A capacity prediction model for the low porosity fractured reservoirs in the Kuqa foreland basin, NW China

Abstract

Based on the description of fracture parameters and the relation between fracture development degree and capacity, a capacity prediction method was discussed of low porosity fractured sandstones in the Kuqa region. For coring section, fracture parameters are described directly by the core; for non-coring section, fracture parameters are available through imaging logging data, and after correction by difference between statistical parameters of core description and imaging logging interpretation in the coring section, the fracture parameters can be quantitatively described more accurately. The correlation of fracture seam and capacity is good in the gas well test section in Dabei - Keshen area and it is used to derive a formula of cracks capacity coefficient. Gas well capacity can be predicted by the regression formula of cracks capacity coefficient vs. meters gas production index. Also the models of uniform and non-uniform fracture distribution were established, capacity was analyzed based on the cracks capacity coefficient, results show that in fractured sandstone reservoirs if the total fracture number is constant, the capacity is small when fractures have a uniform distribution, the productivity is bigger when fractures are concentrated in one section. Key words: Kuqa foreland basin, low porosity fractured sandstone, fracture productivity coefficient, capacity prediction, fracture distribution model