Optimum Production Rate Research Articles

Co Nanoparticles on MnO: Electron Transfer through Ohmic and S-Scheme Heterojunction for Photocatalytic Hydrogen Evolution.

The photocatalytic hydrolysis method represents a significant potential solution to the dual challenges of energy security and environmental sustainability. The selection of suitable photocatalytic materials and systems is of paramount importance for the successful implementation of photocatalytic hydrogen production technology. In this study, in situ reduction of Co nanoparticles on MnO was successfully performed by calcining MnCo-PBA. Furthermore, graphdiyne (GDY) was successfully introduced by physical agitation. The introduction of GDY reduced Co/MnO agglomeration and made the Co/MnO/GDY catalyst exhibit high activity in hydrogen production, with an optimum production rate of 2117.33 μmol·g-1·h-1, which was 4.88 and 2.67 times higher than that of GDY and Co/MnO, respectively. The results of the photoelectrochemical test indicate that the composite catalyst has a better photogenerated carrier separation efficiency. In situ X-ray photoelectron spectroscopy, density functional theory calculations, and electron paramagnetic resonance were used to investigate the electron transfer mechanism during the photocatalytic process, confirming the presence of an S-scheme heterojunction and an ohmic junction, which enhance the separation of photogenerated carriers. The GDY-based heterojunction catalyst constructed in this study has the potential to significantly enhance the hydrogen production activity of bimetallic catalysts.

A parallel bioreactor strategy to rapidly determine growth-coupling relationships for bioproduction: a mevalonate case study

BackgroundThe climate crisis and depleting fossil fuel reserves have led to a drive for ‘green’ alternatives to the way we manufacture chemicals, and the formation of a bioeconomy that reduces our reliance on petrochemical-based feedstocks. Advances in Synthetic biology have provided the opportunity to engineer micro-organisms to produce compounds from renewable feedstocks, which could play a role in replacing traditional, petrochemical based, manufacturing routes. However, there are few examples of bio-manufactured products achieving commercialisation. This may be partially due to a disparity between academic and industrial focus, and a greater emphasis needs to be placed on economic feasibility at an earlier stage. Terpenoids are a class of compounds with diverse use across fuel, materials and pharmaceutical industries and can be manufactured biologically from the key intermediate mevalonate.ResultsHere, we report on a method of utilising parallel bioreactors to rapidly map the growth-coupling relationship between the specific product formation rate, specific substrate utilisation rate and specific growth rate. Using mevalonate as an example product, a maximum product yield coefficient of 0.18 gp/gs was achieved at a growth rate (μ) of 0.34 h−1. However, this process also led to the formation of the toxic byproduct acetate, which can slow growth and cause problems during downstream processing. By using gene editing to knock out the ackA-pta operon and poxB from E. coli BW25113, we were able to achieve the same optimum production rate, without the formation of acetate.ConclusionsWe demonstrated the power of using parallel bioreactors to assess productivity and the growth-coupling relationship between growth rate and product yield coefficient of mevalonate production. Using genetic engineering, our resultant strain demonstrated rapid mevalonate formation without the unwanted byproduct acetate. Mevalonate production is quantified and reported in industrially relevant units, including key parameters like conversion efficiency that are often omitted in early-stage publications reporting only titre in g/L.

A sustainable integrated model for multi-objective planning of an agri-food supply chain under uncertain parameters: A case study

The extended and complex nature of agri-food supply chain systems results in food loss and an asymmetrical flow of information. It is vital to integrate the cultivation, harvest, processing, and distribution decisions for designing a sustainable agri-food supply chain to minimize overall cost and create employment opportunities alongside considering global concerns. A multi-objective, integrated, sustainable mathematical model is presented in this study to maximize the revenue and employment generated while reducing the environmental impacts. The criteria for the evaluation of farmlands are derived from literature, and Geographical Information System (GIS) is used to obtain geospatial data to assess the performance of diverse farmlands across various criteria. The farmlands are then assessed and prioritized using the Best Worst Method (BWM). Among all criteria for selecting the farmlands, favorable temperature and land-use have the highest and lowest impact, respectively. Furthermore, a pricing model is proposed to estimate the price in various customer zones. The robust possibilistic model is suggested to take into account weather patterns, transportation costs, and customer zone demand under uncertain situation. The proposed model is illustrated in the Stevia processing plant in Iran and the tradeoffs between different model parameters and objective functions are studied, and the validity of the model is assessed by sensitive analyses. The outcomes show that to meet robustness, the number of active farmlands and warehouses should be increased by about 11%, which imposes a 10% cost on the model. Based on sensitive analysis, increases in production capacity and demand result in a significant rise in the profit function (12% and 16%, respectively), despite the fact that improvements to farmland and warehouse capacity have little effect on profit, indicating the need for managers to prioritize production rate and advertising. Moreover, the results show the best location for planting stevia, the optimum production rate, the proper number of warehouses, and their capacities in each period.

