bluuebunny/crossref_metadata_2025_split huggingface dataset:
Breaking New Grounds and Records for Unconventional Reservoirs Characterization Using the New Formation Testing and Sampling Technology
Authors: Kelkouli Mohammed , Zaggas John , Boudiba Younes , Akham Abderrahmane , Boumahrat Riad , Ferraz Salah , Bellabiod Sofiane 
Published: November 2019

Abstract
An exploration deep well crossing two reservoirs with different quality and properties, having an objective of: Fluid identification and sampling in extremely tight section (∼0.02mD/cP mobility) as well as in another section that is suspected to be depleted with very high overbalance exceeding legacy tools, knowing the hydrostatic pressure being ∼9500psia.
Wireline formation tester was run using single probe, leading to 65% of tight stations, the rest were valid but with very low mobility. This exposes the tool to an increasing pressure differential exceeding its physical limit and leading to damaging it. This makes any further analysis impossible. The toolstring was upgraded with latest technology of WFT, that is a merge between probe based and dual packer modules. This new technology was designed with extreme environments in mind, that allows sampling in all mobility range from extreme tight to very high with its capability of holding up to 8000psia differential pressure.
In the job described here, some of the tested reservoir sections were differentially depleted, something unknown to customer as this was an exploration environment. Since this information were not know even after the completion of the first and second run, a third run was carried out with the objective of re-investigating the same depths performed by the single probe, but this time 3D Radial Probe was used instead. This gave the advantage of taking the pressure down to almost 0 psia. The potential hydrocarbon zone which was bypassed (seen dry with single probe) was then tested with 3D radial probe giving a reservoir pressure of 2864psia with a mobility of ∼300mD/cP where gas condensate was identified and captured. Now for the extreme tight reservoir section, in combination with high hydrostatic, the mechanical limitation of traditional tools remains the same making sampling and/or fluid ID impossible. An attempt was made using the 3D radial probe, and despite the extreme low mobility ∼0.02mD/cP, an identification of the reservoir fluid (water) was successfully completed without any issue.
The use of 3D Radial Probe technology gave a completely different picture from what was expected, enabled the completion of all objectives and made the impossible (with conventional technology) possibly and easily achievable. This resulted in changing the well strategies accordingly and complete the well successfully. The new technology made the testing of unconventional reservoirs a reality.
Quantitative Seismic Interpretation Workflow for Sweet Spot Identification in Organic-Rich Mudrocks
Authors: Al Ibrahim Mustafa A. , Mukerji Tapan , Hosford Scheirer Allegra 
Published: November 2019

Abstract
Estimating the lateral heterogeneity of geochemical properties of organic rich mudrocks is important for unconventional resource plays. Mature regions can rely on abundant well data to build empirical relationships and on traditional geostatistical methods to estimate properties between wells. However, well penetration in emerging plays are sparse and so these methods will not yield good results. In this case, quantitative seismic interpretation (QSI) might be helpful in estimating the desired properties. In this study, we use QSI based on a rock physics template in estimating the uncertainty of the geochemical properties of organic mudrocks of the Shublik Formation, North Slope, Alaska. A rock physics template incorporating lithology, pore fraction, kerogen fraction, and thermal maturity is constructed and validated using well data. The template clearly shows that the inversion problem is non-unique. Inverted impedances cubes are estimated from three seismic angle gathers (near with angles between 0° and 15°, mid with angle gathers between 15° and 30°, and far with angle gathers between 30° and 45°). The inversion is done using a model-based implementation with an initial earth model derived from the seismic velocity model used in the processing phase. By combining the rock physics template and the results of seismic inversion, multiple realizations of total organic content (TOC), matrix porosity, and brittleness index are generated. These parameters can be used for sweet spot detection. Lithological results can also be used as an input for basin and petroleum system modeling.
Implementation of Tatweer’s Spatial Data Infrastructure and Utilization of Uav’s for Day-to-day Operations in the Bahrain Field
Authors: Nooraldeen Yasser , Puripanda Naresh , Bandla Kranthi , Derbas Zainab , AlNowakhda Ali 
Published: November 2019

