bluuebunny/crossref_metadata_2025_split huggingface dataset:
Assessment of Condensate Banking Growth Using Advanced Pressure Transient Analysis
Authors: Al Khamees Ali , Phillips Guerrero Rodolfo , Alodah Meshari 
Published: March 2023

Abstract
Condensate banking is a process that occurs in gas wells when the reservoir pressure goes below the dew point. The depletion process introduces an additional fluid complexity, which complicates reservoir dynamics and reduces ultimate recovery. In addition, it hinders well performance and productivity due to its growth over production time.
Estimating the current extent of condensate banking and predicting its progression over time plays a major role in optimizing well performance. Using single-phase pressure transient analysis to account for different mobility regions is widely practiced across the industry. However, a non-linear model must be utilized for the conditions where more than one phase exists, such as in gas condensate reservoirs. The model should consider non-linearities such as relative permeability curves for multi-phase systems, and pressure-dependent PVT properties such as viscosity, condensate gas ratio, and fluid compressibility.
Non-linear modeling provides an accurate estimation of the different characteristic regions caused by condensate banking in terms of distance, mobility, and saturation variations, ensuring proper reservoir characterization. Additionally, with the utilization of test design function, non-linear modeling predicts condensate banking development, giving a precious indication of future well and reservoir conditions. The deployment of the advanced non-linear model in the pressure transient analysis (PTA) results in reasonable estimations of condensate banking distance from these wells. Finally, the results of the non-linear method highlighted the difference when compared to single-phase models, showcasing the importance of mimicking actual well and reservoir multi-phase conditions properly.
In this study, we will illustrate pressure transient analysis test designs in condensate reservoirs, highlighting the condensate banking effect on the well performance and the extent estimation of the fluid bank utilizing a non-linear modeling approach as an aid in optimizing well performance.
Critically Stressed Faults and Fractures Analysis
Authors: Alhasan Abdullah , Qahtani Yahya 
Published: March 2023

Abstract
Critical stress analysis is one of the approaches for assessing reservoir quality, and it enhances understanding of the seal capacity and migration pathways in a petroleum system. It also helps identify fractures with high and low conductivity. This analysis assesses the effect of principal stresses to reveal faults that are critically stressed and stable.
Faults were interpreted manually using seismic and other volumetric attributes such as the variance and the ant-track. Principal stresses and fault stress parameters were extracted from mechanical earth models in the area. These faults, along with the principal stresses, were then used as input for a fault stress analysis tool to measure how stressed the faults are. The analysis incorporated depth dependence as the overburden was one of the main parameters affecting the outcome of the study. Finally, the results of the study were calibrated using real-time data such as drilling events from several wells drilled in the area.
With increasing depth, the additional pressure needed for faults and fractures to reach failure increases accordingly. This is expected when considering the overburden effect. Thus, this analysis is considered highly dependent on depth. The shallowest formation showed the highest number of critically stressed faults, while other formations have lower numbers as the depth is increased until there is an insignificant number of stressed faults in the deep formations. In the shallow formations, moreover, the required pressure to fail is insignificant as the overburden stress is low. Furthermore, faults and fractures were expected to require substantial pressure to be critically stressed in the deep formations, and are observed to be considerably stable. Another important factor was the maximum horizontal stress. On the one hand, it helps keep faults open if they are parallel to it, and thus they require substantially less pressure to be conductive. On the other hand, it acts to close those that are perpendicular to it making them much more stable. Thus, the amount of pressure the fault needs to be critically stressed is significantly increased. Finally, the results of the critical stress analysis were validated via real-time well data such as drilling reports.
The objective of this project was to assess and understand faults and fractures in terms of their stress state by analyzing the principal stresses acting on them. This would highly assist in understanding the seal capacity and migration pathways. To sum up, this analysis aids the assessment of the reservoir quality.
An Enhanced Synergistic Effect in Surfactant-Polymer Flooding Under High-Temperature and High-Salinity Conditions
Authors: Chen Shaohua , Huang Tianping , Han Ming , AlSofi Abdulkareem 
Published: March 2023

