bluuebunny/crossref_metadata_2025 huggingface dataset:
Analysis of health seeking behaviour on effective delivery of health services under capitation scheme in Kenya
Authors: Wangai Priscilla Nduku , Njuguna Amos , Ngugi Joseph
Published: October 2019

Under capitation health scheme, a member freely selects a health facility from which to seek health services. There is no restriction of the number of times a member seeks health services from the facility within the contract period. This has affected delivery of health service under capitation contracting. This paper documents a quantitative analysis of the effect of health seeking behaviour on effective delivery of health services. Since human behaviour is assumed to be a natural phenomena, a philosophical view of positivism w?s ?dopted in this research. Accordingly, a scientific approach was used to deduce the influence of health seeking behaviour on the metrics of effectiveness. Out of 1152 health facilities accredited to offer primary healthcare in Kenya, data was collected from a sample of 297 health units using closed ended questionnaires. Logit regression analysis on the data revealed that congestion in out-patient department had a negative effect on quality of health services delivered but a positive effect on accessibility and affordability of the services. Increased frequency of consultation had a negative effect on all the three measures of effectiveness; quality, accessibility and affordability of health service delivery. Corresponding odds ratios were 0.173, 1.105 and 1.295 respectively.
Influence of intellectual stimulation on employee engagement in parastatals in the energy sector in Kenya
Authors: Change Doris
Published: October 2019

Employee engagement continues to pose a challenge to parastatals. Consequently, governments have adopted the transformational leadership style as an effective method of enhancing employee engagement. Nevertheless, it is still unknown whether the establishment of transformational leadership dimensions has boosted employee engagement in the Kenyan energy sector parastatals. The objective of this study was to investigate the influence of intellectual stimulation on employee engagement in parastatals in the energy sector in Kenya. Also, the study sought to determine the moderating influence of employee motivation on the relationship between intellectual stimulation and employee engagement. This study targeted the 10 parastatals within the energy sector in Kenya with a population of 315 middle-level managers. The study adopted a positivist research philosophy to examine the influence on intellectual stimulation on employee engagement and data was collected using structured questionnaires. A correlational research design was conducted with the purpose of determining the strength of the relationship between parameters of intellectual stimulation and employee engagement.The findings showed that employee engagement has a statistical significant relationship with creativity and innovation, r(166) = 0.540, p < 0.01; job design, r(166) = 0.452, p < 0.01 and employee involvement, r(166) = 0.512, p < 0.01. Multiple linear regression analysis revealed that employee motivation positively and significantly moderates the relationship between intellectual stimulation and employee engagement, R2= .409, F(2, 159) = 55.115, p <.05; ? = 0.259, p <.01. The study concluded that creativity and innovation, job design, employee involvement, and employee motivation positively enhance employee engagement.
Ownership structure, bank stability and the financial performance of commercial banks in South Sudan
Authors: Chol Bak Barnaba , Nthambi Elizabeth Kalunda , Kamau Joseph N
Published: October 2019

Since independence in 2011 the Republic of South Sudan has witnessed growth in the financial systems and the overall economy. This has led to growth in the number of the financial institutions in the country. There is however minimal research on their overall performance. Hence the current research sought to determine the effect of ownership structure, bank stability and the financial performance of commercial banks in South Sudan. The population for the study was all the 29 commercial banks in South Sudan. Secondary data was collected for the period 2012-2017 from audited annual financial reports of individual banks and from the Central Bank of South Sudan reports while primary data was collected by use of a semi-structured questionnaire. The research utilized both descriptive and inferential statistical methods in the analysis. The statistical tests to be utilized in the study included t-tests, f-test, regression models and ANOVA models. The results of the study indicated there was a statistically significant moderating effect of ownership structure on the financial performance of commercial banks in South Sudan. The study recommends that the government should adopt better measures to safeguard public owned commercial banks to improve their efficiency and performance.
Understanding the insight of factors affecting mHealth adoption
Authors: Kaium Md. Abdul , Bao Yukun , Alam Mohammad Zahedul , Hasan Najmul , Hoque Md. Rakibul
Published: October 2019

Numerous studies have addressed the different context of mHealth services among diverse user groups. But due to a lack of understanding the insight of factors affecting the mHealth adoption, it’s crucial need to conduct a systematic review on this issue. The objective of this study was to synthesize the present understanding of the influential factors of mHealth adoption. We performed a systematic literature search on eight electronically reputed scientific databases from 2010 to March 2019, such as Science Direct, Springer, IEEE Xplore, JMIR, Taylor & Francis, Emerald, Mary Ann Liebert and Google Scholar. This was accomplished by gathering data including authors, countries, years, target population, sample size, models/theories, and key influential factors. Primarily, a total of 2969 potentially relatable papers were found, of which 50 met the inclusion criteria. It was found that cross-sectional approach, survey methods and structural equation modeling (SEM) were the most explored research methodologies whereas PLS-SEM was found to be the largest used analysis tools. From the analysis, a total of ninety-four influential factors were clearly recognized and the findings represent that the following 15 factors appeared most recurrently and significantly; perceived usefulness, perceived ease of use, social-influence, subjective norms, self-efficacy, trust, facilitating conditions, technology anxiety, performance expectancy, effort expectancy, cost, attitude, resistance to change, perceived privacy and security, and perceived behavioral control. The research results have significant theoretical and practical implications for mHealth services providers, researchers and policy makers with regards to the Sustainable Development Goals (SDGs) allied to healthcare.
Stakeholderparticipation influence on tourism performance in West Pokot County
Authors: Patricia Tulel Cherop , Ombaka Beatrice , Ann Kariuki
Published: October 2019

