bluuebunny/crossref_metadata_2025 huggingface dataset:
Operational Data Repository as the First Step to Digital Oil Field
Authors: Alfajri Reza , Siregar Sakti Parsaulian , Sitanggang Liston , Hutasoit Andar Parulian
Published: October 2021

Digital oil field is a terminology that frequently appeared in the last few years. In the era of industry 4.0 and the proliferation of digital technology, oil and gas companies need to adapt in order to gain advantage in business process development, and this term is the answer. In digital oil field, data is significantly valuable. Therefore, robust database and real time data monitoring need to be developed.

Pertamina EP has established a robust, easy-to-access, and web-based database application called Operational Data Repository (ODR). This application handles end-to-end business process from exploration all the way to commercial. Several modules were integrated for this application and the main modules consist of exploration, exploitation, production, finance, safety and commercial. For every module in ODR, the first task to carry is to create and input master data. After database is created, calculation according to module's purpose is performed. Once the system is there, automatic data acquisition and monitoring will enter the picture.

Exploration module in ODR handles database of Pertamina EP exploration activities. This module include lithology, biostratigraphy, and geochemical data of exploration project in Pertamina EP. This module ensures that initial data of a structure is preserved and available. Exploitation module deals with oil and gas reserves and resources reporting process, well proposal for annual work plan, and surface project monitoring. This module rules development phase from subsurface to surface. Production module shows daily operational activities, production data, and quadrant mapping of wells productivity. Data from this module is taken for evaluating production and operation performance. Finance module handles company's financial report, including revenue, expense, and tax. Safety module handles work permit, hazard identification, risk assessment and control for every project and work plan. Safety is a very important aspect in a company and this module ensures that documents needed to perform work safely is well-documented and easy to submit and access. Last but not least is commercial module. This module consists of gas sales agreement documents (GSA), metering system location, and customer complaints monitoring. ODR has already been well-established, therefore Pertamina EP started its pilot project for automatic data acquisition for eight wells and currently on monitoring phase.

This paper describes Pertamina EP first step to digital oil field, which is developing virtual warehouse to store company's data. The step is strengthened with attempting for automatic data acquisition that will be integrated to the ODR for the next phase.
A Thorough Review of Machine Learning Applications in Oil and Gas Industry
Authors: Temizel Cenk , Canbaz Celal Hakan , Palabiyik Yildiray , Aydin Hakki , Tran Minh , Ozyurtkan Mustafa Hakan , Yurukcu Mesut , Johnson Paul
Published: October 2021

Reservoir engineering constitutes a major part of the studies regarding oil and gas exploration and production. Reservoir engineering has various duties, including conducting experiments, constructing appropriate models, characterization, and forecasting reservoir dynamics. However, traditional engineering approaches started to face challenges as the number of raw field data increases. It pushed the researchers to use more powerful tools for data classification, cleaning and preparing data to be used in models, which enhances a better data evaluation, thus making proper decisions. In addition, simultaneous simulations are sometimes performed, aiming to have optimization and sensitivity analysis during the history matching process. Multi-functional works are required to meet all these deficiencies. Upgrading conventional reservoir engineering approaches with CPUs, or more powerful computers are insufficient since it increases computational cost and is time-consuming. Machine learning techniques have been proposed as the best solution for strong learning capability and computational efficiency. Recently developed algorithms make it possible to handle a very large number of data with high accuracy. The most widely used machine learning approaches are: Artificial Neural Network (ANN), Support Vector Machines and Adaptive Neuro-Fuzzy Inference Systems. In this study, these approaches are introduced by providing their capability and limitations. After that, the study focuses on using machine learning techniques in unconventional reservoir engineering calculations: Reservoir characterization, PVT calculations and optimization of well completion.

These processes are repeated until all the values reach to the output layer. Normally, one hidden layer is good enough for most problems and additional hidden layers usually does not improve the model performance, instead, it may create the risk for converging to a local minimum and make the model more complex. The most typical neural network is the forward feed network, often used for data classification. MLP has a learning function that minimizes a global error function, the least square method. It uses back propagation algorithm to update the weights, searching for local minima by performing a gradient descent (Figure 1). The learning rate is usually selected as less than one.
Installation of Conductor Supported Platform CSP at X Field
Authors: Ngadiman Helmi
Published: October 2021

This technical paper presents the offshore installation execution work of Conductor Supported Platforms (CSP) at ‘X’ field. The knowledge sharing was based on the successful installation of three (3) numbers of CSP for ‘X’ development project. The platforms were installed at approximately of 70m water depth and encountered technical challenges during offshore execution.

‘X’ field is located about approximately 45km North West of Miri, Sarawak. The CSPs were installed by Derrick Barge (DB) via double blocks crane upending method for the substructures and conventional lifting method for the topsides. The CSP was designed for 70 meters water depth with four (4) numbers of vertical legs, four (4) numbers of skirt piles, and one (1) number of pin pile. The weight of the topside was about 600MT, meanwhile the substructure was about 1100MT respectively.

