Sepehr Arbabi

TL;DR: It is proposed that the scaling properties of the viscosity of such gels is analogous to the shear modulus of a static superelastic percolation network that diverges, as ${\mathit{p}}_{\Mathit{c}}$ is approached from below.

TL;DR: A highly accurate method of estimating the elastic percolation threshold p ce is proposed and is proposed, which finds p ce ≃0.737±0.002 for bond percolating on a triangular network.

TL;DR: Using computer simulation, the cumulative elastic energy released during fracturing of heterogeneous solids follows a power law with log-periodic corrections to the leading term, consistent with a recently proposed scaling law and with the scaling of acoustic emissions that precede fracture of composite materials.

TL;DR: In this paper, a general wellbore flow model, which incorporates not only frictional, accelerational, and gravitational pressure drops, but also the pressure drop caused by inflow, is presented.

Abstract: A general wellbore flow model, which incorporates not only frictional, accelerational, and gravitational pressure drops, but also the pressure drop caused by inflow, is presented in this paper. The new wellbore model is readily applicable to different wellbore perforation patterns and well completions, and can be easily incorporated in reservoir simulators or analytical reservoir inflow models. Three dimensionless numbers, the accelerational to frictional pressure gradient ratio R af , the gravitational to frictional pressure gradient ratio R gf and the inflow-directional to accelerational pressure gradient ratio R da , have been introduced to quantitatively describe the relative importance of different pressure gradient components. For fluid flow in a production well, it is expected that there exist three different flow regions along the wellbore, the laminar flow region, the partially-developed turbulent flow region, and the fully-developed turbulent flow region. For wellbore flow with uniform influx, R af in the laminar flow region is a constant which is only dependent on fluid properties, inflow rate and pipe ID, but independent of axial location and pipe roughness; R af in the fully-developed turbulent flow region is related to the axial location and pipe geometry (pipe ID and pipe roughness) and may be independent of the fluid properties and inflow rate; whereas R af in the partially-developed turbulent flow region depends on location, pipe geometry, fluid properties and inflow rate. It is found that the influence of either inflow or outflow depends on the flow regime present in the wellbore. For laminar flow, wall friction increases due to inflow but decreases due to outflow. For turbulent flow, inflow reduces the wall friction, while outflow increases the wall friction. New wall friction factor correlations for wellbore flows have been developed, which can be applied to determine the wall friction shear and the frictional pressure drop for either inflow (production well) or outflow (injection well) and for either laminar or turbulent flow regime. Calculation results show that the accelerational pressure drop may or may not be important compared to the frictional component depending on the specific pipe geometry, fluid properties and flow conditions. It is recommended that the new wellbore flow model be included in wellbore-reservoir coupling models to achieve more accurate predictions of pressure drop and inflow distribution along the wellbore as well as the well production or injection rates.