The support of tourism stakeholders is essential for the development, successful operation, and long-term sustainability of tourism. The aim of this paper was to establish how stakeholder involvement influence tourism sector performance the purpose of getting a deeper understanding of what different stakeholders perceive on their involvement and the benefits that they have gotten or brought to the sector. The theory guiding this paper was an integrated model of destination competitiveness. A descriptive research design was used for the study. The target population consisted of employees of hotels, officials of tour firms and officers in the ministry of tourism in the County Government of West Pokot. Systematic stratified sampling was used and a total of 41 respondents selected. Structured questionnaires were used to collect data from the respondents. Data were analyzed using descriptive and inferential statistics. From the R2 was 0.444 meaning that Stakeholder participation predicted 44.4% of tourism performance in West Pokot County and therefore the Counter government should always consider the stakeholders in matters to do with tourism so as to improve its performance.
Influence of tax planning on financial performance of manufacturing companies listed at Nairobi Securities Exchange
Authors: Oeta Simeon , Kiai Richard , Muchiri Joseph
Published: October 2019

Taxes form a significant portion of a company’s expenses and in order to increase probable returns, tax planning is vital to financing and investment decisions of an entity. This study sought to find out the influence of tax avoidance on financial performance of all the nine manufacturing firms listed on the Nairobi Securities Exchange during the period 2010-2017. The study was anchored on tax planning theory, capital structure trade-off theory, agency cost theory and political power theory. The study adopted a positivism research philosophy and an explanatory research design. SPSS version 23 was used to analyze data where both descriptive and inferential statistics was done. Multiple linear regression model was adopted to study the association between the variables while utilizing panel data. The study findings showed that there is no significant statistical association between tax planning and financial performance of the manufacturing companies listed in the Nairobi Securities Exchange. The findings indicated that capital intensity, research and development expenditure and company size have a positive insignificant association with financial performance. Further, debt to equity ratio indicated an insignificant negative relationship with financial performance. The study points out that the manufacturing companies should invest more in non-current assets and increase expenditure on the research and development expenditure to realize significant positive impact on financial performance. They should also manage their debt to equity ratios to avoid excess financing costs that may be detrimental to their financial performance.
Perceived overqualification and its positive impact on organization employee's behavior
Authors: Abozaid Rafeed faiz , Mansoor Rafique Mansoor , Shah Sayyed Sadaqat Hussain , Harjan Sinan Abdullah , Alalimi Ahmed , Mustafa Almushaira
Published: October 2019

Preceding researchers have tended to focus on the negative aspect of the perceived overqualification and its inadequacy in the organization. We offer an alternative perspective and postulate that perceived overqualification could influence employees’ behavior through an interactive mechanism. We propose that relational skill abilities, in the form of job autonomy of overqualified employees, determine their tendency to experience interpersonal influences, and, thus engage in helping behavior with devastating work deviance behavior. Data were collected from 20 multinational companies in China through a survey of 500 participants. Structural equation modeling was used for the analysis of data. The results indicate that perceived overqualification has a strong indirect impact via interpersonal influence on the helping behavior and workplace deviance behavior, and increase the helping behavior and decrease the workplace deviance behavior at the working environment. Further, outcomes concluded that job autonomy and prosocial motivation have a significant moderating role and increase the employers helping behavior and deteriorations their Workplace deviance behavior.
Corporate governance mechanisms and audit report lag moderated by audit complexity
Authors: Sari Wa Ode Irma , Subroto Bambang , Ghofar Abdul
Published: October 2019

This study aims to verify the correlation between corporate governance mechanisms, reflected independent commissioners, audit committee and audit tenure to audit report lag, and the audit complexity has able to moderate the relationship between corporate governance mechanisms to audit report lag. This study uses a population of manufacturing companies that publish their financial statements on the Indonesian Stock Exchange in 2015-2017. The samples are selected with a purposive sampling method. There is 100 manufacturing company selected as the sample for the period of 2015-2017. This study was tested by using the Moderate Regression Analysis test. The results of this study indicate that the audit committee and audit tenure have a negative effect on audit report lag, but the independent commissioner has an insignificant effect on audit report lag. Audit complexity is proven to increase audit report lag as an increase audit committee. This research provides the capital market authority (OJK) to issue policies and strict sanctions, thus encouraging companies to publish audited financial statements more time.
HEMŞİRELİK EĞİTİMİNE YENİ BAŞLAYAN ÖĞRENCİLERİN MESLEK SEÇİMİNİ ETKİLEYEN FAKTÖRLER İLE BOYUN EĞİCİ DAVRANIŞLARI ARASINDAKİ İLİŞKİNİN İNCELENMESİ
Authors: PAZARCIKCI Fahriye , DİLMEN Belgin
Published: October 2019