Nodal Analysis of Naturally Flowing Wells in Faihaa Oil Field, Yamama Formation

This study focuses on the Yamama Formation, a significant carbonate reservoir in southern Iraq that is one of the most important productive reservoirs in the region. The Formation is characterized by porous limestone interspersed with thin layers of argillaceous and tight limestone. The Yamama reservoir in the Faihaa oil field is divided mainly into four units; YA, YB, YC, and YD. YA and YB units are considered to be the most important oil-bearing subunits due to their good petrophysical properties. The main objective of the study is to determine the optimum production rates of four naturally flowing wells in the Faihaa oil field using the Inflow Performance Relationship and Vertical Lifting Performance curves. The study investigates four critical parameters; tubing size, water cut, reservoir pressure, and wellhead pressure, and their impact on well performance. The study finds that wellhead pressure is the primary determinant of well performance, and deviations from the original tubing size have adverse effects on well performance. An increase in water cut beyond the recommended threshold, coupled with a reduction in reservoir pressure, results in decreasing well performance. The study underscores the importance of careful monitoring and analysis of these parameters to sustain and enhance well performance in the Faihaa oil field, providing valuable insights for well operators and petroleum engineers. The study's findings can be used to optimize well performance and increase oil production rates, with significant implications for the petroleum industry.

Recalculation of Pump Speed and Stroke Length to Increase Production Rate and Volumetric Efficiency of HPU Well BTN-01

In the "BTN-01" well, one of the wells is owned by KSO PT PERTAMINA EP PT Sarana GSS Trembul. The "BTN-01" well is installed with a hydraulic pumping unit pump that experiences decreasing production, and based on tests on January 30, 2023, the output of the "BTN-01" well produces only 216 bfpd with 98% of water cut. The pump operates on 8 SPM of pump speed and 74-inch stroke length, with 43% of volumetric efficiency. As per theory, a proper design of hydraulic pumping unit pump will produce a volumetric efficiency value above 70%. To overcome this problem, it is necessary to perform research, started with an evaluation on the existing design and continue to quantitative research by recalculating the optimum production rate from IPR calculation, recalculating pump speed, recalculating pump stroke length, and recalculating volumetric efficiency to achieve higher value on both production rate and volumetric efficiency of the pump. In the "BTN-01" well, IPR was calculated by the Wiggins method, and it is known that the oil production rate is 5.53 bopd, 421.96 bwpd of water rate, and the fluid production rate is 427.5 bfpd. Based on the results of HPU redesign and recalculation of the optimum production rate, the new value of pump speed is 7 SPM (existing 8 SPM), the pump stroke length is 70 inches (existing 74 inches) with a volumetric efficiency of 78.45% (existing 43%) that can be called optimal.

Prediction of wellbore sand production potential from analysis of petrophysical data coupled with field stress: a case study from the Shah-Deniz gas field (Caspian Sea Basin)

Identifying the optimal azimuth and inclination for wellbore drilling in sandy formations can be considered a valuable aid in reducing sand production risks, lost time, and decreasing drilling costs in the petroleum industry. Therefore, a numerical systematic approach was provided to predict sand production in wellbore SDX-5, drilled in a deep-water sandstone reservoir in the Shah-Deniz gas field (South Caspian Basin), which has never been done previously. Additionally, this systematic approach uses geomechanical and geodynamical criteria, along with petrophysical information (density and sonic log) and tectonic characteristics of the study area, which are influenced by the active tectonic stresses of the Apsheron-Balkhan zone. The subsurface data sources employed are more eco-friendly, available, and continuous than experimental tests. The computations conducted achieved azimuth, inclination, polar, and depth profile plots for the Lower Balakhany Formation. The calculations reveal that the optimum azimuth for the wellbore drilling trajectories is parallel to SHmax and oblique drilling to near horizontal is the result of optimum inclination. Polar plots showed optimum azimuth, inclination, and effect of wellbore trajectory on critical collapse pressure and collapse drawdown pressure with pressure values simultaneously, which identify safer alternatives for achieving higher petroleum production rates without sanding. Depth profile plots provide a simultaneous overview of the values of critical collapse pressure, critical sanding pressure for instantaneous drawdown, and optimum wellbore production pressure during drilling and production operations. Moreover, optimum reservoir fluid production (maximum discharge) rates can be identified and imposed as upper limits to prevent sand production.

