Direct Numerical Simulations for Additive Manufacturing in Porous Media

One of the key global technological and scientific challenges of the 21st century is the sustainable access to energy, water and food while reducing greenhouse gas emissions. Central to this challenge is our understanding of porous media flow processes, specifically our understanding of how fluids such as oil, greenhouse gases or water, flow through the pores of subsurface reservoir rocks, and how these fluids interact physically and chemically with the rock. To enhance this understanding, high-quality experimental data and accurate numerical simulation methods for porous media flow problems are needed.

X-Ray Computed Tomography (X-Ray CT) combined with novel numerical simulation methods has revolutionised our ability to image and quantify the 3D physio-chemical interactions between fluids and rocks at the pore-scale. Yet, the heterogeneity and complexity of natural porous media render it difficult, if not impossible, to conduct repeatable X-Ray CT imaging experiments of flow in natural porous media in a fully controlled environment where hypotheses can be tested thoroughly and new numerical simulation approaches can be applied in a consistent way to aid the interpretation and quantification (or even prediction) of experimental results.

A transformative technology that could overcome this problem is additive manufacturing, also known as 3D printing. The applications of 3D printing are diverse and evolve almost daily, ranging from companies like Boeing that accelerate their production to companies like Audi that already print components of engine intake system to medical research that experiments with printing human tissue or develops affordable tests to detect the Zika virus.

The aim of this proposal is to apply 3D printing technologies to create 2D and 3D microfluidic chips representing natural porous media that can be deployed in repeatable and well-controlled porous media flow experiments supported by state-of-the-art numerical simulations. There are no reported attempts to link experiments using 3D printed microfluidic chips representing natural porous media with direct numerical simulations, let alone using data obtained from flow experiments on 3D printed samples as input for developing an international benchmarking standard for pore-scale numerical simulations and 3D printing of microfluidic chips and porous media (in both, 2D and 3D).

Consultants McKinsey have estimated that the global economic potential of 3D printing will be reach $230bn to $550bn annually in 10 years, viewing it as a key technology providing global economic growth. With major international companies like Thermo-Fisher and ZEISS already offering integrated technical solutions for X-Ray CT imaging and simulation for porous media applications related to energy extraction and greenhouse gas storage, it is likely that significant new business opportunities will emerge if X-Ray CT imaging and simulation technologies are combined with 3D printing. Clearly, the UK would benefit scientifically and economically from being an early adopter of 3D printing technologies for porous media experimentation and simulation.

The key deliverables from this project will be as follows:

1. A unique set of high-quality and fully quantified experimental data involving single- and multi-phase flow using 3D printed microfluidics chis and porous media.
2. Extensions to the state-of-the-art open source CFD code OpenFOAM for modelling the above experiments.
3. A benchmarking standard for pore-scale numerical simulations and 3D printing of microfluidic chips and porous media.
4. New technologies to generate cost-effective 2D and 3D microfluidics chips representing natural porous media for subsequent porous media flow experiments.

These deliverables will impact academic researchers and industry practitioners working on problems related to oil and gas extraction, subsurface energy storage, groundwater contamination, and CO2 storage. In particular, we expect that the project will create benefit for the following communities:

1. National and International Research Communities: Researchers from the UK and overseas working in the field of porous media flow related to groundwater extraction, hydrocarbon production, geothermal energy, and subsurface energy and CO2 storage rely on high-quality experimental data and accurate numerical simulations to quantify and predict how fluids and porous media interact with each other at the pore-scale in order to better understand the aforementioned applications. To ensure a broad uptake of our work, we have developed a bespoke dissemination plan that foresees that all code, experimental results, and input data for the modelling will be made available freely through open source code and open access data, respectively.

2. Energy Industry: The energy industry, from international oil companies and service companies to highly specialised SMEs, relies on new technologies to better quantify the uncertainties and risks related to energy extraction and waste storage. X-Ray CT imaging of porous media flow problems has become a key enabling technology that is routinely used in the energy industry. With major international companies like Thermo-Fisher and ZEISS now offering integrated technical solutions for X-Ray CT imaging and simulation related to porous media flow applications, it is likely that significant new business opportunities will emerge for the wider energy industry if X-Ray CT imaging and simulation technologies can be successfully combined with 3D printing.

3. UK Economy: A strategic goal of the UK is to take leading roles in improving hydrocarbon recovery, storing CO2 in the subsurface, and increasing the use of renewable energy. These are not only cost intensive economies supporting thousands of employees across the UK, the energy industry also relies on new technologies such as X-Ray CT imaging of porous media flow problems to produce natural resources sustainably, especially when it comes to managing hydrocarbon resources in mature basins such as the North Sea (e.g. making the decision to abandon a field vs. extending its life via enhanced oil recovery techniques). Considering that (i) the global economic potential of 3D printing is estimated to reach $230bn to $550bn annually in 10 years, that (ii) there are significant opportunities to link commercial X-Ray CT imaging with 3D printing of porous media samples, and that (iii) there is an increasing need to manage the UK's remaining natural hydrocarbon resources responsibly and sustainably to help ensure the UK's energy security, the UK economy will benefit from becoming an early adopter of 3D printing technologies for porous media flow applications.

4. Wider Public: Using 3D printed porous media and real-time imaging of flow experiments is a wonderful educational tool to explain to non-specialists how fluids such as oil, gas, or water flow through subsurface reservoirs, which will help the wider public to better understand how hydrocarbon extraction or CO2 storage work, and that these technologies are safe and efficient.