These CSPs marked as a pioneer in the installation of its kinds at 70m water depth in COMPANY. The concept required high accuracy of detailed offshore installation engineering. This configuration however had caused some challenges during installation. Among the major challenges were issues on the pin-pile verticality, substructure levelness and upending activities via double blocks crane upending method.

The effective strategies were adopted to improve the on-bottom stability by installing pin pile prior to substructure set down. The pin pile was installed by utilizing Subsea Fast Frame (SFF), in order to achieve pin pile's verticality. The crucial part during pin pile installation was to ensure meeting the verticality accuracy and minimum tolerance may high potentially impact the substructure install ability and meeting level requirement.

However, due to a big annulus gap at pin pile sleeve of the substructure had caused prolong in levelling operation. In order to improve subsequent platforms levelling operations, a set of centralizers were introduced and installed after confirming the pin pile verticality result, in order to reduce the annulus gap. Despite all the challenges aforementioned, the installation of CSPs were completed successfully and most importantly with Zero Lost Time Injury (LTI).
Blast from the Past, Solving Severe Congealed Oil Problems by Combining Existing Solutions
Authors: Hahijary Tirza , Kusuma Aditya Yudha , Jenie John Rizal
Published: October 2021

A mature field in central Sumatra, Indonesia, has been producing heavy oil for decades, and it has shown decreased production. The ESP, as the main lifting method, needs to be replaced more frequently due to mechanical damage by congealed oil. Many wells in that field were forced to be deactivated because of congealed oil plugging along the wellbore. The conventional method to tackle this issue is to pump hot water. This practice however did not give sustainable results after the treatment. The remedy of coiled tubing (CT) well cleanout with a wash nozzle has also not been considered successful because the congealed oil is too hard to penetrate. Furthermore, using mechanical devices such as CT milling tools has not been effective because the deposits stick to the mill. Considering the low-production-rate wells, high-rate fluid injection was proposed to meet cost criteria. Although the well was able to produce afterwards, production kept declining due to the production of congealed oil from the formation. A combination of high-pressure jetting tool and organic dissolver fluid was proposed as an alternative method to break the congealed oil. The method uses kinetic energy from the jetting tool to shatter the solidified oil by pumping brine. Afterwards, a fluid mixture composed of organic dissolver and additive is pumped to dissolve the remaining congealed oil.

Following the treatments, the pilot well showed significant improvements. The treatment successfully revived well production after the well had stopped producing for more than 3 months. The flowback tank was filled with as much as 10-in.-deep broken oil residue. Such a solid removal has not been accomplished with any other technique. The well has been producing for more than 10 months without any pump issues, and production continues to increase. Another three well candidates with low productivity issues were treated with the same technique. All the wells delivered good results. If, in the future, the congealed oil accumulates again, high-pressure jetting and organic dissolver will be the first method used for remediation. All the wells treated with this approach have been producing significantly more than those treated using any other technique, well beyond the target set by the operator.

This study discusses the benefits of combining the techniques of high-pressure jetting, organic dissolver, and high-rate injection to overcome severe congealed oil problems that impair well production. Details the approach are provided, and its effectiveness is compared to other former attempts to solve the congealed oil problem. This case also illustrates the importance of maintaining well interventions to improve production while meeting the cost criteria in this challenging time in the oil and gas industry.
An Industry First: Concept Selection, Material Testing, and Modelling Process for a Successful Managed Pressure Open Hole Gravel Pack Project
Authors: Lin Chih-Cheng , Tallin Andrew G. , Guan Xueyong , Kaura Jiten D. , Luces Sasha F. , Shayegi Sara , Oyler Kenneth W. , Reutzel Ronald A. , LaPointe Michael , Teoh Michael , Palisch Terry T. , Wong George K.
Published: October 2021

One of the major technical challenges to this project was placing horizontal open hole gravel packs (HzOHGP) within the narrow pore pressure to frac-gradient (PPFG) margin in the target reservoirs. This paper addresses the steps taken to overcome this challenge. To maximize the use of the narrow PPFG margin, the project combined a managed pressure drilling (MPD) system with low gravel placement pump rates made possible by an ultra-light-weight proppant (ULWP).  Of the MPD systems available, the Controlled Mud Level (CML) system was selected over the Surface Back Pressure (SBP) system for several reasons. It enabled conventional gravel pack pumping operations and equipment and it accommodated the brine weight needed to inhibit the shales. A series of lab tests showed that the completion fluid density required to inhibit the reservoir shale reactivity was only possible using CML. An overall evaluation of CML showed that it was most suitable and offered the greatest flexibility for the gravel pack job design.