Integrated sand management: modeling of sand erosion in a mature oil field in Malaysia

Sand production can lead to various problems, including erosion in production flow lines that may lead to total production loss for extended periods and costly workover operations. The extent of erosive damage is determined by many factors, among which the flow and sand rates are the most significant. Three main issues must be addressed to ensure an efficient production operation: Sand erosion estimation, Sand monitoring (settling and deposition), and maintaining optimum production rates. If sand production exceeds certain levels, i.e., allowable sand rate, the erosion in the production network becomes problematic. Sand production has been problematic in some wells in Reservoir X. Core, and historical production data was used to build a comprehensive model using Schlumberger PIPESIM™ hydraulic modelling. The software allows for detailed modelling of the production network by which erosion rate, erosion hotspots, and deposition of the produced sand can be quantitatively analyzed. Considering an allowable erosion rate of 0.3 mm/year, the model outcomes indicate that sand erosion is critical in wells J-1, J-2, and L-2. The next step was identifying the hotspots where the produced sand is deposited in the abovementioned wells. The modelling results indicated that sand deposition is primarily severe in the teeline between the platforms. Moreover, the gas-oil ratio was identified as the most influential factor in the sand deposition. Lastly, a sensitivity analysis was conducted on the allowable flow rates and maximum (technical) allowable sand production and erosion rates to find optimum production rates from reservoir X.

Optimization of Horizontal Well Location and Completion to Improve Oil Recovery for an Iraqi Field

Exploitation of mature oil fields around the world has forced researchers to develop new ways to optimize reservoir performance from such reservoirs. To achieve that, drilling horizontal wells is an effective method. The effectiveness of this kind of wells is to increase oil withdrawal. The objective of this study is to optimize the location, design, and completion of a new horizontal well as an oil producer to improve oil recovery in a real field located in Iraq. “A” is an oil and gas condensate field located in the Northeast of Iraq. From field production history, it is realized the difficulty to control gas and water production in this kind of complex carbonate reservoir with vertical producer wells. In this study, a horizontal well design with multi-stage completion is studied and proposed to find optimal oil recovery in the southeast region of the selected field. A bulk oil well sector model is used to simulate the fluid flow of a single-porosity/single-permeability model. Then, a sensitivity analysis has been run to optimize; the well trajectory path, different scenarios on well oil and water production potential, and well completion design. The result of the well sector simulation indicates that the well trajectory with an Azimuth of 89 degrees and with a multi-stage completion design has better production performance under water production constraints. Optimum oil production rates of 1000 to 2000 STB/day, as delaying and controlling early gas and water production challenges is achieved.

THE OPTIMUM DECISION OF OIL AND GAS PRODUCTION SPREADSHEET MODELLING

The optimum revenue of an oil and gas industry is subject to the production volume deliverability and relatively volatile product market price which depends on demand and supply level. Naturally, mature production wells will be dominantly producing water instead of oil and gas, meanwhile, the central processing facilities are having their limited capacity to handle it. This study intends to gain the optimum oil and gas production in mature fields by deciding the opening of well choke valves and considering process facilities limitations as constraints. The model is developed using a simplex LP-based spreadsheet. Three wellhead facilities with a total of forty-seven active producing wells gas, oil, and water data are taken as input parameters. The developed model is validated using the last ten days’ actual production data to identify the error margin consistency, a total of 1,410 data combinations were used. It results in an average error margin of 4.57%-gas and 0.9%-oil. The model could be used as an operator decision reference in opening the well’s choke valve to get the optimum production rate, a minor adjustment might need considering the dynamic process parameter condition.
 
