bluuebunny/crossref_metadata_2025 huggingface dataset:
Integrated High Resolution 3D Model Update in Challenging Mauddud Carbonates, Raudhatain Field, North Kuwait
Authors: Jesudian David Nelson , Coronado Jose Gregorio , Al-Abboud Nour Esam
Published: October 2019

Mauddud Formation is a major oil-producing reservoir in Raudhatain Field of North Kuwait. The Mauddud Formation is an early Albian in age and it was generated an environment of the shallow-water carbonate and consists of Grainstones, Wackestones and Mudstones deposited in ramp settings. In Raudhatain field (RAMA) is undertaking massive development efforts with planned enhancement in Oil production. Reservoir description and distribution of rock properties in 3D space are challenging due to inherent reservoir heterogeneity, in this case primarily driven by depositional and diagenetic patterns.

KOC North Kuwait Reservoir Studies Team (NK RST) has been challenged to increase the production from several key NK oil fields. To achieve this goal, KOC has partnered with Schlumberger to rebuild integrated model with Petrophysics, Geophysics, and Geology and Reservoir data of the Mauddud Reservoir. The original model was required to minimize challenges in new infill locations, increase Oil recovery factor and detect water breakthrough to minimize water production. One of the key issues in creating RAMA reservoir model is integration of all available data in identifying the horizontal permeability, reservoir heterogeneity and identification of thief zones.

A fine Geological grid model with 35M cells, 10 Geological horizons has been built to characterize the Mauddud reservoirs of the RAMA field including the permeability from PLT logs combined with petrophysical and lithological / facies data to add more understanding of the distribution of reservoir properties. Log response group methodology and the undeveloped area in the Saddle (structurally low area) has been modelled for the first time in Raudhatain NK Field. This combined study utilizes the available data and cutting-edge technology using Geo2Flow which resulted in fluid compartmentalization and free water level identification. STOOIP has been upgraded and unlocking potential in new segments of the developed field. The original model was built based on vertical/Deviation wells (345) which lead to discrepancies in the structural interpretation. The new update has been carried out including all horizontal wells to minimize the uncertainty in the structure framework.
A Truly Integrated Wells, Flowline Networks and Process Facilities Model for the Greater Burgan Oilfield
Authors: Al Jadi Issa A. , Desai Sameer Faisal , Al-Ghanim Wafaa , Al-Wazzan Roqaya M. , Al Sabea Salem H. , Al Haddad Saud M. , Franco Francy Milena , Khor Siew Hiang , Saxena Aditya , Zhang Qiong Michael , Hapsari Hairuni Safri , Elayaat Ahmed A.Fouad. , Bodwadkar Suhas V.
Published: October 2019

A proven and effective integrated asset modelling (IAM) approach has been adopted to bring multiple interdependent wells, pipelines networks, and process facilities models together into one single truly integrated asset model for the Greater Burgan Oilfield in Kuwait. The integrated wells-network facility models via the IAM platform also includes a water processing facility model which consists of 2 effluent water disposal plants; a crude oil export pipeline network and a water reinjection network model.

This paper describes how a representative integrated asset model was developed for the Greater Burgan Oilfield through a model centric approach executed within an Integrated Operational Excellence (IOX) Program towards a Digital Transformation initiative by Kuwait Oil Company (KOC) South and East Kuwait (S&EK) Group together with Schlumberger. It also describes how this tool enables the asset teams to evaluate different operating scenarios to further enhance well performance and the overall asset productivity via re-routing well flow path to an appropriate header, identifying well workover opportunities, re-evaluating artificial lift design, adding future wells (for field development) and comprehensive understanding of well integrity and flow assurance studies. The assessment was done not only at a gathering center (GC) level but also asset-wide level where the complete system constraints, interactions and back pressure effects between more than 2000 different wells were fully accounted. The simulated results such as pressure gradient, temperature gradient and erosional velocity ratio gradient across the production networks are presented on the GIS map for easy opportunity identification.

The availability of this fully integrated asset model with up-to date calibrated wells and network models and process models enables KOC engineers to better understand current well performance and production potential, identify any possible bottlenecks imposed by the large complex surface network and process facilities of Greater Burgan Oilfield.

The scope of IAM enablement for the Greater Burgan was to develop an integrated wells-network-facility-crude export-water processing facility-water reinjection network model consisting of all the 14 gathering centers existing in S&EK asset, providing all the essential valuable inputs to business processes for better asset management, faster and more accurate decision-making and breaking the barrier of hydrocarbon flow path from sand face till the export point. In the future, this truly integrated asset model can be coupled to the Greater Burgan reservoir model for comprehensive field development studies.
Improved Interpretation of Single-Well-Chemical-Tracer for Low Salinity and Polymer Flooding
Authors: Kazemi Nia Korrani Aboulghasem , Jerauld Gary , Al-Qattan Abrar
Published: October 2019

We interpreted a series of single-well-chemical-tracer-tests (SWCTTs) estimating residual oil (SORW) to base high salinity waterflood, low salinity waterflood and subsequent polymer flood conducted on a Greater Burgan well. Interpretation of the tests requires history matching of the back-production of partitioning and non-partitioning tracers which is impacted by differing amounts of irreversible flow and differing amounts of dispersion as well as the amount of residual oil.