Bu araştırmanın amacı hemşirelik eğitimine yeni başlayan öğrencilerin meslek seçimini etkileyen faktörler ile boyun eğici davranışları arasındaki ilişkinin incelenmesidir. Bunun yanında, öğrencilerin meslek seçimini etkileyen faktörler ile boyun eğici davranışlarının sosyodemografik ve meslek seçimi özelliklerine göre anlamlı düzeyde farklılaşıp farklılaşmadığı değerlendirilmiştir. Araştırmanın örneklemini, 2016-2017 eğitim-öğretim yılında Türkiye’nin batısındaki bir Sağlık Bilimleri Fakültesinde öğrenime başlayan 145 hemşirelik öğrencisi oluşturmuştur. Veriler, Kişisel Bilgi Formu, Hemşirelikte Meslek Seçimi Ölçeği (HMSÖ) ve Boyun Eğici Davranışlar Ölçeği (BEDÖ) kullanılarak toplanmıştır. Araştırmaya katılan öğrencilerin HMSÖ “Mesleki Uygunluk” alt boyutu puan ortalaması 68,61±18,35, “Yaşamsal Nedenler” alt boyutu puan ortalaması 53,68±15,08 ve ölçek toplam puan ortalaması 63,34±12,55’tir. BEDÖ puan ortalaması 35,73±7,79’dur. Yapılan korelasyon analizi sonucunda BEDÖ puan ortalamaları ile HMSÖ’nin “Mesleki Uygunluk” alt boyutu ve ölçek toplam puan ortalaması arasında istatistiksel olarak anlamlı bir ilişki saptanmamıştır (p>0,05). Ancak öğrencilerin BEDÖ puan ortalamaları ile HMSÖ’nin “Yaşamsal Nedenler” alt boyutu puan ortalaması arasında pozitif yönlü (Boyun eğicilik arttıkça “Yaşamsal Nedenler” puanı artan) %15,3’lük ilişki, istatistiksel olarak anlamlı olmamakla birlikte anlamlılığa yakın bulunmuştur (r=0,153; p=0,066). Bu sonuçlar doğrultusunda mesleğin bilinçli tercih edilmesi, sevilmesi ve istenmesi için gerekli adımların atılması, meslek seçimi kararının öğrenci-aile-eğitimci/rehberlik üçgeni çerçevesinde gerçekleştirilmesi, eğitim kurumlarında öğrencilerde boyun eğiciliği azaltıcı, danışmanlık, liderlik, koordinatör rollerini geliştirici çalışmalara yer verilmesi önerilir.
DÖVİZ KURU OYNAKLIĞINDA ASİMETRİK İŞARET VE BOYUT YANLILIĞININ TEST EDİLMESİ: EURO/TL KUR OYNAKLIĞI ÜZERİNE BİR İNCELEME
Authors: DEMİRGİL Hakan , YILDIRIM Sinan , ÇİÇEK Zübeyde
Published: October 2019

Bu çalışmanın amacı Engel ve Ng (1993) nin işaret ve boyut yanlılığı testleri ile belirlenen asimetrik etkileri dikkate alarak döviz kurlarında yaşanan oynaklığın modellenmesidir. Bu doğrultuda, Türkiye’nin dış ticaretinde en büyük paya sahip Avrupa ülkeleri para birimi EURO’nun TL karşısındaki oynaklığı asimetrik GARCH modelleri ile incelenmiştir. EURO/TL döviz kuru değişkenine ait 1999M01-2019M05 dönemi aylık veriler kullanılmıştır. Ampirik sonuçlar, EURO/TL döviz kuru oynaklık serisinin asimetriye sahip olduğunu göstermektedir. Geçmiş dönem kalıntılarının boyutu ve büyüklüğü, döviz kuru oynaklığının açıklanmasında önemli bir etkiye sahiptir. Asimetrik GARCH modellerinden (E-GARCH, TGARCH ve APGARCH) elde edilen sonuçlar, EURO/TL döviz kurunda meydana gelen pozitif şokların aynı büyüklükte ki negatif şoklardan daha fazla etkiye sahip olduğuna işaret etmektedir. Son olarak, bu modeller kullanılarak elde edilen öngörü hata istatistiklerine göre EURO/TL döviz kuru oynaklığı tahmini için en iyi modelin  TGARCH modeli olduğu sonucuna ulaşılmıştır.
KIRSAL KALKINMADA TKDK’NIN ROLÜ: IPARD I PROGRAMINA İLİŞKİN ISPARTA İLİNDE BİR İNCELEME
Authors: ÖZKUL Gökhan , BOZKURT Ahmet Ali
Published: October 2019