 Keywords: optimal production, mature wells, choke valve opening, spreadsheet modeling

Delaying Water Breakthrough Using Horizontal Wells in Khurmala Oilfield

Water coning presents a serious problem in many oil fields, in terms of reducing oil production rate and increasing production costs. As breakthrough time represents the time until coning occurs, it should be increased by studying the significant affecting parameters and proposing a method to control them. Since horizontal wells are known to have higher potentials than vertical wells, they are used worldwide to delay water coning among other purposes. In this study, four designed horizontal wells are proposed to replace a drilled vertical well in Khurmala oilfield in northern Iraq, and the effect of each on water breakthrough time is studied with four different production rates and six different permeability ratios. PERFORM software is used to model the wells, and calculate the expected breakthrough time for each well. It was found that the 1000-ft horizontal well, and longer wells, will delay water breakthrough time, in all cases. Also, higher permeability ratios increase the breakthrough time for longer wells, by up to 15.69 folds, except with the optimum production rate, and increasing production rate results in decreasing breakthrough time (tBT) in all cases, where doubling the production rate may decrease tBT by more than 73.5%. It is essential to determine the minimum horizontal well length required to delay water breakthrough time, compared to the vertical well, by considering both production rate and permeability ratio. The breakthrough time ratio, depending on the proposed to optimum production rate ratio, can be calculated using the developed correlation with an average error of 1.73%.

Bioeconomic analysis of mackerel resources management (Rastrelliger sp.) at Malacca Strait, Serdang Bedagai Regency, Sumatera Utara

Mackerel (Rastrelliger sp.) is one of the main catch fisheries at Malacca Strait Serdang Bedagai, Sumatera Utara. This research aims to estimate mackerel (Rastrelliger sp.) resource potential with a bioeconomic model for mackerel resources sustainability landed at Tanjung Beringin. This research was conducted in July – September 2021. The method of research used the purposive sampling method. The surplus production method to estimate the Maximum Sustainable Potential (MSY) and the Gordon Schaefer Bioeconomic Model. The total sample fish of Indian mackerel were 272 individuals. The research showed bioeconomic analysis with Schaefer’s surplus production model approach shows that the optimum production rate is 359 tons and the optimum effort is 12148 trips. The Mackerel resources indicate to be biological overfishing.

S-scheme heterojunction of hollow corncob-like ZnIn2S4/LaFeO3 for water splitting and tetracycline degradation

Reasonable design of heterojunction photocatalysts with high-quality interfacial coupling is an effective way to improve the photocatalytic activity of semiconductors. Herein, we successfully decorated Zinc indium sulfide (ZnIn2S4, ZIS) on perovskite Lanthanum ferrite (LaFeO3, LFO) with more active sites by a pre-hydrothermal combined post-calcination method, and constructed S-scheme heterojunction photocatalyst with a unique hollow corncob-like morphology for efficient photocatalytic hydrogen production and tetracycline (TC) degradation. When the mass ratio of LFO is 35% and 15%, the ZIS/LFO photocatalyst exhibits the best hydrogen evolution rate and TC photodegradation performance, respectively. Notably, the optimum hydrogen production rate is 6 times that of pure ZIS with excellent cycling stability. The enhanced photoactivity can be explained by the hollow corncob-like morphology and the formed S-scheme heterojunction with close interface contact between ZIS and LFO, which significantly improves the spatial separation and migration efficiency of photoexcited carriers, while maintaining a high redox potential. Finally, it provides an effective support for the photocatalytic mechanism through calculation results of density functional theory. This work not only provides a novel construction strategy of photocatalysts for efficient photocatalytic hydrogen evolution and organic pollutant degradation, but also opens up a new insight for perovskite-modified S-scheme heterojunction.

Studi Karakteristik Komposisi Produk Katalitik Pirolisis TKKS dengan katalis Al White

Bio-oil can be produced from biomass which has the potential to become an environmentally friendly renewable energy source. Most of the biomass is found as organic waste or used as mulch. Therefore, this renewable energy source needs to be developed so that its utilization can be maximized as a promising energy source with a catalytic pyrolysis process. The raw material used in this research is empty palm fruit bunches (EFB). The purpose of this study was to determine the effect of catalytic pyrolysis temperature on pyrolysis products in the form of char, bio-oil and gas. The experiment was carried out at various temperatures of 300°C, 350°C and 400°C using Al white catalyst. The ratio of Al white catalyst with EFB is 1:2 mixed with the catalyst in the pyrolysis reactor. The desired temperature for the pyrolysis process can be set on the reactor temperature controller. The results showed that the optimum bio-oil production rate of 55.81% was obtained from samples at 350 °C. Bio-oil in this study was divided into BO (bio-oil in the oil phase) and BA (bio-oil in the liquid phase). In this study the bio-oil obtained at process temperatures of 300°C, 350°C and 400°C were 45.28%, 55.81% and 47.40%, with a heating rate of 5.93°C/minute , 6.11 °C/minute, and 6.68 °C/minute and the density of bio-oil ranges from 1.114–1.264 g/ml. BO products are thicker than BA products. BO viscosity is higher at high pyrolysis temperature as well. The most char products at 300oC and the most gas products at 400oC. The higher the pyrolysis temperature, the more gas will be produced. By improving the pyrolysis process, promising bio-oil can be produced with temperature, catalyst treatment, and heating rate playing an important role in it