We applied the state-of-the-art chemical reservoir simulator (UTCHEM) and an assisted history matching tool (BP’s Top-Down-Reservoir-Modeling) to interpret the tests and accurately quantify uncertainty in residual oil saturations post high salinity, low salinity, and polymer floods. Two optimization algorithms (i.e., Genetic algorithm (GA) and Particle-Swarm-Optimization (PSO)-Mesh-Adaptive-Direct-Search (MADS) algorithms) were applied to better address the uncertainty.

Our results show a six saturation unit decrease in SORW post low salinity with no change to the SORW post polymer. This is in-line with our expectations - we expect no change in SORW post-polymer as the conventional HPAM, which does not exhibit visco-elastic behavior, was used in the test. We demonstrate that history matching the back-produced tracer profiles is a robust approach to estimate the SORW by showing that three-or four-layer simulation model assumption does not change the SORW estimated. We accounted for the uncertainty in partition-coefficient in our uncertainty estimates.

We present several innovations that improve history matching back-produced tracer profiles; hence, better SORW estimations (e.g., different level of dispersivity for individual simulation layers to account for different heterogeneity level as opposed to assuming a single dispersion for all layers). We generate more robust estimates of uncertainty by finding a range of alternative history matches all of which are consistent with the measured data.
A New Approach for Rock Typing Using Dimensional Analysis: A Case Study of Carbonate Reservoir
Authors: Abdullah Mohammad , Garrouch Ali
Published: October 2019

In recent years, Petrophysicists have established that rock typing is an essential pre-requisite for estimating permeability in reservoir rocks. Any attempt that does not use rock typing for modeling permeability has been documented to be characterized by a large data scatter and associated with high uncertainty.

In this paper, four common rock typing techniques are compared: Pittman, Lucia, Flow Zone Indicator (FZI), and Global Hydraulic Element (GHE). The performance of these rock typing approaches is assessed through intrinsic models for their ability to predict the permeability of a prominent carbonate field. The FZI and the Pittman approaches gave the best estimates of permeability with a coefficient of determination of approximately 0.98. By contrast, the Lucia approach gave the least precise estimates of permeability with a coefficient of determination of 0.81. The GHE approach gave a satisfactory estimation with a coefficient of determination of 0.90.

A new technique for rock typing, based on dimensional analysis, is presented. Dimensional analysis leads to the derivation of two dimensionless groups: (λ) and (Ω). The λ group is a dimensionless Flow Zone Indicator (FZI) and the (Ω) group is the dimensionless photo-electric adsorption. The main advantage of the dimensional analysis technique is that it relies directly on open hole log measurements, such as the spontaneous potential, bulk density, interval transit time, and photoelectric absorption. A unique power-law relationship exists between the dimensionless FZI group (λ), and the dimensionless photo-electric adsorption group (Ω). For the studied carbonate field, a coefficient of determination of 0.98 was obtained when estimating reservoir permeability with the dimensional analysis rock typing.

This paper will be of interest to subsurface modelers who need to estimate permeability. Using the dimensional analysis approach described and comparing this new method of estimation with established methods, it is proposed that rock typing by dimensional analysis for estimating permeability can be used as an alternative method.
Thermodynamic and Kinetic Investigation of Water Absorption by PAM Composite Hydrogel
Authors: Krishnan Mohan , Michal Feven , Alsoughayer Shahla , Almohsin Ayman , Alsharaeh Edreese
Published: October 2019

In this study, we report the thermodynamics and kinetic parameters for the water absorption by thermo-elastic and self-healing polyacrylamide-commercial graphene (PAM-CG) composite hydrogels. The fundamental studies for such self-healing hydrogels would give us useful insights towards the material design for a specific application. The PAM-CG composite hydrogels were prepared by a two-step method consisting of the synthesis of PAM-CG polymer via inverse emulsion polymerization followed by the preparation of PAM-CG hydrogel by in-situ mixing. The thermal and rheological properties of the composite hydrogels were examined by using thermogravimetric analyzer (TGA), and differential scanning calorimetry (DSC). In addition, the swelling kinetics of the prepared hydrogels were studied as a function of temperature. From the obtained kinetic curves, the hydrogel can absorb water upto 16,000% at 25°C and reaches the saturation in 30 h. Meanwhile, the increase in temperature of the system would result in an overall decrease in the water uptake for the hydrogel. The experimental kinetic data were found to fit in pseudo second-order kinetic model. The calculated free energy (∆G) values are negative and hence the water absorption by the composite hydrogels is spontaneous. The positive enthalpy (∆H) values are indicative of exothermic behavior. The negative entropy (∆S) (i.e. decrease in degree of freedom), values are in line with absorption phenomenon of water molecules by the composite hydrogels. In addition, the PAM-CG hydrogels exhibit excellent recyclability upto eight consecutive cycles.
One-Stage Calcium Carbonate Oil-Based Filter Cake Removal Using a New Biodegradable Acid System
Authors: Mohamed Abdelmjeed , Elkatatny Salaheldin , Basfar Salem
Published: October 2019

Removal of oil-based filter cake is a complex task especially in horizontal and multilateral wells. The presence of oil makes the removal process more challenging because the oil surrounds the weighting materials and prevents acid-filter cake interaction. Therefore, different additives are required to change the wettability of the filter cake to enhance the removal efficiency. This paper introduces a new biodegradable acid system (NBAS) that can efficiently remove oil-based filter cake in horizontal and multilateral wells where calcium carbonate is used as weighting agent.