Türkiye’nin kırsal kalkınma politikaları AB’ye üyelik sürecindeki katılım müzakerelerinden oldukça etkilenmiştir. Bu müzakerelerin bir sonucu olarak AB’ye katılım öncesi dönemde, AB mevzuatına uyum sağlanması ve uyumlaştırılan mevzuatın uygulanması için gerekli idari ve kurumsal altyapının oluşturulması için 2007 yılında Tarım ve Kırsal Kalkınmayı Destekleme Kurumu (TKDK) kurulmuştur. TKDK uygulamış olduğu IPARD (IPARD I ve IPARD II) programlarıyla AB fonlarının etkin bir şekilde kullanılması görevini görerek kırsal kalkınmaya büyük bir katkı sağlamaktadır. Bu bağlamda çalışmada ekonomisi tarıma dayalı illerden biri olan Isparta’da IPARD I programından faydalanan firmaların desteklere ilişkin başvuru ve uygulama süreçlerinde yaşadığı problemler ve bu desteklerin bölge için yaratmış olduğu sonuçlar betimleyici istatistikler, ki-kare testi ve kruskal wallis testi ile incelenmiştir. 109 firmadan elde edilen anket bulgularına göre desteklere ilişkin başvuru ve uygulama süreçlerinde yaşanan problemlerin yüksek seviyede olmadığı, problemlere ilişkin yapılan değerlendirmelerin firmaların destek aldığı tedbir türlerine göre farklılık gösterdiği ve verilen desteklerin kırsal alanda tarım sektörünün gelişimine, istihdam artışına, gelir artışına, halkın becerilerinin gelişmesine katkı sağlayarak daha yaratıcı ve yenilikçi olmalarına katkı sağladığı sonucuna varılmıştır.
The Challenge of 3D Numerical Integration of Heterolithic Facies Characterization in Order to Properly Assess In-Placed Volume Estimation and Capture Reservoir Plumbing System to Improve Production Predictions and Enhance Oil Recovery Operations: An Example from The Seligi Field, Offshore Malaysia Peninsula
Authors: Dwiyarkoro Broto , Hasan Wan Abdul , Razali Muhammad Asyraf , Masni Mohd Khairul
Published: October 2019

Many oil and gas reservoirs contain laminated and/or bioturbated facies. In such cases, conventional petrophysical analysis tends to underestimate reservoir properties resulting in pessimistic in-place volumes estimation and overlooked potential. The objective for incorporating the characterization of bioturbated and laminated facies is to build an anisotropic petrophysical spatial properties distribution describing the static model reservoir plumbing system and yielding practical reservoir simulations to improve production predictions, enhance sweep efficiency and maximize oil recovery.

The approach is based on characterization of heterolithic facies utilizing vertical resistivity (RV) and horizontal resistivity (RH) to provide heterolithic facies tagging, the calibrated macro-micro petrophysical properties, the correlation of RV/RH to KV/KH, the proportion of macroporosity-microporosity and burrow density as the inputs for static modeling. A high density permeametry and core Dual Energy Computed Tomography (DECT) Scan were used as reference to restore facies proportion and maintain reservoir heterogeneity as the impact on scaling factor in building static model.

This Seligi field example demonstrates that low-resistivity pay heterolithic facies remain untapped due to underestimated reservoir properties from a conventional petrophysical approach and illustrates complex flow pathways created by different sweep patterns under dynamic conditions.

From a practical engineering perspective, the heterolithic facies collocate with development uncertainties associated with erratic patterns of flow pathway. Field development opportunities for targeting this type of facies and the challenge for efficient hydrocarbon depletion with more accurate prediction of the spatial configuration and connectivity of high performance are ongoing.

As technology develops to understand reservoir complexity, more published documentations related to heterolithic facies characterization are becoming available in the industry; however, the idea of how to incorporate those characterization results into 3D numerical integration is still very limited. This paper provides an alternative solution for practical integration, both for static and dynamic simulation models, to support management decisions to optimize reserve recovery and maximize NPV.
Effect of Natural Fractures on the Stress-Dependent Permeability and Long-Term Gas Production for the Naturally-Fractured Tight Sandstone in Tarim Basin, China
Authors: Qu Hongyan , Zhou Fujian , Hu Jiawei , Peng Yan , Zhong Yuechen , Pan Zhejun
Published: October 2019

The Keshen gas formation is located in the Tarim basin, western China, characterized with developed heterogeneous natural fractures, with most prospective tight gas opportunities. Though high initial gas production rate is commonly achieved, a rapid decline sometimes occurs during the long-term gas production when an unsuitable drawdown pressure is applied. This paper presents studies of the stress-dependent permeability of the core samples from the ultra-deep, naturally fractured tight gas reservoir in the Tarim basin, China and investigates its impact on the long-term gas recovery.

In this work, tight sandstone samples with different morphology of natural fractures were obtained from three exploration wells in the Tarim Basin. Permeability was measured using the pulse decay method by increasing the effective stress from 600psi to 6500psi, in steps of 1000psi, and repeating the same procedure in the reverse order. In addition, a numerical simulation model was established and validated by fitting the results of the experimental data to study the effect of natural fracture dip on the stress-dependent permeability.