Porphyrin-Based Carbon Dots for Efficient Photocatalytic Reduction of CO<sub>2 </sub>to Methanol

Photocatalytic CO2 reduction to solar fuel is a potential way to overcome the problem of high carbon dioxide concentrations; however, the process still faces enormous challenges, such as the low light absorption efficiency and high carrier recombination rates. This work synthesized tetraphenylporphyrin-based carbon dots (TPP-CDs) for the photocatalytic CO2 reduction to CH3OH under simulated sunlight to extend the absorption region of the CDs. The conduction band of the TPP-CDs has a sufficiently negative reduction potential to reduce CO2. TPP-CDs containing 1 wt.% TPP achieved an optimum CH3OH production rate of 173.35 μmol·gcat-1·h-1, with a remarkable 2.06-fold increase compared to pristine CDs without TPP. In this study, TPP-CDs were synthesized by changing the CD precursors to improve the utilization of visible light and apply them to the photocatalytic reduction of CO2.

Tofu Wastewater (TWW) Treatment and Hydrogen (H2) Production by Using A Microbial Electrolysis Cell (MEC) System

High organic pollutant in tofu wastewater (TWW) raises a negative impact on environmental sustainability and health. Therefore, the TWW must be treated before it is discharged into the environment. Microbial electrolysis cell (MEC) is one of the green technologies that can be used to treat wastewater and generate hydrogen as well. This work tries to investigate the performance of MEC based on the decrement of organic pollutants in TWW. Some important parameters of organic pollutants in TWW such as chemical oxygen demand (COD), biological oxygen demand (BOD), total suspended solids (TSS), total dissolved solids (TDS), total solid (TS), and pH were evaluated before and after MEC operation. The results showed that the COD and BOD levels decreased around 56% and 35% while pH increased from 7.90 to 7.16. Additionally, the TSS, TDS, and TS decreased by around 35.0%, 45.5%, and 33.2%. In addition, the optimum hydrogen yield (YH2) and hydrogen production rate (QH2) were obtained at 114 ± 0.1 mL H2/g COD 360 ± 20 mL H2/L/d. Overall, the MEC system could be used to reduce the level of organic pollutants in TWW and generated H2 at the same time.

Evaluation Study of Electric Submersible Pump (ESP) IND-1000 Pump Model with Analysis of the Flow Rate of Crude Oil in Production Well

ESP is an artificial lift with the principle of a centrifugal pump, where the production fluid that enters through the intake will be thrown by the impeller into the diffuser which will then be directed to the impeller above it so that this process repeats until the production fluid reaches the surface. The longer the production well is produced, the smaller or weakened the Pwf pressure will be, therefore an evaluation is needed in order to produce optimal production. The data needed include: well production rate (Qo), well flow pressure (Pwf), Pump Intake Pressure (PIP), Total Dynamic Head (TDH), Pump type, namely IND-1000 pump, Number of stages, Type of motor, HP motor, motor voltage, Electric current, OD motor, Total voltage, and Total starting voltage. The evaluation methodology used is to determine the optimum production rate through IPR calculations using the vogel method, Pump Intake Pressure (PIP), Total Dynamic Head (TDH), number of stages, and horse power (HHP). From the results of this evaluation, the optimal production rate (Qopt) value was obtained, which was 988.552 BPD. This optimal production rate value is still included in the capacity range, which is between 600-1260 BFPD. Because the optimal production rate is still within the range capacity, this production well does not require a new pump replacement.

Construction of nanosized MoP decorated highly crystalline carbon nitride sphere as an excellent photocatalyst for boosted photocatalytic hydrogen production

High-crystalline carbon nitride (HCCN) is recognized as a promising semiconductor photocatalyst in alleviating the energy crisis and protecting the environment in the current field of photocatalysis. However, the ordinary crystalline carbon nitride is generally morphologically irregular with few surfactant sites, which limits its further application. In this work, we successfully constructed spherical HCCN embedded with MoP nanoparticles as a co-catalyst by a simple calcination treatment to form a stable and efficient MoP-HCCN composite photocatalyst. As expected, as-prepared MoP-HCCN composites presented superior photocatalytic activities for water splitting into H 2 production, and the optimal 5 wt.% MoP-HCCN exhibited the optimum photocatalytic hydrogen production rate up to 10594.29 μmol·g -1 ·h -1 with the corresponding AQE reached 7.2%, which is 3.4 times than pristine HCCN and 109.9 times than amorphous carbon nitride (ACN), respectively. The significant promotion in photocatalytic property is mainly due to the synergistic reaction between MoP and HCCN for effectively enhancing the segregation and rapid transportation of photogenerated electron-hole pairs. Finally, the feasible photocatalysis mechanism of MoP-HCCN compound photocatalyst is inferred. This work presents a promising design idea for developing efficient HCCN-based composite photocatalytic for hydrogen production.

