bluuebunny/crossref_metadata_2025_split huggingface dataset:
Prediction of Souring in Infill Wells using Standalone Extended 2D Simulator for a Malaysian Offshore Field
Authors: Salleh Intan Khalida , Panuganti Sai Ravindra , Misra Sanjay , M Ibrahim Jamal Mohamad , Hamza Norashikin , Sorbie Kenneth Stuart , Cruickshank John , Tewari Raj Deo 
Published: November 2019

Abstract
Hydrogen sulfide (H2S) production in a sea water injected, high temperature offshore reservoir is causing concern, because the existing wells and facilities are not designed for sour service. This is challenging for the design and material selection for two upcoming infill opportunities in this reservoir, which will be dictated by the reservoir souring predictions.
The reservoir under consideration is one of the major reservoirs in a prominent Malaysian offshore brown field area. The reservoir commenced production in 2002 closely followed by the start of sea water injection. Injection of the sulphate containing sea water has been known to trigger H2S production because of the activity of sulphate reducing bacteria (SRB). Understanding the need for modeling H2S generation and propagation, PETRONAS and Heriot-Watt University have jointly developed a simple standalone extended 2D reservoir souring simulator, referred to as a 2D+ Souring Model.
The 2D+ Souring Model considers two phase flow (oil and water) in the porous medium (rock formation) based on the normal multiphase flow equations. The full reservoir flows are simulated by building "panels" to connect all of the corresponding injectors and producers. Each panel is a layered cross-sectional model with different permeability layers. The geo-thermal considerations are based on heat transfer due to convection and conduction. The simulator considers bacterial growth both in planktonic and sessile forms. Monod microbial kinetics is applied for the growth of SRB and NRB, leading to the consumption of sulphate/nitrate and substrate (volatile fatty acids) which in-turn is linked to H2S generation. Along with H2S propagation, H2S scavenging by rock and H2S partitioning between the various phases is also accounted for.
This paper explains the souring simulation and H2S, oil and water production history matching conducted for the reservoir. For infill wells souring prognosis, the model is run based on parameters obtained from history matching. It provided reasonable souring predictions which have been used for the infill well material specification and design.
Review and Prospect of the Development and Field Application of China Offshore Chemical EOR Technology
Authors: Li Baozhen , Zhang Jian , Kang Xiaodong , Zhang Fengjiu , Wang Shanshan , Zhao Wenshen , Wang Xiujun , Wei Zhijie 
Published: November 2019

Abstract
The research and application of chemical EOR technology has been carried out worldwide for many years, and many theoretical and practical achievements have been obtained in China's onshore oil fields. At present, it has become one of the most important means to develop mature oilfields for stable & improved production in oilfield. Also, it has been successfully applied in China offshore oilfields as a major EOR technology. CNOOC has preliminarily established a chemical flooding (polymer, polymer-surfactant, polymer-weak-gel, etc) technology system including high-efficiency chemical flooding agents, platform injection facilities, and produced liquid treatment technology. Since 2003, pilot tests and field applications were carried out in S, L and JW oilfields, and predicted oil increment and good economic benefits have been achieved, which proved that offshore chemical EOR technology is feasible and economical. It has explored a new road for increasing the recovery of offshore oilfields, and provided a solid technical guarantee for their economic and efficient development.
Verification of Slim Ultra-deep Resistivity Inversions in a Complex Geological Environment
Authors: Clegg Nigel , Hansen Eirik , Ma Jin , Lozinsky Clint 
Published: November 2019

