bluuebunny/crossref_metadata_2025_split huggingface dataset:
Quantifying Well Integrity Risk at Scale: A Repeatable & Data Driven Analysis of Well Integrity in Unconventional Gas Fields
Authors: Thomas T. J. , Norman B. J. 
Published: October 2023

Abstract
This paper presents the results of a well integrity research project conducted on 1,605 unconventional gas wells in Queensland Australia, and discusses the methodology employed which can be applied to other fields. This paper focuses on the methodology used by the research team, which had been termed ‘barrier logic’, a set of standardized questions, exemplar answers and numerical values assigned to each of the answers which is than scored against an industry standard Risk Assessment Matrix. This methodology was used to assess all the wells in the selected fields, and provided the operating company that manages them an up-to-date and consistent risk scoring for their entire well stock. The methodology developed during this research provides several benefits to well operators, such as: reducing the level of individual bias and error based on multiple employes scoring risks, streamlines decision making on remediation work, as risk scoring has been reviewed and agreed in advance and providing a more accurate assessment of individual wells’ integrity based on the construction and operation activities being individually assessed. Many operators would share the same benefits of applying this, or a similar methodology to their well stock and several key insights and recommendations for others are provided at the end of this paper.
The use of large data analytics, machine learning and broader AI for predictive analysis, especially for production optimization and completion failure forecasting, is a rapidly growing field of expertise in Oil and Gas. For example, there are over 50 conference papers and journal articles registered on SPE's OnePetro that contain the term ‘Machine Learning’ in their title for 2023 alone. This paper adds to this growing body of research, showing the benefits to operating companies when data centric analysis and the digitization of data and processes is applied.
Reviving of Gas Well Using the Mobile Wellhead Gas Compressor Technology
Authors: Alhajri F. M. , Samsudin Z. 
Published: October 2023

Abstract
Reviving "ceased to flow" wells no longer has to be a complicated procedure. The Mobile Wellhead Compressor (MWHC) technology has a compact design of gas and liquid handling systems, suitable for reviving wells and boost the gas production as an alternative to the conventional Coiled Tubing Nitrogen Lifting (CTNL). The objective of this paper is to present the findings obtained from a thorough engineering evaluation of trial testing the MWHC technology in a gas well.
The MWHC technology was deployed to revive a ceased to flow gas well due to liquid loading as a result of flowing below the required velocity. The production enhancement by lowering system back pressure was the best solution to revive the well and unload the associated liquid in order for the well to be able to join the production trunk line.
As for the trial test results, the mobile wellhead gas compressor performed well within its design parameters. The unit successfully managed to reduce the wellhead pressure to atmospheric pressure during the well revival and handled the produced fluids (Gas & Liquids) during the flow regime, leading to easy well reviving and liquid unloading. Post-trial, well parameters were found healthy and satisfactory along with achieving the trial objective of making the well alive and bringing it back into production with no further need for compression equipment. The performance of the system was very remarkable as the well was revived in less than 13 hours, which is an excellent promising result compared to the CTNL 7-14 days duration. Therefore, the mobile wellhead compressor was deemed an acceptable cost-effective alternative to CTNL.
In summary, the MWHC technology with such service, size and features is very unique whereby combination of different types of compressors and liquid pump are packaged together along with the proprietary control system. The mobility advantage of the compressor will allow quick and easy movement to cover a wide range of wells. In addition, the technology is a cost-effective solution compared to the conventional CTNL.
Accurate Prediction of the Saturation Pressures of Hydrocarbons in Unconventional Reservoirs: A Modified Alpha-Function for the Peng-Robinson Equation of State
Authors: Lin Lixing , Babadagli Tayfun , Li Huazhou Andy 
Published: October 2023