Abstract
Two hydrophobically associating polyacrylamide (HAPAM) polymers were synthesized through free-radical micellar polymerization using different hydrophobic monomers. One polymer product – HAPAM-1 contains a linear alkyl chain, and the other one HAPAM-2 bears an aromatic group which is more compact comparing the alkyl hydrocarbons. The properties of both polymer solutions were investigated in high-salinity water (HSW). The interaction between the polymers and a non-ionic surfactant – dodecyl glucopyranoside (DDG) was studied in the HSW at 50 °C using formulations composed of 2 g/L polymer and a series of DDG concentrations. The polymer solutions exhibited a Newtonian plateau at lower shear rates followed by a significant shear-thinning region at higher shear rates. HAPAM-1 exhibited a more pronounced shear-thinning effect than HAPAM-2 due to more rigid hydrophobic junctions self-assembled by the aromatic groups. Upon addition of DDG, the zero-shear viscosities of polymer solutions were found to peak at 15 mg/L of DDG concentration to both polymer solutions. The interfacial tension (IFT) between oil and water obtained from HAPAM-2/DDG solution was lower than that of the DDG solution without polymer, suggesting a synergistic effect between HAPAM-2 and DDG which further reduced IFT. However, the IFT of DDG solution was not affected in the presence of HAPAM-1. Micromodel experiments indicated that the oil production efficiency by initial HSW injection was quite low, then displacement of residual oil was dramatically improved by injection of HAPAM-1/DDG or HAPAM-2/DDG solution. Extended HSW flooding slightly increased the oil production for both chemical flooding systems. The performance of HAPAM-2/DDG in oil displacement was better than HAPAM-1/DDG, which could be attributed to the higher solution viscosity and lower IFT resulting from more pronounced interaction between HAPAM-2 and DDG. This study aims at probing the effect of different types of hydrophobic units on surfactant-polymer interaction and correlating such interaction with the effectiveness on improving oil production by oil displacement in a porous media.
CO2 Huff-n-Puff: An Experimental and Modeling Approach to Delineate Mass Transfer and Recovery from Shale Cores
Authors: Alahmari Saeed , Raslan Mohammed , Khodaparast Pooya , Gupta Anuj , Duncan Jewel , Althaus Stacey , Jessen Kristian 
Published: March 2023

Abstract
Gas injection has been demonstrated to be an effective approach to enhance recovery from ultra-tight fractured reservoirs where the role of molecular diffusion often becomes dominant. The open literature offers a large collection of work concerned with gas injection studies and projects, employing carbon dioxide (CO2), methane (CH4) and other gases, and reports a considerable improvement in oil recovery over primary production. CO2 injection has an additional advantage over other gases through the potential for geological sequestration. This explains the growing interest in studying diffusive mass transfer during CO2 injection to delineate the sequestration potential in concert with enhanced oil recovery from unconventional resources. However, additional work is needed to arrive at a comprehensive understanding and representation of diffusive mass transfer in ultra-tight fractured formations.
In this paper, we study diffusive mass transfer in shale cores by conducting and simulating CO2 Huff-n-Puff (HnP) experiments at high pressure and temperature. Two cores from a formation in the Middle East were evacuated and then saturated at 3500 psi and 50°C with a synthetic oil consisting of decane (nC10), dodecane (nC12), tetradecane (nC14) and hexadecane (nC16). We performed multiple HnP cycles at varying injection conditions: 2900-4000 psi and 70 °C. Diffusive mass transfer was then investigated via (1) evaluating the effect of injection pressure on oil recovery, (2) analyzing produced oil compositions, and (3) studying the pressure decline during the soaking period.
Our experimental observations show that a higher oil recovery is achieved when injecting at a higher pressure. We also observe that molecular diffusion acts as a dominant recovery mechanism in the HnP experiments, as evident from analyzing the produced oil composition and from examining the pressure behavior versus time during the soaking periods: The observed decline rate in the pressure during soaking signify that molecular diffusion dictates the mass transfer during the HnP experiments. Additionally, we note that miscibility conditions will change from one HnP cycle to another, as the injected gas mixes with an oil composition that changes between cycles.
We have used the CMG-GEM compositional simulator to interpret the HnP experimental results. When multicomponent diffusion coefficients were computed using the correlation of Sigmund (1976) the simulator is unable to provide a reasonable prediction of oil recovery and produced oil compositions. To achieve a better prediction of diffusive mass transfer in ultra-tight fractured reservoirs, a representation that is based on a more fundamental description of the multicomponent diffusion coefficients is hence required, as discussed in-depth by Alahmari and Jessen (2021) and Shi et. al. (2022).
Multidiscipline Well Construction Process Integrates Advanced Engineering Design and MSF Technologies to Deliver Arabian Gulf Trilateral Well
Authors: Adewuya Opeyemi , Alqurashi Mahmoud , Urbina-Arias Rommel , Alodah Faisal 
Published: March 2023