Different permeability decline characteristics were observed for tight sandstone samples with different dominant flow channels (i.e., matrix or natural fractures). Due to the existence of natural fractures in the tight reservoir, the stress dependency and hysteresis of permeability is larger. Specifically, the hysteresis of stress dependent permeability is the largest if a natural fracture is through the whole sample and vertical to the end faces. Moreover, for the samples studied in this work, the permeability declines more as the effective stress reaches 3000psi if the natural fracture dip is large compared to that of the samples with a smaller natural fracture dip. Furthermore, a control strategy was proposed to address the stress sensitivity of permeability through the numerical simulation results.

Interpreting the permeability decline characteristics provides insights of the gas production behavior from tight sandstone reservoir while proper reservoir pressure needs to be maintained to mitigate the sharp production decline and enhance the ultimate gas recovery for the tight reservoirs with developed natural fractures.
Application of Artificial Intelligence in the Petroleum Industry: Volume Loss Prediction for Naturally Fractured Formations
Authors: Al-Hameedi Abo Taleb , Alkinani Husam H. , Dunn-Norman Shari , Al-Alwani Mustafa A. , Alkhamis Mohammed M. , Al-Bazzaz Waleed H.
Published: October 2019

Recently, artificial intelligence has gain popularity in the drilling industry since more wells are drilled in hostile environments. One of the most difficult problems have been encountering the drilling operation is the problem of lost circulation. The complexity of the lost circulation problem is due to the interaction between the parameters that are causing this issue. The aim of this work is to create artificial intelligence models to predict lost circulation, equivalent circulation density (ECD), and rate of pentation (ROP) prior to drilling for naturally fractured formations.

Lost circulation events from 500 wells were collected and analyzed to comprehend the impact of each drilling parameter on lost circulation. The data were cleaned and outliers were removed. Partial least square (PLS), a supervised machine learning algorithm, was utilized to create three models to estimate mud losses, ECD, and ROP before drilling. The models went through a cross-validation process to validate them. In addition, the models were tested with new data that were not used in the process of creating the models.

The results showed that the three models can predict mud losses, ECD, and ROP within a reasonable margin of error. Testing the models with new data of 30 wells drilled showed that the models' predictions closely track the actual values from the real data. Moreover, the new models were compared with previously developed models for naturally fractured formations. The new models showed better predictions for the actual values than the previously developed models, suggesting the ability of the new models to predict mud losses, ECD, and ROP within an acceptable error. In addition, a 10% sensitivity analysis was conducted for all models to quantify and understand the effect of each parameter on every model. Mud weight (MW) had the highest impact on the ECD and mud losses models revealing that in order to minimize mud losses and ECD, the first action should be trying to use as low MW as possible. On the other hand, weight on bit (WOB) showed the highest positive influence on the ROP model and total flow area (TFA) of the nozzles showed the highest negative impact on the ROP model. Thus, the models developed in this study can be used to regulate the drilling parameters to minimize mud losses.

The methodology used in this study to develop estimation models for mud losses, ECD, and ROP can be applied to create predictive models in other formations if the required data are available.
Using Computer Simulation to Overcome Unforeseen Challenges during Start-Up and Commissioning of a Water Injection System
Authors: Addicott Glyn
Published: October 2019

This paper will discuss a past Hydraulic Analysis Limited (HAL) project and the challenges of commissioning a Water Injection (WI) system. The paper will demonstrate how the use of an accurate pipeline simulator which models the full control system can reduce both commissioning time and risk by identifying issues early. The simulator can then be used to modify and tune the control systems prior to and during commissioning.

A computer simulator of a Water Injection system on a Floating Production Storage and Offloading (FPSO) vessel was constructed, including all pipework, pumps and control systems. The simulator was initially used for a design based hydraulic and surge analysis study. During commissioning, the simulator was updated with as-built information and was then used as a commissioning support tool to tune and optimise the various control systems prior to commissioning. All commissioning tests were simulated and assessed before being carried out so that potential issues could be identified and resolved using the simulator.

The simulator identified a number of unforeseen issues associated with the start-up of the hydraulic systems. If these issues had not been identified early then there would have been significant delays to the project. The number of hours expended during commissioning was significantly lower than expected with little ‘fire-fighting’ of problems. The simulator was used on a daily basis to check every commissioning activity via a morning web conference meeting and screen share to run through the simulation results and show the expected pressure and flow readings for that days tests. The expected pressure and flow readings could then be compared to the actual readings during the commissioning tests, ensuring a high level of confidence. By comparing the simulator output to the actual site pressure and flow readings, any unexpected system response was rapidly identified and the system was safely shutdown prior to unacceptable operating conditions occurring. The cause of the problem was then identified and resolved through modifications to the FPSO control systems.
A Physic-Based Scaling Curve of Gas Production Under Compaction: A Leading Way to Better Machine-Learning Prediction
Authors: Sajjad Farasdaq , Chandra Steven , Naja Savinatun , Suganda Wingky
Published: October 2019

We present a simple analytical solution to diagnose gas production under compaction. This solution scales production profile of different wells and collapses them into a single general curve. The curve will later serve as the "learning" function for physic-based machine-learning prediction.

