Maximize Fracking Profitability with ANSYS

This article explains how ANSYS and few other tools can be used to perform hydraulic fracturing, or commonly known as fracking, to reduce costs and increase profitability of shale gas projects.

Shale Gas

Shale gas is a form of natural gas trapped within shale formations. Because of its abundance, shale gas is a lot cheaper than it has been in years. Hydraulic fracturing or fracking helps in extracting it efficiently.

According to American Enterprise Institute, “the direct benefit of increasing oil and gas production includes the value of increased production attributable to the technology. In 2011, the USA produced 8.5 trillion cubic feet of natural gas from shale gas wells. Taking an average price of $4.24 per thousand cubic feet, that’s a value of about $36 billion, due to shale gas alone.” As a result of increase in fracking, natural gas imports in United States reduced by 25 percent between 2007 and 2011.

What is Fracking?

The term simply means creating fractures using hydraulic fluids. In this technique, production teams pump huge volumes of water and proppant at high pressure into the gas well. They also mix a few chemicals, which improve fracking performance, along with the water during pumping. Shale layers, being less permeable, minimize the flow of the natural shale gas trapped.

Fracking is useful in creating a connected fractured network between pores of the rock through which natural gas escapes out. In the first step, production teams drill horizontally along the shale layers. From the perforations, specialists pumps water into the rock. Since water is sent in with high pressures, the shale layers fractures. Once the pressure is decreased, they retrieve water from the shale layers leaving behind sand particles. However, the proppant dwells in the rock layers keeping the cracks open thereby allowing gas to escape.

Benefits and Disadvantages of Fracking

Fracking helps in accessing the natural shale gas trapped deep down beneath the earth. With traditional methods of extraction, we cannot exploit this energy potential. Recently-developed methods of vertical and horizontal drilling added favor to fracking. They permit drilling thousands of feet deep inside the ground in order to access the trapped shale gas.

It is said that shale gas causes lesser air pollution when compared to other dirty fuels like coal and oil. However there are ways in which fracking itself can cause more devastating effects such as air emissions and climate change, high water consumption, water contamination, land use, risk of earthquakes, noise pollution, and health effects on humans.

Economic Benefits of Simulation

To achieve an optimal design for a gas well, standard industry practice is to conduct a large number of field trials that require high capital investment and time which significantly increases the project value.

In order to obtain a profitable production of shale gas, I recommend you to use a fully coupled 3D hydraulic-mechanical simulation. Obviously the costs of such simulation are a lot lower than traditional methods. Many of our customers in the Oil & Gas industry have yielded better output with a higher project profitability.

You can find the schematic view of simulating Hydraulic Fracture below.Schematic view for fracking simulation

Essential Pre-Requisites for Simulation

We gather the input data for simulation from different physics such as geology, petrophysics and geomechanics. From the geology of the rock structure, we extract the lithology and layering, altitudes of beddings and natural fracture data. Accurate determination of petrophysical properties for both the reservoir and fluid contents is necessary. We also need to consider features like porosity, permeability and saturation for the reservoir. It also includes evaluating the properties that help in determining the hydrocarbon concentrations in the reservoir and its ability to produce the gas.

Along with the surface and sub-surface properties of the rock, the in-situ stress parameters also have same importance in simulation. I also account for elastic properties and strength parameters of intact rocks. The geomechanical studies of the rock structure also reveal the strength parameters of natural fractures, if any. Using multiPlas, I model these rock-specific material parameters and joints.

Of course, gathering this data can look daunting to you. However our expertise combined with strengths from Dynardo GmbH – the leading global experts in simulation of hydraulic fracturing – can help!

Fracking Simulation – Readying the Model

In the simulation of fracking process, I use a sequential coupled hydraulic-mechanical modeling approach. Therefore, I construct two models – a hydraulic flow model and a mechanical model simultaneously.

3D model with different soil layers for fracking simulation
3D model with different soil layers

To account the strength and stress anisotropies of the rock structure, I need to consider a 3D model. These variables help us to constantly monitor the behavior of fracking process. To capture the anisotropic nature of the rocks, you’ll need strength and stress anisotropies of the rock matrix and fracture system.

Sequentially Coupled Hydraulic-Mechanical Analysis in ANSYS

In ANSYS Mechanical, we start with a transient hydraulic flow analysis (analogous to transient thermal analysis) to understand the pore pressure field. The pressure increases in the fracture-initiated locations due to the pumping of fluid and low permeability of rock. If the pressure is large enough, the rock starts to fail and fractures open up. As a result, the permeability of the rock structure increases and changes the pressure distribution in the hydraulic flow model. From a mechanical perspective, pressure increase changes the effective stresses within the rock. After every fluid time increment, change in the mechanical forces from pore pressure change will be introduced into the mechanical analysis. The forces on every discretization point of the smeared continuum are computed from the pore pressure gradient.