Abstract
The use of multilateral well designs and architectures have progressed significantly since the introduction nearly three decades ago. It has become the de-facto approach for unlocking incremental production performance and increasing drainage density in sands and limestone reservoirs. The tri-lateral well featured in this paper is a TAML Level-2 design with each 6000 ft lateral geosteered and completed by running open-hole packers equipped with ball-activated frac-ports and sleeves on a non-cemented liner hanger system in the motherbore and drop-off systems in laterals-1 and 2. The pre-drill exercise encompassed technical considerations to determine from ---- reservoir type to well architecture, MSF technology, modelling for fracture stimulation effectiveness and well construction techniques --- to ensure success.
Beyond established reservoir development strategies such as Maximum Reservoir Contact (MRC), the robustness and effectiveness of directed stimulation fluid to achieve frac stage deep acid stimulation at design pressures requires open-hole stage isolation technologies and devices that enable confirmation of completion of treatment operation. Additionally, working from bottoms-up, junction construction, debris management, securing well integrity during whipstock installation, window milling and whipstock retrieval are operational phases that pose significant challenge and risk to loss of well.
The collaboration between Multilateral equipment design and engineering companies and Operators focus on simplifying junction construction, High frac pressure Open-hole packers as well as affirmative frac port open and close surface indicators. Innovative engineering solutions has produced advanced open-hole isolation and completion hardware and material science developments are offering path clean-up and unobstructed reservoir fluid flow after stage stimulation.
The integration of the latest multilateral construction technologies and techniques for ensuring mission-critical objectives leverages a multidiscipline collaboration approach to ensure well delivery and reservoir performance. Critical success factors discussed in this paper are, 1. Tri-lateral wellbore construction and recovery of junction construction devices, 2. Running and setting lower completion string, 3. Operating stage isolation devices and effective stimulation of each stage guided by advanced frac-stimulation modelling analysis and 4. Unrestricted reservoir flow through lower completion flow control devices.
Perforation Design and Gun Selection Workflow – A Successful Case History for Deep Penetrating Gun
Authors: Samy Ayman , Gilliat Jim , Khalilov Ruslan , Pashayev Nariman , Mammadov Rufat , Akbarov Akbar , Bahalov Elmar , Allahverdiyev Maarif 
Published: March 2023

