油藏水驱开采时移地震监测岩石物理基础测量

Petrophysical measurements for time-lapse seismic monitoring of reservoir waterflooding recovery

岩石物理测量是油藏水驱开采时移地震监测的基础.在实验室对来自胜利油田的5块岩石样品模拟储层条件进行了水驱和气驱动态岩石物理弹性测量,重点分析了流体替换、温度、孔隙压力对岩石纵、横波速度的影响.实验表明,在水驱情形下,由于流体替换和温度、孔隙压力变化所引起的岩石纵横波速度的变化均很小,实施时移地震监测具有较大的风险性.相比之下,气驱可能引起较为明显的纵波速度变化,有利于时移地震监测的实施.进一步完善实验方法、丰富实验内容、是今后时移地震岩石物理实验研究的主要任务.

Petrophysical measurements are the basis of time-lapse seismic monitoring of reservoir waterflood recovery. Under the modeled reservoir conditions as well as performance of water injection and air injection, petrophysical elastic measurements are carried out on five samples from the Shengli oilfield in laboratory. The facus is to analyze ,the influence of pore fluid substitution and temperature and pore pressure on compressional and shear wave velocities. The experiments show that variations of rock compressional and shear wave velocities caused by pore fluid substitution and temperature as well as pore pressure are very small in the condition of water injection, implying large risk for time-lapse seismic monitoring. In comparison, air injection can produce clear change of compressional wave velocity, which help carry out time-lapse seismic monitoring. Improving experimental methods and enriching experimental contents are the major tasks of petrophysical measurements for time-lapse seismic monitoring in the future.