The special ceramic ULWP had to be qualified and tested.  The qualification testing ranged from standard API and compatibility tests to full scale flow loop testing. The flow loop tests were needed to measure the ULWP transport velocity for the target wellbore geometry. Understanding the transport velocity is critical for gravel pack design and job execution planning. Once MPD and ceramic ULWP were selected, the gravel pack placement operations were simulated to demonstrate that their features increased the likelihood of successfully gravel packing in the target reservoirs.  Small PPFG margins decrease the probability of success of placing a HzOHGP.  In the target formations, the pressure margin is insufficient to safely execute HzOHGP conventionally; instead, the project combined MPD and the low pump rates facilitated by using ULWP to control circulating pressures to stay inside the narrow margin and place the gravel packs. The integration of CML and ULWP into in a gravel pack operation to control circulating pressures has never been done. The concept and its successful field implementation are industry firsts.
Setting New Milestones for Coiled Tubing Intervention in Mega-Reach Wells
Authors: Wheatley Edward Jason , Correia Gladwin , Adi Samhar , Molero Nestor , Silva Cremilton , Galvan Irma , McClelland Garry , French Andrew , Bragaw Thomas
Published: October 2021

Maximizing reservoir contact through extended-reach and mega-reach wells has become a prevalent field development strategy for major offshore operators in the Middle East. This is especially true for the giant oilfield "A", where drilling targets go beyond 40,000 ft. measured depth (MD), with MD/TVD ratios in excess of 4.5:1. Such challenging horizons call for a detailed re-evaluation of well interventions.

In 2019, the well surveillance program in the field A required intervention in a mega-reach well with a MD over 35,500 ft. and 4.5:1 MD/TVD ratio. This reach was unthinkable only a few years ago but has been made possible thanks to several recent key technological advancements, such as coiled tubing (CT) equipped with optical fiber and new CT hydraulic tractors, proactive and detailed planning during the drilling phase, the development of highly engineered CT string designs, surface equipment upgrades, and accurate software modeling.

The target well is an oil producer with horizontal section beyond 23,000 ft., completed with 6 5/8-in. pre-perforated liner and 23 swellable packers placed across the 8 1/2-in. open hole section. A multiphase production logging tool was selected to assess the production profile along its horizontal drain. With a target depth beyond the reach of conventional wireline, CT equipped with optical fiber emerged as the optimum solution to facilitate reach and overcome the weight and pumping limitations of wired CT. A comprehensive CT reach modeling exercise compared the performance of several 2-in. and 2 3/8-in. CT string designs and identified operational requirements and reach gains from CT hydraulic tractors. As a result, an engineered 2-in. CT tapered string of near 36,700 ft. was developed, capable of being equipped with optical fiber line, while delivering the required flow rate and differential pressure to the CT hydraulic tractor without compromising any operational safety margin. At the time of manufacturing, this was considered the longest CT string ever produced and fitted for downhole telemetry. The operation itself set new records for well interventions in mega-reach wells, with a CT reach above 35,500 ft. MD, including a hydraulic tractoring footage over 15,650 ft. MD with spaced slugs of chemical friction reducer.

This case study explains how to develop a safe, robust, and effective solution to mega-reach well challenges using the CT-conveyed optical fiber telemetry technology in one of the deepest wells in the field A, setting a new global record in CT reach. The lessons learned are now the reference for other operators in the Middle East and across the globe for performing interventions in wells that continue to be stretched in its extended reach. It also depicts why telemetry through optical fiber is key to the success of such projects and provides an overview of technology needs for the future of mega-reach well developments.
Linear and Nonlinear Controls of Wireline Logs on Automated Grain Size Estimation Using Machine Learning Approach
Authors: Anifowose Fatai Adesina , Alshahrani Saeed Saad , Mezghani Mokhles Mustafa
Published: October 2021

Wireline logs have been utilized to indirectly estimate various reservoir properties, such as porosity, permeability, saturation, cementation factor, and lithology. Attempts have been made to correlate Gamma-ray, density, neutron, spontaneous potential, and resistivity logs with lithology. The current approach to estimate grain size, the traditional core description, is time-consuming, labor-intensive, qualitative, and subjective. An alternative approach is essential given the utility of grain size in petrophysical characterization and identification of depositional environments.

This paper proposes to fill the gap by studying the linear and nonlinear influences of wireline logs on reservoir rock grain size. We used the observed influences to develop and optimize respective linear and machine learning models to estimate reservoir rock grain size for a new well or targeted reservoir sections. The linear models comprised logistic regression and linear discriminant analysis while the machine learning method is random forest (RF). We will present the preliminary results comparing the linear and machine learning methods. We used anonymized wireline and archival core description datasets from nine wells in a clastic reservoir. Seven wells were used to train the models and the remaining two to test their classification performance. The grain size-types range from clay to granules. While sedimentologists have used gamma-ray logs to guide grain size qualification, the RF model recommended sonic, neutron, and density logs as having the most significant grain size in the nonlinear domain.

The comparative results of the models' performance comparison showed that considering the subjectivity and bias associated with the visual core description approach, the RF model gave up to an 89% correct classification rate. This suggested looking beyond the linear influences of the wireline logs on reservoir rock grain size. The apparent relative stability of the RF model compared to the linear ones also confirms the feasibility of the machine learning approach.