Abstract
Due to the confinement and strong adsorption to the pore wall in meso- and nano- pores, fluid phase behavior in the confined media, such as the tight and shale reservoirs, can be significantly different from that in the bulk phase. A large amount of work has been done on the theoretical modeling of the phase behavior of hydrocarbons in the confined media. However, there are still inconsistencies in the theoretical models developed and validations of those models against experimental data are inadequate.
In this study, we conducted a comprehensive review of experimental work on the phase behavior of hydrocarbons under confinement and analyzed various theoretical phase-behavior models. Emphasis was given to the modifications to the Peng-Robinson equation of state (PR EoS). Through the comparative analysis, we developed a modified alpha-function in PR EoS for accurate prediction of the saturation pressures of hydrocarbons in porous media. This modified alpha-function accounts for the pore size and was derived based on the regression results through minimizing the deviation between the experimentally measured and numerically calculated saturation pressure data. Meanwhile, the thermodynamic properties of propane were calculated in the bulk phase and in the nanopores. Finally, we validated the newly developed model using the experimental data generated within our research group.
By applying the modified PR EoS, a more accurate representation of the experimentally measured saturation pressure data in confined nanopores was achieved. This newly developed model not only enhanced the accuracy of the predictions but also provided valuable insights into the confinement effects on the phase behavior of hydrocarbons in nanopores. Notably, we observed significant changes in the properties of propane within confined nanopores, including suppressed saturation pressure and fugacity, indicating a greater tendency for the gas to remain in the liquid phase. Additionally, the gas compressibility factor and enthalpy of vaporization were found to increase highlighting increased difficulty in transitioning from liquid to gas phase under confinement. To validate its applicability, the newly developed model was applied to the experimental data obtained in real rock samples. Interestingly, it was observed that the phase change in these samples predominantly occurred in the smallest pores. This finding highlights the importance of considering the pore size distribution when studying the phase behavior of hydrocarbons in a capillary medium even if the rock has high permeability.
This study provided a simple and easy-to-implement modification to the PR EoS for accurate prediction of the phase behavior of petroleum fluids under confinement. The modification to PR EoS was more straightforward and simplified compared to the modifications available in the literature.
Fracture Network Characterization Beyond Wellbores: A New Approach to Identify Water Corridors through Advanced Resistivity Analysis
Authors: Manuaba Ida Bagus Gede Hermawan , Aljishi Mohammad K , Santoso Gagok Imam , Dolan James T 
Published: October 2023

Abstract
Carbonate rocks are often characterized as containing complex porosity systems from primary to secondary, and even intertwined multi-porous systems. Consequently, this creates a challenge for petrophysicists and geologists with identifying the impact of such a complex system on wells’ productivity. This paper studies delineating fracture network proximity and architecture beyond the wellbore and successfully identifying water corridors for completion enhancement.
This paper presents a novel methodology for integrating wellbore-centric micro-electrical borehole imaging with an ultra-high-resolution bed boundary mapper (UHR-BBM). The approach integrates the quantification and categorization of fractures around the wellbore acquired through resistivity image, and fluid network in a radius of up to 30 ft around the wellbore derived from UHR-BBM. The process encompasses a workflow starting from invasion profile determination to UHR-BBM geo-signals enhancement with fracture details prior to ultimately mapping their network extension and fluid characterization. Advanced borehole analysis provided new insight into textural variations and litho-facies when analyzing fractured zone, opening a gateway to incorporating geological features into the petrophysical analysis. Accordingly, it was observed that fractures could contribute an additional percentage of secondary porosity, improving the productivity index of such formation. However, through conducting the aforementioned analysis, some of the fractures were featured as water-driving factors when their proximity beyond the wellbore was uncovered. Moreover, resistivity analysis concluded that the water-driving factors could have implications when the true resistivity affects the modeling process. Ultimately, the completion design shall be altered to isolate such zones, enhancing hydrocarbon recovery with minimized water cuts, as will be shown in one of the examples.
This methodology utilizes a new technique of incorporating shallow and deep measurements to quantify fracture systems, asses their proximity to the wellbore, and determine their potential impact on the well performance. This analysis facilitates a new approach to well completion design optimization, prolonging the life of the well and enhancing productivity.
Is Petroleum Engineering Curriculum Change Far from Academic?
Authors: Samuel Robello 
Published: October 2023

Abstract
The changing environment, demography of workforce and the advancements of technology require the urgency of the reforms needed in the petroleum engineering education and curriculum. Restructuring of the petroleum industry due to the protracted downturn is also aiding the accelerating pace of change. In alignment with the industry, the talent pipeline from the education system should also be in lockstep alignment. Curriculum changes are also required to take into consideration the topics and subjects related to sustainable energy sources as the world transitions to clean energy. This will help provide the students an opportunity to acquire interdisciplinary knowledge. Present-day education system must move away from the model of "learn at school" and "do at work" as the industry has moved away from "on the job" training or induction training. So, the petroleum engineering education must move to "learn and work" school model so that students are ready to take up the job from day one. The new approach should include basic engineering, advanced engineering and experiential learning that culminates to the required expertise to get assimilated in the workforce. The paper presents and addresses the scope and approach for a new curriculum for petroleum engineering education. This paper is an extended and repeat of text version of the paper SPE-206305-MS titled, "Petroleum Energy Engineering Education Reform: Flipping the Curriculum" paper presented at the SPE Annual Technical Conference and Exhibition, Dubai, UAE, September 2021 (Samuel 2021). This paper has an alternative solution and improves the theoretical framework of the course curriculum.
Best Practices in DFIT Interpretation - Comparative Analysis of 80 DFITs in the Canadian Montney Shale Play
Authors: Virues Claudio , Robertson Alexandra , Sendecki Bruce 
Published: October 2023

