bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparative Study of Field Development Scenarios of the Elk City Gas Reservoir using Reservoir Simulation
Authors: Wigwe Marshal E. , Basit Mohammad I. , Elldakli Fathi , Dambani Samuel , Mmuenu Rosemary , Soliman Mohamed Y.
Published: August 2020

Well placement is a critical aspect of Field development planning in order to fully understand the extent of the field to further effectively develop and drain the field. In most cases, the structure of the formation is initially unknown, in addition to other geologic and petrophysical properties that will aid in calculation of GIIP and EUR. The use of analogy alongside decline curve analysis have been great starting points to drill the first few wells while additional data are being collected to enable the use of more advanced tools like reservoir simulation for full-field development study.

This paper presents a study on the production of a gas field and the contributions from seven vertical wells that had been drilled. These seven wells are designated wells p1 to p7. Wells p1, p2 and p6 are located on the anticlines, p3 and p7 are located on the front edge of the reservoir, and p4 and p5 are placed at the center between the two domes. Contour, isopach, isopermx, isopermy and isoporosity maps were used for grid generation, while other modeling software were used for reservoir simulation and visualization. Four base cases were simulated to study the effects of grid sizes and use of local grid refinement (LGR). Four additional "experimental" cases were studied to explore alternative well placement and potential benefit for horizontal and hydraulically fractured wells.

The two poor performing wells (p3 & p7) were considered as good candidates for hydraulic fracturing. Unfortunately, the results were not promising as both wells showed less than 1% improvement in gas recovery and hence may not justify the investment. The use of alternative well placements scenarios for these wells resulted in about 9% incremental recovery while conversion to horizontal wells added a further 3% in recovery. This last investment will be further justified if a dual lateral is considered rather that two separate wells.
Water Control in High-Water-Cut Well Using Cutting-Edge Polymers: Production Optimization Methodology Applied in Burgan Field, Kuwait
Authors: Al-Fadhli Wuroud , Kurma Ravi , Bhatia Kutbuddin , Alboueshi Alaa , Abdelbaky Amr
Published: August 2020

A significant challenge in the mature South Kuwait Burgan field is assuring maximum hydrocarbon flow through high water-prone sandstone intervals. Recently, water control or conformance treatments have been considered to make oil production from these reservoirs more economically feasible. This paper discusses the application of a novel downhole chemical methodology that has created a positive impact in overall productivity from this field.

The production profile in this field has been challenging in terms of increasing water volume, which poses a great threat to continued economic viability and may lead to lower production rates, a reduction in recoverable reserves, and premature abandonment. Some of the production-gathering centers cannot handle the ever-increasing volumes of produced water and are operating beyond design capacity. In order to solve this challenge, a downhole chemical treatment was modified as a fit-for-purpose treatment to address the unique challenges of electric submersible pump (ESP)-driven well operations, formation technical difficulties, high-stake economics, and high water potential from these formations. A unique hydrophobically modified water-soluble polymer (HRPM) was implemented in a high water-cut well to selectively reduce water production. Because this well was producing with an ESP, the treatment was pumped down the annular space. A preflush was pumped ahead of the HRPM treatment to remove deposits that could prevent the polymer from effectively adsorbing to the rock surface. The treatment was then overdisplaced with brine.

This technology incorporates an HRPM that is adsorbed on the rock surface, resulting in the alteration of rock surface characteristics. The hydrophobic modification to the base polymer chain adds unique associative properties to the system, which selectively reduce the water's effective permeability in the reservoir, impeding water flow and facilitating increased hydrocarbon flow. A direct result of the implemented treatment is that the post-operation well test and production data show a high sustained hydrocarbon production at a smaller choke size with significantly reduced water cut. This successful treatment confirmed the optimized conformance technology as a solution for the first well in this field.

In order to achieve maximum reduction in water production, this technology is customized based on the temperature and permeability of the treatment zones, thus ensuring it is fit-for-purpose. Furthermore, this paper summarizes the candidate selection, design processes, challenges encountered, production response, and lessons learned from this treatment and can be considered a best practice for addressing high water production challenges in similar conditions in other fields.
A Novel Algorithmic Design and Implementation for Predicting Crude-Oil PVT Properties
Authors: Olatunji Oladipo , Mogbolu Jonathan
Published: August 2020