This is an acceptable and promising result. Future research will focus on conducting more rigorous quality checks on the grain size data, possibly introduce more heterogeneity, and explore more advanced algorithms. This will help to address the uncertainty in the grain size data more effectively and improve the models performance. The outcome of this study will reduce the limitations in the traditional core description and may eventually reduce the need for extensive core description processes.
Quantification of Fluid Production Distribution in Deviated Wells with High Gas-Liquid Ratio Using a Flow Array Sensing Tool
Authors: González José Wilfredo , Linares Alejandro Jose , Rodriguez Diego Armando , Rivera Gerson Orlando , Schoepf Virginie M. , Abbassi Linda
Published: October 2021

The objective of this paper is to depict the quantification of the production rates of the different phases in deviated wells with high gas-liquid relation using the Flow Array Sensing Tool (FAST). The readings of standard Production Logging Tools (fullbore flowmeter, density, and capacitance) are centralized, therefore they are affected if there is re-circulation of the heavy phase (liquid). The phase segregation and possible apparent down flow of the heavy phase makes it very difficult to determine the distribution of the produced fluids, and in some cases the spinner flowmeter tends to stop or gives inaccurate readings. The cause of these inaccurate readings is that the centralized spinner is affected by positive flow in the high side and negative flow in the low side of the wellbore, and the spinner shows no flow or even apparent downhole flow, when there is a real positive flow.

The FAST tool used during the acquisition of the production logs is an ultracompact production logging tool (3 ft long) that is capable to measure multiphase flows with an array of 8 sensors, two in each arm and located 90° apart. These sensors are based on MEMS (Microelectromechanichal Systems), and among the interchangeable sensors we have optical probes that takes ultra-rapid measurements of the refractive index and can determine hold-up of water, oil and gas; the electrical probes that measures conductivity to differentiate hydrocarbons from water, and magnetic probes with micro-spinners to determine the flow rate. Both the three phase optical probes and the electrical probes have excellent response including water hold-ups over 90% that cannot be measured with a standard capacitance tool.

The data logged with FAST in deviated wells was processed and interpreted to obtain the apparent flow velocity profiles of each of the 4 micro-spinners and with the three phase optical probes, and the relative bearing curves the velocity maps, and hold-up maps where obtained. The velocity map showed that there was negative flow in the low side of the well and positive flow in the high side while the hold-up map showed the light phase (gas) in the high side of the well. Both maps showed clearly the flow pattern and were used to quantify the production of each perforation and the total rate matched closely the surface rate (within 2% deviation).

With the hold-up and velocity maps, the real flow rates were obtained with high confidence, and the flow pattern were shown clearly in deviated wells. The three phase optical probes, and electrical probes are excellent indicators of water and hydrocarbons inflow in a wide range of hold-ups.
Deployment of Downhole Mechanics Measurement System and Drilling Dynamics Modelling to Enhance Overall Drilling Performance Under Complete Mud Losses Environment
Authors: Echevarria Garnica Edgar , Moreira Gustavo Alves , Ruzhnikov Alexey
Published: October 2021

Drilling surface 16-in. and 12.25-in. sections in Middle East often accomplished by complete mud losses where downhole dynamic changed completely. To increase the performance and reduce drilling time the Positive Displace Motors (PDM) are used, however drilling under complete mud losses scenario may lead to a failure of the PDM, Measure While Drilling (MWD) tool, jar and any other components of the Bottom Hole Assembly (BHA). This manuscript describes the study of BHA dynamic in total loss scenario aiming to increase Rate of penetration (ROP) and decrease mechanical failures.

The changing in drilling dynamics under complete mud losses increases the severity of shock and vibrations (S&V), BHA whirl and, consequently, leads to downhole failures. Local practices have been used to control this risk by taking an over conservative approach, limiting Weight on Bit (WOB) and Revolution per Minute (RPM) to very low levels, affecting overall performance. To comprehensively understand the level of shock and vibrations under complete mud losses based on the modeled data, a Downhole Mechanics Measurement (DMM) system was used in the BHA to acquire the required data in real time to confirm and further improve the modeling of drilling dynamics. A drilling schedule with several combinations of WOB and RPM was developed to cover the full drilling envelop.

This study provided valuable understanding on the drilling dynamics while drilling under complete mud losses and allowed to clearly define the limiting boundaries to optimize ROP without jeopardizing the mechanical integrity of the BHA, particularly the PDM and drilling jar. On each formation drilled, RPM, WOB were changed to cover all possible combinations and, using the continuous real time measurement, ROP was optimized based on the level of shocks and vibrations experienced. Furthermore, the recorded mode Low and High-frequency data enabled to model the drilling dynamics and to quantify the effects of shocks and vibrations on the BHA. As a result, the wells have been drilled with significant ROP improvement (saving one day per run) and without downhole failures, achieving higher than expected performance results.
Development of Oil Formation Volume Factor Model using Adaptive Neuro-Fuzzy Inference Systems ANFIS
Authors: Alakbari Fahd Saeed , Mohyaldinn Mysara Eissa , Ayoub Mohammed Abdalla , Muhsan Ali Samer , Hussein Ibnelwaleed Ali
Published: October 2021