Abstract
Current practice for conducting minifrac or diagnostic fracture injection tests has been changing with time. The Alberta Energy Regulator (AER) has a pressure and deliverability testing directive that has guidance on those tests. This guidance was updated in late 2021. Many operators from the Canadian Montney shale play submit minifracs to AER, 80 of these minifracs were summarized statistically in this paper. Closure, reservoir pressure, and permeability were the main analyzed parameters in the paper scope.
Requirements for pressure and deliverability tests are set out by this newly updated directive. Industry uses minifrac in horizontal wells with multistage fracture treatments when developing unconventional reservoirs. Closure, initial reservoir pressure is commonly being determined with the common well test. Holistic or tangent vs. compliance method are compared for closure pressure in this paper. Readers are eager to replicate results, so for After Closure Analysis (ACA) methods equations that govern the analysis are provided in detail.
Published or commercially available holistic and compliance models are compared for closure pressure. Published or commercially available ACA Soliman and Nolte methods are compared for permeability and reservoir pressure. Horizontal wells in 80 unconventional shale field case studies are presented. The fact that the signature of closure pressure is not apparent is a significant finding. Similarity of closure pressure outcomes or estimates for tangent vs compliance is remarkable. Differentiation of reservoir pressure determination for either linear or radial flow are observed. Interpretation on net pressure impact is evaluated and ultimately differentiation on ACA permeability determination is assessed. Analogous shale plays operators in USA and current Canadian Montney Shale play operators will find practical and direct implications. To calculate effective fracture half length and optimize fracture design and well spacing accurate permeability values are needed. To design hydraulic fractures with geomechanics applications accurate closure pressure values are essential. To conduct Rate Transient Analysis (RTA) for resources and reserves assessment in similar unconventional shale plays accurate initial reservoir pressure as an input is fundamental.
Comparing analytically closure pressure methods in unconventional shale plays is novel. In addition, practicing engineers or well testing interpreters will find the comparison of different after closure analysis relevant.
Reducing NPT Using a Novel Approach to Real-Time Drilling Data Analysis
Authors: Wang Junzhe , Sajeev Shyam Kareepadath , Ozbayoglu Evren , Baldino Silvio , Liu Yaxin , Jing Haorong 
Published: October 2023

Abstract
Early detection and characterization of anomalous events during drilling operations are critical to avoid costly downtime and prevent hazardous events, such as a stuck pipe or a well control event. A key aspect of real-time drilling data analysis is the capability to make precise predictions of specific drilling parameters based on past time series information. The ideal models should be able to deal with multivariate time series and perform multi-step predictions. The recurrent neural network with a long short-term memory (LSTM) architecture is capable of the task, however, given that drilling is a long process with high data sampling frequency, LSTMs may face challenges with ultra-long-term memory. The transformer-based deep learning model has demonstrated its superior ability in natural language processing and time series analysis. The self-attention mechanism enables it to capture extremely long-term memory.
In this paper, transformer-based deep learning models have been developed and applied to real-time drilling data prediction. It comprises an encoder and decoder module, along with a multi-head attention module. The model takes in multivariate real-time drilling data as input and predicts a univariate parameter in advance for multiple time steps. The proposed model is applied to the Volve field data to predict real-time drilling parameters such as mud pit volume, surface torque, and standpipe pressure. The predicted results are observed and evaluated.
The predictions of the proposed models are in good agreement with the ground truth data. Four Transformer-based predictive models demonstrate their applicability to forecast real-time drilling data of different lengths. Transformer models utilizing non-stationary attention exhibit superior prediction accuracy in the context of drilling data prediction.
This study provides guidance on how to implement and apply transformer-based deep learning models applied to drilling data analysis tasks, with a specific focus on anomaly detection. When trained on dysfunction-free datasets, the proposed model can predict real-time drilling data with high precision, whereas when a downhole anomaly starts to build, the significant error in the prediction can be used as an alarm indicator. The model can consider extremely long-term memory and serve as the alternative algorithm to LSTM. Furthermore, this model can be extended to a wide range of sequence data prediction problems in the petroleum engineering discipline.
Liza Unity: Start-Up and First Year Operations
Authors: Verma Saurabh Kumar , Ramachandran Kartik 
Published: October 2023