With the cusp in the advances in Artificial Intelligence and Machine Learning, there have been several development of AI-based PVT models. Although they have offered some advantages in one way or the other, their easy implementation and flexibility have been limited due to computational complexities, and the relatively vast amount of memory allocation required. Also, some of the classical PVT models are wrought with certain setbacks. Some of these models are only accurate within specific conditions of crude-oil type and properties, and hence fail when there are small variations in crude oil properties or when there are different genetic sources or prevalence for the crude oil type. Here in this paper, we have developed a novel algorithmic design and implementation based on a combination of mathematical combinatorics and linear algebra. Using the superposition principle in an ingenious way, we built new, improved and better models from existing PVT correlations and models. Our resulting algorithm known as IntelliPVT offers more robust, more accurate and faster PVT model predictions. IntelliPVT has been written both in MATLAB and Python. Using real field data published in literatures, journals and books, and compared with other realistic conventional PVT correlations, IntelliPVT outperformed these correlations and predicted Crude-Oil PVT properties of Formation Volume Factors, Solution Gas-Oil Ratios, Bubble Point Pressures, Viscosities, and Crude oil compressibilities to the least Root Mean Square Error, R-Squared values between 0.91 and 0.99, and the lowest minimum mean square error with very high computational speed. The novel algorithm offers more accurate results with a faster implementation and applicability to all crude-oil types including heavy oils. Its implementation will ensure a better subsurface characterization, improved reservoir management as well as surface design along the whole spectrum of the oilfield lifecycle.
Benefits of Real-Time LWD Static Borehole Image in Reservoir Navigation Service
Authors: Toyobo Oluwaseun , Imomoh Victor , Okafor Rosemary
Published: August 2020

The world's increasing demand for energy has driven energy service companies to develop newer and cost-effective technologies. Such technologies include borehole imaging and geosteering tools, embedded with smart sensors, used for reservoir navigation service. Reservoir navigation service utilizes real-time drilling and LWD (logging-while-drilling) data to optimally position the wellbore relative to a reservoir geometry, given certain drilling and geological uncertainties. To reduce the geological uncertainty, logging with real-time borehole imaging service has proved to be very useful.

The term borehole imaging refers to the generation of logs that are based on the circumferential measurement of a petrophysical parameter along a borehole. LWD borehole imaging provides 100% borehole coverage, high azimuthal and vertical resolution. From the detection of beds to bedding orientation, from lithological boundaries to other structural discontinuities, borehole imaging helps to improve the subsurface geological interpretation during reservoir navigation services.

This paper will review the structural, sedimentological and petrophysical benefits of real-time LWD static borehole images. It will also discuss how the incorporation of borehole imaging in reservoir navigation can improve well placement for optimum hydrocarbon recovery.
Application of ANN in Predicting Water Based Mud Rheology and Filtration Properties
Authors: Oguntade Tomiwa , Ojo Temiloluwa , Efajemue Ewarezi , Oni Babalola , Idaka Joy
Published: August 2020

With the evolution of technology, data is a major sector of engagement in the oil and gas industry. Various studies are done on the subject of artificial intelligence and Artificial Neural Networks are commonly employed. The study seeks to apply artificial intelligence to the prediction of water based mud rheology and filtration properties. Artificial Neural Network (ANN) from MATLAB was used to predict the properties wherein a number of samples were tested in the laboratory and the values from experimentation were input into the neural network and trained to predict more values without physical experimentation. Plastic Viscosity, Apparent Viscosity and Yield point were the rheological properties considered while filtrate volume and cake thickness were the filtration properties looked into. The two statistical parameters used for selecting the neural network with the best predictions were correlation coefficient (R2) and mean squared error (MSE). The ANN predictions were also validated with a new data set. ANN with 15 neurons in the hidden layer and 8 neurons in the hidden layer gave the best predictions for rheology and filtration respectively. The hidden layer with 15 neurons gave an R2 value of 0.92234 and the MSE value was 9.2494. The hidden layer containing 8 neurons gave an R2 value of 0.99978. and an MSE value of 0.694173.
Success Story of Well Interventions Identified via Surveillance Maps
Authors: Dennar Linda , Adebayo Adejoke , Uyouko Ime , Ahmed Suleiman , Nwandu Somto , Chidiebere Christabel
Published: August 2020

Surveillance mapping is a reservoir management process first developed by Shell and Exxon for the Brent field in the UK North Sea. It involves an integrated reservoir-wide management process with the objective of not only understanding subsurface dynamics during production but also delivering a future work programme that will maximize reservoir potential.1

Surveillance Mapping was recently deployed in candidate selection for Short Term Oil Generation and Work Over activities in the Zoom reservoir located in the Niger Delta area. The Zoom reservoir is an East West Trending anticlinal structure, predominantly shore face deposits with incised channels. The Zoom reservoir, which is a large structure, commenced production in August 1991 and 50MMstb of oil has been produced to date. Thirteen oil wells have produced from the Zoom reservoir. These wells were drilled in phases post updates of various development plans published in 2003 and 2010. Production performance across the reservoir started declining due to natural water encroachment, poor productivity issues, well and flow line sabotage etc. This triggered an aggressive strategy to identify suitable remedial action that would support the drive for resuscitating the wells in a cheap and safe manner.