Abstract
Operators have used ultra-deep azimuthal resistivity tools for geostopping in landing situations and for geosteering and geomapping in horizontal wells for several years. However, their use in slim boreholes, where 4¾-in. tools are required, is a relatively new application of the technology. Operators often require ultra-deep azimuthal resistivity data, even in wells where pressure changes or stability issues require slim borehole sections to reach a target. In these scenarios, 1D inversion canvasses, which display the position of resistivity boundaries above and below the wellbore, and azimuthal resistivity images, which display changes in the resistivity to the side of the wellbore, are valuable as an aid for optimal well placement and for mapping formation and fluid changes away from the wellbore.
This paper presents early field results for a new 4¾-in. ultra-deep resistivity tool. Verification of the tool results is vital to demonstrate that design changes to accommodate the smaller diameter do not degrade the results relative to larger tool sizes, and that the tool accurately maps the resistivity profile around the well. The case history presented describes a mature field with a complex geology and a history of production and water injection, resulting in fluid boundaries that show significant displacement from their original positions and a complex morphology. It is, therefore, important to verify the ultra-deep resistivity results with multiple additional data sources, such as seismic and other established logging-while-drilling (LWD) tools.
The inversion results show a complex geological structure. Faulting, expected from the seismic data, has resulted in the displacement of formation boundaries, and sharp resistivity boundaries show the influx of water into the reservoir. These significant geological features are evident in the ultra-deep resistivity data. Other data sources, such as seismic, density, and shallow-resistivity data, help to verify the structural features and the fluid boundary positions. Evaluation of azimuthal resistivity images from the ultra-deep tool provides further reservoir understanding, because they can demonstrate that the formations dip across the wellbore and that some of the faults cross the well path at an oblique angle.
Even where the subsurface geology is very complex, as in this case study, the 1D ultra-deep resistivity inversion results successfully represented the position of formation and fluid boundaries. In addition, azimuthal resistivity data from the tool provided additional information that leads to greater reservoir understanding. There is no evidence to suggest that the smaller diameter of the 4¾-in. tool has compromised the quality of the data.
Single Phase Retarded Acid System with Degradable Fibers Unlocks Production Potential in Tuba Formation, North Kuwait
Authors: Al-Enezi Badriya , Liu Peiwu , Liu Hai , Kanneganti Kousic Theja , Aloun Samir , Al-Harbi Sultan , Al-Ibrahim Abdullah 
Published: November 2019

Abstract
A recent study showed that Tuba reservoir, a limestone-rich formation, has the highest oil in-place of all upcoming reservoirs in North Kuwait. This tight formation has three main layers - Tuba Upper (TU), Tuba Middle (TM), and Tuba Lower (TL) with several reservoir units alternating with non-pay intervals. The reservoir units contain significant proven oil reserves; however, production performance after conventional acid fracturing treatments has been historically subpar. As part of new development plan, two horizontal wells, one in TU and one in TL were drilled to evaluate the production potential of a new completion strategy and technologies.
This paper presents one such technology, a single-phase retarded acid system used as a pilot project study. In contrast with previous conventional emulsified acid systems, the single-phase retarded acid minimized tubing friction, thus enabling high pumping rates for the entire treatment. Alternating with the acid system, a viscoelastic surfactant-based leakoff control fluid system allowed the acid stages to reach deeper into the formation. To aid, degradable fiber technology was pumped in several stages to achieve near-wellbore diversion and further control leakoff into large natural fractures, thus improving the stimulated reservoir volume. These fibers are designed to completely degrade with time and temperature after the treatment. Delivery of the complex acid fracturing treatment was optimized in real time for each stage based on bottomhole pressure trend and response.
Combining a new single-phase retarded acid system with chemical diversion technology has proved to be effective in maximizing lateral coverage and etched fracture half-length. Post-treatment evaluation of TU horizontal well revealed the initial production was as much as 150% higher than offset vertical wells after conventional treatments with gelled acid and as high as 100% higher than a previous multistage horizontal well treated with emulsified acid. The TL horizontal well was just put into production recently and is showing encouraging results considering the lower reservoir quality compared to TU formation.
The success of this technique and technical combination delivered breakthrough results for this region and has engaged new interest in developing the Tuba reservoir.
Innovative Solutions to Manage Slug Buildup in Multi-Phase Pipelines through Bypass Pigging
Authors: Kollamgunta Saikiran , G.V.R.A. Srinivasa Rao , Singh Harendra , Kamal Faris Ragheb , Takieddine Oussama 
Published: November 2019