Abstract
Perforation design including gun size, type, charge weight, configuration (shot density, entrance hole, phasing) and deployment options can significantly impact well productivity post perforation. Gun selection is a key process to ensure that the optimum gun that can yield maximum well productivity and minimum skin due to perforation has been considered. Gun performance modelling and sensitivity analysis should be conducted to compare the performance of various guns and to select the optimum gun suitable for well and reservoir conditions.
Gun performance under downhole condition is a complex process and uncertainty analysis should be considered when converting API gun test data into downhole condition. It is always preferred to use stressed-core test data such as API section II/IV. However, data analysis and alteration might still be required to replicate the exact downhole condition.
This paper presents a successful case history of perforating 130 m in a single coiled tubing conveyed run using Live Well Deployment system in 6,000-m deep gas and condensate reservoir with an average permeability of 10 mD and reservoir pressure of 12,500 psi. Production has increased by 20% compared to reference wells due to the intensive perforation testing and design process conducted to this well prior to operation.
Extensive modelling work has been conducted to evaluate the performance of deep penetrating guns compared to conventional guns, in addition to uncertainty analysis and risk assessment regarding the impact of using API section-I compared to Section-II/IV data. The paper demonstrates a robust workflow for gun selection and gun performance evaluation process, which can be used as guideline to perforation design process.
Fit-For-Purpose Model for Dielectric Data Interpretation for Enhanced Formation Evaluation
Authors: Abdallah Wael , AlZoukani Ahmed , Al Hamad Mohammed , Ma Shouxiang 
Published: March 2023

Abstract
Great progress in technology development of dielectric logging has been made in the last decade, mainly by establishing the capability of multi-frequency measurements for more robust determination of near wellbore water-filled porosity and flush zone resistivity, in addition in providing the potential of characterizing reservoir petrophysical properties such as rock tortuosity. To interpret acquired dielectric data, several models have been developed and used in the industry. The objective of this laboratory study was to evaluate the commonly used models, identify conditions under which each model is applicable, and establish a workflow to select the most suitable model for targeted applications.
This study was performed on limestone core samples. Routine and special core analysis including resistivity and dielectric measurements were conducted. Three commonly used dielectric models (CRIM, Bimodal, and SMD) were evaluated. Properties having major influence on these models are brine salinity, brine saturation, and Archie parameters m and n. Effects of these properties on the dielectric data interpretation models were studied systematically, by comparing the models’ outputs to direct laboratory measurements. For core samples fully saturated with fresh water of salinity ranging from 2 to 23 kppm NaCl, all three models provide consistent results of inverted water-filled porosity when compared with core weight porosity. The inversion results are robust and independent of whether the salinity is constrained or not. In a saline environment of 200 kppm NaCl, the inverted water-filled porosities are found to be slightly higher than core porosity. Comparing between inverted dielectric textural parameter MN and Archie resistivity parameter m shows that the Bimodal model performs better than the SMD model at this high-water salinity environment.
Based on these results, a simple linear regression correction scheme is proposed for each salinity range investigated. The proposed algorithm is structured to correct the output of each model using statistical mean at specific salinity conditions. Finally, we introduce a fit-for-purpose model selection for dielectric data interpretation for enhanced formation evaluation.
Estimation of Missing Molecular Weight and Specific Gravity of Heptane Plus Fraction in PVT Laboratory Report
Authors: Al-Marhoun Muhammad 
Published: March 2023

Abstract
The molecular weight and specific gravity of heptane plus fractions (C7+) are essential in characterizing crude oils. The hydrocarbon analysis of reservoir fluid test usually reports molecular weight and specific gravity of C7+ in the PVT report. Sometimes these values are missing; therefore, estimating them is crucial. This study aims to develop new empirical correlations to estimate the missing molecular weight and specific gravity of the C7+. The experimentally measured hydrocarbon analysis of reservoir fluid tests from the Middle East crudes is the basis for developing the correlations. The input parameters for the correlations are available molecular weight, the specific gravity of C7+, and stock tank oil-specific gravity. The newly developed correlations outperform the existing correlations based on high correlation coefficients and low values of average absolute percent relative error and standard deviation.
Operational and Logistical Optimizations in Large Offshore Matrix Acid Stimulations
Authors: Saleh A. A. , Bukhamseen R. , Jaber A. A. , Almazrou A. H. 
Published: March 2023