Five wells were identified as potential Short-Term Oil Generation candidates and have been executed successfully with good rewards. This paper will review the success story of candidate wells scoped from the surveillance map and its impact on the optimization of the reservoir potential.
Novel Analytical Technique for Evaluating Static Mud Filtration During Drilling of Horizontal Wells
Authors: Owoseni Sunday , Alonge Oluwaseun , Isehunwa Sunday
Published: August 2020

Horizontal wells have become increasingly important in the development of oil and gas fields due to their added advantages such as increased offtake rates, high drainage areas, and reduced pressure drawdowns. However, many horizontal wells experience rapid production decline due to near-wellbore formation damage caused during drilling and completion operations. Formation damage caused during drilling and completion operations can be reduced if the mechanism of filtration through mud cakes is well understood. Several published analytical models tend to neglect the very important component of filtration around the heel of horizontal wells. A model that describes static mud filtration in horizontal wells during drilling, incorporating damage around the heel was developed and solved using an approximate analytical technique. The results show that drilling mud filtration can be higher in horizontal than vertical wells. It was also observed that filtration at the heels of horizontal wells can be very significant, with the radius of curvature having a great effect on the filtrate volume. The analytical solution also confirmed observations made by several previous researchers that the properties and thickness of mud cakes and the viscosity of the drilling muds affect the volume of mud filtrates during the drilling of horizontal wells.
Alternative Crude Oil Evacuation Project in Swampy Terrain; Challenges and Lesson Learnt
Authors: Kingsley-Akpara Chiamaka , Ezuka Ifeanyi , Owarume Michael
Published: August 2020

The entire crude oil exploration and production business chain is not complete without an effective evacuation system especially in difficult terrains. The conventional evacuation means is via pipeline; however, this paper presents the economic feasibility of an alternative crude oil evacuation project in OML 42, in the Niger Delta location; lessons learnt and high impact variables in both capital and operating expenditures. The authors share a broad concept of the potentialities, the cost of operations, and some of the problems which were encountered in deploying alternative crude evacuation system.
Field Development Planning based on Static, Dynamic and Geomechanical Modelling of X Field, Niger Delta, Nigeria
Authors: Ezebialu Kenechukwu , Ubituogwale Michael , Odegua Eunice , Idehen Abigail
Published: August 2020

The "X" field is prospective but largely underdeveloped as only four vertical wells have been drilled. The purpose of this project was to prepare a field development plan by building a 3D static geologic reservoir model and estimating the in-place hydrocarbon volumes, simulating the static model to understand how the reservoirs would perform with time and building a 1D Mechanical Earth model to understand wellbore stability. The geological consistency of this model required a cross domain integration of seismic data, well log data and subsurface knowledge across the various subsurface disciplines. Three reservoirs were mapped and well correlation was carried out across the four wells (W–E). Depositional environments were reconstructed using well log information and other available geologic information. Three major lithofacies were interpreted: sands of the upper shoreface, sand-silt-shale intercalation of the lower shoreface, and marine shales. The result from the petrophysical analysis and property modeling showed that the average porosity is approximately 30%, permeability is majorly around 100mD and water saturation range from 0.347-0.461%. In-place volume estimated using the model generated was 568 MMSTB of oil. The model was simulated using different scenarios to forecast field performance. From the 1D Mechanical Earth Model (MEM) constructed, it was observed that the dominant stress regime of this field is typical of normal faults and the orientations of these stresses are in harmony with the regional stress regime of the Niger Delta. By using 1D MEM data, wellbore stability analysis for problematic layers was performed and the optimum mud weight was recommended to prevent common drilling problems and at the same time to maintain stable wellbore.
Deployment of a Digital Oil Field Technology Solution for Real-Time Monitoring and Production Optimization of a Gas-Condensate Field in Western-Niger Delta Region of Nigeria
Authors: Kanu Aime , Afolabi Folorunso
Published: August 2020

In oil and gas fields, the availability of data enables front-line operators and asset teams make informed decisions to intervene, troubleshoot and optimize the production system for oil and gas production targets to be achieved. In most cases, the data is not available thus frontline operators reactively intervene to address production challenges which inadvertently leads to equipment and facility shut-down, unscheduled downtime and ultimately significant production deferment. We have hitherto seen a transition to data-driven decision systems, also referred to as Digital Oil Field (DOF) technology.

DOF Technology is the integration of data, automation and instrumentation technologies that provides a realistic overview of field processes which helps monitor operations for proactive intervention in order to reduce cases of production deferment. It entails real-time monitoring for improved Well and Reservoir Facility Management (WRFM), Production Optimization, Asset Integrity Management and most importantly overall improvements to safety of personnel, that is, minimizing the risk of exposure to high pressure systems at wellhead locations and ensuring significant cost savings. The data gathering framework uses Random Phase Multiple Access (RPMA) and IIOT (Industrial Internet of Things) network anchored on a cloud platform. These services are owned and operated by a local fully Nigerian owned company.

Within the framework of DOF Technology, high-fidelity real-time monitoring sensors have been deployed to 8 gas-condensate producing wells flowing to a Non-Associated Gas (NAG) facility with 5 Processing trains utilizing Joule-Thompson Technology for hydrocarbon dew pointing. The facility has a total installed capacity of 465 MMscf/d and delivers custody of the processed gas according to West African Gas Pipeline (WAGP) specifications via two legacy sales lines 16" and 20" respectively to Nigeria Gas Company (NGC).