The new biodegradable acid system (NBAS) consists of 50 vol.% biodegradable acid and 5 vol.% mutual solvent. HPHT filtration experiments were performed to evaluate the filter cake removal efficiency and the retained permeability. The filtration and removal experiments were conducted on real core samples (Indiana limestone and Berea sandstone) at a temperature of 212°F and 300 psi differential pressure. Afterwards, the NBAS was evaluated by measuring physical properties and conducting corrosion, compatibility and thermal stability studies.

The obtained results showed that the NBAS was compatible and thermally stable for more than 48 hrs at 212°F and 300 psi. The NBAS has a density of 1.05 g/cm3, viscosity of 1.47 cP, and surface tension of 32 dynes/cm at room temperature. The corrosion rate of the developed system was 0.03 lb/ft2 which is acceptable according to oil and gas industry practices. Removal experiments showed that filter cake was completely removed from the core samples. For Berea sandstone, 100% of the permeability was regained while the retained permeability for Indiana limestone was 122.5% confirming the complete removal of external and internal filter cake as well as core samples stimulation.

The new acid system can be considered as an efficiant solution for oil-based filter cake removal that is biodegradable and cost effective where the reservoir permeability can be regained in one stage only.
Characterization of Barriers to Flow in Burgan Reservoirs Using Geological and Dynamic Pressure Data, Burgan Field, Kuwait.
Authors: Filak Jean-Michel , Alawadh Laila , Alrefaei Bashayer
Published: October 2019

The Burgan sands Formation is one of the main reservoirs of Greater Burgan field in Kuwait, producing under primary depletion since the late 1940s. Massive sands reservoirs (Lower Burgan BGSL2 and Middle Burgan BGSM) interpreted as deposited in fluvio-tidal depositional environments, alternate with lower quality and muddy interbedded sandstones (Lower Burgan BGSL1 and Upper Burgan BGSU), deposited in tidal-influenced delta settings. The complex reservoir architecture of these sand reservoirs is dependent of the sinuosity and complexity of the channel system but also on the lateral extend and distribution of the muddy deposits that will create heterogeneities and barrier to flow.

In the context of future development plans of the Burgan reservoirs, the Burgan Subsurface Team implemented a workflow to identify the main barriers to flow at the interface between the massive and the lower net-to-gross reservoirs. This workflow combines geological (cores), petrophysical (Rock-Types, conventional logs) and dynamic data (pressures), to characterize the main barriers to flow between the different reservoirs. Shale barrier types and thicknesses of shales are picked and defined from logs using wireline conventional log data, and the huge database of pressures available was used to visualize and check the impact of the shale barriers on the connectivity of the reservoir and the pressure drop or continuity between the sandy units.

This multiple approach allows to capture the main geological heterogeneities (shale barriers) by their type and thicknesses and combining the information with dynamic data (pressures within the reservoir zones) gave a direct link to the connectivity (pressure communication or not) between the main reservoirs. The data generated by these two approaches were used to produce maps of connectivity as well as maps of pressure differences between the main reservoirs.

Modeling complex reservoir heterogeneities in clastic environments is a challenge in the oil industry. An accurate sand body distribution is crucial for a good understanding and representation of the reservoir behavior but a good representation and image of the barrier to flow is fundamental to complete the picture. In the context of the future development of Burgan reservoirs, such workflow and products will be very useful to take some decisions about the strategy to develop efficiently such type of reservoirs.
Near Line RTL as a Comprehensive Solution of the Massive Seismic Data Growth
Authors: Alalfy Mostafa
Published: October 2019

The massive seismic data growth is a typical exponential function. The current size is tens of PB's and it hardly can be managed. As per the acquisition plan, the expected size in few years is a zettabyte (ZB). The team studied many technologies and solutions. The Online and/or the Offline systems will not meet our end users requirements. The Near Line Robotic Tape Library is the comprehensive solution for such issues that fulfill the needs.

The first step was defining the current issues versus the business needs of the users. Next we studied the available technologies in the market e.g. Online RTL, Offline RTL, Near Line in addition to other similar cases in IOC's and NOC's. The Near Line RTL with enhanced workflows and data standards, was the best in our case. It depends on a very strong naming system. The Barcode system insures that no errors occurred. The interactive data allocation exchange between Fast Disk, Slow Disk and Taps are very effective. The loading/exporting are very quick even with hundreds of TB's files.