I setup the coupling inside ANSYS in an explicit manner. Consequently, one iteration cycle is performed for every time step. The time step needs to adequately represent the progress of the fracture growth. At each time step, a transient hydraulic flow analysis starts first. Then the mechanical analysis with the updated pressure field from the hydraulic flow model is conducted. The mechanical analysis results in updated stress, plastic strain fields and hydraulic conductivities. i apply the updated hydraulic conductivities to the hydraulic model in the subsequent time step.

Crack expansion in the model while performing fracking analysis
Crack expansion in the model

In mechanical analysis, the development of fractures is represented by a plastic model in ANSYS. As a result, I cannot directly measure fracture openings and hence I’ll need to calculate it based on the plastic strains.

Model Calibration & Optimization of Fracking Paramaters

Because of large number of statistically-varying and reservoir parameters, the reservoir model needs advanced calibration procedure. At first, I will need to calibrate numerical parameters such as maximum permeability of open joints or energy dissipation at pore pressure frontier.

After calibration of all the parameters, I identify the most important parameters contributing to maximum crack volume using optiSLang software. As you will recognize, maximum crack volume correlates to maximum shale gas output. I validate the behavior of such important parameters and then calibrate the analysis model to the field measurements. I use the calibrated model later in order to optimize the simulated volume and predict the gas production rate of the wells.

Summary & Outlook

Evidently, application of simulation to the fracking process will underline its predictability. Simulation cut downs the costs of field trials, brings down the time-to-market thereby significantly increases the project profitability.

If you’re into gas exploration, you should contact us filling this form or by writing to sales@cadfem.in. We’ll be glad to explain some of our recent projects that have benefited customers in Oil & Gas industry.

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The Decade That Was …

In the CADFEM Journal (previously Infoplaner; in German), an announcement was made in the first issue of 2007 about the commencement of India business. This March, CADFEM Engineering Services India (CADFEM India) celebrates its 10th birthday – a decade in business. The company started out as a four person team with the vision that it could help customers in India recognize and realize the benefits of simulation-driven product development. 10 years on, the company has evolved into a confident engineering business, with over 50 colleagues, that has helped hundreds of engineers to realize their product promise.

The Decade That Was …

During this time so much has changed. The world has got smaller, faster and ever more changing. Technology has both been an enabler and a challenge to small businesses and large enterprises alike. As a responsible business, the company’s constant endeavour has been to offer customers the best-in-class solutions to their engineering problems. Today CADFEM India is proud to have gained trust from several local and global companies whose engineers rely on its products, services and know-how on a daily basis.

CADFEM India is a strong channel partner to ANSYS in India by offering the full range of physics (structural, fluids and electronics) across India. This partnership is helping CADFEM increase the rate of adoption of simulation in the country. The organization is structured towards providing and supporting customers with ANSYS software. Today the company has more than 40 engineers comprising of the core technical team, sales and marketing that engage customers in multiple areas of engineering analysis. The team is highly skilled to offer training programs for novices and experienced engineers on a plethora of engineering topics. Several customers, with origins in Germany, are long standing customers of CADFEM in India. CADFEM is the preferred simulation partner for customers owing the nature of strong and high-quality support. Deepak Joseph, the Head of Development (Truck) at Knorr-Bremse Technology Center India, and his team in Pune have been recipients of CADFEM’s technical support regularly. While thanking CADFEM for offering “extended support” to his team, Deepak recently said that CADFEM ”helped us understand ways to achieve accuracy.”

Listing of milestones of CADFEM India

All tools which are critical for success

CADFEM India offers several complementary solutions such as optiSLang (of Dynardo GmbH), Rocky DEM (particle simulations) and simulation-ready hardware. Since engineering simulation requires more than just software, CADFEM India supplies all the tools which are critical for success in simulation – all from one source. As a result, customers in India not only benefit by receiving leading software and IT-solutions, but also obtain support, consultancy and transfer of know-how. The core philosophy ingrained within every colleague is to ensure that customers realize the most return of their simulation investment. Dynardo’s CEO, Dr. Johannes Will, says “Over the last 7 years, CADFEM India has become an important partner for Dynardo to serve the optiSLang business in India as well as to support the Dynardo consulting activities. I personally enjoy that relationship and look forward to intensify the joint business success over the next years.” Since 2011, CADFEM India has organized the Indian edition of the Weimar Optimization & Stochastic Days. In 2016, over 80 attendees came together to discuss the topics of optimization and robust design for sixth year in a row.