Abstract
Tatweer Petroleum adopted the best GIS practices when implementing Tatweer’s Spatial Data Infrastructure and utilizing Unmanned Aerial Vehicles (UAV) for day-to-day Operations in the Bahrain Oil Field.
The initial milestone of the project was to have a detailed geospatial survey of the entire Bahrain Field, which was completed and introduced as the first "As-Built Geo-Spatial Map" of the Bahrain Field since the first oil well drilled in 1932. This allowed us to develop and deliver reliable GIS solution that eliminated conflicts and overlaps between projects, facilitating user acceptance. This led to the introduction of the concept of Spatial Data Infrastructure at an organizational level, which empowered the company with open access to high precision and up-to-date GIS services.
Following the SDI project and As-Built GeoSpatial Map, the GIS team is leading the initiative in utilizing Unmanned Aerial Vehicles (UAV), also known as Drones, to address the unique needs of the daily operations by providing safe, efficient, and cost-effective maintenance and inspection solution. Surveying and mapping is time-consuming, difficult, and often dangerous. UAV’s are used to allow surveyors and mappers to collect unlimited aerial data with precise measurements, while saving time, money, and manpower. They provide premium processing and analytic capabilities to support critical processes such as volume measurements, terrain mapping, site planning, etc. The survey data produces highly accurate, best-in-class orthophotos and Digital Elevation Models (DEMs).
This paper demonstrates the process of creating the first "As-Built Geo-Spatial Map" for the Bahrain Field, building Spatial Data Infrastructure, and utilizing Drone technology for day-to-day operations.
Geomechanical Assessment of Compaction Related Well Integrity Risks For A Large Field In Sultanate Of Oman
Authors: AL-Aamri Mohammed , Mahajan Sandeep , Mukhaini Hamed 
Published: November 2019

Abstract
One of the PDO’s largest producing field with vertically stacked carbonate reservoirs gas from shallower Natih Formation, and produces oil from lower Shuaiba formation with waterflood recovery. Natih formation is a highly compacting formation characterized using rock mechanics laboratory measurements. Currently there are more than 500 Shuiaba wells that are active, which penetrate through the highly compacting Natih Layer above. Reservoir compaction of Natih A has induced damage to several wells most likely due to compression and buckling of the casing within the production interval. The field has obeservations to well integrity and impact to production performation related to the casing deformation resulting from the compaction.
The well Integrity issues for Shuaiba wells are being resolved with work over operations, repairs. In few severe cases, it was required to abandon the well. All of these issues impact operational expenditure and production (loss and/or deferment). Risk assessment for wells with future depletion (or time) can provide input to manage the risk, plan adequate mitigations and capture the impact in the future drilling campaigns for well stock. To do so it was important to identify and quantify well counts, which have high potential to have well integrity issues or risk of failure
In the studied field, subsurface compaction is being monitored/measured since 2000, using Compaction Monitoring Instrument (CMI) that measures compaction between preplaced radioactive markers in the formation and the casing in five CMI monitoring wells. Data of CMI compaction log, historical well failures, spatial well locations, rock mechanics measurements was integrated to quantify risk of expected well failures in future. The results from the CMI logging showed that the compation in the entire reservoir interval is not uniform and upper layers in the reservoir intervals were subjected to very high compaction strains compared to lower layers. The Uniaxial Pore Volume Compressibility (UPVC)) coupled with analysis of CMI data provides a forecast for maximum compaction strain in the upper reservoir layers up to 5 % at abandonment pressure.
The analysis of reported/observed well failures reveals that approximately 77% of the impacted wells were during 1971-2000. Using these inputs a risk assessment matrix for well failures was developed, which provided potential wells with high risk of failure/well integrity issues, which accounted to about 34% (~ 85 wells) of the active wells. Results of this study provided input to capture in the development plans and build adequate mitigations to help minimize production loss/deferment
Human Factors and Performance: Reducing Errors and Improving Safety
Authors: Khan Salman , Yaqoob Shamrose 
Published: November 2019

Abstract
Companies employ a variety of tactics to reduce workplace incidents. However, behavioral-based programs have proven highly effective because safety becomes a collective responsibility shared by all employees. This paper will focus on one such program, called Human Performance (HuP). Key facets of the program include safety training, raising awareness of employees’ susceptibility to human error, and informing them how to design management systems as well as to promote behaviors to prevent safety incidents.
People bring to their job their own personal mix of skills, knowledge, experience, attitudes, motivation, habits, and personality. These individual characteristics influence behavior in complex and significant ways. Through training, employees can recognize where errors occur and use the proper tools to change their habits and reduce injuries or quality errors.
The novelty of this approach is to empower workers to contribute equally to their own safety and operational excellence, rather than relying on written policies. The efforts focus on safety within and outside the company.
Gas Development and Monetization via Floating Facilities FLNG, FCNG, FGTL and FSRU
Authors: Yussoff Ir. Ikhwan 
Published: November 2019

