Research on integrative multi-media modelling and simulation method for tight formation horizontal well development

Abstract

Tight formations usually have large area of coverage. There is large areal heterogeneity for reservoir petrophysics, rock facies, formation thickness, physical properties and oil saturations, in different reservoir blocks, in area between different wells, and also in different segments of a single well. Tight reservoirs have different scales of natural fracture development. Hydraulic fracturing also forms different scales of complex hydraulic fracture network, which has large macroscopic heterogeneity with prominent multi-scale features. Unconventional tight reservoirs consist of different scales of porous media from nano-sized to nano-micron to micron-sized. There is large difference for compositions and quantity distributions in pore spaces with different scales. Different scales of pores present discrete discontinuous distribution in space, with large heterogeneity in spatial distribution. There is large difference for geometric parameters and physical properties in different scales of porous media. Different scales of pores present large microscopic heterogeneity and multiple porous media features. All of these features make conventional reservoir modelling and numerical simulation theory and technology not applicable in this scenario. In this paper, a new multimedia modelling and simulation method for volume fracturing of horizontal wells in tight reservoirs is introduced in detail by using the unconventional reservoir modelling software Untog, taking a single well as an example.