Analysis Of Production Data Research Articles

Evaluation of Methods for Estimating Lake Surface Water Temperature Using Landsat 8

Changes in lake water temperature, observed with the greatest intensity during the last two decades, may significantly affect the functioning of these unique ecosystems. Currently, in situ studies in Poland are conducted only for 38 lakes using the single-point method. The aim of this study was to develop a method for remote sensing monitoring of lake water temperature in a spatio-temporal context based on Landsat 8 imagery. For this purpose, using data obtained for 28 lakes from the period 2013–2020, linear regression (LM) and random forest (RF) models were developed to estimate surface water temperature. In addition, analysis of Landsat Level-2 Surface Temperature Science Product (LST-L2) data provided by United States Geological Survey (USGS) and the National Aeronautics and Space Administration (NASA) was performed. The remaining 10 lakes not previously used in the model development stage were used to validate model performance. The results showed that the most accurate estimation is possible using the RF method for which RMSE = 1.83 °C and R2 = 0.89, while RMSE = 3.68 °C and R2 = 0.8 for the LST-L2 method. We found that LST-L2 contains a systematic error in the coastal zone, which can be corrected and eventually improve the quality of estimation. The satellite-based method makes it possible to determine water temperature for all lakes in Poland at different times and to understand the influence of climatic factors affecting temperature at the regional scale. On the other hand, spatial presentation of thermics within individual lakes enables understanding the influence of local factors and morphometric conditions.

Nuclear model analysis and optimization of production data of the medically interesting 66,67,68 Ga via alpha induced reactions on 63,65 Cu targets

Evaluation of the 63Cu(α,n)66Ga, 65Cu(α,2n) 67Ga and 65Cu(α,n)68Ga reactions was done to study the production of medical radionuclides 66Ga, 67Ga and 68Ga respectively. 63Cu(α,2n)65Ga and 65Cu(α,3n)66Ga reactions were also evaluated for the estimation of radioisotopic impurities. Cross section data of each reaction were compiled and normalized to the standard values of decay data and monitor reaction. To check the consistency of the literature data, three nuclear model calculations were performed, using nuclear model codes; TAYLS 1.9, ALICE-IPPE, and EMPIRE 3.2. A well-developed evaluation methodology based on the normalized experimental data and nuclear model calculations was used to generate the statistically fitted cross sections. From the fitted cross sections, thick target yields for each reaction were calculated for the estimation of radioisotopic impurities. Finally, a suitable energy region for the production of 66Ga, 67Ga and 68Ga was suggested with a minimum level of radioisotopic impurities.

A comparative study on outlier detection techniques for noisy production data from unconventional shale reservoirs

Decline curve analyses (DCA) and rate transient analyses (RTA) are widely used to characterize the fluid flow through porous media and forecast future production. Oil and gas production data are routinely analyzed for history matching and optimizing the well stimulation methods in hydrocarbon exploration and production lifecycle. However, outliers add significant uncertainty and non-uniqueness to results from production data analysis. This study provides a structured and comprehensive overview of five widely used outlier detection (OD) techniques for identifying and removing outliers in production data. Each OD technique measures deviation differently and, therefore, has a different outcome even when applied to the same dataset, creating the need to test several methods and find the optimal technique for identifying and removing outliers from production data. First, we generated production data from a typical multi-fractured horizontal well using a numerical reservoir simulator and added random noise to the data. Then, we used five different OD techniques to identify the prelabeled outliers from the synthetic production data. Finally, we identified the best-performing OD algorithm by comparing the various evaluation metrics such as the mean absolute error (MAE), precision, sensitivity, and F1 score. Results showed that the angle-based OD (ABOD) had the best MAE, precision, sensitivity, and F1 score of 8%, 85%, 98%, and 0.90, respectively. The next best-performing OD technique was distance-based OD (DBOD), with MAE, precision, sensitivity, and F1 score of 16%, 71%, 100%, and 0.83, respectively. We tested the ABOD method on several field production datasets by assuming different outlier thresholds (fraction of the data points likely to be outliers). Visual inspection of the processed data showed that the ABOD method effectively identified and removed the outliers from a relatively clean dataset (outlier threshold of 20%) and a highly noisy dataset (outlier threshold of 80%). This algorithm is intuitive and can effectively identify and remove outliers from the field production data to improve production forecasting, reserves estimation, and rate transient analysis for multi-fractured horizontal oil and gas reservoirs.

