Julian Ortiz

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An LSTM Approach for SAG Mill Operational Relative-Hardness Prediction

Minerals

Ore hardness plays a critical role in comminution circuits. Ore hardness is usually characterized... more Ore hardness plays a critical role in comminution circuits. Ore hardness is usually characterized at sample support in order to populate geometallurgical block models. However, the required attributes are not always available and suffer for lack of temporal resolution. We propose an operational relative-hardness definition and the use of real-time operational data to train a Long Short-Term Memory, a deep neural network architecture, to forecast the upcoming operational relative-hardness. We applied the proposed methodology on two SAG mill datasets, of one year period each. Results show accuracies above 80% on both SAG mills at a short upcoming period of times and around 1% of misclassifications between soft and hard characterization. The proposed application can be extended to any crushing and grinding equipment to forecast categorical attributes that are relevant to downstream processes.

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Ultrasound Elastography Detects Age‐Related Changes in Adult False Vocal Folds

Journal of Ultrasound in Medicine

Steam Additives to Reduce the Steam-Oil Ratio in SAGD: Experimental Analysis, Pilot Design, and Field Application

Day 1 Wed, March 16, 2022, 2022

Producing bitumen using SAGD requires a significant amount of water and energy, resulting in a la... more Producing bitumen using SAGD requires a significant amount of water and energy, resulting in a large amount of greenhouse gas emissions. Therefore, reducing the steam-oil ratio (SOR) in SAGD is critical to make the oil recovery process profitable and sustainable in a carbon-constrained world. This paper presents the potential benefits of co-injecting water-soluble volatile additives with steam in SAGD. The objective of the process is to decrease the SOR while maintaining SAGD-like oil production rates at economical chemical additives concentrations. Through a comprehensive experimental study, multiphase behaviour of the additive-water-bitumen system, mixture's viscosity, additive thermal stability, adsorption, emulsion stability, and recovery performance were evaluated. Extensive coreflooding experimental tests quantified the potential for improved oil recovery and SOR reduction. The experimental variables included additive concentration, water-oil ratio, and temperature. The st...

Analysis of the Performance of Various Well Liner Completion Strategies in Surmont

Day 3 Thu, January 28, 2021, 2021

ConocoPhillips operates Surmont, which is the first Steam-Assisted Gravity Drainage (SAGD) projec... more ConocoPhillips operates Surmont, which is the first Steam-Assisted Gravity Drainage (SAGD) project to implement Flow Control Devices (FCDs) in producer wells. This study was conducted to evaluate the production performance of different liner completion strategies. The analysis compared well pairs completed with slotted liners (SL) to producers completed with FCDs, both liner deployed (LD-FCD) and tubing deployed (TD-FCD), and investigated the impact of FCDs in injectors. An extensive analysis was conducted using available production and temperature data along the wells. The wells were completed using various fixed-resistance FCD settings, while some wells were completed using variable setting designs. As time went on, several of the slotted liner producer wells were retrofitted with tubing-deployed FCD completions. One of the key objectives of the study was to determine the success rate of tubing-deployed FCDs and their performance relative to liner-deployed FCD wells. Another objec...

Investigating the Performance of Various FCD Geometries for SAGD Applications

Day 1 Tue, January 26, 2021, 2021

Steam-Assisted Gravity Drainage (SAGD) is a complex process that often requires more control rela... more Steam-Assisted Gravity Drainage (SAGD) is a complex process that often requires more control relative to conventional applications during production operations. Flow Control Devices (FCDs) have been identified as one of the technologies that offer improved downhole steam utilization and injection/production efficiency. The first FCD completions, with a helical geometry, were installed in SAGD wells at the ConocoPhillips Surmont project over a decade ago. The installations have shown improved steam chamber conformance and reduced steam-oil ratio (SOR) while accelerating bitumen production. Since then, various FCD geometries have been investigated and used, with several of them explicitly designed with a steam blocking capability. This study used a numerical simulator to investigate the performance of these various FCD geometries. This comprehensive study started testing several geometries in a flow loop and using the data obtained to develop a mechanistic model to characterize the fl...