The Near Line RTL with our customized workflows and data flow system has the advantages of both

other systems i.e. Online and Offline. It is the first implementation in the world. However the challenges are tremendously huge, the system shows a very effective performance and seamlessly interactive environment. The users now can deal with a seismic files with hundreds of TB's easily. The customized system in addition to the barcodes are controlling the process. The asset end users now heavily depend on that system and that is why we expanded that system (in term of capacity). Customizable, easy extendable, friendly system was strongly recommended during planning phase for such purpose. A real case, one of our users has an urgent request (seismic file of 240 TB) and he requested it in less than couple of days, we did it in one hour!

The Conclusion: managing massive data files e.g. seismic, became easier with the RTL technology. The Near Line system with a customized workflows and standards will be a very comprehensive solution that not only fits, but also exceeds the success criteria and the business needs. Many companies now are evaluating such system, where we suggest aforementioned customization.

The Project is a step forward towards the optimized three end-members managements i.e. Technology, People and Processes. The unbalanced management of these resources is a cause of inefficiency and issues/gaps. The magic key of balancing these resources will save the efforts, time which means money in addition to performance enhancements.
Carbon Capture & Storage Management for Kuwait Oil Company, Kuwait
Authors: Hussain Zainab , Owayed Fatima , Rao Parisudda
Published: October 2019

Kuwait Oil Company (KOC) has commissioned a study to determine the potential contribution that Carbon Capture and Storage alone (CCS), Carbon Capture and Storage with Enhanced Oil Recovery (CCS-EOR) or other identified measures could make to reducing Kuwait's / KOC's Greenhouse Gas (GHG) emissions, by implementation of recommendations. This study was examined various methods to reduce GHG emissions, including CCS, and will provide a strategy for the implementation of various GHG emission reduction technologies for KOC of international and national requirements to address the global challenge of climate change, with particular focus on the Middle East and the Oil and Gas industry.

A cost effective GHG emission reduction target for KOC is proposed to limit GHG emissions as Business as Usual in 2030. Achieving this target requires implementing the Prioritized GHG Emissions Reduction Plan with specific Key Performance Measures (KPMs) for KOC. This Plan is based on a package of GHG emission reduction measures that would be cost neutral to KOC. Adopting a similar approach across the whole of Kuwait is expected to reduce emissions by 2030 projections. CCS and CCS-EOR would accrue costs but have the potential to make the greatest contribution to reducing GHG emissions. This Study recommends CCS and CCS-EOR are suitable for longer-term consideration. Furthermore, the top management KPMs has been identified that will help the management to monitor and control the GHGs emissions to address the global challenge of climate change.
Petroleum Systems and Exploration Plays of Offshore Kuwait
Authors: Ibrahim Muhammad W. , Christoffersen Trond
Published: October 2019

An update of an internal study of regional Jurassic and Cretaceous petroleum systems of Mesopotamian Basin that incorporated recently published cluster analyses correlations of source rocks to trapped oil families, reprocessed regional seismic surveys, and stratigraphic correlations of wells, fields and discoveries by current and past operating companies in offshore sectors of Iran, Iraq, Kuwait and Saudi Arabian-Kuwaiti DZ at the northern Arabian Gulf (Figures 1A and 1B).

The study aims at integrating the updated parameters of the proven regional petroleum systems, and recently reprocessed seismic anomalies with the structural evolution of offshore Kuwait in order to identify regional play fairways and delineate their trends and seismic stratigraphic analogues in Offshore Kuwait. We supplement the discussion with examples from a Regional Data Set of more than 20,000 km of high-quality 2D seismic data from the eastern side of the Northern Arabian Gulf (Figures 1A and 1B) complemented by well information and published geological information. The goal is to assess the usefulness as well as limitations of regional using analogues in future exploration offshore Kuwait.
Turning Threat into Opportunity: NORM Management Helps to Recoup the Deferred Production from North Kuwait
Authors: Saleh Nada , Chetri Hom , Al-Mutawa Majdi
Published: October 2019

North Kuwait has a vision to produce about 1 million BOPD within next couple of year. As a part of this strategy, all efforts & opportunities are being synchronized to maximize the production. A serious threat to this plan was confronted by observation of Naturally occurring radioactive materials (NORM) at some of the producers, a new challenge for which the asset did not anticipate or had any plan earlier. The paper proposal covers how this threat was converted into an opportunity. A comprehensive review of the wells with NORM was done to understand the link to specific reservoir related issues or zone's mineralogy. As this kind of production problem has been faced for the first time in North Kuwait, brainstorming and technical pros & cons were investigated with internal as well as external consultants. A due diligence was conducted to existing rules & procedures within KOC and Kuwait. Case histories from different parts of the world were reviewed as to how such issues had been resolved. Measurement of NORM, accuracy & validity was also looked into, which varied from vendor to vendor. Thus the gathered knowledge was shared with all stake holder teams.