The oil formation volume factor is one of the main reservoir fluid properties that plays a crucial role in designing successful field development planning and oil and gas production optimization. The oil formation volume factor can be acquired from pressure-volume-temperature (PVT) laboratory experiments; nonetheless, these experiments' results are time-consuming and costly. Therefore, many studies used alternative methods, namely empirical correlations (using regression techniques) and machine learning to determine the formation volume factor. Unfortunately, the previous correlations and machine learning methods have some limitations, such as the lack of accuracy. Furthermore, most earlier models have not studied the relationships between the inputs and outputs to show the proper physical behaviors. Consequently, this study comes to develop a model to predict the oil formation volume factor at the bubble point (Bo) using an adaptive neuro-fuzzy inference system (ANFIS). The ANFIS model was built based on 924 data sets collected from published sources. The ANFIS model and previous 28 models were validated and compared using the trend analysis and statistical error analysis, namely average absolute percent relative error (AAPRE) and correlation coefficient (R). The trend analysis study has shown that the ANFIS model and some previous models follow the correct trend analysis. The ANFIS model is the first rank model and has the lowest AAPRE of 0.71 and the highest (R) of 0.9973. The ANFIS model also has the lowest average percent relative error (APRE), root mean square error (RMSE), and standard deviation (SD) of -0.09, 1.01, 0.0075, respectively.
Comparison of Porosity Change Due to Geochemical Reaction between Samples from High CO2 Field and Depleted Field
Authors: Sazali Wan Muhammad Luqman , Md Shah Sahriza Salwani , Misnan M Shahir , Kashim M Zuhaili , Othman Ahmad Faris , Kantaatmadja Budi Priyatna
Published: October 2021

When developing a high CO2 field, oil and gas companies must consider the best and most economical carbon capture and storage (CCS) plan. After considering the distance of the storage site and storage capacity, PETRONAS has identified 2 carbonate fields, known as X Field and N Field in East Malaysia as the potential CO2 storage site. Interestingly, both fields are different, as X field is a high CO2 green field, while N field is a depleted gas field. The research team’s initial hypothesis is that N Field would have more severe geochemical reaction between CO2, brine and carbonates compared to X Field, since X field is already saturated with CO2. In order to test the hypothesis, samples from these two fields were selected to undergo static batch reaction analysis, and changes in porosity were determined using Digital Core Analysis (DCA). Both X and N fields are carbonate gas fields, with aquifer zone located below gas zones. The aquifer zones are the preferable CO2 injection zone because the deeper the zone, the longer it will take for the plume migration to happen. For static batch reaction analysis, samples each field were selected from the aquifer zone. After Routine Core Analysis (RCA) and Quality Control (QC), the samples were scanned under the high resolution microCT scan, before they were saturated into the respective synthetic brine. After saturation is completed, both brine and samples were placed inside a batch reactor, where the reactor’s pressure and temperature are set according to the field’s pressure and temperature. Once stabilized, the supercritical CO2 is injected into the brine, and was left for 45 days with constant observation. After aging with supercritical CO2, the samples were then scanned under microCT scan once again, using the same resolution, before being analysed via image processing software. Using registration algorithm software, both pre and post CO2 aging images were overlapped and subtracted digitally. The difference images were analyzed to determine the change in porosity. Samples from X Field has around 1% p.u. increase in porosity, while samples from N field shows increment of 2% p.u. porosity. While N field (depleted field) has higher reaction compared to X field (high CO2) field as per hypothesis, the difference is very minimal, which is much less than expected. The usage of DCA in the analysis enabled the team to determine minute changes that were happening during CO2 batch reaction. Without DCA, the 1% changes usually regarded as equipment’s error margin. The next step would be modelling, where the lab results will be upscaling into field scale, for modelled longer period of time. Hence, although the porosity changes between X and N field are very small under laboratory condition, it can have greater impact in field scale.
Experimental Investigation of a Novel Nanosilica for Blocking Unwanted Water Production
Authors: Alabdrabalnabi Mohammed , Almohsin Ayman , Huang Jin , Sherief Mohammed
Published: October 2021

Nanotechnology is the design and application of engineered nanoparticles with one minimum dimension in the range of 1 to 100 nanometers. To achieve a specific target, innovative methods are highly required to overcome the challenges in the oil and gas industry, such as undesired water production. Herein, we present an advanced nanosilica, a new eco-friendly, cost-effective, and promising approach to control undesirable water production.

The objective of this work is to evaluate our nanofluid system that can be used for water management in different water production mechanisms, including: high permeability streak, wormhole, and fractured reservoirs. A systematic evaluation of novel nanosilica/activator for water shut-off application requires an examination of the chemical properties before, during, and after gelation at given reservoir conditions. The placement of this water shut-off system is highly dependent on gelation time and viscosity. Therefore, we emphasized in this study on investigating these gelation kinetics by conducting extensive rheology experiments at varied temperatures and activator concentrations. We have looked into evaluating the optimum breaker for the gel as a contingency plan for improper placement.

