Abhinav Kohar

Abhinav Kohar

Austin, Texas, United States
14K followers 500 connections

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My org is building Lumi™…

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    SLB

    Houston, Texas, United States

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    Houston, Texas, United States

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    Houston, Texas, United States

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    United States

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    United States

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    Urbana-Champaign, Illinois Area

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    Houston, Texas Area

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    Mumbai Area, India

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Education

Licenses & Certifications

Volunteer Experience

Publications

  • Condition Based Maintenance of Oil Field Cement Pumper: A Data Driven Approach

    SPE Western Regional Meeting, 2024, SPE-218870-MS

    In this paper we describe the method and application of the four PHM models we developed and implemented in 2023. The first three distinct models monitor the performance of three different centrifugal pumps designated for distinct functionalities within our system. The fourth model monitors the performance of the radiator that dissipates heat from the coolant that regulates the temperature of lubrication systems for the engine and transmission. All four models were tested on historic data and…

    In this paper we describe the method and application of the four PHM models we developed and implemented in 2023. The first three distinct models monitor the performance of three different centrifugal pumps designated for distinct functionalities within our system. The fourth model monitors the performance of the radiator that dissipates heat from the coolant that regulates the temperature of lubrication systems for the engine and transmission. All four models were tested on historic data and successfully deployed to identify deviation from healthy operating zones in the production jobs. The results are promising, given the models have identified 22 defects since deployment.

    The Dataiku platform was used for data processing, analysis, and algorithm development for models. The first three models were developed using a polynomial regression method along the root mean square error (RMSE) metric. The fourth model was developed using a curated dataset to delineate the zone of interest and to define the thresholds for detecting deviations. The results of the PHM models were visualized on interactive dashboards, statistically significant outliers are analyzed in real time, and used to alert the operations and maintenance teams in the field.

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  • MWD Tools’ Electronic Components Data Driven Failure Detection,

    2024 SPE Western Regional Meeting, SPE-218834-MS

    Within the oil and gas industry, measurement-while-drilling (MWD) tools have several sensors to provide telemetry data that allow performing either live or post-job health diagnostics of the tool components and effectively replace/repair them to avoid unnecessary nonproductive time. Nevertheless, health checks are often purely telemetry-based, not using past job information to quantify cumulative component degradation, which increases the probability of failure during subsequent…

    Within the oil and gas industry, measurement-while-drilling (MWD) tools have several sensors to provide telemetry data that allow performing either live or post-job health diagnostics of the tool components and effectively replace/repair them to avoid unnecessary nonproductive time. Nevertheless, health checks are often purely telemetry-based, not using past job information to quantify cumulative component degradation, which increases the probability of failure during subsequent jobs.

    This work proposes a methodology that (1) introduces historical data to improve on failure detection and (2) benchmarks it against single-job-based models over the same features for a particular MWD tool. We find that by stacking historical features (as multivariate time series), failure prediction using one-dimensional convolutional neural networks provides better estimates of the probability of failure.

    We apply our methodology to five of the most common electronic component failure detection models trained over the time series the telemetry channels of 38 coiled tubing drilling MWD assets, totaling 752 jobs, and present the comparison between single-job-based models (with an average F1-score 0.66) and historical data-based models (with an average F1-score of 0.75).

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  • Mitigating Nonproductive Time: A Novel Algorithm for Dsl Fault Detection

    IPTC

    Digital slickline (DSL) has been introduced to improve the efficiency of intervention operations in both onshore and offshore wells. DSL cables provide a real-time two-way-telemetry path between the acquisition system at the surface and the downhole sensors. Most nonproductive time (NPT) in DSL operations stems from telemetry issues due to cable faults despite the system's robustness. To address this, we developed a data-driven framework for identifying potential cable damage and its…

    Digital slickline (DSL) has been introduced to improve the efficiency of intervention operations in both onshore and offshore wells. DSL cables provide a real-time two-way-telemetry path between the acquisition system at the surface and the downhole sensors. Most nonproductive time (NPT) in DSL operations stems from telemetry issues due to cable faults despite the system's robustness. To address this, we developed a data-driven framework for identifying potential cable damage and its approximate location using the DSL logging telemetry data, including communication signals, pressure, and depth. We tested our method on 992 real-case downhole jobs across almost 30 countries. To validate our method, we compared the method predictions for 60 jobs with labeled potential faults (i.e., cable damage), reaching an accuracy of 98% when considering whether the job has a fault. Thus, our framework enhances cable management, reducing NPT and associated costs.