A rapid growing flood of big data in the oil and gas industry reveals a substantial opportunity to the better understanding of hydrocarbon reservoir. With machine learning, one can turn a numerous amount of data to predict future production and determine field economics. However, the quality of the prediction from machine learning is dependent on the learning function selected that most of the time does not concatenate any physical aspects of the problem. In this paper, we offer a better machine learning with a physics-based function to estimate future gas production under severe compaction.

We construct a physic-based master curve by solving the coupled Darcy-Biot equation for vertical gas well under reservoir compaction. We assume that the flow is radial and the porosity is transiently changing by the reduction in pore pressure due to gas production. Finally, we reduce the complexity of the coupled non-linear equation to two scaling optimization parameters: a mass scaling factor to scale the recovery factor and time scaling factor to scale the diffusion time.

We verify our model with a field case from KLX field, Indonesia. This gas field produces an enormous amount of gas with subsidence as the side effect. The subsidence was identified by knowing the change in platforms level. By collapsing the production profile of all existing wells into a single master curve, we capture the universal scaling parameters that represent the behavior of gas flow under reservoir compaction. Furthermore, we can substitute the resulted master curve as the learning function for to the machine-learning model to predict and diagnose other fields in the future that undergo the same phenomena.

We find that reservoir compaction leads to a higher recovery factor of gas for a long term. However, the high subsidence rate is not a favorable condition for the offshore field as the production facilities on the platform will submerge under sea level in a matter of years. Thus, the field owners must consider some subsidence mitigations such as injection and maintaining critical production rate.

Our novelty is to produce a general scaling to describe gas production under compaction, which is later useful for the development of our machine-learning process to simplify the prediction process, not involving extensive and expensive numerical simulation.
A Scalable Parallel In-Situ Combustion Reservoir Simulator for Large Scale Models
Authors: He Ruijian , Wu Shuhong , Chen Zhangxin , Yang Bo , Liu Hui , Shen Lihua
Published: October 2019

As a competitive recovery method for heavy oil, In-Situ Combustion (ISC) shows its great potential accompanied by technological advances in recent years. Reservoir simulation plays an indispensable role in the prediction of the implementation of ISC projects. With the computational complexity, it is imperative to develop an effective and robust parallel in-situ combustion simulator. In this paper, a mathematical model for ISC is proposed, which takes full consideration of ISC related physical phenomena, including multi-dimensional multi-component three-phase flow, heat convection and conduction, chemical reactions, and mass transfer between phases. In the mathematical model, different governing equations and constraints are involved, forming a complicated PDE (partial differential equation) system. For physical and chemical behaviors, some special treatments for the ISC simulator are discussed and applied. Also, a modified PER (Pseudo-Equilibrium Ratio) method is proposed in this paper. A fully implicit scheme is applied, and discretization is implemented with the FDM(Finite DifferenceMethod). In solving nonlinear systems, the Newton Method is introduced, and both numerical and analytical Jacobian matrices are applied. Due to the complexity of an ISC problem, an appropriate decoupling method should be considered for which the Gauss-Jordan transformation is developed. Then, with certain preconditioners and iterative solvers, a numerical solution can be obtained. The results of different models are presented, which are validated with the results by CMG STARS. Also, the scalability of parallelization is shown, indicating the excellent performance of parallel computing. This accurate, efficient and parallel ISC simulator applies to complex reservoir models.
Harnessing the Power of Natural Language Processing and Fuzzy Theory to Improve Oil and Gas Data Management Efficiency
Authors: Asfoor Hasan , Kaskas Walid
Published: October 2019

Recent years have witnessed advancements in the oil and gas (O&G) industry related to the 4th Industrial Revolution and advanced analytics. O&G data has been a key that fuels these advancements. Proper management of O&G data could unleash the full potential of analytics for the O&G industry. Tackling this challenge may involve time consuming manual steps that may introduce inaccuracies along the way. In this work we aim to improve the efficiency of O&G data management in three aspects. First, by simplifying the tagging process of O&G files and largely reducing the manual work involved. Second, by enhancing the searchability of O&G files. Third, by reducing the overhead of data redundancy.

Our approach utilizes Natural Language Processing (NLP) techniques and Fuzzy theory concepts to produce three elements. The first element is a metadata extractor, which can automatically extract search keywords from O&G files. The second element is an algorithm we built to tag O&G files. This algorithm can be trained against predefined business categories and label a target file with the right category. It can also produce a (fuzzy) degree of membership of the file to other categories. This algorithm can be used to automate tagging of legacy historical files. The third element is a utility that we built to enable data managers find similar and duplicated files across multiple O&G file repositories. It also combines the first two elements to simplify and automate tagging of historical, untagged, files and migrate them to a central repository. Our approach and algorithms do not use any metadata defined manually by users. Rather, they work entirely on textual content inside files to tag them, discover similarities and extract their metadata.

