Fundamentals of sand control fluid flows

在油气枯竭的时代，资源开发将不可避免地越来越多地集中在固结程度较低和难度较大的储层上。在过去的15-20年里，“防砂”已经成为油气行业完井服务组合中越来越重要的一部分。为了防止储层固体造成生产堵塞，并对周围的储层进行部分机械支撑，通常使用分级固体颗粒（通常是沙子，或特殊设计的陶瓷）充填井，即砾石充填。该项目侧重于一些基本的物理过程，为了能够可靠地设计和执行裸眼完井，需要了解这些物理过程。本项目分为2个子项目。(我)子项目。首先，我们打算研究标准的水砾石充填技术。这种类型的充填在目前的水平井砾石充填完井中占很大比例。我们将重新检查当前的过程力学模型，主要关注稳定流动，改进泥浆局部行为的物理模型，并开发一个瞬态过程模型。主要目标是量化当前的操作，并以一种适应新操作场景的方式了解当前限制和故障的物理原因。(子项目二世)。其次，我们打算研究替代路径配置中的粘性泥浆，其中流体被转移到较小的二次管道（分流管）中，通过分流管可以绕过堵塞，以确保砾石充填均匀。粘性浆料包括各种具有较高粘度的非牛顿流体，以帮助颗粒传输，但摩擦损失通过粘弹性湍流减阻来减轻。我们打算在两个方向上开展工作：(a)进行高速循环测试，以表征这些流体的井下流动状况，并量化减阻机制；(b)结合数值模拟开发流变模型，以便能够预测和优化这些流动。

In an era of hydrocarbon depletion, it is inevitable that resource development will focus increasingly on less consolidated and difficult reservoirs. In the past 15-20 years "sand control" has become a growing and significant part of the portfolio of well completion services used in the oil and gas industry. To prevent reservoir solids from causing production blockages and to partially support the surrounding reservoir mechanically, it is common to pack the well with graded solid particles (usually sand, or specially designed ceramics): so called gravel-packing. The proposed project focuses on some of the fundamental physical processes that need to be understood in order that open hole completions can be reliably designed and executed. The project is organized in 2 sub-projects.(Sub-project I). First, we intend to study standard water gravel-packing techniques. This type of packing accounts for a large percentage of current gravel-packed completions in horizontal wells. We will re-examine current mechanical models for the process, which focus largely on steady flows, improve the physical models for the local behaviour of the slurry and develop a transient process model. The main objective is to quantify current operations and understand the physical reasons for current limitations and failures in a way that is adaptable to new operational scenarios.(Sub-project II). Second, we intend to study viscous slurries in alternate path configurations where fluids are diverted to smaller, secondary ducts (shunt tubes) through which blockages may be bypassed to ensure a uniform gravel pack. Viscous slurries include various non-Newtonian fluids with higher viscosities to aid in particle transport but with frictional losses which are mitigated via viscoelastic turbulent drag-reduction. We intend to work in 2 directions: (a) running high speed flow loop tests to characterize the down-hole flow conditions of these fluids and quantify drag reduction mechanisms; (b) developing rheological models in conjunction with numerical simulation to be able to predict and optimize these flows.