Fuzzy Evaluation of Process Quality with Process Yield Index

With the rapid development and evolution of the Internet-of-Things (IoT) and big-data analysis technologies, faster and more accurate production data analysis and process capability evaluation models will bring industries closer to the goal of smart manufacturing. Small sample sizes are also common, due to destructive testing, the high costs of detection, and insufficient technological capacity, and these undermine the reliability of the statistical method. Many studies have pointed out that a confidence-interval-based fuzzy decision model can incorporate accumulated data and expert experiences to increase testing accuracy for small samples. Therefore, this study came up with a confidence-interval-based fuzzy decision model based on a process yield index. The index not only reflects process capability but also has a one-to-one mathematical relation with the process yield so that it is convenient to apply in practice. The proposed model not only diminishes the probability of misjudgment resulting from sampling error but also improves the accuracy of testing under the situation of small sample sizes, thereby contributing to the development of smart manufacturing.

Place identity and authenticity in minority language revitalisation: Scottish Gaelic in Glasgow

Aims and objectives: This paper first aims to examine how young Gaelic-English bilinguals in immersion education produce aspects of Gaelic phonology. We second consider the extent to which they acquire aspects of a traditional dialect. Third, we investigate how young new speakers outside of a traditional community negotiate place identity and authenticity. Methodology: Our methodology first consists of quantitative acoustic and auditory phonetic analysis of word list production data, accompanied by mixed effects regression. Second, we employ qualitative analysis of interview data from the same participants. Data and analysis: Data are presented from 22 speakers aged 13–14 in Gaelic Medium Education in Glasgow and 15 speakers aged 13–14 in GME on the Isle of Lewis. For comparison with a traditional dialect, we also include three speakers from Lewis aged 65–80. Our quantitative analysis considers 3,605 tokens in total and the qualitative analysis considers interview data with all speakers. Conclusions: Our findings show that young speakers reproduce traditional aspects of Gaelic phonology, though generally to a lesser extent that older speakers. Young new speakers in Glasgow recognise that they do not speak a traditional dialect of the language. They are beginning to create a new authenticity associated with belonging to Glasgow, which represents a new acquisition setting. Originality: This study is the first to explore acquisition of dialect and phonology among young new speakers of Gaelic. We explore perceptions of dialect and the implications of not coming from a traditional Gaelic-speaking area for the first time in young people. Implications: Revitalisation settings can lead to successful language acquisition but may also contribute to dialect levelling. However, institutional support structures can lead to increased confidence and new place identities emerging in young speakers.

Constraining the nuclear gluon PDF with inclusive hadron production data

The nuclear parton distribution functions (nPDFs) of gluons are known to be difficult to determine with fits of deep inelastic scattering (DIS) and Drell-Yan (DY) data alone. Therefore, the nCTEQ15 analysis of nuclear PDFs added inclusive neutral pion production data from RHIC to help in constraining the gluon. In this analysis, we present a new global analysis of nuclear PDFs based on a much larger set of single inclusive light hadron data from RHIC and the LHC. Using our new nCTEQ code (nCTEQ++) with an optimized version of INCNLO we study systematically the limitations of the theory and the impact of the fragmentation function uncertainty.