This paper presents the application and deployment of the DOF Technology Solution for Real-Time Monitoing of Gas Wells in remote locations to primarily ascertain health status of producing wells, flow assurance and deliverability to customer for power generation and industrial development.
The New Faces of Corrosion and Damage Detection in Oil and Gas Facilities: A Brief of What has Worked So Far and How it Can Work for You
Authors: Alum Moses , Eze Tobechukwu
Published: August 2020

The Oil and Gas processing plant is replete with pressurized static equipment such as Pressure vessels, pipelines/risers, pipings, tanks, Pressure safety valves (PSV) and Heat exchangers usually made of metal alloys. In addition, these facilities also consist of massive metallic structural components such as offshore Jacket legs, platform supports, FPSOs Hulls, decks, flare stacks etc. The integrity of these equipment and structures has been and will continue to be a major cause of concern in the oil and gas industry especially as facilities age.

Analysis of major refinery incidents over the past 35 years has shown that loss of containment due to corrosion contributed to more than 25% of the root cause of these incidents. On a larger scale, corrosion in its different forms contributes to more than 42% of the failure mechanisms in all engineering structures.

Despite improvement in engineering designs and materials, this trend still persist in the 21st century, therefore determining, predicting, monitoring and controlling corrosion to avoid failures and extend the life of facilities has become an industry of its own. As a result, new Inspection methods, strategies, techniques, equipment and/or software to determine damage mechanisms, analyze Inspection results, predict time-to-failure and ultimately propose solutions to mitigate and avoid corrosion failures abound. However the Inspection effectiveness of these novel techniques is much more important than the novelty of the technology in itself.

This paper shares experiences on some of the real-life case studies where some of these new techniques and methods have been applied and it worked. This ranges from pulsed eddy current to determine corrosion under insulation, crawler technique for in-service water tank inspection, flare tip in-service inspection using drones, and inspection of unpiggable pipelines. It is believed that the feedback can help operators make quicker decisions on what next inspection tool/technique to select from, given an array of multiple new Corrosion and damage detection methods available.
Determination of Heavy Metals Concentration in Nigeria Tar Sands
Authors: Anochie Victor , Agogo Hezekiah , Ogolo Oghenerume , Elechi Anthony
Published: August 2020

Nigeria's bitumen deposits are estimated at 37 billion barrels in reserve, covering 120 kilometers costal belts of the South-Western part of the country, with most of the reserves in Ondo state. With growing interests in the extraction of bitumen in Nigeria, it is important to note that development of tar sand contributes toxic metals to the environment. This research is focused on the determination of heavy metals concentration in Nigeria tar sands. Tar sand samples were collected from three different locations namely Aye Rail head, Loda Irele, and Agbabu in Ondo State. Heavy metal analysis was carried out to determine the concentrations of eight metals; Mn, Cd, Pb, Fe, Zn, Ni, Cr, and Cu using atomic absorption spectrophotometry techniques and energy dispersive x-ray Spectroscopy. Results obtained indicates that Fe had the highest concentration across the three samples with a concentration of 4.8 ppm, 6.075 ppm and 114.65 ppm in Aye Rail head, Loda Irele, and Agbabu samples respectively. Pb was not detected in Aye Rail Head sample, as Cd and Cr were not also detected in Loda Irele sample. For Aye Rail head sample, concentration of metals was low except for Fe, Ni, and Cr with values above the recommended standard set by WHO and NIS. Similarly, for Lori Irele sample, Pb, Fe and Ni showed higher concentrations. While the sample from Agbabu indicated a higher concentration of metals such as Mn, Cd, Pb, Fe, Ni and Cr, making it more toxic in terms of heavy metals. Amongst the heavy metals investigated, only Zn and Cu were below the recommended limits in the three samples. Results from this study provides information for exploration activities and environmental impact assessment of the region.
Numerical Based Optimization for Natural Gas Dehydration and Glycol Regeneration
Authors: Okoro Emmanuel E. , Sanni Samuel E. , Olatunji David I. , Igbinedion Paul , Oni Babalola , Orodu Oyinkepreye D.
Published: August 2020