Application of Diagnostics Charts for Performance Analysis of the SAGD Producers Pre- and Post-Installation of Flow Control Devices

SPE Canada Heavy Oil Conference, 2020

A composite step method for equality constrained optimization on manifolds

We present a composite step method, designed for equality constrained optimization on differentia... more We present a composite step method, designed for equality constrained optimization on differentiable manifolds. The use of retractions allows us to pullback the involved mappings to linear spaces and use tools such as cubic regularization of the objective function and affine covariant damped Newton method for feasibility. We show fast local convergence when different chart retractions are considered. We test our method on equilibrium problems in finite elasticity where the stable equilibrium position of an inextensible transversely isotropic elastic rod under dead load is searched. AMS MSC 2000: 49M37, 90C55, 90C06

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Second order directional shape derivatives of integrals on submanifolds

Mathematical Control & Related Fields, 2021

We compute first and second order shape sensitivities of integrals on smooth submanifolds using a... more We compute first and second order shape sensitivities of integrals on smooth submanifolds using a variant of shape differentiation. The result is a quadratic form in terms of one perturbation vector field that yields a second order quadratic model of the perturbed functional. We discuss the structure of this derivative, derive domain expressions and Hadamard forms in a general geometric framework, and give a detailed geometric interpretation of the arising terms.

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An SQP Method for Equality Constrained Optimization on Hilbert Manifolds

SIAM Journal on Optimization, 2021

Copper mining: 100% solar electricity by 2030?

Applied Energy, 2020

Extracting copper is energy-intensive. At the same time, copper is a key material for building th... more Extracting copper is energy-intensive. At the same time, copper is a key material for building the energy systems of the future. Both facts call for clean copper production. The present work addresses the greenhouse gas emissions of this industry and focuses on designing the future electricity supply of the main copper mines around the world, from 2020 to 2050, using distributed solar photovoltaic energy, storage, and a grid connection. We also consider the increasing energy demand due to ore grade decline. For the design, we use an optimization model called LEELO. Its main inputs are an hourly annual demand profile, power-contract prices for each mine, cost projections for energy technologies, and an hourly annual solar irradiation profile for each mine. Our findings show that it is attractive for the mines to have, today, a solar generation from 25% to 50% of the yearly electricity demand. By 2030, the least-cost solution for mines in sunny regions will be near fully renewable, while those in other regions will take until 2040. The expected electricity costs range between 60-100 €/MWh for 2020 and 30-55 €/MWh for 2050, with the lower bound in sunny regions such as Chile and Peru. In most assessed locations, the very low solar energy costs will compensate for the increased demand due to declining ore grades. For the next steps, we recommend representing the demand with further detail, including other vectors such as heat and fuels. In addition, we recommend to include the embodied emissions of the technologies to get a more complete picture of the environmental footprint of the energy supply for copper production.

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SAGD Circulation Strategy Utilizing Flow Control Devices

Day 3 Thu, November 21, 2019, 2019

For ConocoPhillips, technology is a key driver and development accelerator to continuously improv... more For ConocoPhillips, technology is a key driver and development accelerator to continuously improve its SAGD operations. The deployment of conventional Flow Control Device (FCD) technology in Surmont has allowed ConocoPhillips to realize shorter circulation times and higher oil production rates. These benefits have been realized while ensuring liner and well integrity. Optimizing the well start-up process in SAGD has been a challenge at Surmont and in the industry in general. SAGD well start-up involves heating bitumen through a mostly conductive process to allow the SAGD mechanism to initiate. A recent breakthrough in the circulation strategy for wells equipped with FCDs at Surmont was developed and implemented by the ConocoPhillips Technology and Operation teams. This new approach has been possible by integrating FCD characterization and erosion testing with complex engineering principles such as convective heating, sand control, reservoir multiphase flow and wellbore flow dynamics...

Characterization of Flow Control Device Performance with Distributed Fiber-Optic Sensors

SPE Annual Technical Conference and Exhibition, 2019

It is becoming common to install inflow control devices (ICDs) along steam-assisted gravity drain... more It is becoming common to install inflow control devices (ICDs) along steam-assisted gravity drainage (SAGD) production liners to enhance temperature conformance and accelerate depletion. Additionally, some operators advocate the installation of similar outflow control devices (OCDs) along the injection well of the SAGD well pair. Collectively, these inflow and outflow devices are often referred to as FCDs. Industry adoption of flow control devices (FCDs) has increased, and several devices are commercially available for use in SAGD. In an effort to optimize FCD design and selection, a joint industry partnership (JIP) was formed (Vachon et al. 2015) and flow loop testing conducted to establish FCD performance curves and erosion tolerance over a wide range of pressure, temperature, and steam quality (SQ) consistent with a typical SAGD well environment. In conjunction with flow loop testing, several full-scale FCD deployments were completed at the JIP fields, including pilot wells at th...