As almost 30-40 MBOPD was the locked in potential, fast track actions have been taken to create a contract to manage wells suffering from NORM. After going through a fast track identification of suitable vendor, contract was awarded to one of the international vendor. Accordingly, workover rigs were made ready to handle NORM remediation operations professionally. Simultaneously, technical evaluation of the performance of wells infected with NORM was done to understand the phenomenon and the relationship with the changes in reservoir pressure / stimulation. A workover schedule was prepared and implemented to revive the shut-in production potential to the GCs, resulting in a bump in oil production for North Kuwait. As a result of the strategy adopted, deferment of oil production due to NORM, which hovered to more than 1.5 years in the past, is prevented, thus helping production target requirements for the Asset. Performance evaluation of wells indicated that there is a strong relationship of reservoir pressure and stimulation with the NORM level.

NORM management requires an integrated team approach, ranging from working units to the organization level and a proactive analytical approach to understand the impact of ongoing sub-surface operations on NORM tendencies. The proper understanding and analysis done in overcoming the NORM has aided in enhancing and sustaining the production via having extended productive life for the wells.
Cyclic Water Flood for Enhanced Injection Efficiency & Reduced Water Re-Circulation in Sabiriyah Mauddud, North Kuwait
Authors: Saleh Nada , Al-Shuaib Mariam , Chetri Hom , Al-Zaabi Hamad
Published: October 2019

Sabiriyah Mauddud is one of the largest carbonate reservoirs in North Kuwait on active water flood since last 20 years using sea water as the injectant. The reservoir is purely a depletion drive reservoir, responding to water flood quickly in terms of increase in reservoir pressure as well as preferential flow of injectant into the nearby producers, thus stressing the existing water handling capacities at the gathering centers. Almost 40% of the injected water re-circulated between the injectors & producers, thus disabling the complete benefit of the ongoing water flood activities. A new initiative has been tried at two of the injectors for cyclic injection for optimal balance between pressure requirements and water cut levels.

While water flooding Sabiriyah Mauddud, surprises in terms of rock & fluid understanding influenced quick water cut build up, reaching to more than 90% in some wells. A comprehensive G&G; Reservoir engineering and surveillance data aided to understand the connection factors between the injectors and producers. A fit for purpose tool developed to evaluate the water re-circulation has been used to short list the wells with "bad" water, requiring attention to control. As such bad water had been mainly due to direct short circuiting with the nearby injectors, team decided to go for handling such water from injector management point of view rather than working over the well for conformance related isolation of water producing zone. Cyclic water injection is the best solution so as to minimize the water re-circulation and stay within the operating range of the ESP in the associated producers, with properly spaced cycles of closure & opening. The initiative has been implemented at two of the injectors recently with positive results.

The cyclic injection has reduced the water cut at the associated producers up to 30%, thus improving the oil cut significantly. This has reduced the water handling requirements at the gathering centers. The closing action planned for few high water cut wells has been canceled as a result of this strategy. The concept is planned to be implemented in remaining injectors of Mauddud once there are evidences of bad water re-circulation in multiple wells associated with these injectors.

Water flood & production efficiency using cyclic water injection approach is a proven way to manage undesirable water encroachment in producers in Sabiriyah Mauddud, the results of which are interesting & worth sharing with the global professionals.
A Fast Embedded Discrete Fracture Model Based on Proper Orthogonal Decomposition POD Method
Authors: Rao Xiang , Cheng Linsong , Cao Renyi , Jia Pin , Du Xulin
Published: October 2019

This paper presents a fast embedded discrete fracture model (EDFM) based on POD method to improve the computational efficiency. Firstly, this paper gives a brief review of EDFM and derive the form of functional equations of pressure vector or saturation vector for global equations, and this form indicates the dimension of the discrete dynamic system is about the number of cells. Then, the time costs of EDFM are analyzed in detail, and the analysis shows that reducing the order of global equations is critical to decrease the time cost. Finally, this paper derives the POD basis function expansion of the pressure or saturation vector and gives the new global equations with a low order. The accuracy and efficiency of the fast model is compared in case of different sample numbers and mode numbers, and the results show that the POD-based EDFM can significantly improve the computational efficiency while ensuring enough accuracy.
Signal Analysis of Phase Inversion in Oil-Water Mixtures
Authors: Al-Jindan Jana , Ahmed Yusuf , Noui-Mehidi Mohamed Nabil
Published: October 2019

The present paper is concerned with an experimental study of the acoustic signature of phase inversion in an oil-water mixture system. The experimental results from a batch system revealed that the correlation between the acoustic fields produced by a water-continuous dispersion has a different signature from an oil-continuous dispersion. Phase inversion could be clearly identified based on the acoustic field generated by the stirrer. This dynamic characteristic of the phase inversion phenomenon could be of use in a practical system, such as a mixing system or flowlines to detect phase inversion when it occurs.
Understanding Production Performance & Rock Behavior By Using Different Diversion Techniques in Carbonate Matrix Acidizing Process
Authors: Omer Mohammed , Babey Andrew , Fragachan Francisco
Published: October 2019

In stimulated carbonate formations, one damage mechanism is the loss of near wellbore rock compressive strength upon matrix acidizing. Improper designed acidizing jobs may excessively soften the rock and negatively impact the mechanical response of near wellbore rock during production. In this work, an integrated geomechanical workflow is presented and applied to optimize acid placement and fluid diversion treatment in a Middle East carbonate reservoir.

