bluuebunny/crossref_metadata_2025_split huggingface dataset:
Utilizing Capillary Pressure Measurements and Water Saturation Logs to Determine Reservoir Quality in a Giant Middle Eastern Carbonate Field
Authors: Alramahi Bashar , Jaafar Qaed , Al-Qassab Hisham 
Published: December 2021

Abstract
Classifying rock facies and estimating permeability is particularly challenging in Microporous dominated carbonate rocks. Reservoir rock types with a very small porosity range could have up to two orders of magnitude permeability difference resulting in high uncertainty in facies and permeability assignment in static and dynamic models. While seismic and conventional porosity logs can guide the mapping of large scale features to define resource density, estimating permeability requires the integration of advanced logs, core measurements, production data and a general understanding of the geologic depositional setting. Core based primary drainage capillary pressure measurements, including porous plate and mercury injection, offer a valuable insight into the relation between rock quality (i.e., permeability, pore throat size) and water saturation at various capillary pressure levels.
Capillary pressure data was incorporated into a petrophysical workflow that compares current (Archie) water saturation at a particular height above free water level (i.e., capillary pressure) to the expected water saturation from core based capillary pressure measurements of various rock facies. This was then used to assign rock facies, and ultimately, estimate permeability along the entire wellbore, differentiating low quality microporous rocks from high quality grainstones with similar porosity values. The workflow first requires normalizing log based water saturations relative to structural position and proximity to the free water level to ensure that the only variable impacting current day water saturation is reservoir quality.
This paper presents a case study where this workflow was used to detect the presence of grainstone facies in a giant Middle Eastern Carbonate Field. Log based algorithms were used to compare Archie water saturation with primary drainage core based saturation height functions of different rock facies to detect the presence of grainstones and estimate their permeability. Grainstones were then mapped spatially over the field and overlaid with field wide oil production and water injection data to confirm a positive correlation between predicted reservoir quality and productivity/injectivity of the reservoir facies. Core based permeability measurements were also used to confirm predicted permeability trends along wellbores where core was acquired.
This workflow presents a novel approach in integrating core, log and dynamic production data to map high quality reservoir facies guiding future field development strategy, workover decisions, and selection of future well locations.
Addressing Corrosion Stress Cracking Issue of Magnesium Frac Plugs Used in Ultra HPHT Shale Well Development
Authors: Dunne Timothy Ryan , Yue Wenhan , Zhao Lei , Nettles Damon , Cheng Peng , Ren Jiaxiang , Liu Yu 
Published: December 2021

Abstract
The paper discusses the unrecognized issue of accelerated cracking and dissolution of stressed high strength dissolvable magnesium components at elevated temperature. A high strength dissolvable magnesium alloy was selected for inclusion in a frac plug designed for 125°C to 175°C service after thorough tensile, compression, and dissolution testing of the alloy. After a 125°C plug field test, the plug exhibited catastrophic, premature failure. Laboratory plug testing of two magnesium alloys for the slips replicated the failure at 140°C in tap water. Dissolution testing of coupons in a more aggressive media showed inadequate mass loss to compromise functionality. It was theorized that the passivating magnesium layer was unable to form due to the stress applied to the components with magnesium's inherent reactivity with water. Slow strain rate testing was used to study the potential mechanism causing stress corrosion cracking. Two high temperature high strength alloys, DM-1 and DM-2, were tested at 4 x 10^-6 in/in/s in 140°C tap water. DM-1 demonstrated a decrease in yield from 52.4 ksi to 33 ksi, a 37% reduction as well as a decrease in ductility from 10.9% to 0.8%, a 93% decrease. DM-2 demonstrated a decrease in yield from 59.3 ksi to 32.3 ksi, a 46% reduction as well as a decrease in ductility from 10.3% to 0.7%, a 93% decrease. A scanning electron microscope evaluation showed both materials possessed a highly developed secondary phase surrounding the grain boundaries. The development and subsequent investigation of an alternative magnesium alloy, DM-3, showed semi-continuous secondary phases and was investigated for a substitute at a component level. While the ultimate tensile strength decreased minimally, the ductility decreased by 36%. Laboratory testing of the plug in identical conditions with the DM-3 slips was still successful. It is imperative for high temperature magnesium plug material selection to ensure the alloy does not have highly interconnected secondary phases which may cause sudden failure during field operation.
The Root Cause Analysis and Successful Control of an Oilwell Blowout in the Middle East
Authors: Ashena Rahman , Ghorbani Farzad , Mubashir Muhammad , Nazari Sarem Mahdi , Iravani Amin 
Published: December 2021