Predicting Granitic Buried-Hill Reservoirs Using Seismic Reflection data—A Case Study From the Bongor Basin, Southwestern Chad

Predicting the distribution of fractured and dissolved reservoirs in granitic buried hills is a prerequisite for finding high-quality hydrocarbon reservoirs and improving the success rate of exploration activities. Granitic buried-hill reservoirs in the Bongor Basin are characterized by strong heterogeneity and poor lateral continuity. Through the analysis of seismic, core, logging and dynamic production data, this study predicts the distribution of fractured reservoirs and fractured-cave reservoirs in the granitic buried hills in the BC Block of the Bongor Basin. In this study, we predict fractured reservoirs using coherence cubes and linearly enhanced attributes and identify fractured-cave reservoirs with single-frequency attribute bodies. Integrated predictions of fractured reservoirs and fractured-cave reservoirs are conducted using attribute fusion techniques. With these methods, good results have been achieved in reservoir prediction in BC buried hills. Furthermore, this study summarizes a set of granitic buried-hill reservoir prediction techniques for densely inverted rift basins in the Central African Rift System.

PENGARUH PENDEKATAN MATEMATIS REALISTIK TERHADAP KEMAMPUAN PEMAHAMAN KONSEP MATEMATIS PESERTA DIDIK

The research was conducted with the aim of knowing mathematic learning with a realistic mathematics approach has an effect on the ability to understand students’ mathematical concepts better. Conducted using a quasi-experimental research type, the learning process applied involves two types of classes, namely the experimental class and the control class. PMR-based learning is used in the experimental class, while the control class is used for conventional learning. Considering that mathematics lessons cannot be separated from students' creative learning abilities, in addition to the posttest only control design in the form of a final test of understanding the concept of research instruments, such as learning creativity questionnaire sheets are also given to students. Using Statistical Product and Service Solutions (SPSS) data analysis techniques with a probability value (significant) of 5%, it shows a positive influence which means that H0 is rejected and H1 is accepted. Based on the descriptive data obtained, it is known that the mean posttest learning outcomes in the experimental class (PMR) are greater than the control class (conventional), which illustrates the application of learning using PMR has a significant influence on the ability to understand mathematical concepts and learning creativity of class VIII SMP Muhammadiyah 1 Babat.

A new approach to production data analysis of non-volumetric naturally fractured gas condensate reservoirs

A significant amount of hydrocarbon exists in naturally fractured formations. Due to the limitations of classical reservoir evaluation methods, the ongoing researches have focused on the analysis of production data to describe reservoir dynamic. Among the existing methods, the flowing material balance (FMB) technique brings a straightforward and accurate method of reserve estimation. Often, the same approach as the single porosity reservoirs are utilized for naturally fractured formations and fewer studies have been performed with the dual-porosity model. Regarding the importance of such reservoir types, the purpose of this study is to propose a new production data analysis approach by implication of a modified compressibility parameter to the conventional FMB equations to achieve an accurate estimation of initial gas in place and average reservoir pressure in non-volumetric naturally fractured gas condensate reservoir. In the current study, we applied the aquifer influence on reservoir performance in the FMB equation by a modified isothermal rock compressibility factor, without using complex multi-phase reservoir modeling. Due to inherent uncertainty associated with aquifer parameters, the production data analysis in this study proceeded in two phases. In the first phase with the assumption of known aquifer parameters, output data were obtained. In the second phase, based on the best-fitted aquifer parameters in advance, the impact of variation of aquifer input data on the validity of output results was studied using the Monte-Carlo simulation approach. To validate the proposed method, different simulation models with variable reservoir and fluid properties were defined and the results were compared against a commercial compositional simulator. The obtained results proved the accuracy of the proposed method. Therefore, applying the modified rock compressibility in the conventional FMB method would result in a simple yet accurate method that requires the least input data to estimate initial gas in place and average reservoir pressure.