Laboratory and Field Testing of a Steam-Limiting Flow Control Device Developed for Thermal Applications

Day 3 Wed, October 02, 2019, 2019

A review of laboratory and field testing of a new flow control device is presented in this paper.... more A review of laboratory and field testing of a new flow control device is presented in this paper. The device is designed specifically to limit steam breakthrough in thermal operations. For the past few years, four companies operating Steam Assisted Gravity Drainage (SAGD) facilities in Alberta's oil sands have come together to study downhole Flow Control Devices (FCDs) in a laboratory setting and to share field data of the application of such devices. Within this collaboration, a new device was designed to address the challenge specific to thermal operations, namely limiting steam breakthrough into production wells. Laboratory tests were undertaken to define the steam-limiting characteristics of this device under field representative SAGD conditions at full scale rates, temperatures and pressures. Tests were performed with oil to gauge viscosity sensitivity, as well as with water and steam at various inflow rates, temperatures and steam qualities. Testing was also performed with...

$Research paper thumbnail of Geological Facies Recovery Based on Weighted $$\ell _1$$-Regularization$

Geological Facies Recovery Based on Weighted $$\ell _1$$-Regularization

Mathematical Geosciences, 2019

A weighted compressed sensing (WCS) algorithm is proposed for the problem of channelized facies r... more A weighted compressed sensing (WCS) algorithm is proposed for the problem of channelized facies reconstruction from pixel-based measurements. This strategy integrates information from: (i) image structure in a transform domain (the discrete cosine transform); and (ii) a statistical model obtained from the use of multiplepoint simulations (MPS) and a training image. A method is developed to integrate multiple-point statistics within the context of WCS, using for that a collection of weight definitions. In the experimental validation, excellent results are reported showing that the WCS provides good reconstruction for geological facies models even in the range of [0.3-1%] pixel-based measurements. Experiments show that the proposed solution outperforms methods based on pure CS and MPS, when the performance is measured in terms of signal-to-noise ratio, and similarity perceptual indicators.

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Optimization of a SAG Mill Energy System: Integrating Rock Hardness, Solar Irradiation, Climate Change, and Demand-Side Management

Mathematical Geosciences, 2019

Integration of renewable energy into mining and processing operations is becoming necessary as pa... more Integration of renewable energy into mining and processing operations is becoming necessary as part of a strategy towards sustainability in the minerals industry. A solar photovoltaic plant along with a battery energy storage system (PV-BESS) can provide a long-term solution to cope with increasing energy costs, thus reducing the tension with other societal competing needs for a key resource such as clean energy. However, sizing these systems is challenging, in face of uncertain ore grindability and solar power availability. In this paper, we present an application of an integrated model to size the PV-BESS, where the variability of ore grindability is modeled using geostatistical tools, solar irradiance variability is captured using a Markov chain simulation model, and the entire system is optimized through linear stochastic optimization, considering a fixed mine schedule for the feed of a semiautogenous grinding (SAG) mill. The main goals are to minimize the costs associated with operating the SAG mill in the presence of a PV-BESS system, understand how the sizing and costs change under the influence of stochastic drivers, and reveal the potential for demand-side management in mines. The size and costs of the necessary infrastructure are determined for a model of estimated grindability and an ensemble of 50 simulated models of grindability, and compared against the sizing and cost of the ground truth. The effect of climate change on solar energy availability is accounted for by forecasting the ratio of excellent, good,

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A path-level exact parallelization strategy for sequential simulation

Computers & Geosciences, 2017

Sequential Simulation is a well known method in geostatistical modelling. Following the Bayesian ... more Sequential Simulation is a well known method in geostatistical modelling. Following the Bayesian approach for simulation of conditionally dependent random events, Sequential Indicator Simulation (SIS) method draws simulated values for K categories (categorical case) or classes defined by K different thresholds (continuous case). Similarly, Sequential Gaussian Simulation (SGS) method draws simulated values from a multivariate Gaussian field. In this work, a path-level approach to parallelize SIS and SGS methods is presented. A first stage of rearrangement of the simulation path is performed, followed by a second stage of parallel simulation for non-conflicting nodes. A key advantage of the proposed parallelization method is to generate identical realizations as with the original non-parallelized methods. Case studies are presented using two sequential simulation codes from GSLIB: SISIM and SGSIM. Execution time and speedup results are shown for large-scale domains, with many categories and maximum kriging neighbours in each case, achieving high speedup results in the best scenarios using 16 threads of execution in a single machine.