The model consists of petrophysical characterization of the formation, coupled wellbore flow model, rock dissolution model, rock physical model, wellbore stress analysis and lastly production prediction. The model first simulates stimulation fluid movement within wellbore and couples it with transient flow in reservoir. The primary analysis determines the distribution of reactive fluid along the well and predicts porosity evolution across the reservoir domain upon stimulation. Then, the developed geomechanical engine simulates the mechanical behavior (compressional or shear failure) of stimulated rock under different stress conditions during production stage.

This paper introduces an integrated geomechanical workflow to stimulate matrix acidizing and describe dynamic reservoir compaction and its influence on production performance, which varies significantly with the stress condition, formation types and design strategy. In the presented case study, various diversion techniques are analyzed, and overall production are compared to assess the stimulation efficiency by considering the effect of rock failure. The comparative analysis identifies an optimized diversion technique and design, which can minimize near wellbore rock failure and sustain production for a longer term.

This model enables a reliable prediction of acidic fluid distribution and identification of key controlling parameters to maximize conductive reservoir volume and mitigate premature wormhole collapse. Depending on the diversion technique and reservoir conditions, the workflow can provide a proactive solution to improve matrix acidizing design to enhance overall recovery. The presented case study can aid to build a customized and optimized strategy for matrix acidizing for middle east carbonate formations.
LDS - Leak Detection System at Trieste/Visco Pipeline
Authors: Surace Luca , Sorrentino Massimiliano , Capaldi Fabio
Published: October 2019

The aim of the leak detection system (LDS) project was to install and manage a tool able to detect leaks on the Trieste-Visco pipeline, i.e. to prevent potential environmental damage. The Trieste to Visco pipeline is a 10-inch, 58km multiproduct pipeline that is mainly buried and transports refined fuels. The pipeline follows the lay of the land, mainly rural areas, at an average depth of 2,5 mt apart from road and river crossings. The project began in November 2016 and finished in March 2018. The identified solution, Atmos Wave Flow®, using pressure sensors along the whole pipeline and flow sensors at pipeline start/end, coupled with interpretation software can raise alarms providing the exact location of the leak with a +/-50m precision and a 20 l/min, 0.48 % of the nominal transfer flow, leak rate. The project has been managed jointly by KRI and KUPIT IT Group involving technology developed by Atmos International (Atmos). The Atmos Wave Flow® solution includes four different leak and theft detection technologies to assure optimal, redundant, pipeline monitoring: it combines the reliability and accuracy of the mass balance (flow) method with the sensitivity, speed, and accuracy of "negative pressure wave" techniques to achieve the highest sensitivity, location accuracy, minimum response time, and low false alarm rate. The control room operator has been provided with a simple GUI to monitor the pipeline pressure/flow status which raises alarms on leak detection while playing a continuous sound until acknowledgment. The system detected and located two real theft attempts in September and October 2017, during the observation and tuning phase of the project. Following the system alarms, Atmos theft detection engineers analysed the data offline to improve the theft location accuracy to within 300m for each theft event. The theft events occurred during both static (shut-in) and dynamic conditions.
Modeling the antimicrobial resistance of enterobacteria responsible for Urinary Tract Infections in Benin: another way to Control or survey Antimicrobial Resistance
Authors: DOUGNON VICTORIEN , ASSOGBA Phénix , GNIMATIN Jean-Pierre , AGBANKPE Jerrold , KOUDOKPON Hornel , DEGUENON Esther , FABIYI Kafayath , Consortium Global Taskforce for AMR Control , FAGLA Sèdami Romarique MEDEGAN , LOKO Yêyinou Laura Estelle , KOUKOUI Omédine , DJOGBENOU Luc , DOUGNON Jacques , BANKOLE Honoré , BABA-MOUSSA Lamine
Published: October 2019

Background: Infectious diseases are serious public health issue both in developing countries and industrialized countries. In developing countries, they are the main cause of high mortality rates. In the second group, existing resistance to antibiotics is developing growing at an alarming rate. The purpose of this study was to produce data of national interest to implement sustainable control of antimicrobial resistance as well as it spreads. Methods: One hundred ninety (190) urine samples were collected in several hospitals in Benin from patients suspected of having a urinary tract infection. After getting the inform consent from patients, samples collections were performed under aseptic conditions and were further subjected to bacteriological tests in the laboratory. The resistance profile of the bacterial strains identified was then established. The search for betalactamase production was performed by the synergy test between amoxicillin + clavulanic acid and cephalosporins. Mathematical modeling of the resistance of the strains identified by 2024 was finally carried out using compartmental deterministic models. Results: Two hundred thirty (230) strains were identified from urine samples. Male individuals were the most affected by urinary tract infections. Individuals in the 21-30 age groups were predominant. Escherichia coli was the most isolated bacterial species (32.43%) in this study followed by Klebsiella pneumoniae (26.85%) and Enterobacter cloaceae (25.92%). The susceptibility testing of isolates bacteria to antibiotics showed a strong resistance of strains to amoxicillin (91.82%). The lowest resistance obtained was observed with imipenem (2%). The betalactamase was produced by 24.03% of the strains identified. Escherichia coli (32.43%) was indeed the most productive of betalactamase followed by Klebsiella pneumoniae (31.03%). Mathematical modeling revealed a rampant rise in the resistance of bacteria to the antibiotics tested. Conclusions: These results provide important data for public health. They deserve constructive advocacy so that more specific actions are taken in relation to antimicrobial resistance.
Societal engagement in adolescence and future connection to education and employment in early adulthood – A follow-up-study
Authors: Just-Noerregaard Vivi , Andersen Johan Hviid , Nohr Ellen Aagaard , Vestergaard Jesper Medom , Winding Trine Nohr
Published: October 2019