Measurements of the nanosilica fluid’s initial viscosity exhibited a low viscosity, less than 10 cP at normal temperature and pressure (NTP) conditions; this provides significant benefit for mixing at surface and pumping requirements for pilot testing. The nanosilica gelation time can be tailored by adjusting activator concentration to match field job design at a given temperature, which is more than 200°F. The gelation time revealed an exponential relationship with temperature and reversible proportionality. The nanosilica gel proved to be a thermally stable fluid system along with different activation ratios. For breaker tests, the gellant fluid showed complete breakdown at altered temperatures to mimic downhole conditions. Our lab observations conclude that nanosilica fluid is verified to be acceptable as a water shut-off system for field applications.

This novel nanofluid system is a promising technology to control water production from oil wells. The system has low initial viscosity that can be injected in porous media without hindering the injectivity and getting at risk of fracking the sand. In case of inappropriate placement, the fluid can break down entirely using a non-damaging chemical breaker instead of using mechanical approaches that might damage the completion.
Effect of GnRH Agonist Alone or Combined With Different Low-dose hCG on Cumulative Live Birth Rate for High Responders in GnRH Antagonist Cycles: a Retrospective Study
Authors: He Yuxia , Tang Yan , Chen Shiping , Liu Jianqiao , Liu Haiying
Published: October 2021

Background: There is insufficient evidence regarding the impact of dual trigger on oocyte maturity and reproductive outcomes in high responders. Thus, we aimed to explore the effect of gonadotropin-releasing hormone agonist (GnRHa) trigger alone or in combination with different low-dose human chorionic gonadotropin (hCG) regimens on rates of oocyte maturation and cumulative live birth in high responders who underwent a freeze-all strategy in GnRH antagonist cycles.Methods: A total of 1343 cycles were divided into three groups according to different trigger protocols: group A received GnRHa 0.2 mg (n=577), group B received GnRHa 0.2 mg and hCG 1000 IU (n=403), and group C received GnRHa 0.2 mg and hCG 2000 IU (n=363). Results: There were no significant differences in age, body mass index, and rates of oocyte maturation, fertilization, available embryo, and top-quality embryo between the groups. However, the incidence of moderate to severe ovarian hyperstimulation syndrome (OHSS) was significantly different between the three groups (0% in group A, 1.49% in group B, and 1.38% in group C). For the first frozen embryo transfer (FET) cycle, there were no significant differences in the number of transferred embryos and rates of implantation, clinical pregnancy, live birth, and early miscarriage between the three groups. Additionally, the cumulative ongoing pregnancy rate and cumulative live birth rate were not significantly different between the three groups. Similarly, there were no significant differences in gestational age, birth weight, birth height, and the proportion of low birth weight among subgroups stratified by singleton or twin.Conclusions: GnRHa trigger combined with low-dose hCG (1000 IU or 2000 IU) did not improve oocyte maturity and embryo quality and was still associated with an increased risk of moderate to severe OHSS. Therefore, for high responders treated with the freeze-all strategy, the GnRHa single trigger is recommended for final oocyte maturation, which can prevent the occurrence of moderate to severe OHSS and obtain satisfactory pregnancy and neonatal outcomes in subsequent FET cycles.
Progesterone Gel and Placebo were Equally Effective in Preventing Preterm Birth Among Women with Preterm Labor
Authors: Stjernholm Ylva Vladic , Vladic Tomislav , Marchini Giovanna
Published: October 2021

Introduction The aim of this trial was to evaluate the effect of maintenance treatment with vaginal progesterone gel compared to placebo in preventing preterm birth after the onset of preterm labor.Methods A randomised controlled trial in Sweden in 2009 − 18. Women with preterm labor were randomized to daily doses of progesterone gel 90 mg (n = 29) or placebo (n = 29) after standard treatment with intravenous tocolytics. Women with intravenous tocolytics alone served as controls.Results The latency to delivery was 58 ± 34 days with progesterone and 64 ± 51 days with placebo (p = 0.83), compared to 2 ± 2 days in the control group (progesterone and placebo vs control p < 0.001). The rate of preterm birth before 34 weeks was 34 % after progesterone and 38 % after placebo (p = 0.34) compared to 100 % in the control group (p < 0.001 respectively). The composite neonatal morbidity (p = 0.65) and neonatal intensive care unit admission (p = 0.12) were comparable between the progesterone and placebo groups, but lower in these groups compared neonates of women in the control group (p < 0.001 respectively). Conclusion Maintenance treatment with progesterone gel and placebo were equally effective in preventing preterm birth among women with preterm labor. Both progesterone and placebo prolonged pregnancy more effectively than intravenous tocolysis alone. We hypothesize, that the acidic gel base reinforced the biochemical barrier at the uterine cervix, which counteracted ascending pathogen invasion and subsequent inflammation and thereby delayed preterm birth. The present results suggest, that non-hormonal agents that reinforce the biochemical cervical barrier can be useful for the prevention of preterm birth in clinical practice.
Efficacy of Liraglutide in Patients With Diabetic Nephropathy: A Meta-Analysis of Randomized Controlled Trials
Authors: Mali Niroj , Su Feng , Ge Jie , Fan WenXing , Zhang Jing , Ma Jingyuan
Published: October 2021