In addition to the software business, many customers consider CADFEM India as a reliable engineering consulting partner. Several customers choose to contact CADFEM to seek simulation on demand. CADFEM India’s Managing Director, Madhukar Chatiri says that “this offers a good opportunity for us to demonstrate the power of ANSYS to the customer.” Over the years, CADFEM has solved many engineering problems in automotive, aerospace, consumer appliances, rotating machinery, watches, food & beverage and many more industries. One such example of a strong customer relationship is with Traunreut-based Bosch und Siemens Hausgeräte GmbH (BSH). For over two years from 2008, BSH worked intensively with two engineers from CADFEM India. As a result, there has been a strong partnership between BSH and CADFEM India. Speaking about this, Dan Neumayer, Head of Pre-Development at BSH said “we could have a mutual cultural understanding and a common way of thinking and working. This intensive learning forms a particularly important basis for our long-term cooperation and we see this as one fundamental success factor.”

Group Photo in the decade that was
Mrs. & Mr. Guenter Mueller while visiting CADFEM India in 2015
esocaet program starts in September 2017

One of the top most challenges for employers in India is the low number of engineers skilled with simulations. To bridge this demand-supply gap, CADFEM India has invested in ANSYS Authorized Training Centre that started in September 2015; over 50 engineers have graduated from this centre. Furthermore, CADFEM has partnered with PES University in Bangalore to bring the much-acclaimed esocaet Master Program in Applied Computational Mechanics to India. The esocaet program offers tremendous opportunities to engineers for continuous learning. The first course will begin in September 2017.

CADFEM India has been operationally profitable since many years – this has allowed the company to scale its investments in India consistently. The company has a long-term orientation, offers employees a lot of independence but functions as a responsible partner to customers. This allows the company to respond with agility to the dynamic needs of the market.

The company has geared up for the next decade of business in the Indian subcontinent. Having recognized the needs of the market, the company is betting big in the areas of Additive Manufacturing, Electronics and Digital Cities. CADFEM India has made another significant investment into the newest partner of CADFEM International – CADFEM SEA Pte. Ltd. in Singapore.

In 2016, the company was recognized as one of the 20 Most Promising Engineering & Design Solution Providers in India by the popular CIO Review magazine. Madhukar still fondly recalls the day when he formulated the vision for the Indian business in his mind. He adds “What a journey it has been for many of us! While waiting for our connecting flight at Mumbai airport, Guenter Mueller discussed the idea of a joint company in India. We thank our customers and partners for choosing to work with us. It has been and is our pleasure to serve the engineering market in India in the past decade.”

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Weekly Simulation Round-Up | Issue 4

Banner for Weekly Simulation RoundupWelcome to this edition of Weekly Simulation Round-Up. As usual, we bring you the most interesting articles from this week.


Computational Fluid Dynamics for Patient-Specific Surgeries

In this article, a researcher of Cardiothoracic Surgery from the Shanghai Children’s Medical Center talks about simulation-driven medical surgeries. He states that “the long-term prognosis for babies born with single ventricle heart defects can depend on the location of vascular connections made during corrective surgery”. Based on the babies’ cardiovascular anatomy, the medical center researchers employ ANSYS CFD to determine the optimal personalized surgery for improving surgical effectiveness and to obtain a better quality of life for children (read more).


Simulation of “Material Other Than Grain” Separation Process

For farmers engaged in grain production, separation of stones, straw and dust from grains is a regular activity. Can simulation techniques help such farmers to reduce cost and time-to-market, and increase grain production ramp-up? The answer is yes!

Using Rocky DEM, a state-of-the-art discrete element particle simulator, along with computational fluid dynamics performed using ANSYS Workbench, the material other than grain (MOG) separation process can be simulated. There’s potential for the MOG equipment makers to redesign or improve for higher separation efficiency.


Optimus Prime, anyone? 

Antimon is a BMW 3-series car that transforms into a robot in under 30 secs. It converts from a BMW into a grand robot completed with powerful arm movements and a Transformers-like face. It took the company eight months to complete Antimon using an actual car (Watch on YouTube).


Diamonds Convert Nuclear Waste into Clean Energy

British Scientists have developed a method of turning nuclear waste into batteries using diamond. By encapsulating a short-range radioactive material in an artificial diamond, small electrical charge can be generated even after insulating harmful radiation. Researchers estimate that a carbon-based battery would generate 50% of its power in 5,730 years (read more).


Structural Design Optimization of Electrical Transformer Tanks

One of our customers, Crompton Greaves Ltd., presented their experiences with optimizing structural design of their electrical transformer tanks. To achieve this, their engineers used the state-of-the-art tool for optimization and variation analysis – optiSLang and ANSYS Mechanical. Through this exercise, they were able to obtain ~10% weight reduction and over 17% reduction in Equivalent Stress (read more).


So, folks, that was all for this week. We will be back again with a new edition next week. Do feel free to share your feedback or questions with us.

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