Abstract
One of the major challenges in multi-phase pipelines is to manage slug during pigging to ensure safe and smooth operation of downstream facility. The liquid slug accumulated during pigging can result in process upset, shutdown if the downstream facilities are not designed to handle the anticipated slug volume. This paper discusses the benefits of by-pass pigging to efficiently handle the slug volume resulting in optimal use of assets and without compromising the field production.
By-pass pigs are specially designed pigs with holes on the discs that allow part of the fluid to move from behind to the front of the pig. This design feature helps minimize the liquid slug accumulation in front of the pig and significantly reduces the slug volume as compared with conventional pigs. Dynamic Flow Simulator is used to analyze the performance of bypass pig. However, the use of bypass pigs involves careful assessment with respect to well fluids impurities such as presence of wax, solids or high asphaltenes which may block the holes and thus influence the operational efficiency.
The liquid slugs generated during pigging operation can cause severe operational problems in terms of level and pressure fluctuations in a separator leading to poor separation, potential liquid flooding, increased flaring, emergency shutdown and production loss. In order to minimize the slugging impact, sufficient buffer volume is provided in the slug catcher/separator to accommodate the slugs generated in the pipeline during various operations. However, considering surge volume in existing separators, Brownfield Projects can impose risk due to space constraints. To mitigate the risk, production levels are normally reduced during pigging operations leads to production deferment. However, during revamp of existing facilities for higher production capacity or changed operating conditions where existing equipment sizes impose constraints, bypass pigging has been shown to provide useful and practical solutions. This option can also useful in providing reduced slug catcher sizes for "Greenfield Facilities" as well. Very importantly, the bypass pigging operation eliminates production loss with no facility upsets. The benefits of this technique are established through transient simulations, before being adopted in facility design and operation. This paper discusses the related case studies.
This paper discusses the benefits of bypass pigging and the challenges to accommodate the increased surge volume in the existing slug catcher/separator system during pigging operation. The application of bypass pigging to limit slug volume is demonstrated using Dynamic Multiphase Flow Simulator and compares the results with conventional pigging operation. The proposed design solutions are based on NPCC's extensive and successful experience in tackling challenges in design of slug handling facilities especially in Brownfield projects.
Riser Design Automation with Machine Learning
Authors: Bhowmik Subrata , Noiray Gautier , Naik Harit 
Published: November 2019

Abstract
The objective of the paper is to investigate the optimal riser configuration through a comparison of two different riser design automation frameworks based on multi-objective optimizations using a Random Forest (RF) based metamodel coupled with Evolutionary Algorithm (RF-EA) and Radial Basis Function (RBF) based metamodel coupled with Evolutionary Algorithm (RBF-EA). The hybrid framework demonstrates the multi-objective optimization for minimizing material cost and minimizing fatigue damage along the riser.
Steel Lazy Wave Riser (SLWR) configuration is considered for the riser design optimization. The configuration consists of multiple design variables such as top angle, sag bend elevation, hog bend elevation, length of the buoyancy section, the module diameter and the layback distance. The riser configuration optimization is time-consuming and exhaustive due to nonlinear time domain analysis and due to a large number of load cases for extreme load and fatigue load analysis. Metamodel for the riser is the alternative option to use in the optimization algorithm instead of Final Element (FE) model for the dynamic analysis of the riser. Two different machine learning approaches, i.e. RF and RBF are used to develop the metamodels and coupled with Evolutionary Algorithm (EA) to form hybrid optimization method. Both the methodologies minimise both the riser cost and fatigue damage of the SLWR. Therefore, both the methodologies generate the optimal solutions which shows how design changes impact the trade-off between these two diffrent objectives. RF-EA provides a comparatively better configuration compared with RBF-EA.
The riser design optimization using machine learning assisted metamodel can save considerable computational time and require less need for design experience.
Exploration Challenges in the Northern Emirates: A UniQ Approach to Structural Definition
Authors: Trezzi Stefano , Glushchenko Anna , Vasilyev Pavel , Al Bulushi Abdullah Mubarak , Cox Edward , Al Hamadi Masoud Ahmed , Stewart Neil 
Published: November 2019

Abstract
This study summarizes the efforts taken to provide reliable structural delineations offshore the northern United Arab Emirates, an area where previous attempts failed to provide purposeful results.
With the employment of latest acquisition and processing techniques, a new high-density full azimuth volume shows clear uplift over legacy results. Structures never detected before are imaged, contributing to the de-risking of future well placement. These results are indicative of the challenges when acquiring and processing seismic data in the Northern Emirates.
The use of latest technologies was required to overcome several geophysical challenges, such as complex near surface, near-vertical thrust sequences and multiple faulting planes. All these elements contributed in generating extreme noise contamination, where a fast-varying geology with high dips made separation of primaries from noise one of the most difficult tasks.
Key pre-imaging technologies such as near surface characterization, 5D regularization to radial symmetry, as well as a tomographic velocity model building approach with iterative inputs from interpreters have been fundamental to converge to a solid velocity model that allows for a reliable structural imaging.
The work is particularly relevant for offshore exploration targets in the Northern Emirates, a region that has recently seen a growth in interest from local and international operators.
Reducing Pipeline Maintenance Costs, Time, and Resources Through Nonintrusive Diagnostics
Authors: Stewart Neil , Jack Graham 
Published: November 2019

