Non-Monotonic Saturation and Pressure Profiles as a Testing Ground for Dynamic Multi-Phase Flow Models

Author(s):  
David A. DiCarlo

There has been great recent interest in dynamic models of multi-phase flow. This is for two reasons: one, theoretical arguments suggest that the traditional multi-phase flow equations are not complete; two, various experimental measurements are unable to be described by the traditional models. In this talk, we discuss the observation that constant flux infiltrations into sands produce non-monotonic saturation and pressure profiles. We show how this non-monotonic behavior is the strongest evidence of dynamic effects in porous media, as other reported experimental evidence can be the result of varying measuring volumes, and/or media heterogeneities. Thus the extensive data set obtained for these non-monotonic provides the best testing ground for the various proposed dynamic extensions.

2011 ◽  
Vol 230 (22) ◽  
pp. 8304-8312 ◽  
Author(s):  
C.-H. Park ◽  
N. Böttcher ◽  
W. Wang ◽  
O. Kolditz

Author(s):  
Ashutosh Tewari ◽  
Stijn De Waele ◽  
Niranjan Subrahmanya

Production surveillance is the task of monitoring oil and gas production from every well in a hydrocarbon field. A key opportunity in this domain is to improve the accuracy of flow measurements per phase (oil, water, gas) from a multi-phase flow. Multi-phase flow sensors are costly and therefore not instrumented for every production well. Instead, several low fidelity surrogate measurements are performed that capture different aspects of the flow. These measurements are then reconciled to obtain per-phase rate estimates. Current practicesmay not appropriately account for the production dynamics and the sensor issues, thus, fall far short in terms of achieving a desired surveillance accuracy. To improve surveillance accuracy, we pose rate reconciliation as a state estimation problem. We begin with hypothesizing a model that describes the dynamics of production rates and their relationship with thefield measurements. The model appropriately accounts for the uncertainties in field conditions and measurements. We then develop robust probabilistic estimators for reconciliationto yield the production estimates and the uncertainties therein. We highlight recent advancements in the area of probabilistic programming that can go a long way in improving the performance and the portability of such estimators. The exposition of our methods is accompanied by experiments in a simulation environment to illustrate improved surveillance accuracy achieved in different production scenarios.


Author(s):  
William Sherman ◽  
Eric Loth

A virtual reality (VR) technique has been developed to allow user immersion (stereo-graphic rendering, user tracking, and object interactivity) in generic unsteady three-dimensional multi-phase flow data sets. This article describes the structure and logic used to design and construct a VR technique that employs a multi-phase flow-field computed a priori as an input (i.e. simulations are conducted beforehand with a researcher’s multi-phase CFD code). The input field for this flow visualization is divided into two parts: the Eulerian three-dimensional grid nodes and velocities for the continuous fluid properties (specified using conventional TECLOT data format) and the Lagrangian time-history trajectory files for the dispersed fluid. While tracking the dispersed phase trajectories as animated spheres of adjustable size and number, the continuous-phase flow can be simultaneously rendered with velocity vectors, iso-contour surfaces and planar flood-contour maps of different variables. The geometric and notional view of the combined visualization of both phases is interactively controlled throughout a user session. The resulting technique is demonstrated with a 3-D unsteady data set of Lagrangian particles dispersing in an Eulerian description of a turbulent boundary layer, stemming from a Direct Numerical Simulation of the Navier-Stokes equations.


Author(s):  
К.А. Новиков

Сформулированы и доказаны принципы максимума для нескольких моделей многофазной фильтрации. Первый принцип справедлив для фазовых насыщенностей в несжимаемом случае модели двухфазной фильтрации с постоянными вязкостями, а второй - для глобального давления в моделях двух- и трехфазной фильтрации Two maximum principles for several multi-phase flow models are formulated and proved. The first one is valid for phase saturations in an incompressible two-phase flow model with constant viscosities. The second one is valid for the global pressure in two- and three-phase flow models with constant viscosities and is also valid for phase pressures in the case of zero capillary pressure.


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