Abstract
Guyana's oil and gas production commenced in December 2019 with the Liza Destiny floating production, storage, and offloading (FPSO) vessel for the first phase development of the Liza Field located in the south-eastern portion of Stabroek Block, offshore Guyana. Esso Exploration and Production Guyana Limited (EEPGL) achieved first oil on Liza Unity, the second FPSO in Guyana, in February 2022. A robust process of implementing lessons learned from Liza Destiny commissioning and start-up were adapted by the Liza Unity team. The Liza Unity FPSO is moored approximately 190 km offshore Guyana in 1600-1700 m of water depth. The FPSO is designed to develop the remaining portions of the Liza field, that were not targeted in first phase of development. The subsea system includes eight subsea manifolds (four production and four injection) tied back directly to the FPSO through ten flowlines, ten risers and two dynamic umbilicals to provide power, control and subsea chemicals.
Personnel safety, process safety, and environmental performance were prioritized during start-up. Liza Unity achieved background flare within 60 days of start-up with operations continuing to bring new wells online and achieve the initial investment basis oil production capacity of 232 kbd in six months.
This paper will present:
The strategy and integrated approach to achieve first oil, ramp up to the initial investment basis oil production capacity, and production optimization, while maintaining focus on personnel safety, process safety and the environment Well start-up strategy, reservoir data gathering, and reservoir management of a complex reservoir with wide range of fluid properties Start-up challenges and mitigations First Water-Alternating-Gas (WAG) conversion in Guyana Reliability performance
The overall journey from first oil to achieving the initial investment basis oil production capacity was carried out by the Liza Unity team within its first year of operations. This is a result of an integrated approach demonstrated by all the technical and operations disciplines. This paper will elaborate on the challenges tackled by Liza Unity while generating value for all the stakeholders and the people of Guyana.
Digital Twin for Development & Subsurface Integration - A Window into the Future
Authors: Gan T. , Sumadh E. , Sagram B. 
Published: October 2023

Abstract
The Digital Twin (DT) provides a virtual and digital representation of existing assets, spanning everything from onshore facilities to offshore platforms, pipelines and subsurface data, all in one location. It has been used for the flagship Manatee project to develop 3 stacked reservoirs, which will be one of the largest projects in Shell Trinidad and Tobago (STT). Gas from these wells is expected to be processed via a new platform and transported via a long offshore pipeline pipeline to the Beachfield onshore facility. The DT was used to identify design modifications required at this onshore site and visualize the proposed offshore assets. It integrates existing facilities and new design data, including site survey, subsurface and wells data to optimize the well planning.
With access to an integrated visualization platform for both surface and subsurface 3D and 4D data and engineering design documentation, virtual site visits were conducted to assess the existing facility. Integrating the 3D model with the pipelines, bathymetry data of the proposed pipeline routes and subsurface data, the team was able to design and engineer future upgrades required for the upcoming development. Furthermore, DT was used to visualize the proposed well paths, platform design, rig access and subsurface reservoir data which supported platform location, layout, and orientation decisions.
The full project scope, in the form of a complete 3D model was created for both onshore and offshore assets. DT allowed the teams to have a better understanding of the site layout and area constraints that would have been impossible to envisage using 2D drawings alone. The proposed models assisted with identifying possible design issues, thus reducing the likelihood of errors and lowering costs associated with rework and corrections. The teams used high-resolution photogrammetry to support the environmental team in determining the best landing site for the pipeline and fiber optic cable. This was done by navigating through bathymetry and geohazards to land the new pipeline route from the platform to Beachfield. Overall, access to a digital representation of the facilities, led to a significant manhour saving for the teams, enabling integrated, efficient working and improved decision quality.
Overall, the use of the DT has been estimated to deliver direct cost savings of several millions per year and generate double digits millions of indirect value from safety design and rework during project decision gates handover and project schedule integration. Furthermore, given the limitations due to the pandemic, CO2 emissions and the carbon footprint were lowered as there was a reduced number of helicopter flights offshore and drives towards the onshore facilities.