Abstract
The PETRONAS Floating LNG concept was envisaged to monetize stranded gas resources. At the same time, PETRONAS has also exploring the development of Floating Compressed Natural Gas (FCNG) and Floating Gas to Liquids (FGTL) as part of the "Technology Challenge Initiatives". In completing the elements in the overall LNG value chain, an FSRU will also become one of the fast track method to import LNG especially to the non-LNG importer country.
The two floaters namely PFLNG1 & PFLNG2 was built by PETRONAS to monetize the gas for offshore Sarawak and Sabah respectively which in turn increased the country's LNG production capacity. As part of the aim to commit to green house or flaring mitigation, PETRONAS is also gearing up towards the evaluations of miniscale Floating CNG vs Floating GTL. On the supply side, the development of Floating Storage Regasification Unit (FSRU) is believed to be an added value to PETRONAS as one of the biggest LNG exporter in the world.
The fast track nature of the project presents a challenge to the Gas and Upstream Business in meeting the target date. The advantages of having a floating facilities as a solution to monetize the stranded gas field and mitigating the flaring/ venting activities will be covered considering the risk identified throughout the development phases. The important of front end engineering has led to a fit for purpose design and excellent construction methodology.
The famous debate with regards to offshore vs onshore gas development will be revisited aligned with the technology maturity and market availability. Speaker will review the new facilities as a viable option in the future for any gas developments requiring a quick solution. Extensive technology selection exercises were conducted in finalizing the turret mooring, gas treating, liquefaction, regasification, cargo containment and offloading systems.
Designers and licensors have done rigorous design optimisation and marinization studies on impact of floater motion where it was evaluated against an extensive list of criterias. Specific offshore and marine technology selection for the facilities will be discussed in the effort of realizing the aim to bring conventional gas facilities to offshore environment. Speaker will share the challenges in selecting the right equipments in order to suit the condition including sea state, weather and regulatory requirements.
New Integrated Analytical Approach for Multiphase Inflow Performance Relationship
Authors: Al-Rbeawi Salam 
Published: November 2019

Abstract
This paper introduces an analytical approach for generating the inflow performance relationships (IPR) of different reservoirs depleted by different wellbore types at different conditions. The main focus of this paper is given to multiphase flow (oil, gas, water) and two-phase flow (oil, gas) during transient and pseudo-steady state flow conditions. The proposed approach presents new integrated models for the IPR that correlates the wellbore pressure with the multiphase total flow rate or the normalized pressure and rate by the bubble point pressure and single-phase flow rate at this pressure. These models consider the changes in reservoir fluid physical properties and reservoir relative permeabilities by coupling PVT data and relative permeability curves. The motivation of this study is reducing the uncertainty in the IPR of reservoirs undergoing the multiphase flow.
Predicting multiphase IPRs may go throughout three tasks. The first is developing the pressure functions of reservoir mobility and total compressibility by developing several correlations for reservoir fluid properties such as oil, gas, and water formation volume factor as well as gas solubility in oil and water. Several correlations are needed also for relative permeability behavior of the three fluids with the pressure. These correlations can be generated by the multi-regression analysis of PVT data and relative permeability curves. The second represents developing the analytical models for the flow regimes that could be developed during the entire production life of the reservoirs. The single and multiphase flow IPRs for different flow regimes are predicted in the third task. The proposed IPR in this study is plotted between the wellbore pressure and the total flow rate at reservoir condition or the normalized reservoir pressure and flow rate.
The observations obtained from this study are: 1) The proposed approach for the multiphase flow IPRs is not only time-variant but also depends on the flow condition whether transient or pseudo-steady state flow. 2) The IPR of the multiphase flow gives lower performance than the single-phase flow. 3) The IPR of the early time transient production is better than the late time pseudo-steady state production. 4) It is highly recommended to develop the models of fluid properties for each reservoir instead of using the models presented in the literature.
The novel points presented in this paper are: 1) Introducing a new approach for the inflow performance relationships in the reservoirs experiencing multiphase flow and depleted by horizontal wells or multiple hydraulic fractures. 2) Introducing the pressure functions of the multiphase flow reservoir mobility and multiphase flow total reservoir compressibility that consider the changes in reservoir fluid properties and relative permeabilities with production time and pressure in constructing the IPRs.
Miscible Gas Injection in Heterogeneous Carbonate Reservoirs with Extensive Baffles
Authors: Wei Chenji , Wang Yuhe , Li Baozhu , Zhang Jingjian , Zhang Wan , Wu Jin 
Published: November 2019

