Sand Prediction: A Practical Finite-Element 3D Approach for Real Field Applications

Abstract

Sand production is a critical issue in Oil & Gas industry. During the production of a well, sand production may have negative consequences such as risk of well failure, erosion of pipelines and surface facilities and need for sand separation and disposal. Knowing the conditions for the onset of sand production allows optimizing sand free production and, eventually, avoiding or delaying the use of sand control methods. The aim of this work is to establish a reliable workflow for the estimation of the conditions for sand production, in real field cases, by means of Finite Element Modelling. With this respect, the fundamental requirement is to set-up a 3D coupled model that can be easily adjusted the most complex conditions (e.g. stress anisotropy, deviated wells, complex perforations patterns). The most suitable geometries and associated meshing strategies to describe the wellbore, the perforation tunnels and the surrounding formation are analyzed. The drilling and completion phases were also simulated to compute the correct stress distribution before the production. Fluid flow and rock deformation are simulated in a fully coupled way to investigate accurately the effect of drawdown. Shear failure of reservoir rock, considered as an elasto-plastic medium, is the main sand production mechanisms analyzed and the damage of the rock around the perforations is evaluated by analyzing the distribution of the equivalent plastic strain. A real field case is simulated and the results of the Finite Element model are consistent with the ones obtained by means of an analytical model and with field observations. Moreover, this numerical approach allows quantifying the spatial distribution and the severity of the damage of the rock around the perforations, facts that are either oversimplified or not considered at all in analytical models. For future applications, this model can be straightforwardly extended to more complex conditions and can also be improved to provide volumetric sand prediction. SPE 134464The common drawback of all these approaches is their cost and their negative impact on the productivity of a well: the correct assessment of the risk of sand production from a well can be a key factor in establishing the most profitable compromise between the maximization of the production and the control of costs for eventual sand management actions. Therefore, various approaches were proposed in literature to evaluate the eventual onset of sand production and, if possible, to quantify it. Available approachesPredicting the onset of sand production is a geomechanical issue that has been investigated for a long time (see e.g.[10], [19], [5] and [3], even if not an exhaustive list of the earlier works). The approaches developed throughout the years can be divided into three categories. The first class includes the development of methods based upon empirical relationships between the onset of sand production and some parameter that characterize either the mechanical properties of the rock (e.g. P-wave transit time [21] ) or the o...

Research advance of numerical simulation methods for sand production prediction of unconsolidated sandstone

“…(Morita et al, 1989;Bai et al, 2012). Volonte et al established a reliable workflow through finite element modeling to estimate the actual sanding conditions (Volonté et al, 2010). As shown in Figure 1A, the rock failure around the perforation is evaluated by analyzing the distribution of equivalent plastic strain, and the Cosserat continua is introduced to simulate the slit type of failure around the borehole, so as to achieve the purpose of sand production prediction (Muller et al, 2011;Saski et al, 2021).…”