Abstract
In 2017, a blowout and explosion occurred in a drilling oilwell in the Middle East. After drilling to the depth of 2,610 m, tripping was decided in order to change the bit. When the crew were pulling the drill string out of the hole with the drill-string being at the depth of 1332 m, blowout and explosion occurred. The well was a development well drilling almost horizontally (82 degrees inclination angle) into a highly-pressured gas-cap and oil pay-zone of the oilfield. In this work, following a brief explanation of the root causal factors of the incident, we give an account of the blowout control methods applied to put an end to the blowout. Both the top-kill method and the bottom-kill method by relief well drilling, were simultaneously implemented to control the blowout. Finally, the blowout was successfully controlled by the bottom-kill after 58 days. During top-kill operations, all equipment was cleared away and this contributed to proceeding to permanent abandonment immediately after the relief well success. Finally, the adverse effect of the blowout on the environment (HSE) was qualitatively discussed.
A Fast Calculation Method for Natural Fractures Activation Considering Stress Shadow and Study on the Law of Natural Fractures Activation State Changes
Authors: Qiao Yan , Zhang Yang , Jiang Tianhong , Zhang Guobin , Chen Qing , Shang Litao , Hou Tengfei 
Published: December 2021

Abstract
During hydraulic fracturing process of the Permian Basin in North America, the cluster spacing has been shortened to 3m, and stress shadow can no longer be ignored. Many scholars have studied the influence of stress shadows to optimize cluster spacing. For reservoirs with natural fractures, how to activate more natural fractures through hydraulic fracturing has become the purpose. However, few scholars have studied changes in the activation law of natural fractures under stress shadow conditions. This paper establishes stress change value around single fracture according to Sneddon formula, and calculates the maximum and minimum principal stress according to plane principal stress calculation formula. Considering attenuation of net pressure, stress field of multiple fractures is established, and influence of various factors on stress re-orientation is studied. Finally, considering attenuation of net pressure with distance, according to discriminant formulas of tension & shear activation, the proportion of natural fractures that are easily activated is calculated. By designing orthogonal experiments, the influence of different factors on the proportion of activated natural fractures was studied. The stress increase in the direction of the minimum principal stress is much greater than the increase in the direction of the maximum principal stress. The stress increases in the direction of the maximum principal stress at the tip of the hydraulic fracture. The tip position between hydraulic fractures is "neutralized" due to the superposition of shear stress. Stress-fracture angle and the in-situ stress difference are the common main influencing factors for both tensile and shear activation, but the net pressure has little effect on the tensile activation of natural fracture. The fracture spacing has little effect on the activation of natural fractures. When formulating the fracturing scheme, we should pay more attention to the net pressure rather than the fracture spacing. This article provides a fast calculation method for the activation state of natural fractures considering the stress shadow, which provides a reference index for activating more natural fractures and increasing the production of a single well.
Integrating Pore Geometrical Characteristics for Permeability Prediction of Tight Carbonates Utilizing Artificial Intelligence
Authors: Khan Mohammad Rasheed , Kalam Shams , Abbasi Asiya 
Published: December 2021

Abstract
Accurate permeability estimation in tight carbonates is a key reservoir characterization challenge, more pronounced with heterogeneous pore structures. Experiments on large volumes of core samples are required to precisely characterize permeability in such reservoirs which means investment of large amounts of time and capital. Therefore, it is imperative that an integrated model exists that can predict field-wide permeability for un-cored sections to optimize reservoir strategies. Various studies exist with a scope to address this challenge, however, most of them lack universality in application or do not consider important carbonate geometrical features. Accordingly, this work presents a novel correlation to determine permeability of tight carbonates as a function of carbonate pore geometry utilizing a combination of machine learning and optimization algorithms.
Primarily, a Deep Learning Neural Network (NN) is constructed and further optimized to produce a data-driven permeability predictor. Customization of the model to tight-heterogenous pore-scale features is accomplished by considering key geometrical carbonate topologies, porosity, formation resistivity, pore cementation representation, characteristic pore throat diameter, pore diameter, and grain diameter. Multiple realizations are conducted spanning from a perceptron-based model to a multi-layered neural net with varying degrees of activation and transfer functions. Next, a physical equation is derived from the optimized model to provide a stand-alone equation for permeability estimation. Validation of the proposed model is conducted by graphical and statistical error analysis of model testing on unseen dataset.
A major outcome of this study is the development of a physical mathematical equation which can be used without diving into the intricacy of artificial intelligence algorithms. To evaluate performance of the new correlation, an error metric comprising of average absolute percentage error (AAPE), root mean squared error (RMSE), and correlation coefficient (CC) was used. The proposed correlation performs with low error values and gives CC more than 0.95. A possible reason for this outcome is that the machine learning algorithms can construct relationship between various non-linear inputs (for e.g., carbonate heterogeneity) and output (permeability) parameters through its inbuilt complex interaction of transfer and activation function methodologies.
Matrix Refinement in Mass Transport Across Fracture-Matrix Interface: Application to Improved Oil Recovery in Fractured Reservoirs
Authors: Alruwayi Sarah Abdullatif , Uzun Ozan , Kazemi Hossein 
Published: December 2021

