Modeling Fractured Horizontal Wells As Dual Porosity Composite Reservoirs – Application to Tight Gas, Shale Gas and Tight Oil Cases

Abstract

Multiply-fractured horizontal wells are an efficient way to produce from tight gas, shale gas and tight oil formations. In this work, we present a linear composite model with a dual porosity inner zone to model production from a multiple fractured horizontal well. The composite solution uses linear dual porosity flow solution for the inner reservoir and a linear single porosity solution for the outer reservoir combined with continuity of pressure and flux at their interface. Solution to the problem was obtained in Laplace space. The solution that we have obtained is simple and fast, yet effective and can be applied to model production from fractured horizontal wells. For the cases of interest, we observe three linear flow periods in this model. The first linear flow is from the fractures into the wellbore, followed by linear flow in the matrix to the fractures and lastly linear flow in the outer single porosity reservoir to the inner reservoir. Each of these three linear flow periods is separated by a transition depending on the properties of the fracture, matrix and the outer reservoir. We use a numerical simulator to examine the validity of some of the assumptions made in the development of the work. While the model that we have made consists of only linear flow solutions, the numerical model accounts for two dimensional flows in all media. New solutions are presented in the form of type curves.

A Semianalytical Model for Multiple-Fractured Horizontal Wells with SRV in Tight Oil Reservoirs

“…With the increasing demand of energy market and great progress of hydraulic fracturing technology, the exploration of unconventional resources such as tight oil, tight gas, and shale gas becomes more and more important [1][2][3][4][5]. Compared to the conventional hydraulic fracturing and horizontal wells, multiple-fractured horizontal wells technology can form a certain enhanced region with induced fractures near the hydraulic fractures, which changes the flow pattern, reduces the flow resistance, and improves the production of a single well [6,7].…”

Rate Decline Analysis of Vertically Fractured Wells in Shale Gas Reservoirs

“…Brown et al, established an analytical trilinear flow model to investigate the production performance of a fractured well in an unconventional reservoir [28]. In recent years, the composite flow models have been applied to analyze the production performance of fractured wells [29][30][31][32][33]. Stalgorova et al, established an analytical model, as an extension of the trilinear flow solution, for unconventional reservoirs with multiply-fractured horizontal wells [34,35].…”

A composite model to analyze the decline performance of a multiple fractured horizontal well in shale reservoirs

“…With the help of a numerical simulator, Freeman (2010) and Cheng (2011) examined the effects of gas desorption and discerned the typical flow regimes of an MFH well. Imad et al (2011) developed a composite model that combined an outer zone of single porosity with an inner zone of dual-porosity but ignored the diffusion and desorption in shale. In addition, onedirection linear flow is assumed in both the inner and outer regions, which is acceptable for certain reservoir scales.…”