Exergy is a simultaneous measure of the quantity and quality of energy. This helps to identify the inefficiency of the process and allows engineers to determine the cause and magnitude of the loss for each operating unit. Natural gas dehydration via absorption using glycol is the most economically attractive approach, and this advantage can only stand if lower energy consuption relative to adsorption process can be obtained; thus, timely prediction and identification of energy consumption is vital. In this study, an energy utilization predictive model for natural gas dehydration unit energy consumption was developed. This numeric approach will increase accuracy and reduce the high simulation time often encountered in using other simulation software. To achieve this novel idea, a multilayer perceptron approach which is a deep learning neural network model built on python using Tensorflow was adopted. The model used for this study is implemented to further increase the accuracy of the output set variables which are matched with simulation result. Since we are dealing with a non-linear function, rectified linear unit (ReLU) function was used to activate the neurons in hidden layers so as to strengthen the model to be more flexible in finding relationships which are arbitrary in the input parameter. These input parameters are fed into the steady state model and sent to various branches of fully connected neural network models using a linear activation function. Each branch produces a result for each output parameter thereby fitting the model by reducing the mean squared error loss. The training data were not normalized but left in their original form. Results showed that the adopted double hidden layer with 5 branches are uniquely branched in such a way that it predicts values for a single output variable, which is an upgrade to the former work done with a single hidden layer in literature. The accuracy analysis showed that the proposed double hidden layer approach in this study out-performed the single hidden layer.
The Evaluation of Coconut Fibre as a Loss Circulation Material in Drilling Operation
Authors: Owolabi Ololade , Emmanuel Ayodele , Okafor Ikechukwu , Daniel Ngwu , Igbine Anita , Gloria Maduabuchi
Published: August 2020

This study attempts to show the effectiveness of using coconut fibre as a loss circulation material in drilling operation. The research incorporated a practical approach. Laboratory experiments was conducted to design drilling muds with the desired loss circulation materials. Their rheological properties and permeability plugging ability was ascertained and compared to determine the most effective loss circulation material blend. To formulate the loss circulation materials, the coconut fibre was processed and particle sizing distribution was conducted on the processed coconut fibre. The coconut fibre was separated into coarse sizes (3350, 2360, 1700 and 1180) and medium be sizes (850 and 425). The distinction between the formulated muds is the loss circulation material combination in them. The three drilling muds had medium-coarse coconut fibre ratio of 60:40, 40:60 and 30:70. The rheological properties of each drilling mud was determined to show suitability of use as a drilling fluid. Experimental results showed similar rheological properties for each mud and they are all suitable for use. The PPT test and ES test were conducted on the mud samples as well. These experiments were conducted at a desired temperature of 200°C and filter press pressure of 1500psi. The thickness of the produced mud cake was measured.

By comparing the amount of unrecovered fluid (fluid loss), the least fluid loss was observed in the mud with medium-coarse coconut fiber combination of 60:40
Subsea Pipeline On-Bottom Stability Optimisation
Authors: Iyalla Ibiye , Hossain Mamdud
Published: August 2020

Current knowledge and understanding of pipeline on-bottom stability is based on research programmes from the 1980's such as the Pipeline Stability Design Project (PIPESTAB) and American Gas Association (AGA) in Joint Industry Project. These projects have mainly provided information regarding hydrodynamic loads on pipeline and soil resistance in isolation. In reality, the pipeline stability problem is much more complex involving cyclic hydrodynamic loadings, pipeline response, soil resistance, embedment and pipe-soil-fluid interaction. Thus, resulting in the use over-conservative analysis approach and costly stabilisation techniques for subsea pipeline stability.

Computational Fluid Dynamics (CFD) modelling was used to investigate and establish the interrelationship between fluid (hydrodynamics), pipe (subsea pipeline), and soil (seabed). The effect of soil types, soil unit weight, pipe diameter and weight on embedment was examined. The overall pipeline stability alongside pipeline diameter and weight and hydrodynamic effect on both soil (resulting in scouring) and pipeline was also investigated. The use of CFD provided a better understanding of the complex physical processes of fluid-pipe-soil interaction. The results show that soil type has a significant effect on the degree of embedment when considering the combined effect of pipe weight and diameter. The analysis also show that embedment is a result of the combined effect of pipe displacement and seabed scouring.

This work shows the weakness of the current approach to pipeline on-bottom stability analysis and its inherent over-conservatism leading to the use of costly stabilisation techniques.
Towards Transparency in Oil Spill Management in Nigeria
Authors: Ekperusi Abraham O. , Imiuwa Maurice E. , David Adekunle O.
Published: August 2020

The Nigerian oil and gas industry has undergone significant changes in exploration, production, transportation and processing of crude oil and refined products due to several key reforms in the sector over the years. These reforms have positioned the upstream, midstream and downstream of the petroleum industry for global competitiveness. Despite these feats, the petroleum industry has a long history of giving lukewarm attention to the issues of environmental management, especially in the Niger Delta region where oil operations are prevalent. The unsustainable exploitation of natural resources by the oil and gas industry, and the reactionary approach of third party activities have resulted in the significant degradation of ecological systems, adversely affecting biological diversity and life support functions for local communities. The legal, regulatory and institutional framework in place has proved inefficient for the holistic protection of the environment, economic livelihood and health of people in the region. As we move into the next decade, there is need for all concerned stakeholders in the oil sector to proactively work together to map out a new path to sustainable exploration of natural resources and improve transparency in the management of oil spill to halt and reverse the environmental degradation in the region.
£55M Shell Petroleum Development Company's Compensation to the Bodo Fishermen and Community: The Effectiveness of Polluter Pays Principle in the Liability Settlement
Authors: Oranye Nkechinyelu , Adenikinju Adeola
Published: August 2020

