝导流能力计算模型。通过上述模型分别计算了岩石颗粒粒径、闭合应力、颗粒剥离填充水力裂缝情况下,颗粒铺置方式及颗粒破碎对无填砂裂缝导流能力的影响。计算结果表明:储层的岩石颗粒粒径越大,闭合应力越小,无填砂水力裂缝导流能力越高;岩石颗粒剥离填充水力裂缝情况下,颗粒铺置层数越多,无填砂水力裂缝导流能力越大;考虑颗粒破碎情况下,岩石粒径越大,无填砂水力裂缝导流能力下降越明显。上述模型的建立为未填砂水力裂缝导流能力计算提供了依据。
Fracture conductivity is mainly obtained from experiments, and only several theoretical models are used for calculating packed fracture conductivity, while hardly any models for unpacked fracture conductivity exist. According to the closure characters of unpacked fracture, and combined with Carman-Kozeny formula and Walsh model, a calculation model of unpacked hydraulic fracture flow conductivity in sandstone reservoir is established. By the consideration of particle stripping filling and by adopting Har- din particle breakage model, a computational model of unpacked hydraulic fracture flow conductivity is established by the consider- ation of particle supported and particle breakage. From the above models, the effects of lay mode of particle and particle breakage on unpacked fracture conductivity were calculated by the consideration of grain diameter, closure stress, packed hydraulic fracture. The calculation results show that the larger the rock grain size is, the smaller the closure stress and the higher the unpacked fracture conductivity will be. In addition, take particle stripping into account, the larger the grain size is, the greater the unpacked hydraulic fracture flow conductivity will be. By the consideration of particle breakage, the larger the particle size is, the smaller the unpacked fracture conductivity will be. The above models provide basis for the calculation of unpacked hydraulic fracture flow conductivity.
出处
《油气藏评价与开发》
CSCD
2017年第1期27-31,共5页
Petroleum Reservoir Evaluation and Development
关键词
无填砂裂缝导流能力
砂岩储层
水力压裂
颗粒粒径
闭合压力
计算模型
unpacked fracture flow conductivity, sandstone reservoir, hydraulic fracture, particle diameter, closure stress, compu-tational model