ANALISA PRODUKTIVITAS TANAMAN KARET (Havea brasiliensis Muell. Arg) KLON PB 260 DENGAN MENGGUNAKAN BERBAGAI SISTEM SADAP DI AFDELING I KEBUN BANGUN PT. PERKEBUNAN NUSANTARA III

The productivity of rubber plantations is determined by the type of clone, the age of the plant, the level of land suitability, and the exploitation system applied. The exploitation system applied determines the productivity of the rubber plantation because it is related to the use of the skin and the physiological process of latex. Implementing the right exploitation system can ensure high and sustainable productivity. On the other hand, the implementation of the wrong exploitation system can result in low productivity and shorten the economic life of the plant. This study aims to determine the productivity of rubber plants in clone PB 260 with various tapping systems. This research was conducted at Afdeling I Kebun Bangun PT. Perkebunan Nusantara III using a descriptive analysis method by collecting secondary data on the productivity of the PB 260 clone rubber plant from 2016 – 2020. The parameters observed were the production data of the PB 260 clone rubber plant with various tapping systems. The results of this study indicate that the analysis of rubber plant productivity data in 2016 – 2020 had the highest production in 2017 with a planting year of 2009 and the lowest in 2020 with a planting year of 2000. Meanwhile, overall, the highest production was in 2018 and the lowest was in 2016. The factors that influence the high and low productivity are caused by the tapping system that is not permanent or changing, the lack of application of fertilization, the reduction in the number of trees in the field caused by being attacked by JAP (White Root Fungus), KAS (Dry Alur Sadap), Moldy Road, fallen trees due to strong winds, and the age of the plants. The relationship between production and cost of goods/kg is that the greater the production obtained, the lower the cost of goods/kg.

ANALISA PRODUKTIVITAS TANAMAN KARET (Havea brasiliensis Muell. Arg) KLON PB 260 DENGAN MENGGUNAKAN BERBAGAI SISTEM SADAP DI AFDELING I KEBUN BANGUN PT. PERKEBUNAN NUSANTARA III

The productivity of rubber plantations is determined by the type of clone, the age of the plant, the level of land suitability, and the exploitation system applied. The exploitation system applied determines the productivity of the rubber plantation because it is related to the use of the skin and the physiological process of latex. Implementing the right exploitation system can ensure high and sustainable productivity. On the other hand, the implementation of the wrong exploitation system can result in low productivity and shorten the economic life of the plant. This study aims to determine the productivity of rubber plants in clone PB 260 with various tapping systems. This research was conducted at Afdeling I Kebun Bangun PT. Perkebunan Nusantara III using a descriptive analysis method by collecting secondary data on the productivity of the PB 260 clone rubber plant from 2016 – 2020. The parameters observed were the production data of the PB 260 clone rubber plant with various tapping systems. The results of this study indicate that the analysis of rubber plant productivity data in 2016 – 2020 had the highest production in 2017 with a planting year of 2009 and the lowest in 2020 with a planting year of 2000. Meanwhile, overall, the highest production was in 2018 and the lowest was in 2016. The factors that influence the high and low productivity are caused by the tapping system that is not permanent or changing, the lack of application of fertilization, the reduction in the number of trees in the field caused by being attacked by JAP (White Root Fungus), KAS (Dry Alur Sadap), Moldy Road, fallen trees due to strong winds, and the age of the plants. The relationship between production and cost of goods/kg is that the greater the production obtained, the lower the cost of goods/kg.

USING sma-its2 PRIMER FOR ITS2 (Internal Transcribed Spacer-2)-BASED MOLECULAR CHARACTERIZATION OF Anopheles minimus FROM KULONPROGO, YOGYAKARTA - INDONESIA