Abstract
Objectives/Scope: This paper addresses the complex logistical challenges associated with the planning and execution of a large-scale offshore matrix acid stimulation treatments job performed on a small workover rig. It captures the challenges and the smart solutions deployed as an example, and quantitatively reflects on how the adopted solutions improved the operations in terms of achieving the technical objectives, minimizing job duration, rig space utilization and safety.
Methods, Procedures, Process: Offshore acid stimulation complexity rapidly multiplies whenever larger volumes of acid are involved. Our example reviews an offshore matrix acid stimulation where, for the first time within the region, more than 1300 Bbl of acid treatment was placed across a reservoir in an offshore workover rig, while a typical offshore workover rig matrix acid stimulation will not exceed 300 Bbl treatment. To address the challenges associated with such large offshore matrix acid stimulation jobs, a number of key methodologies were adopted. Most importantly, tailored fit measurements of available rig space and choosing the most suitable equipment's layout and acid tanks having the required dimensions, capacity and weights, were all, of crucial importance considering the limited workover rig space with other CTU and N2 services also present.
Results, Observations, Conclusions: A unique and complex offshore matrix acid stimulation treatment was successfully completed where 1326 Bbl of acid treatment was pumped across target reservoir with zero hours NPT and zero LTI. Careful planning, strong communications and close coordination between all parties involved were the fundamental elements to the success of this operation. It was also noted that selective premixing of chemicals at service company base enabled further optimizing of rig space utilization and a reduction of operational risks and rig time. Hence it can be concluded that with proper planning and careful consideration of the details, such large offshore matrix acid stimulation jobs can be more frequently deployed in offshore workover rigs which will have positive impact on well productivity and performance.
Novel/Additive Information: This large-scale offshore matrix acid stimulation treatment job was a first of its kind within the region in terms of job complexity and acid volumes, it is a good reference to many lessons learned and it opens the door for a new and wider horizon of applications for offshore matrix acid stimulation technologies.
Reservoir Simulation Evaluation of Cyclic Steam Stimulation Strategies in Tayarat Carbonate Heavy Oil Reservoir
Authors: Evro Solomon , Alshamali Adnan , AL-Faresi Fahad , Mishari Al-Qattan , Al-Ostad Nejoud , Krasnova Galina , Hayat Laila , Suresh andana , Mandani Hasan , Jimenez Carlos , Ali Sher 
Published: March 2023

Abstract
The Tayarat formation extends over a large area; this formation has a diverse and complex geology and has heavy oil fluid system. A previous review of the analogous technologies that apply to the Tayarat heavy oil formation shows that it would be economically impossible to deploy a single reservoir development technology in all the areas of the field. In this project, we evaluated cyclic steam stimulation strategies focusing on applying different well completions.
We have applied a compositional numerical simulation model using CMG Stars to investigate the application of different cyclic steam stimulation strategies. This includes using a traditional vertical well with a single steam injection point in the entire zone of the reservoir. We also investigated the use of vertical wells with dual string completion, where the short string injected into the upper parts of the formation while the long string injected into the lower part of the reservoir. With the horizontal well injection, we investigated open-hole completion and the case of using a horizontal well with multi-stage hydraulic fracturing.
The potential of injecting steam at a higher rate with horizontal wells is attractive and requires more investigation. Apart from reducing the well count, we could overcome the surface constraints challenge in the field by stepping out of the congested areas and placing the horizontal section in the targeted part of the formation. With the advances in horizontal wells with multi-stage hydraulic fracturing in the industry, carbonate reservoirs such as Tayarat with low permeability could benefit from more reservoirs contact and possibly better steam distribution if we introduce adequate hydraulic fracture stimulation in the formation.
The results of this study show that we could reduce our drilling footprint substantially by implementing a horizontal well with multi-stage hydraulic fracture stimulation in developing parts of the Tayarat carbonate heavy oil reservoir. Cyclic steam injection with vertical wells completed with dual strings shows a production advantage over a similar vertical well completed with a single string in similar zones. At the same time, horizontal wells with multi-stage hydraulic fracturing stimulation offer marginal benefits. The risk of increased hydraulic stimulation costs could undermine the value created by horizontal drilling and completion.