Background: Attainment to education and employment is essential for young people to develop the skills needed to participate in society and maintain a stable connection to the labour market in adult life. This study examined associations between societal engagement, measured by leisure time activities (LTA) and part-time work (PTW), in mid (14/15 years) and late (17/18 years) adolescence and a positive connection to education and employment in early adulthood, accounting for potential gender and socioeconomic differences. Method: A cohort of young people born in 1989 was followed in a prospective study with questionnaires in 2004 (n=3,054) and 2007 (n=2,400) where information on LTA and PTW was collected. Information on connection to education and employment was collected from a register of social benefits when they were 25-29 years old and divided into high and low societal connection. The associations were examined using logistic regression and stratified by gender and childhood socioeconomic groups. Results: PTW was, both in mid and late adolescence, positively associated with societal connection (OR: 1.7 [95% CI 1.3; 2.2] and 1.9 [1.4;2.6]). LTA in mid adolescence was associated with societal connection (OR:1.6 [1.2;2.1]). Among the males LTA and PTW showed strongest associations with societal connection in mid adolescence (ORs up to 2.2), whereas the associations for females seemed strongest in late adolescence (ORs up to 2.8). Conclusion: The study showed that adolescent societal engagement had notable positive associations with connection to later education and employment, with stronger impact of PTW compared to LTA. The study identified differences between genders and the timing of engagement. Associations were consistent across socioeconomic groups.
Association among Parkinsonism-related motor complaints, cerebral small vessel disease, and cerebrovascular risk factors in a community-dwelling population
Authors: Guo Yang , Ji Cai-hong , Han Fei , Zhang Jiang-tao , Zhai Fei-fei , Zhou Li-xin , Ni Jun , Yao Ming , Jin Zheng-yu , Zhang Shu-yang , Cui Li-ying , Zhu Yicheng
Published: October 2019

Background Parkinsonism-related motor complaints are commonly seen in the elderly. Our study aimed to investigate the association among Parkinsonism-related motor complaints, cerebral small vessel disease and cerebrovascular risk factors in a community-dwelling population in a Chinese rural area.Methods Individuals who were 50 years old or older, were independently living, were well-functioning, and had no history of ischemic or hemorrhagic stroke, were included. Brain magnetic resonance imaging (MRI), quantified motor function assessment, and questionnaire screening for Parkinsonism-related motor complaints were performed. Clinical data including cerebrovascular risk factors were collected. In univariate analysis, Chi-square test and student t-test were used to compare dichotomous variables and continuous variables, respectively, between individuals with or without motor complaints. In multivariate analysis, binary Logistic regression models were generated to determine risk factors for Parkinsonism-related motor complaints. General linear models were used to compare motor parameters between individuals with or without motor complaints. Results In the final analysis, 854 people were included. Individuals with motor complaints had a longer time for finger taping (6.2s v.s. 5.6s, p = 0.006), and a longer time for 3m-walking(4.0s v.s. 3.6s, p = 0.034) than did those without motor complaints. Hypertension was associated with motor complaints (odds ratio, 1.82; 95% confidence interval [CI], [1.21, 2.73]; p = 0.004). Age was not associated with motor complaints; none of the neuroimaging markers of cerebral small vessel disease was associated with motor complaints. Conclusion Hypertension is associated with Parkinsonism-related motor complaints. Better management of hypertension may prevent mobility limitation in the elderly. The questionnaire that we used for Parkinsonism is not suitable for screening small vessel disease in a community-dwelling population.
Comparison of single posterior debridement, bone grafting, and instrumentation with single anterior debridement, bone grafting, and instrumentation in treatment of thoracic spinal tuberculosis
Authors: Zhou Yongchun , Li Weiwei , Gong Liqun , Zhou Jiao , Luo Jing
Published: October 2019

