鄂尔多斯盆地晋西地区致密气储集层产能物性下限的确定

Determination of Lower Limit of Productivity of Tight Gas Reservoir in Jinxi Area of Ordos Basin

鄂尔多斯盆地晋西地区致密砂岩储集层物性较差,属于致密储集层。部分相对高孔渗层段自然生产可获取工业气流,部分低孔渗层段经过压裂改造可获得可观的工业气流,也存在一部分经过压裂改造后依旧无产能的无效层段,导致研究区的储集层生产方式以及生产情况变得复杂。针对该问题,采用经验统计法与直接关系法,确定鄂尔多斯盆地晋西地区储集层的产能物性下限,经验统计法确定了无效储集层的孔隙度下限为6%,渗透率下限为0.1×10^(-3)μm^2,直接关系法确定了自然生产储集层的孔隙度下限为10%,渗透率下限为1.0×10^(-3)μm^2,无效储集层的孔隙度下限为6%,渗透率下限为0.1×10^(-3)μm^2。为研究区制定储集层生产方式,确定生产层段提供一定的依据,一方面可以规避无效储集层,提高生产效率,另一方面还可以选择合适的生产方式,节约生产成本。

The physical property of tight sandstone reservoir in the Jinxi area of Ordos Basin is poor. It belongs to the tight reservoir. Part of the relatively high porosity and permeability layers in natural production can get industrial gas flow. Part of low porosity and permeability layers through fracturing transformation can obtain considerable industrial gas flow. There are also a part of invalid layers without production capacity after fracturing transformation. The rresult in reservoir production mode and production situation of the study area more is complicated. According to this problem, empirical statistical method and direct correlation method are used to determine the lower limit of productivity in Jinxi area of Ordos Basin. The porosity of invalid reservoir is 6% and the permeability is 0. 1 ×10^-3 μm2 by using empirical statistical method. The porosity lower limit of the natural production reservoir is 10% and the permeability is 1 . 0 ×10 ^-3 μm2. The porosity of invalid reservoir is 6 % and the permeability is 0. 1 × 10^- 3 μm2 by using direct correlation method. It can provide a certain basis for developing reservoir production mode and determining the production layers. On one hand, it can avoid the invalid reservoir in improving production efficiency; on the other hand, it can also choose the appropriate mode of production to save production costs.