Background: The efficacy of liraglutide to treat type 2 diabetic nephropathy (T2DN) remains controversial. Thus, we conducted this meta-analysis to systematically evaluate the clinical effect of liraglutide on T2DN patients. Methods: Eight databases (PubMed, Web of Science, the Cochrane Library, EMBASE, Chinese National Knowledge Infrastructure (CNKI), Wanfang database, China Science and Technology Journal Database and China Biology Medicine Database (CBM)) were searched for published articles to evaluate the clinical efficacy of liraglutide in subjects with T2DN. The Revman 5.3 and Stata 13 softwares were used for analyses and plotting. Results: A total of 18 randomized controlled trials (RCTs) with 1580 diabetic nephropathy patients were screened. We found that the levels of UACR, Scr, Cysc were lower in experimental group of T2DN patients treated with liraglutide than control group intervened without liraglutide. Liraglutide also reduced the levels of blood glucose (including FBG, PBG and HbA1c), body mass index (BMI), and anti-inflammatory indicators (TNF–α, IL-6). However, there was no significant difference in BUN and eGFR between experimental group and control group.Conclusions: Liraglutide reduced the levels of Blood Glucose, BMI, renal outcome indicators and serum inflammatory factors of patients with T2DN, suggesting the beneficial effects of liraglutide on renal function.
Investigation of Blood-Brain Barrier Disruption in an Animal Model of Mania Induced by d-Amphetamine
Authors: Géa Luiza Paul , Wollenhaupt-Aguiar Bianca , Watts Devon , Maich William , Kapczinski Flavio , Sharma Roohie , Mishra Ram , Rosa Adriane Ribeiro , Frey Benicio N.
Published: October 2021

Background: Bipolar disorder (BD) is a recurrent chronic psychiatric disorder. Evidence indicates that many individuals with BD exhibit high serum levels of inflammation and oxidative stress markers, which are further associated with mood symptoms and cognitive dysfunction. Due to the crosstalk between the periphery and central nervous system in BD, the disruption of the blood-brain barrier (BBB) has been proposed as a key mechanism of the pathophysiology of the disorder. This study aimed to investigate claudin-5 expression – a major protein of the BBB – in the brain of an animal model of mania induced by d-amphetamine (AMPH) and evaluate the effects of treatment with lithium. Results: AMPH-injected animals exhibited increased overall activity in the open field test. In the serum, TBARS levels were augmented in the lithium-treated groups, regardless of AMPH injection, while TNFα was not detected. In the brain, TBARS and TNFα did not differ between groups but were positively and strongly correlated in the ST of AMPH-injected rats. Contrary to the primary hypothesis, AMPH and lithium injections did not affect brain claudin-5 protein levels.Conclusions: This is one of the first attempts to investigate the effects of AMPH on BBB integrity. Although no evidence of BBB disruption was found in the current study, our results provide evidence and rationale for future research to elucidate the importance of such alteration in BD.
Sex-specific Effects of Localized Muscle Fatigue on Upper Body Kinematics During a Repetitive Pointing Task
Authors: Yang Chen , Côté Julie N.
Published: October 2021

BackgroundFemales are reported to have a higher risk of musculoskeletal disorders than males. Among risk factors for musculoskeletal disorders, the mechanism of muscle fatigue remains unclear. Especially how females and males adapt to localized fatigue is poorly understood. The purpose of the study was to examine the sex-specific effects of fatigue location on shoulder, elbow and spinal joint angles, and angular variabilities during a repetitive pointing task.MethodsSeven males and ten females performed a standing repetitive pointing task when they were non-fatigued (NF), elbow-fatigued (EF), shoulder-fatigued (SF) and trunk-fatigued (TF), while trunk and upper body tridimensional kinematic data was recorded. Joint angles and angular variabilities of shoulder, elbow, upper thorax, lower thorax, and lumbar were calculated. ResultsResults showed that shoulder angles changed the most after EF in males, but after SF in females. The similarities between sexes were that SF increased the variabilities at upper (lateral flexion: 0.15° greater than NF, rotation: 0.26° greater than all other conditions) and lower thorax (lateral flexion: 0.13° greater than NF, rotation: averagely 0.1° greater than all other condition) in both sexes. TF altered upper thorax variability (0.36° smaller than SF), lower thorax angle (lateral flexion: 3.00° greater than NF, rotation: 1.68° greater than SF), and lumbar angle (averagely 1.8° smaller than all other conditions) in both sexes. However, females had greater lower thorax angle (lateral flexion: 8.3° greater, p=0.005) as well as greater upper (rotation: 0.53° greater, p=0.006) and lower thorax (rotation: 0.5° greater, p=0.007; flexion: 0.6° greater, p=0.014) angular variabilities.ConclusionsThe overall greater lower and upper thorax angular variabilities suggested a more unstable spinal movement pattern in females. The kinematic differences between sexes highlighted a few sex differences in adapting the localized muscle fatigue.
Costimulation of TLR8 responses by CXCL4 in Human Monocytes Mediated by TBK1-IRF5 Signaling and Epigenomic Remodeling
Authors: Ivashkiv Lionel B. , Yang Chao , Bachu Mahesh , Brauner Caroline , Yuan Ruoxi , Du Yong , Kioon Marie Dominique Ah , Chesi Giancarlo , Barrat Franck
Published: October 2021