The Organisation for Economic Cooperation and Development (OECD) defines the Polluter Pay Principle (PPP) as that which ensures the environment is remedied close to or its original state following an action or inaction that results in the pollution of the environment. It provides for compensation of those affected by the impact of the pollution. The principle includes prevention of pollution, measures for control, the cost for clean-up and the liability. PPP is thus, an environmental principle which has developed over the years and has increasingly been accepted especially in the oil and gas industry. In the recent past, in an out-of-court settlement, Shell Petroleum Development Company (SPDC) agreed to pay Bodo community in the Niger Delta, the sum of £55 million for two major oil spills that resulted in environmental degradation and loss of livelihood. This paper investigates, in the light of the principles of International Environmental Law, the effectiveness of PPP in the liability settlement by SPDC to the Bodo community. Through an analytical approach, this paper compared the settlement to the liabibility settlement mechanism as outlined by the Civl Liability Convention which entered into force in 2003. It discovered that the settlement catered not just for the compensation of the community but also for the remedition of the environment based on international standards. This study is relevant; highlighting the need for oil companies to take all necessary precautions to ensure the environment is protected during their operation. This is important for attainment of the sustainable development goals.
A Case of Achieving Sustainable Annular Sealing in a Deepwater Marginal Nigerian Field
Authors: Musah Mobolaji , Asokhia Benjamin , Bagal Joseph , Adeniyi Dapo , Chum Wai Hoe
Published: August 2020

The industry has been relying on cement as primary method for annular sealing. The initial evaluation considers a formation integrity test and a cement bond log. This shows good results in 85% of the cases and cement squeeze is the main remediation method. The ultimate measure of the sealing performance is production: more than 50% of the wells have sustained casing pressure in the B-annulus or are producing in degraded mode. Additional solutions are required to improve the sustainability of the industry.

The present paper discusses a case history in a marginal well in Nigerian deepwater. Primary cement evaluation was successful, in line with the industry statistic of 85% successful cases. However, production started with 60% Basic Sediments and Water (BS&W) and after six months of production, the well was shut-in due to excessive gas production. The investigation identified that the target Turonian oil sand was separated by thin shales from bottom water and gas cap.

In the sidetrack, two Well Annular Barrier (WAB) were used to augment the cement. The WAB is a metal-expandable packer that sets in open hole to assure sealing. One WAB was installed between the oil zone and the gas cap, and another one between the oil zone and the bottom water. The operation was successfully executed and the WABs expanded in wet cement after bumping the plug. Three years later, the well is still producing with 0.2% BS&W.

This paper discusses the well conditions that contributed to insufficient cement sealing, the WAB application in the field, and the field results.
Enabling Reservoir Management Excellence through Real Time Surveillance of an Unmanned Onshore Gas-Condensate Field Platform
Authors: Okpala Justin , Adedokun Oluwasegun , Jaja Adagogo , Olubukola Olubukola , Ogugua Emeka , Olayomi Joseph , Aitokhuehi Inegbenose , Korede Peters , Awonuga Kunle , Eruvbentine Obor
Published: August 2020

The increasing need to acquire reservoir surveillance data for agile reservoir management continues to drive the popularity of real-time data acquisition and transmission technology solution. This is even more important for remote or unmanned well locations. A fit-for-purpose real-time data acquisition and surveillance system, leveraging the Sonam Field application, was implemented at a newly installed and unmanned platform for two Field X gas-condensate reservoirs, Onshore Nigeria. Value realized within a two-month period stands at $0.23MM.

This paper discusses the implementation of Real-Time Reservoir Management (RTRM) solution on this unmanned platform. Two NAG wells were drilled in Field X from this unmanned platform with each completed in a gas-condensate reservoir. The RTRM solution setup was slightly modified from the Sonam application to fit the location. Sensors for casing and flowline pressure/temperature data, transmitters, including solar panels and batteries to provide continuous power to the system, were introduced.

The RTRM installation on this facility has fostered collaboration between the Asset Engineers and Operations. Opportunistic shut-ins were leveraged to acquire data for Pressure Transient Analysis (PTA) used to determine completion efficiencies of the wells for optimal production. Additionally, significant time that would have been spent on logistics planning, as well as personnel and material mobilization for this PTA operation were avoided. It has also enabled proactive decisions to be made on well/facility issues and allowed interventions to be appropriately scheduled.