Malaria is a public health threat caused by the Plasmodium infection transmitted by the Anopheles mosquito. Malaria vector control is highly dependent on the ability to determine mosquito species' vectorial and bionomic capacity. Species identification based on morphological characteristics as well as DNA-barcoding approaches is a very important step in determining vectorial capacity. Our research group has redesigned a new ITS2 primer, namely, sma-its2, which is specifically able to identify the Anopheles (An.) mosquito vector but cannot identify other mosquito vectors. This study wanted to test this primer's specificity further for identification of other Anopheles mosquitoes. We used An. minimus collected from Kulonprogo, Yogyakarta – Indonesia. The methods used in this research are as follows: landing collection, morphological identification, isolation of genomic DNA, PCR (Polymerase Chain Reaction), PCR product purification, sequencing, and data analysis. An. vagus from Bangsring, Banyuwangi – Indonesia, which had previously been identified using the same primary, was used as a positive control. The results of the morphological analysis showed that both species were in accordance with the vector identification key used in this study. The molecular analysis showed that the sma-its2 primer could amplify the ITS2 sequence of An. vagus and An. minimus, producing 650 – 700 bp. However, further analysis of the ITS2 sequences of both species, resulted in the same species, namely An. vagus, with a different accession number in GenBank. This showed that the sma-its2 primar can be used to identify An. vagus but cannot be used to identify An. minimus. Analysis of the primer position in the ITS2 sequences showed the presence of 3 nucleotides in the forward sma-its2 primer that was not recognized by the An. minimus sequences and thus, hinder the successful identification of these species.

PENGEMBANGAN E-MODUL BERBASIS MOBILE LEARNING UNTUK MATA KULIAH METODE PENELITIAN

The purpose of this research is to develop mobile learning-based e-module teaching materials for research methods courses.This research method is a research and development method using the ADDIE model with e-module development steps, namely: 1) Analysis; 2) Design; 3) Development; 4) Implementation; 5) Evaluation. The sample in this study were all tarbiyah students, namely the PAI study program who took research methods courses, namely semester 5 with a total of 93 students. The sampling technique is a saturated sample technique from the population used as a sample in the study. The data collection techniques of this research are observation, questionnaires and documents. This research instrument is in the form of expert validation sheets and practical assessments by students. This research design is experimental with pre-post test only design with piared sample t test analysis.The results showed that the analysis of product design and data that could be presented in expert judgment showed that the e-module had very good criteria with a significance value of 0.000 0.005, which means that there is a significant difference between learning before and after learning using e-modules based on mobile learning. E-module has a very practical assessment by students as a reference in independent learning with an average score of 4.5 with a very good category. This e-module provides an alternative for students to learn independently, more efficiently and effectively in the learning process outside the classroom.

American English pitch accents in variation: Pushing the boundaries of mainstream American English-ToBI conventions

Linguists interested in intonation have long struggled to establish a maximally broad set of annotation conventions that function equally well across varieties of American English. The current study tests the advantages and limitations of the widely-used MAE-ToBI conventions, focusing on the H* and L+H* distinction, for three varieties of American English: African American English, Appalachian English, and Jewish English. Results of quantitative analysis of production data from 30 speakers of the three varieties finds major differences in rate of use of the H* and L+H* pitch accent as well as the phonetic realizations of these pitch accents, which may not be captured solely using the MAE-ToBI conventions. These differences appear not only between MAE-ToBI and the other three varieties, but also between the varieties themselves in unique ways that may shed light on the nature of sociolinguistic variation at the level of intonation, as well as the debated status of the distinction of H* vs. L+H* as a phonological or phonetic distinction. These findings provide further motivation for the development and use of annotation systems that explicitly consider sociolinguistic variation as well as phonetic parameters. Such systems will become even more essential as both sociolinguists and phoneticians expand intonational analysis beyond so-called “standard varieties” in order to arrive at a richer and more accurate picture of the intonational system of American English.

Engineering Poster E7: A new approach for production forecasting from individual layers in multi-layer commingled tight gas reservoirs