CXCL4 regulates responses of immune cells to endosomal TLRs and has been implicated in the pathogenesis of inflammatory and fibrotic diseases. However, mechanisms by which CXCL4 modulates TLR responses, and its functions in monocytes/macrophages, are still unclear. Here we report that CXCL4 changes the profile of the TLR8 response in human monocytes by selectively and dramatically amplifying inflammatory gene transcription and IL-1β production while partially attenuating the IFN response. Mechanistically, costimulation by CXCL4 and TLR8 synergistically activated TBK1/IKKε and repurposed these kinases towards an inflammatory response via coupling with IRF5, and by activating the NLRP3 inflammasome without the need for a second signal. CXCL4 strongly induced chromatin remodeling in a cooperative and synergistic manner with TLR8 signaling, inducing de novo enhancers associated with inflammatory genes. These findings identify signaling and epigenomic mechanisms that underly synergistic activation of inflammatory genes by CXCL4 and TLR8, provide a new paradigm for modulation of TLR responses that is relevant for cytokine storm, and suggest targeting the TBK1/IKKε-IRF5 axis may be beneficial in inflammatory diseases.
Quercetin inhibits intrahepatic cholangiocarcinoma by inducing ferroptosis and inhibiting epithelial-mesenchymal transformation via the NF-κB pathway
Authors: Song Yinghui , Zhang Zhihua , Chai Qin , Xia GuoYi , Yu Zhangtao , Yang Ranzhiqiang , Huang Junkai , Li Yuhang , Peng Chuang , Jiang Bo , Liu Sulai
Published: October 2021

Intrahepatic cholangiocarcinoma (ICC) is a rare high-fatal hepatobiliary malignancy, the treatment option of ICC is very limited, and the prognosis is also poor. Recently, emerging evidence has shown the potential of quercetin (QE) for cancer therapy. We explored the effect and mechanism of QE on ICC in vitro and in vivo. CCK-8 assay and Clonogenic assay showed that QE could inhibit ICC cells proliferation and survival. PI staining suggested QE could induce ICC cells arrest in G1 phase. AV/PI staining suggested QE could promote ICC cells apoptosis. Wound Healing Assay and Transwell chamber experiment suggested QE could inhibit ICC cells EMT. RNA-seq, the changes in the structure of mitochondria by electron microscopy and the key markers of ferroptosis (free iron ions, MDA, SOD, GPX4) were supported QE could promote ferroptosis in ICC cells. Molecular docking showed that QE had direct interaction with NF-κB and GPX4. In vivo, treatment with QE inhibited tumor growth and prolonged survival time of tumor-bearing nude mice. Our data for the first time suggest that QE is a new ferroptosis inducer and combinative treatment of inhibiting NF-κB in ICC cells by inducing ferroptosis and inhibiting EMT, which will hopefully provide a prospective strategy for ICC patients.
The Effects of the MTHFR 677C>T (rs1801133) Genetic Variant on Susceptibility and Disability in Multiple Sclerosis Patients are Mediated by Homocysteine but Not Folate Levels
Authors: Ribeiro Claudia Mara , Oliveira Sayonara Rangel , Flauzino Tamires , Alfieri Daniela Frizon , Simão Andrea Name Colado , Lozovoy Marcell Alysson Batisti , Maes Michael , Reiche Edna Maria Vissoci
Published: October 2021

We investigated whether the MTHFR 677C>T (rs1801133) variant and plasma homocysteine and folate are associated with multiple sclerosis (MS), disability, disability progression, and inflammatory biomarkers. We included 163 MS patients categorized using the Expanded Disability Status Scale (EDSS) as mild (EDSS<3) and moderate/high (EDSS≥3) disability, and 226 healthy controls. Disability progression was evaluated using Multiple Sclerosis Severity Score (MSSS) and the MTHFR 677C>T was genotyped using real time polymerase chain reaction. The levels of some inflammatory biomarkers and inflammatory activity index (IAI) were determined. There was no association between the MTHFR 677 C>T genotypes and MS, EDSS, and MSSS (p>0.05). Plasma folate and homocysteine were higher and adiponectin was lower in MS patients than controls (p<0.001). Moreover, 21.8% of the EDSS variance was explained by age, IAI and C-reactive protein (CRP) (all positively associated); 10.9% of the MSSS variance was predicted by IAI and CRP (both positively) and vitamin D3 (negatively), whereas 54.4% of the MS-EDSS-MSSS score was explained by the regression on age, IAI, homocysteine, folate, and CRP (all positively) and adiponectin, body mass index, and vitamin D3 (all negatively), female sex and the MTHFR 677 TT genotype. In patients and controls, 16.6% of the variance in the homocysteine was explained by the MTHFR 677 TT genotype and age (both positively), folate (negatively) and male sex. In conclusion, the MTHFR 677C>T variant was not directly associated with MS, disability, and disability progression; however, the TT genotype showed indirect effects on MS susceptibility and disability mediated by homocysteine.