We tested our approach on an O&G dataset of text documents related to drilling, exploration and production. This dataset comes in different formats (reports, spreadsheets and presentations) and is distributed over multiple repositories. The test included two scenarios: document tagging and discovering duplicated files. The results show that our tagging algorithm was able to achieve over 95% tagging accuracy. Automated file tagging with such accuracy can significantly reduce the steps to classify O&G files. This can be useful when migrating legacy data to a central repository. The test also resulted in discovering all duplicated files with a similarity score between 95% and 100%. This enables data managers to migrate the correct version of duplicated files to a central repository and thus achieve data accuracy, reduce the search effort, and also reduce disk space required.

Our work introduces a unique approach to optimizing the efficiency of O&G data management and automate key steps such as document tagging. In addition, we believe that the tagging algorithm we built is unique in the O&G industry.
Liquid-Bead Solution for Lightweight Cement Slurries
Authors: Chan Lakmun , Vasquez Jorge , Flores Leon Carlos
Published: October 2019

Design, execution, and evaluation of cement operations using a new liquid-bead cement system helped achieve the necessary top of cement for development wells in Brunei. Glass beads are a common lightweight material used within the oil industry to generate low-density slurry designs with competent compressive strength development. For Brunei offshore operations, using dry beads poses many challenges, such as rig silo management, quality control of blends, and waste. A new approach has been proposed using a liquid-bead system to produce lightweight cement slurries by adding beads stabilized within a fluid as another liquid additive to help reduce the need for dry bulk blending of beads. Planning, execution, and post-operation evaluation methods were developed for this new approach.

The liquid beads can be added to cement slurries using liquid additive pumps. For Brunei's operation, a mobile injection skid was developed to inject liquid beads at a predetermined rate into the suction header of the cement unit triplex pump while the base slurry is being mixed and pumped at a predetermined rate on the fly. Extensive laboratory tests were performed on the liquid slurry and the final set product to demonstrate the liquid-bead influence on cement properties compared to a dry-blend bead design. To validate this technology, a field mixing trial was performed at the rigsite. Cement evaluation with conventional logging tools poses an additional challenge for beaded slurries. To evaluate cement placement, a bond log post-process analysis was performed.

The first Brunei offshore trial operation, executed during April 2018, was a 9 5/8-in. production casing where 13 m3 of a liquid-bead cement slurry design was mixed, pumped, and successfully placed within the annulus. Laboratory testing validations and injection skid and post-operation cement evaluations are discussed.
Interrelationships of Rock Elastics Properties to Petrophysical Pore Structure and Geometric Details of Sandstone
Authors: Akbar Muhammad Nur , Salam Agihtias , Awab Malik , Prakoso Suryo
Published: October 2019

This paper presents new interrelationships of elastic properties of the porous rock to petrophysical parameters in order to enhance better understanding on how compressional and shear waves velocities, young modulus, bulk modulus, lame’s coefficients, and Poisson’s ratio correlate with permeability, porosity, petrophysical geometric details of the pore system, and microscopic geological features.

This study employs 215 sandstone core-plugs from North West Java Basin. The approach used utilizes the Kozeny-Carman equation with Re-arrangement made on this equation leads to rock typing based on pore structure similarity, similar in pore shape factor and tortuosity. By plotting pore geometry against pore structure variable, it shows that P- and S-wave velocities, young modulus, bulk modulus, Poisson’s ratio, and lame’s coefficients data can be clearly grouped based on rock type and have strong correlations with permeability, pore geometry, and pore structure parameters. This grouping method enables to investigate the main influential factors that systematically control rock elastic properties. The interrelationships of each parameter of P-wave and S-wave velocities, young modulus, bulk modulus, Poisson’s ratio, and lame’s coefficients versus pore geometry and pore structure were constructed. The critical finding is that each relation among the rock groups of each elastic property is clearly separated. Each rock type has a similar pattern in that P-wave and S-wave velocities increase with pore geometry and pore structure variables. These velocities tend to be high with an increase in Kozeny constant. However, for a given porosity for all the groups, these velocities increase remarkably with a decrease in Kozeny constant. In other word, velocities increase with either an increase in the complexity of pore systems or, at the same pore complexity, a decrease in specific internal surface area. In addition, young modulus, bulk modulus, and lame’s coefficients also increase with pore geometry and pore structure in each rock type.

As a novelty, this study helps to characterize the elastic properties based on porosity and permeability data in the form of pore geometry and pore structure. Furthermore, this work can help us to predict some elastic properties at in-situ condition as long as we have the porosity and permeability values interval.
Novel Time Saving Well Integrity Assurance Methodology
Authors: Stein Arild
Published: October 2019

Objectives/Scope

To enable and verify an installed barrier in any well with wireline intervention only. Removing the need for large pressure testing volumes or equipment to test installed barriers from surface. Especially when there potentially are structural issues in well barrier envelope that can limit the pressure test, inefficiencies or weak spots in the subsea structure or Xmas tree / well barrier envelope.