Abstract
Miscible gas displacement is a promising enhanced oil recovery method in carbonate reservoirs technologically and economically. Though miscibility can be well understood using core-scale experimental and numerical models, the miscible displacement process in complex heterogeneous and multi-dimensional carbonate reservoirs is more complicated and needs further analysis. In this paper, we present our effort in probing the miscible gas displacement characteristics in a carbonate reservoir with baffles based on data from a real field.
Using compositional modeling, we evaluate miscible gas injection process in heterogeneous carbonate reservoir with baffles. Together with the detailed miscible front development in specific parts of the reservoir, the analysis also takes advantage of gravity stabilization realized by implementing the corresponding injector-producer pattern.
This paper presents an analysis of miscible gas displacement process, which can be considered as an extension from a simple one-dimensional model to more complex heterogeneous and multi-dimensional system. Using data from a real carbonate reservoir with baffles, we analyze the CO2 injection for the drive processes. The analysis is combined with the consideration of the effects of baffles and wettability. Mainly due to the multi-dimensional flow, our results show that the minimum miscibility pressure is higher than one-dimensional system. Besides, our results indicate gravity stabilization could be well maintained by proper injector-producer pattern. We also report the sensitivity analysis for wettability changes in carbonates.
This paper offers a study to analyze and evaluate miscible gas flooding process in heterogeneous carbonate reservoirs. Using a real case data, the study can help reservoir engineers to better design miscible gas flooding for other similar situations.
Machine Learning Approach to Classify Water Cut Measurements using DAS Fiber Optic Data
Authors: Alkhalaf Muqbil , Hveding Frode , Arsalan Muhmmad 
Published: November 2019

Abstract
A crucial part of optimizing well production is accurate flow metering for both onshore and offshore environments. The industry currently relies on test separators and multiphase meters. These methods have limitations in terms of cost, transportation and safety. In this paper, an alternative method to classify water cut measurement in oil wells based on Distributed Acoustic Sensing (DAS) data and machine learning will be discussed. Fiber optics is an effective tool to perform downhole logging, however, the challenge usually resides in the analysis and processing of the logged data. After performing a flowing survey on an oil well a dataset was developed using the logged DAS data in combination with production logging tool (PLT) measurements. After extraction, processing and labeling the raw DAS data, this dataset is used for training supervised machine learning models.
In this paper, different classical machine learning models to train this dataset is assessed in terms of accuracy, speed and training/testing segments. The data gathered from the PLT shows a limitation in the variation of water cut percentages between the zones ranging from 71% to 76%. This limits our ability to assess the validity of the model, risk of overfitting, since most points share a similar target value. This is also reflected on the Rayleigh backscatter collected by the laser box where samples from different production zones share a similar value distribution across most frequency ranges. Three different classification machine learning models were selected simple Decision Tree and two ensemble method models—adaptive boost and Random Forest. The ensemble method models offer a parallel and sequential training schemes that increases the variance and reduce the bias in the model. After splitting and shuffling the data, were 10% of the original data was used for training, all models were trained in different percentages of the training set. Multiple metrics were chosen to assess the model's performance including accuracy, F-score and confusion matrices. Random forest classifier appears to be the best choice for this challenge, with a maximum accuracy of 98% and F-score of 0.99. The models show high dependency on low frequencies—lower than 500 Hz—where value distribution across production zones in DAS measurements is comparatively higher. Both ensemble method models are less bias with a maximum feature weight of about 0.1, in contrast, the simple Decision Tree model was highly dependent on a single frequency response. In future work, a more complex and diverse dataset will be collected from wells with a wider range of variances in terms of conditions and types. Moreover, after creating a more robust dataset alternative approaches can be assessed both classical machine learning models—regression and classification—and deep learning.
Integrated Reservoir Characterisation of an Emerging Unconventional Resource Play in the UAE
Authors: Newby Warren , Abbassi Soumaya , Fialips Claire , D.M. Gauthier Bertrand , Padin Anton , Pourpak Hamid , Taubert Samuel 
Published: November 2019

Abstract
The Upper Jurassic (Oxfordian to Late Kimmeridgian) Diyab Formation has served as the source rock for several world-class oil and gas fields in the Middle East. More recently it has become an emerging unconventional exploration target in United Arab Emirates (UAE), Saudi Arabia, Bahrain and its age-equivalent Najhma shale member in Kuwait.
The Diyab is unique in comparison to other shale plays due to its significant carbonate mineralogy, low porosities, and high pore pressures. Average measured porosities in the Diyab are generally low and the highest porosity intervals are found to be directly linked to organic porosity created by thermal maturation. Despite low overall porosities, the high carbonate and very low clay content defines an extremely brittle target, conducive to hydraulic fracture stimulation. This coupled with a high-pressure gradient facilitates a new unconventional gas exploration target in the Middle East. However, these favorable reservoir conditions come along with some challenges, including complex geomechanical properties, a challenging stress regime and the uncertainty of whether the presence of natural fractures could enhance or hinder production after hydraulic fracture treatment.
Only recently has the Diyab been studied in detail in the context of an unconventional reservoir. This paper presents an integrated approach allowing a multidisciplinary characterisation of this emerging unconventional carbonate reservoir in order to gain a better understanding on the plays’ productivity controls that will aid in designing and completing future wells, but already encouraging results have been observed to date.