Abstract
In this paper, we will show that it is highly beneficial to model dual-porosity reservoirs using matrix refinement (similar to the multiple interacting continua, MINC, of Preuss, 1985) for water displacing oil. Two practical situations are considered. The first is the effect of matrix refinement on the unsteady-state pressure solution, and the second situation is modeling water-oil, Buckley-Leverett (BL) displacement in waterflooding a fracture-dominated flow domain.
The usefulness of matrix refinement will be illustrated using a three-node refinement of individual matrix blocks. Furthermore, this model was modified to account for matrix block size variability within each grid cell (in other words, statistical distribution of matrix size within each grid cell) using a discrete matrix-block-size distribution function. The paper will include two mathematical models, one unsteady-state pressure solution of the pressure diffusivity equation for use in rate transient analysis, and a second model, the Buckley-Leverett model to track saturation changes both in the reservoir fractures and within individual matrix blocks. To illustrate the effect of matrix heterogeneity on modeling results, we used three matrix bock sizes within each computation grid and one level of grid refinement for the individual matrix blocks.
A critical issue in dual-porosity modeling is that much of the fluid interactions occur at the fracture-matrix interface. Therefore, refining the matrix block helps capture a more accurate transport of the fluid in-and-out of the matrix blocks. Our numerical results indicate that the none-refined matrix models provide only a poor approximation to saturation distribution within individual matrices. In other words, the saturation distribution is numerically dispersed; that is, no matrix refinement causes unwarranted large numerical dispersion in saturation distribution. Furthermore, matrix block size-distribution is more representative of fractured reservoirs.
Rapid Reservoir Modelling: Sketch-Based Geological Modelling with Fast Flow Diagnostics
Authors: Jacquemyn Carl , Hampson Gary J. , Jackson Matthew D. , Petrovskyy Dmytro , Geiger Sebastian , Machado Silva Julio D. , Judice Sicilia , Rahman Fazilatur , Sousa Mario Costa 
Published: December 2021

Abstract
Rapid Reservoir Modelling (RRM) is a software tool that combines geological operators and a flow diagnostics module with sketch-based interface and modelling technology. The geological operators account for all interactions of stratigraphic surfaces and ensure that the resulting 3D models are stratigraphically valid. The geological operators allow users to sketch in any order, from oldest to youngest, from large to small, or free of any prescribed order, depending on data-driven or concept-driven uncertainty in interpretation. Flow diagnostics assessment of the sketched models enforces the link between geological interpretation and flow behaviour without using time-consuming and computationally expensive workflows. Output of RRM models includes static measures of facies architecture, flow diagnostics and model elements that can be exported to industry-standard software. A deep-water case is presented to show how assessing the impact of different scenarios at a prototyping stage allows users to make informed decisions about subsequent modelling efforts and approaches. Furthermore, RRM provides a valuable method for training or to develop geological interpretation skills, in front of an outcrop or directly on subsurface data.
Investigation of Zohr Hydraulic Flying Lead Reaction Drive Shafts
Authors: Hussein Hesham , Badran Shady 
Published: December 2021