Photocatalytic H2 production over S-scheme Co3Se4/TiO2 nanosheet with super-hydrophilic surface

Photocatalytic H2 evolution represents a sustainable technology to acquire green energy via a solar energy conversion process. The development of photocatalysts with simple preparation and superior activity is still highly desired. In this work, the H2 evolution activities of cobalt selenide (Co3Se4) microspheres decorated TiO2 were investigated for the first time. The 25 wt% Co3Se4/TiO2 hybrid delivers an optimum H2 production rate of 6065 μmol·g−1·h−1 in 20 vol% TEOA under 300 W Xe lamp irradiation, which is 12.5 and 13.4 times that of pristine TiO2 (484 μmol·g−1·h−1) and pure Co3Se4 (453 μmol·g−1·h−1), respectively. The enhanced activity benefits from the S–scheme heterojunction formed between Co3Se4 and TiO2, which can obviously promote the separation of charge carriers and reduce the overpotential of H2 generation. Besides, the surface composition of the sample after reaction was revealed through XRD, TEM, XPS and water contact angle measurements, the results show that the microstructure of the composite sample remains unchanged after reaction, and a thin oxide or hydroxide layer was in–situ formed on the surface of Co3Se4, leading to a super–hydrophilic surface of Co3Se4/TiO2 and endowing with long reaction stability. This work broadens the application of Co3Se4 in energy conversion and provides a promising option to replace traditional noble metal photocatalysts.

Integrated Design and Analysis of Corrosion Rate Model on Tubular Pipe of Oil and Gas Production Well

Corrosion occurrence in the oil and gas production system is an example of an unavoidable problem. This problem is caused by the presence of water and corrosive material fraction along with the produced hydrocarbon. On the way from the reservoir to the surface, the mixture between water fraction and the corrosive substance might adhere to the wall of conduit steel pipe (e.g. tubing, casing, and flowline) and can lead to corrosion on the wall. The corrosion problem can have a major impact on the economics of the production because the cost of production equipment is relatively expensive and workover operation is very costly. Therefore, planning and mitigation for a better production system need to be performed, so that the rate of corrosion can be controlled, and its economic impacts can be minimized. The purpose of this study was to create an integrated model of the corrosion rate calculation on the tubing by the Petroleum Engineering Study Program of Bandung Institute of Technology (ITB). Several terms related to the production process were considered in this model: the characteristics of the produced fluid, flow regimes, pressure and temperature conditions along the tubing, the trajectory of the well, the type of tubing material used, and the use of inhibitors. The model was developed from the model developed by C. de Waard, Liane Smith, and Mike Billingham. The corrosion rate calculation model was then validated using field data and the results were compared with the result from industrial commercial software, Electronic Corrosion Engineer (ECE®). The corrosion rate calculation model were able to predict the rate of corrosion in oil and gas wells accurately. A software-based system was created based on this integrated and accurate proven model. By using this software, the production system can be simulated and tested for various conditions, and then the result can be compared with each other to obtain the optimum fluid production rate with minimum corrosion rate. In addition, this software is capable to determine the most suitable tubing material which will be used in a given production environment and condition.

An Imperfect Production Model for Breakable Multi-Item with Dynamic Demand and Learning Effect on Rework over Random Planning Horizon

In recent times, in the literature of inventory management there exists a notorious interest in production-inventory models focused on imperfect production processes with a deterministic time horizon. Nevertheless, it is well-known that there is a high influence and impact caused by the learning effect on the production-inventory models in the random planning horizon. This research work formulates a mathematical model for a re-workable multi-item production-inventory system, in which the demand of the items depends on the accessible stock and selling revenue. The production-inventory model allows shortages and these are partial backlogged over a random planning horizon. Also, the learning effect on the rework policy, inflation, and the time value of money are considered. The main aim is to determine the optimum production rates that minimize the expected total cost of the multi-item production-inventory system. A numerical example is solved and a detailed sensitivity analysis is conducted in order to study the production-inventory model.