Poster E7 Estimating future production in multi-layer tight gas reservoirs is necessary, but problematic. Initial production looks promising but soon decreases to levels that are much lower than first anticipated. Boundary-dominated flow to which common production data analysis can be applied to, takes up to 8 years to establish, yet future production estimations must be made at the time of drilling. Common industry software does not fully assess individual layer contribution because large uncertainties exist in layer-specific contributions to total production. Many engineers tend to use analysis methods designed for single-layer wells, which leaves future production estimations with large errors, and this can have potentially long ranging consequences for a company. This paper presents a new way of estimating future production in multi-layer tight gas reservoirs by incorporating the uncertainty that can be found in individual layer contributions. Our approach utilises single tank material balance and matches total well production data by changing layer-specific properties. A workflow has been created for the programming language Python that includes a Bayesian element to honour the uncertainty in individual layer effective permeability and individual layer gas in place. Applying this workflow to many wells in a specified area allows probability distribution functions for layer effective permeability and layer gas in place to be generated. This will result in attaining more realistic production forecasts in the form of P10, P50 and P90 for multi-layer tight gas reservoirs, and allowing the engineer to make better-informed early assessments of the future production of wells. To access the poster click the link on the right. To read the full paper click here

Lag times in toe-to-heel air injection (THAI) operations explain underlying heavy oil production mechanisms

From a time value of revenue point of view, it is preferred that the time between reservoir stimulation and oil production response is small. Heavy oil combustion processes have a lag time between air injection and liquid production, but the common practice in production data analysis uses simultaneous injection and production data when seeking a relationship between them. In this research, the time scales of production for the Kerrobert toe-to-heel air injection (THAI) heavy oil project in Saskatchewan, Canada, is analyzed by using cross correlation analysis, i.e. time delay analysis between air injection and oil production. The results reveal two time scales with respect to production response with two distinctive recovery mechanisms: (1) a short time scale response (nearly instantaneous) where oil production peaks right after air injection (directly after opening production well) reflecting cold heavy oil production mechanisms, and (2) a longer time scale (of order of 100–300 days) response where peak production occurs associated with the collective phenomena of air injection, heat generating reactions, heat transfer, and finally, heated mobilized heavy oil drainage to the production well. This understanding of the two time scales and associated production mechanisms provides a basis for improving the performance of THAI.

Evaluation of Water Channeling Problems and Planning for Its Improvement Using the Remedial Cementing Method and Its Economics in Well AB-30 Field AB PT. Pertamina EP

The AB-30 well is an oil producing well located in the AB Field. Production performance data shows that AB-30 shows excessive water production behavior or is a high water cut production well. In addition, the interpretation of CBL data shows an amplitude value of <10 mV in the productive interval. This condition is an indicator that the primary cementing activity in this well is not good. Therefore, a comprehensive and integrated analytical method is needed to identify the problem of excess water production and to design and plan water shut-off activities through squeeze cementing as an effort to mitigate the problem of high water cut to economic analysis.The research begins by identifying the problem of excess water production, whether caused by water channeling, water coning, changes in water oil contact, or by the physical properties of the reservoir rock. Identification is done through production analysis and water diagnostic plots. The next stage is to evaluate the interpretation of CBL Logging results to strengthen the results of production data analysis. After confirming that the problem of excess water production is caused by poor cement bonding cement, the next step is to calculate the cement work program in order to repair the bad cement bonding. Subsequently, the productive zone interval re-perforation was carried out according to the results of the OH Loh Co Log evaluation. No less important is to conduct an economic analysis as a basis for whether or not this work is feasible.The result of this research is that the water shut-off activity went well and was able to reduce the level of excess water production in the AB-30 well and optimize oil production so as to provide a good economic indicator of oil recovery. Remedial cementing work for bonding repair was carried out at well AB-30. The first work is to close the existing layer, followed by Logging evaluation (CBL-USIT). The evaluation results showed that the cement bonding was good with the CBL amplitude parameter < 10 mV. After that, the productive zone reperforation was carried out. The economy by considering the values of economic indicators such as Pay Out Time and Rate Of Investment showed positive results so that the priority and strategy of well intervention could be continued. The results obtained before the well intervention were 148 BOPD oil production, 97% water cut after well intervention was 880 BOPD average oil production, 0% water cut for 1.5 months

Reservoir Characterization of a Tight Gas Field Using New Modified Type Curves for Production Data Analysis—A Case Study from Ordos Basin