Abstract
Maintaining pipelines in optimum condition is a costly and time-consuming process for operators, which requires many resources. To help ensure an asset remains in a good operational state, it is necessary to understand its condition to allow it to be maintained in an efficient and cost-effective manner. Current methods for deposit assessment are limited to intrusive methods, theoretical modeling, or external measurement. This paper details a compressive solution to these challenges using pressure wave analysis.
The method is based on analyzing the signal response generated by a pressure wave transiting the system as it is affected by geometrical changes in the system. By capturing high resolution pressure measurement on an ultrahigh speed logger, the generated pressure wave can be recorded for analysis. Applying acoustic velocity gradient modeling in conjunction with the effect of the of the system and the fluid parameters, the profile of the internal bore of the system can be accurately determined without the use of intrusive or localized external tools.
Detailed is how the theory behind the method is confirmed by results observed when used during a controlled full-scale field-trial environment in addition to subsequent activities to survey system profiles. A case study is presented, demonstrating that the method allows operators to make decisive asset performance decisions and review deposit buildup in a safe and cost-effective manner without having to stop production. The theoretical method for calculation of acoustic velocity for known system and fluid parameters is shown to be accurate within tolerances compared to the acoustic velocity gained in the field by recording the time of flight between two known points. It is demonstrated that restrictions can be detected to a level of accuracy of plus or minus three millimeters of thickness, verified by comparison with other inspection methods.
The described is a unique method for determining the internal profile of systems, which can offer significant advantages from traditional bore determination methods. It can provide information in a repeatable and verified level of accuracy without the requirement for expensive and time consuming intrusive intervention, this allows operators the opportunity to target remediation work in the most efficient and cost effective manner, therefore maximizing production uptime and throughput.
Geological Facies and Static Rock Types in a Highly Heterogeneous Lower Cretaceous Carbonate Reservoir from an Onshore Field in Abu Dhabi, UAE
Authors: De Benedictis Dario , Al Maskari Shaymaa , Al Hashmi Noor 
Published: November 2019

Abstract
A Lower Cretaceous reservoir in one of the Abu Dhabi onshore oilfields is the focus of this study aimed 1) to understand, predict and distribute the impact of diagenesis on the reservoir quality, and 2) to define the reservoir Static Rock Types (SRT). This will eventually help to define and predict the reservoir flow units to better frame strategies and choices for reservoir static and dynamic modelling, and to support the decision-making process for the oilfield business plan.
A fully integrated geological-petrophysical approach was used to carry out the study.
Nine geological facies are recognized in the reservoir and grouped in four main reservoir facies categories: 1) rudist-bearing facies, 2) grain-supported skeletal and Orbitolinid facies, 3) Bacinella/Lithocodium-coral facies, and 4) mudstone-supported facies. Rudist-bearing and Bacinella/Lithocodium-coral facies represent the best reservoir facies.
Rudist deposits mainly formed stacked patches- or sheet-like accumulations of reworked skeletal debris on platform top settings in the northeast of the field. In the main reservoir section, geological facies distribution mainly follows the hydrodynamic trend of the depositional settings. Rudist facies properties primarily depend on the depositional texture and the original shell mineralogy and structure (e.g. Caprinids vs. Caprotinids-Requienids).
Bacinella/Lithocodium-coral deposits form stacked shallowing-up peritidal cycles, representing the genetic units of the lower section of the reservoir. Evidences of epikarst in the uppermost cycles indicate the location of a major sequence boundary correlatable also to neighboring fields.
The impact of diagenesis appears strongly driven by the depositional facies characteristics, and a paragenetic sequence is proposed for this reservoir.
A link between geological facies features, including original grain mineralogy and depositional settings, and reservoir quality parameters is established, allowing the prediction and distribution of reservoir properties in the reservoir laterally and stratigraphically.
Seven SRTs are identified by integrating geological observations and the result of the petrophysical synthesis. SRTs definition closely follows the reservoir stratigraphic framework, allowing creating a two-fold scheme: two SRTs characterize the cyclic peritidal deposits of the Bacinella/Lithocodium-coral section, and five SRTs are identified in the upper rudist-rich section. Petrophysical evidences from MICP data also strongly support this approach.
A refined geological concept and stratigraphic framework is proposed for the reservoir to integrate the results of the sedimentological/petrographic analysis and petrophysical synthesis.
Through linking geology and petrophysics, a new robust scheme of SRTs is created to enhance the identification and prediction of the reservoir flow units.