This paper reinforces the tremendous value of the RTRM and highlights the collaboration between multidisciplinary functional groups to overcome challenges of security and power to achieve success.
Elevated levels of miR-483-5p in oocytes aggravates premature ovarian insufficiency induced by CDDP by targeting the FKBP4
Authors: zhao huihui , Gu Wenqing , Ouyang Huogui , Pan Wenbin , Zhang Hanbin , Shuai Ling , Diao Ruiying , Wang Liping
Published: August 2020

Background: Premature ovarian insufficiency (POI) is characterized by a loss of ovarian function before 40 years-of-age and represents an existing challenge cause of female infertility. POI is one of the dominant causes of cis-diaminedichloroplatinum (cisplatin, CDDP)-induced reproductive impairment. However, the detailed mechanisms underlying POI induced by CDDP remain unclear.Methods: The POI C57B6/J mouse model was created by administering CDDP. The effects of FKBP4 were investigated using isobaric tags for relative and absolute quantification analysis (iTRAQ), real-time quantitative PCR (qRT-PCR) and western blotting. Target prediction was predicted using TargetScan software. Levels of sex hormones were tested using Enzyme-linked immunosorbent assays (ELISA).Results: We found that the FKBP4 protein was down-regulated in the ovaries of CDDP model. Target prediction identified FKBP4 as a potential target for miR-483-5p, which was expressed at high levels in both the ovaries and serum of CDDP-POI mice, and in the serum from POI patients. In vitro experiments further confirmed that FKBP4 was the target for miR-483-5p in human cervical cancer cells (HeLa). The overexpression of FKBP4 in human granulosa cells (KGN) alleviated the apoptosis caused by CDDP and the overexpression of miR-483-5p. Furthermore, the overexpression of miR-483-5p in oocytes caused injury to the ovaries, and disrupted the levels of sex hormones in CDDP-POI mice (AMH: P < 0.01; E2: P < 0.01; FSH: P < 0.01).Conclusions: Analyses showed that miR-483-5p targets the FKBP4 protein in a mouse model of POI induced by CDDP. Elevated levels of miR-483-5p in oocytes could aggravate POI induced by CDDP by targeting FKBP4. Overall, our data demonstrate that miR-483-5p was responsible for the underlying pathophysiology of POI induced by chemotherapeutic treatments, such as CDDP.
Estimation of 24-hour urine protein excretion using urine albumin-to-creatinine ratio
Authors: Liu Xin , Zhao Yonghong , Hong Daqing , Feng Yunlin
Published: August 2020

The authors have requested that this preprint be removed from Research Square.
Active Tunable THz Metamaterial Array Implemented in CMOS Technology
Authors: Liu Yongshan , Sun Tong , Wu Xiaojun , Bai Zhongyang , Sun Yun , Li Helin , Zhang Haoyi , Chen Kanglong , Ruan Cunjun , Sun Yuzu , Hu Yuanqi , Nie Tianxiao , Wen Lianggong
Published: August 2020

Terahertz (THz) metamaterial modulators offer multifaceted capabilities for various practical applications such as THz imaging, wireless communications, sensing, et cetera. However, compared to the modulation devices for other electromagnetic bands, the ubiquitous proliferation of THz applications is severely impeded by the tremendous lack of complementary metal-oxide-semiconductor (CMOS) compatible technology. Here we demonstrate a CMOS based actively tunable THz metamaterial array (C-ATTMA) with split ring resonators (SRRs). The THz metamaterial modulators can be externally controlled with an electrically-controlled dynamic. The C-ATTMA fabricated by the 180 nm CMOS technology featuring a resonant frequency of 0.30 THz was connected to the source and drain of a bottom metal-oxide-semiconductor field effect transistor (MOSFET) through the vias. By delicately controlling the MOSFET gate voltage, the equivalent circuit response of the C-ATTMA was actively engineered, enabling tailoring THz resonance frequencies. Under a gate voltage of 1.8 V, we successfully realized a 35 GHz modulation bandwidth with [[EQUATION]] phase modulation. The exhibited CMOS-compatible electrically-regulated THz metamaterials may provide enormous potentials for implementing THz wireless communications, information encryption, THz compressed sensing imaging, et cetera.
Cardiovascular Risk Prediction in Diabetes – Changes in the Prognostic Values of Modern Cardiovascular Biomarkers in Relation to Duration of Diabetes Mellitus
Authors: Resl Michael , Vila G , Heinzl M , Luger A , Neuhold S , Prager R. , Wurm R , Hülsmann M , Clodi Martin
Published: August 2020

