弱凝胶封堵高渗透带性能及启动低渗层的条件

通过低渗岩心驱替实验,研究水驱启动及驱动压力梯度,发现油层渗透率的增大,启(驱)动压力梯度降低,呈幂律指数关系式,最小启动压力梯度为0.006 MPa/m;最高启动压力梯度为0.13 MPa/m;通过高渗岩心驱替实验,研究凝胶的封堵性能,发现高渗带的渗透率越低,聚合物凝胶的突破转向压力梯度(最高压力值)、注入压力梯度、平衡注入压力以及封堵压力梯度也越高。通过计算得到不同线速度条件下,高渗带封堵1.0 m时,高渗带及基质渗透率对驱动油层前缘半径影响,发现基质油层的渗透率越高、高渗带的渗透率越低,基质油层的水驱前缘半径越大;反之越小。

Plugging performance of weak gel in high permeability zone and Conditions for starting low permeability layer

Through low permeability core flooding experiment, in order to study the water flooding starting and driving pressure gradient, it was found that the permeability increases, starting pressure(also driving pressure) gradient move to lower the and have a power-law exponent relationship between the permeability and pressure grad. From the result of the flooding experiment ,the minimum starting pressure gradient is 0.006MPa/m, the highest starting pressure gradient is 0.13MPa/m; Through the permeable core flooding test to research plugging property of gel ,it was found that the lower permeability, the breakthrough pressure gradient , injection pressure gradient and balanced injection pressure and sealing pressure gradient is higher also. Under the condition of different line speed, when high permeability zone plugging length is 1.0m, calculation permeable and matrix permeability on the driving effect of drainage radius. It is found that the matrix of the permeability of the matrix and permeable higher, matrix reservoir water-flooding front radius is bigger; On the contrary, it is smaller.