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  • Deep learning models for high-frequency financial data

    IDEALS

    The limit order book of a financial instrument represents its supply and demand at each
    point in time. The limit order book data can be used to predict the future price of the
    financial instrument. We develop deep learning models to capture the high dimensional
    data distributions (on Rd) of the limit order data. These models exploit the underlying
    structure of this complex data. We develop a uniform data grid model for limit order book
    data to achieve state-of-the-art accuracy…

    The limit order book of a financial instrument represents its supply and demand at each
    point in time. The limit order book data can be used to predict the future price of the
    financial instrument. We develop deep learning models to capture the high dimensional
    data distributions (on Rd) of the limit order data. These models exploit the underlying
    structure of this complex data. We develop a uniform data grid model for limit order book
    data to achieve state-of-the-art accuracy for predicting price changes in a stock. We also
    develop a novel way to use non-uniform events from the limit order book data to train a
    non-uniform grid data model. This model substantially and consistently outperforms our
    uniform data grid model. Both the models have been trained and tested over a wide range of
    periods spanning multiple years for many stocks. The out-of-sample predictions are stable
    across time for both the models as shown by tests for multiple stocks. Given the huge size
    of the dataset we use a cluster of CPUs and GPUs to perform our experiments.
    ii

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  • Support for power efficient mobile video playback on simultaneous hybrid display.

    IEEE Computer Society

    Mobile devices, such as smartphones, e-books, and tablets, have limited battery capability because of the constraint of battery size and mobility requirement. However the large color displays on those devices put more tensions on this situation as the displays consume a large portion of the total battery power. A TOLED-EPD hybrid display that integrates a transparent OLED (TOLED) with an electrophoretic display (EPD) has been emerging to reduce the energy usage of displays. The technology…

    Mobile devices, such as smartphones, e-books, and tablets, have limited battery capability because of the constraint of battery size and mobility requirement. However the large color displays on those devices put more tensions on this situation as the displays consume a large portion of the total battery power. A TOLED-EPD hybrid display that integrates a transparent OLED (TOLED) with an electrophoretic display (EPD) has been emerging to reduce the energy usage of displays. The technology displays information selectively on one of the displays based on the update rate of content, thus reduces the energy usage. In this paper, we propose a design of mobile video playback, Decoder4Hybrid, for the hybrid displays. The proposed approach supports encoded video playback based on the update frequency of each block, which is exploited by the hybrid display controller to determine which display should be used to show a MPEG encoded block. A fast DCT-based heuristic algorithm is proposed to detect the changes between frames at block level with minimal computation cost. Experimental results show that the proposed approach can save up to 40% power with acceptable video quality.

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Projects

  • Byzantine fault tolerance and large scale graph processing on hadoop

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Honors & Awards

  • Siebel Scholar

    Tom and Stacy Siebel Foundation

    https://en.wikipedia.org/wiki/Siebel_Scholars
    The Siebel Scholars program was established by the Thomas and Stacey Siebel Foundation in 2000 to recognize the most talented students at the world’s leading graduate schools of business, computer science, bioengineering, and energy science. Each year, more than 90 graduate students at the top of their class are selected during their final year of studies based on outstanding academic performance and leadership.

  • President of India Gold Medal

    Shri Pranab Mukherjee, President of India

  • IIT Patna Institute Gold Medal

    Ajai Chowdhary, Founder HCL, Chairman IIT Patna

  • State Bank of India Award

    State Bank of India

  • DAAD-WISE Scholar

    German Academic Exchange Service

    Deutscher Akademischer Austauschdienst or German Exchange Service is one of the most coveted internship which provides 2-3 months internship opportunity at universities in Germany. 100 scholars selected all across India.
    The selection is based on academic achievements, leadership potential, and candidate's overall profile.

    https://www.daad.de/deutschland/stipendium/datenbank/en/21148-scholarship-database/?daad=1&detail=50015295&origin=4&page=1&q=wise&status=1&subjectGrps=

  • Excellence award

    Kapil Sibbal, Minister Human Resource & Development, Government of India

  • Silver Medal, Indian National Mathematics Olympiad

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Test Scores

  • GRE

    Score: 329/340

  • TOEFL

    Score: 116/120

  • IIT JEE Mains

    Score: All India Rank 729

    Out of 1.1 Million candidates (General Category)

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