Abstract
The HFLs for the Zohr Phase 1 project contains a cobra head at each end that incorporates the female couplers and the locking mechanism. Beginning in February 2020, and with the most recent incident recorded in September 2020, a total of 4 supplied HFL reaction drive shafts (RDS) failed subsea, resulting in partial separation of the HFL cobra heads from their respective fixed stabplates with a loss of hydraulic supply pressure and subsequent automatic well shut ins. HFL failures occurred on both the XT and HIPPS side of the HFLs on 3 different well sites. A further RDS tested at the laboratory from the UTA end of an HFL showed signs of microscopic cracking consistent with the failed specimens suggesting it may have had the potential to lead to a failure in the future.
The failed HFLs were retrieved and returned onshore, the HFL locking mechanism was stripped down to gain access to the failed ends of the RDS and a visual inspection was performed. The initial inspection after partial disassembly to reveal the inside of the HFL locking mechanism identified that the RDS had completely failed at a location on the threaded portion of the RDS. Surface deposits were collected from each probe surfaces and analysed using scanning electron microscopy (SEM), together with energy- dispersive X-ray (EDX). A piece 10mm long was taken from each of the four probes for quantitative chemical analysis. Standard tensile and Charpy V-notch impact and Vickers hardness surveys have been conducted.
Each of the failed probe exhibited an intergranular fracture surface morphology. This was confirmed through metallography/EBSD. No single initiation site was located on fracture surfaces, although some regions showed a mixed fractographic morphology, with some small areas of micro-void coalescence. Secondary intergranular cracking and corrosion was apparent at various locations, in each of the failed probes, including in thread roots, in samples 183 and 188, and just above the thread, in sample 052. These observations points towards an environmentally assisted cracking mechanism (i.e. stress corrosion cracking). Metallography revealed two layers within surface films, both in cracks and on the fracture surface: an inner layer, rich in nickel, sulphur and aluminium, and an outer, rich in copper and sulphur. Mechanical testing and chemical analysis revealed consistent results across the probes.
The probe material was specified as Nibron Special (CuNi14Al3/DIN 2.1504) with a size of 2inch. Would be challenging to get the full root cause of using this material for subsea applications as it is resistant to seawater. Another factor contributed allows risk of material failure which should be eliminated for all subsea industry or taken into consideration to avoid further failures.
Using Zero-Offset VSP to Identify Interbed Multiples Generators, A Case Study from South Oman
Authors: Al Badi Othman Abderhman , Al Battashi Majid Mohammed , Al Rubaiey Amani Mohammed , Al Kharusi Elias Suleiman 
Published: December 2021

Abstract
The presence of interbed multiples is a serious concern in surface seismic processing and interpretation. Its impact is huge especially if they are masking the desirable primary reflections such as the targeted reservoirs area. The conventional demultiple methodologies such as stacking, and deconvolution often fail to suppress all the interbed multiples. Therefore, a need for other measurement is crucial to eliminate the remaining ones (Burton and Lines, 1997).
There are several approaches, data-driven or model-driven, currently available to predict the interbed multiples. However, they require an accurate identification of the multiple generators (Lesnikov and Owus, 2011). The identification of the origin of these multiples seems to be the most effective solutions to remove them, however it is not an easy task.
The allure of Zero Offset Vertical Seismic Profiles (ZOVSPs) in having the receivers placed close to the subsurface horizons, allow both upgoing and downgoing wavefields to be recordable and separable. It's the combination of short window and long window deconvolution operators which are derived based on our knowledge of downgoing wavefield which help us to determine the multiples generators at their exact depths in the subsurface.
This paper demonstrates how Zero offset VSP successfully helped to identify the major multiples generators in one of the exploratory fields in south Oman. These generators then used as an input to demultiple technique named as Extended Interbed Multiple Prediction (XIMP) that eliminates the multiples within surface seismic. As the result of the multiple elimination, the seismic to well tie tremendously improved and the reliability of the overall horizon interpretation is enhanced.
Boosting HSE Management More Efficiently and Sustainably: How Innovation Can Bring Change in Traditional HSE Mindsets?
Authors: Yonebayashi Hideharu , Kobayashi Atsushi , Hirano Susumu , Okawara Masami , Iwata Takao 
Published: December 2021

Abstract
As a part of laboratory Health, Safety and Environment (HSE) management system, the working environment control is applied to eliminate various occupational hazards for workers. This control is a continuous effort in our petroleum R&D laboratory as the working environment management system. As an element in the management system, workplace inspection has been taken into the regular HSE activity. Even traditional and well established, the workplace inspection has been continuously improved and optimized from various aspect of inspection design, inspection members selection, check list, and feedback. To make the continual improving practices more practical and effective, workplace features such as laboratory specific environment and ad-hoc research programs have been incorporated into the inspection design. All findings are summarized immediately after every inspection, and subsequently which types of risks hidden in the findings and necessary corrective actions are discussed. All of them: findings, risks, and corrective measures should be swiftly shared with all employees in the workplace. A check list format has been optimized from both aspects of easier recording by inspectors and correctly feedback to responsible personnel to take right counter measures. The paper analyses a large data of workplace inspection results in recent 10 years. The analysis reveals that hazardous sources are decreasing in recent years because of maturity of HSE culture in our laboratory. A combined cycle of inspection activity and data analysis would be useful for understanding the current status of working environment control and considering further updating plan. This paper discusses a practical example of laboratory HSE management system from both of detailed and high levels. Furthermore, a potential is discussed for a future workplace inspection using artificial intelligence and deep learning. The enterprising discussion contributes employee's traditional mindset fresh.