Background: Based on the complex pathophysiology of type 2 diabetes and atherosclerosis we hypothesized a dynamic change in prognostic value of cardiovascular biomarkers over time. Methods: In this prospective study 746 patients with type 2 diabetes mellitus, being followed up for 60 months were analysed. The primary endpoint was defined as unplanned hospitalization for cardiovascular disease or death. Beside others, especially the prognostic performance of the biomarkers of interest (GDF-15, NT-proBNP, hs-TnT) was evaluated in relation to quartiles of diabetesduration.Results: In patients having a diabetes duration below 7 years lnGDF-15 (HR 2.84; p < 0.01) and lnhs-TnT (HR 2.96; p<0.01) were significant predictors of the primary endpoint. LnAge (HR 40.11; p < 0.01) and lnNT-proBNP (HR 1.61; p <0.01) were significant predictors in patients with a diabetes duration between 7 and 12 years. In the third quartile (diabetes duration 12-22 years) lnAge (HR 13.09; p =0.041), urinary albumin to creatinine ratio (HR 2.74; p = 0.001) and lnNT-proBNP (HR 1.81, p < 0.001) predicted the endpoint. In patients with a diabetes duration above 22 years, lnAge (HR 50.79; p = 0.002) and lnNT-proBNP (HR 2.1; p < 0.01) were the only significant predictors of the endpoint. Conclusion: Prognostic power of cardiovascular biomarkers changes dynamically in relation to duration of type 2 diabetes mellitus. In patients with shorter duration of the disease markers of subclinical cardiovascular dysfunction and inflammation perform better than markers of systemic advanced organ dysfunction and cardiovascular disease.
Amlexanox enhances temozolomide-induced anti-tumor effects in human glioblastoma cells by inhibiting IKBKE and the Akt-mTOR signaling pathway
Authors: Xiong Jinbiao , Guo Gaochao , Guo Lianmei , Wang Zengguang , Chen Zhijuan , Nan Yang , Cao Yiyao , Li Ruilong , Yang Xuejun , Dong Jun , Jin Xun , Yang Weidong , Huang Qiang
Published: August 2020

Background: Temozolomide (TMZ), as the first-line chemotherapeutic agent for the treatment of glioblastoma multiforme (GBM), often fails to improve the prognosis of GBM patients due to the quick development of resistance. The need for more effective management of GBM is urgent. The aim of this study is to evaluate the efficacy of combined therapy with TMZ and amlexanox, a selective inhibitor of inhibitor of nuclear factor kappa-B kinase subunit epsilon (IKBKE), for GBM. Methods: in vitro, cell viability assay, apoptosis analysis, western blot, migration and invasion assay were used. In vivo, intracranial tumor models were constructed and the immunohistochemistry were used. Results: We found that combined treatment resulted in significant induction of cellular apoptosis and the inhibition of cell viability, migration and invasion in primary glioma cell and in the human glioma cell line, U87 MG. TMZ enhanced expression of phosphoration of adenosine 5‘-monophosphate-activated protein kinase (p-AMPK) and amlexanox led to reduction of IKBKE, with no impact on p-AMPK. Furthermore, we demonstrated that, compared to other groups treated with each component alone, TMZ combined with amlexanox effectively inhibited phosphorylation of protein kinase B (AKT) and mammalian target of rapamycin (mTOR). In addition, the combination treatment also clearly reduced in vivo tumor volume and prolonged median survival time in the xenograft mouse model. Conclusion: These results suggest that amlexanox sensitized primary glioma cell and U87 MG cell to TMZ at least partially though the suppression of IKBKE activation and the attenuation of AKT activation. Overall, combined treatment with TMZ and amlexanox may provide a promising possibility for improving the prognosis of glioblastoma patients in clinical practice.
Classifying information-sharing methods: a citation-mining systematic review
Authors: Nikolaidis Georgios Filippos , Woods Beth , Palmer Stephen , Soares Marta O
Published: August 2020

BackgroundSparse relative eectiveness evidence is a frequent problem in Health Technology Assessment(HTA). Where evidence directly pertaining to the decision problem is sparse, it may be feasible to expand theevidence-base to include studies that relate to the decision problem only indirectly: for instance, when there isno evidence on a comparator, evidence on other treatments of the same molecular class could be used;similarly, a decision on children may borrow-strength from evidence on adults. Usually, in HTA, such indirectevidence is either included by ignoring any dierences (`lumping`) or not included at all (`splitting`). However,a range of more sophisticated methods exists, primarily in the biostatistics literature. The objective of thisstudy is identify and classify the breadth of the available information-sharing methods.MethodsForwards and backwards citation-mining techniques were used on a set of seminal papers on thetopic of information-sharing. Papers were included if they specied (network) meta-analytic methods forcombining information from distinct populations, interventions, outcomes or study-designs.Results: Overall, 89 papers were included. A plethora of evidence synthesis methods have been used forinformation-sharing. Most papers (n = 78) described methods that shared information on relative treatmenteects. Amongst these, there was a strong emphasis on methods for information-sharing across multipleoutcomes (n = 39) and treatments (n = 23), with fewer papers focusing on study-designs (n = 10) orpopulations (n = 6). We categorise and discuss the methods under four 'core' relationships ofinformation-sharing: functional, exchangeability-based, prior-based and multivariate relationships, and explainthe assumptions made within each of these core approaches.ConclusionsThis study highlights the range of information-sharing methods available. These methods oftenimpose more moderate assumptions than lumping or splitting. Hence, the degree of information-sharing thatthey impose could potentially be considered more appropriate. Our identication of four `core` methods ofinformation-sharing allows for an improved understanding of the assumptions underpinning the dierentmethods. Further research is required to understand how the methods dier in terms of the strength of sharingthey impose and the implications of this for health care decisions.