Objective To explore the clinical effect of single posterior debridement, bone grafting, and instrumentation and single anterior debridement, bone grafting and instrumentation in the treatment of thoracic spinal tuberculosis of adult patients. Methods: A retrospective analysis was made by involving 38 adult patients with thoracic spinal tuberculosis from between June 2013 and December 2015. Of the 38 patients, 21 patients were categorized in single anterior approach group and underwent single posterior debridement, bone grafting, and instrumentation (Group A). The remaining 17 patients were classified in single posterior approaches group (Group B), which received single posterior debridement, bone grafting and instrumentation. Clinical manifestations, laboratory and imaging results of the two groups were analyzed subsequently. Results: All patients were followed up for 23.9 ± 3.8 m (range, 19–36 m). Bony fusion was achieved in all bone grafts. The operation time and intraoperative blood loss in group B were significantly less than those in group A (P<0.05). The VAS scores, ESR, and CRP levels 6 weeks after operation and at the final follow-up were significantly lower than the preoperative levels (P<0.05). At the last follow-up, ASIA improvement no significant difference between groups (P>0.05). Furthermore, the postoperative and final-follow-up kyphosis angles in group B were both significantly smaller than those in group A (P<0.05). Group A had a postoperative angle correction rate smaller than group B, and its postoperative angle loss was greater than group B’s (P<0.05). Conclusion: Single posterior debridement, bone grafting, and instrumentation can achieve similar curative effect as single anterior debridement, bone grafting and instrumentation in the treatment of thoracic spinal tuberculosis, but also accompanied by additional advantages of shorter operation time and less bleeding .
Suboptimal management of hypertriglyceridemia in the outpatient setting is associated with the recurrent pancreatitis
Authors: Yan Ping , Zhao Hong-Xian , chen xia
Published: October 2019

Background Hyperlipemia is a well-established etiology of acute pancreatitis (AP). However, few data are available in the medical literature about the management of triglyceride levels in the outpatient setting in patients with hypertriglyceridemic acute pancreatitis (HTG-AP). We evaluated the blood triglyceride levels and the follow-up of triglyceride management in patients with HTG-AP.Methods This retrospective study enrolled patients with HTG-AP from January 2013 to March 2019 in Affiliated Hospital of Southwest Medical of University. By reviewing the hospitalization records and the follow-up data, the clinical features, blood triglyceride levels, lipid-lowering medications use and blood triglyceride levels monitoring after hospital discharge were analyzed.Results 133 patients (46 women, 87 men; median age at presentation 37.4 years) diagnosed with HTG-AP were enrolled in the study. 32 cases (24.1%) presented with recurrent acute pancreatitis (RAP). Patients who had RAP were younger and had higher blood triglyceride levels compared with that of single attack ( P < 0.05). No difference of serum amylase levels, hospitalization duration and mortality rate were observed between non-RAP and RAP. Lipid monitoring was only observed in 12.8% of patients and 10 patients(7.5%) took medications to control blood triglyceride levels after hospital discharge. The follow-up of triglyceride levels in the outpatient setting were higher in RAP patients than that of non-recurrent cases ( P < 0.05). Among the patients who had measured their triglyceride levels after discharge, 83.3% of patients with RAP had at least 1 follow-up of triglyceride level that higher than 500 mg/dL, while no patient had one HTG-AP attack displayed triglyceride levels higher than 500 mg/dL.Conclusions Triglyceride levels after hospital discharge higher than 500 mg/dL may be associated with an increasing risk of relapse of clinical acute pancreatitis events. Inappropriate management of triglyceride control in the outpatient setting may be associated with an increasing risk of relapse of clinical HTG-AP events.
Laryngeal mask versus endotracheal intubation for pre-hospital emergency airway management: a meta-analysis of randomized manikin and human studies
Authors: Li Hao , Duan Ming-da , Zhang Yun-liang , You Shao-hua , Song Yu-xiang , Zhang Xuan , Liu Min , Liu Wen-gang , Hou Ai-sheng , cao jiangbei
Published: October 2019

Background Pre-hospital emergency airway management plays an important role in pre-hospital care. Laryngeal masks are increasingly employed for the airway management of pre-hospital critical patients and have achieved promising results. Although several randomized controlled trials have reported benefits, the efficacy of laryngeal masks in pre-hospital emergency airway management compared to endotracheal intubation have not been systematically reviewed.Methods Electronic databases (PubMed, Cochrane Library, Embase, Scopus and CNKI) were searched up to April 2019 for related randomized studies. Outcome indicators were overall intubation success rates, success rates of the initial intubation, insertion time, ventilation efficiency rates, SpO2 rise time and blood gas index. Two investigators selected the trials, extracted the data according to inclusion and exclusion criteria, and assessed the quality of the literature according to the Jada score. The meta-analysis was performed using stata14.0 software.Results We included 9 randomized manikin studies and 31 human studies. Meta-analysis of the manikin studies showed that the overall intubation success rates of the laryngeal mask group [RR=1.10, 95% CI (1.02, 1.18), P<0.05] and the success rates of first intubation [RR=1.25, 95% CI (1.01, 1.55), P <0.05] were significantly higher than the endotracheal intubation group. The insertion time of the laryngeal mask group was also significantly shorter [SMD = -1.53, 95% CI (-1.88, -1.17), P <0.05]. In human studies, excluding the success rates of first intubation and insertion time, the laryngeal mask was superior to endotracheal intubation and improved the patients’ blood gas index and shortened the SpO2 rise time. All the results were statistically significant.Conclusions Compared to endotracheal intubation, laryngeal masks could quickly and effectively improve patient ventilation in pre-hospital emergencies, highlighting its utility for clinical application .