The wireline toolstring includes a setting tool with a monitoring system to log the setting signature of the plug.

A verification plug installed above the barrier with a verification module alters the pressure/forces below and sends the measured values to the setting tool above. The bespoke product setup provides a verified, documented barrier. Case history from a pilot job included to illustrate the principle.

Methods, Procedures, Process

The plug installation depth in the well is a compromise between requirements and verified structural integrity of the tubing, especially if installing a bridge plug as the primary barrier. The setting forces, anchoring and sealing signature of the plug is monitored and recorded. This individual signature will be verified against a library of ISO approved barrier installation profiles. Anomalies can be identified and trigger the need for a decision to release and relocate the plug. A verification plug may be installed near the primary plug. The verification plug installation signature will be surveyed in the same way as the primary plug to determine its proper installation. Verification is then achieved using the verification module between the installed plugs and logged by the setting tool above.

Results, Observations, Conclusions

Pressure manipulation in the volume between two installed plugs will cause a load in the direction of flow on the lower primary plug and a (an industry standard) test from above by the verification plug. Upon completion, this operation produces the necessary documentation to leave the plug(s) as an approved barrier in the wellbore. Equipment is re-usable after re-setting at surface.

Novel/Additional Information

By documenting this sequence, we now have a lower plug verified as a barrier and can remove the verification plug above or leave it as a secondary tested and verified barrier if needed. All performed without needing to use large volumes of test medium from surface and waiting for thermal adaptation and fluid segregating to get a stable test readout at surface.
A New Method to Predict and Assessment the Risk of Shallow Water Flow in Deep-Water Drilling
Authors: Wang Huanhuan , Yang Jin , Hong Jiayao , Zhang Dongyufu , Meng Lingyu , Xu Jiajun , Chen Lei
Published: October 2019

Shallow water flow is one of the geological disasters faced by deep water drilling operations. The common way to predict shallow water flow is applying qualitative prediction of seismic profiles and the accuracy is low. This paper proposes a new approach based on simulation experiment to quantitative predict the shallow water flow in deep water.

Based on the characteristics of propagation velocity of acoustic wave in deepwater and rock media, the simulation experiments of acoustic wave characteristics of shallow water flow have been conducted. The influence of shallow water flow in seabed soil on the propagation velocity of acoustic wave in rock and soil is revealed. The simulation experiments also show the relationship between the pressure and porosity changes in shallow water formation and the propagation velocity of acoustic wave. As a result, a template for predicting and identifying shallow water flow by acoustic wave is established, and the risk grade of shallow water flow to drilling is evaluated.

The results show that the greater the detected acoustic velocity, the greater the shallow water flow pressure in the formation and the greater the risk of drilling. The pressure and porosity of shallow water flow stratum are in a power exponential function relationship with the acoustic wave velocity. According to the site application results, the accuracy of this prediction model is more than 80%, meet the requirement of deepwater drilling design and site construction.
Alternate Path Horizontal Openhole Gravel-Pack Completion in Soft-Weak Carbonate Gas Reservoir: Offshore East Java
Authors: Firmanto Tri , Aoki Toru , Onggo Indra , Jayadi Agus , Akbari Aulia , Merati Putu Astari , Cerron Dante
Published: October 2019

Increasing natural gas demand in Indonesia has driven many operators to develop potential gas field assets, whether offshore or onshore, across Indonesia. One such field is BC which is located offshore East Java in a tectonically active area and part of the ABC complex. The field is composed of carbonate rock which is globigerinid in nature, with the presence of different facies such as packstone, wackstone and grainstone, of which the latter has the best permeability. An extensive geomechanical study was conducted and one of the conclusions was that solids and fines production to some degree are likely to happen from the carbonates in this field. To minimize the risk of solids production, an openhole gravel pack (OHGP) system was designed and deployed.

Horizontal OHGP involving screens equipped with shunt tubes for alternate packing are commonly deployed in unconsolidated sandstone formations around the world. The use of filter cake breakers, during or after OHGP placement, is regularly included as part of these treatments. The BC is a carbonate field, besides the low frac gradient and the naturally fissured characteristics associated to the rock which makes it prone to high leak-off, the completion strategy required a special designed filter cake breaker inert to the formation and capable of helping to minimize the lift-off pressure; the challenge required a different approach.

The successful completion of these wells required the use of state-of-the art gravel pack placement simulator, special analysis of Bottom Hole data during gravel pack placement and customized gravel pack fluid, capable of transporting proppant and clean the filter cake afterwards.

One deviated and three horizontal wells with 9 5/8-inch casing and average of 8.6-inch openhole diameter were drilled and successfully completed. Gravel pack placement interpretation using bottomhole gauge data indicates full annular packing for all OHGP cases. After completion, wells were started smoothly with no solids production observed.

This paper highlights key technical challenges and risks encountered during the preparation, design, execution, and evaluation stages of this operation and discusses how these challenges were overcome and the risks mitigated. Finally, the lessons learned and their implementation towards the improvement and optimization of future operations are discussed.