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Modulating the Catalytic Activity of Cerium Oxide Nanoparticles with the Anion of the Precursor Salt

The Journal of Physical Chemistry C, 2017

In this work, we tested our hypothesis that surface chemistry and antioxidant properties of ceriu... more In this work, we tested our hypothesis that surface chemistry and antioxidant properties of cerium nanoparticles (CNPs) are affected by presence of counterions. We first employed various precursor cerium (III) (Ce(III)) salts with different counterions (acetate, nitrate, chloride, sulfate) to synthesize CNPs following the same wet chemical methodology. Electron spin resonance (ESR) studies provided evidence for the formation of radicals from counterions (e.g., NO 3 • 2− from reduction of NO 3 − in CNPs synthesized from Ce(III) nitrate). Physicochemical properties of these CNPs, e.g., dispersion stability, hydrodynamic size, signature surface chemistry, SOD-mimetic activity, and oxidation potentials were found to be significantly affected by the anions of the precursor salts. CNPs synthesized from Ce(III) nitrate and Ce(III) chloride exhibited higher extent of SOD-mimetic activities. Therefore, these CNPs were studied extensively employing in-situ UV-Visible spectroelectrochemistry and changing the counterion concentrations affected the oxidation potentials of these CNPs. Thus, the physicochemical and antioxidant properties of CNPs can be modulated by anions of the precursor. Furthermore, our ESR studies present evidence of the formation of guanine cation radical (G• +) in 5′-dGMP via UV-photoionization at 77 K in the presence of CNPs synthesized from Ce(III) nitrate and chloride and CNPs act as the scavenger of radiation-produced electrons.

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Channelized facies recovery based on weighted compressed sensing

2016 IEEE Sensor Array and Multichannel Signal Processing Workshop (SAM), 2016

A new image reconstruction algorithm is proposed based on weighted compressed sensing (WCS) for t... more A new image reconstruction algorithm is proposed based on weighted compressed sensing (WCS) for the problem of channelized facies recovery from pixel-based measurements. This algorithm integrates information from: (1) signal structure dependencies in a transform domain (the discrete cosine transform); and (2) multiple-point statistics obtained from a training image. In the experimental side, excellent results are reported showing that the WCS scheme provides good reconstruction for geological facies models even in the [0.3%-1%] range of data. Experiments show that the proposed solution outperforms methods based on CS and MPS, when reconstruction performance is measured in terms of similarity perceptual indicators (MSSIM).

Tissue deposition and toxicological effects of commercially significant rare earth oxide nanomaterials: Material and physical properties

Environmental toxicology, Jan 3, 2016

Rare earth oxide (REO) materials are found naturally in earth's crust and at the nanoscale th... more Rare earth oxide (REO) materials are found naturally in earth's crust and at the nanoscale these REO nanoparticles exhibit unique thermal, electrical, and physicochemical properties. REO nanoparticles are widely used in different industrial sectors for ceramics, glass polishing, metallurgy, lasers, and magnets. Recently, some of these REO nanoparticles have been identified for their potential application in medicine, including therapy, imaging, and diagnostics. Concurrent research into the REO nanomaterials' toxicities has also raised concern for their environmental impacts. The correlation of REO nanoparticles mediated toxicity with their physiochemical properties can help to design nanoparticles with minimal effect on the environment and living organisms. In vitro assay revealed toxicity toward Human squamous epithelial cell line (CCL30) and Human umbilical vascular endothelial cells (HUVEC) at a concentration of 100 µM and higher. In vivo results showed, with the exceptio...

Parallelization of simulation algorithm with GPU for constructing high resolution models of Earth Sciences variables

Simulation of continuous variables is an important aspect in the construction of numerical models... more Simulation of continuous variables is an important aspect in the construction of numerical models of Earth Sciences variables. In many cases, there is a need for high resolution models either to model large volumes or surfaces, or to characterize on a very dense grid some spatial phenomena. Traditional simulation algorithms such as turning bands and sequential Gaussian simulation must be adapted to handle such large models and to perform the computations in a reasonable time. Parallelization requires a review of the algorithm design. We present the changes and performance improvements of parallelizing the turning bands algorithm using graphical processing units (GPU). Our implementation focuses on parallelization of the unconditional simulation step. One example is presented comparing the performance of a serial simulation implementation versus our parallelized implementation of turning bands. Speed ups of up to 60 are reached and an analysis of possible additional improvements is p...

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