Using data from 56 tight gas wells from the study field (Y field) in the Ordos basin of China, this paper presents performance-based reservoir characterization of the study field from production data and geophysical data. Post-fracturing evaluation is realized by applying our new modified production decline type curves for fractured wells. Compared to traditional type curves, our newly proposed modified dimensionless type curves help identify field data diagnostics for various flow regimes of fractured wells and also facilitate the curve matching process with real data to obtain fruitful and crucial reservoir and fractured well information, including key parameters such as reservoir flowing capacity (kh), well productivity, fracture length, drainage area and original gas in place. This paper intends to promote the extensive application of this new technique. With the support of the reservoir information provided by production decline analysis using our modified type curves, the commercial flow units are delineated in terms of interrelated porosity-permeability of sandstone based on pore throat aperture crossplotting and corresponding flow unit productivity. Furthermore, two crossplots of well logging interpreted porosity versus resistivity are constructed, suggesting their good correlated relationships with relative flow unit productivity and initial gas abundance in place, respectively. The two crossplots enable qualitative evaluation of formation penetrated by well, which makes them very useful and practical as wireline logging is basically available for every well. The well production routine is also analyzed systematically by considering a well’s inflow performance, tubing performance and minimal liquid-carrying gas flow rate to investigate if a gas well is producing at optimal conditions or if a measure should be taken to improve the well’s production. Through analysis of the Y field, this study introduces an integrated workflow with the support of the new modified type curves to effectively help understand the reservoir characteristics and the flow behaviors of the tight gas field. The key takeaway from this study is that the new modified dimensionless production decline curves in terms of qDM vs. tDM can be applied in field practice to achieve a systematically comparable understanding of the performance of MHFHWs globally.

A structured comparison of decentralized additive manufacturing centers based on quality and sustainability

Companies are increasingly adopting decentralized manufacturing strategies to manage multiple, geographically scattered manufacturing centers that are characterized not only by similar types of equipment, working methods, and productions, but also by variable mixes and volumes. This trend also applies to additive manufacturing, a well-established technology that allows the flexibility and customization of production to be increased, without significantly increasing the per unit cost. Thus, the need arises to monitor the performance of individual centers in a structured way, and to make practical comparisons of such centers. However, achieving this task is not so straightforward, given the inevitable differences in the characteristics of manufacturing centers and their productions. This paper presents a methodology that can be used to analyze and compare the production performance of a plurality of manufacturing centers from two different viewpoints: (i) quality, through a multivariate statistical analysis of product data concerning conformity with geometrical specifications, and (ii) process sustainability, with the aim of achieving a reduction in energy consumption, carbon dioxide emissions, and manufacturing time, through regression models pertaining to the selected metrics. The proposed methodology can be adopted during regular production operations, without requiring any ad hoc experimental tests. The description of the method is supported by an industrial case study.

A new approach for production forecasting from individual layers in multi-layer commingled tight gas reservoirs

Estimating future production in multi-layer tight gas reservoirs is necessary, but problematic. Initial production looks promising but soon decreases to levels that are much lower than first anticipated. Boundary-dominated flow to which common production data analysis can be applied to, takes up to 8 years to establish, yet future production estimations must be made at the time of drilling. Common industry software does not fully assess individual layer contribution because large uncertainties exist in layer-specific contributions to total production. Many engineers tend to use analysis methods designed for single-layer wells, which leaves future production estimations with large errors, and this can have potentially long ranging consequences for a company. This paper presents a new way of estimating future production in multi-layer tight gas reservoirs by incorporating the uncertainty that can be found in individual layer contributions. Our approach utilises single tank material balance and matches total well production data by changing layer-specific properties. A workflow has been created for the programming language Python that includes a Bayesian element to honour the uncertainty in individual layer effective permeability and individual layer gas in place. Applying this workflow to many wells in a specified area allows probability distribution functions for layer effective permeability and layer gas in place to be generated. This will result in attaining more realistic production forecasts in the form of P10, P50 and P90 for multi-layer tight gas reservoirs, and allowing the engineer to make better-informed early assessments of the future production of wells.