bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Decision Tree Regression Modeling Scheme for Estimating the PVT Properties of Kuwaiti Crude Oil Systems Using Incomplete Datasets
Authors: Almashan Meshal , Narusue Yoshiaki , Morikawa Hiroyuki 
Published: November 2019

Abstract
Accurate prediction of the Pressure-Volume-Temperature (PVT) properties of crude oils is required in the reservoir engineering studies and in improving the strategies of the oilfield development. For the past decade, machine learning has been successfully competing with the expensive and time-consuming experimental determination and the limited empirical correlations for estimating the reservoir fluid properties. In many situations, the PVT properties report may include some missing data that would limit the functionality of the empirical correlations. In this study, a decision tree regression model is proposed that is able to accurately estimate the PVT properties of crude oils using incomplete PVT reports. The proposed model predicts the bubble point pressure (Pb) as a function of the gas specific gravity, the oil API gravity, the temperature and the solution gas-oil ratio, based on a decision tree regression modeling scheme. An imputation technique has been applied to the incomplete datasets by using the mean value for each feature to fill in the missing values and then the complete dataset is fed into the predictive model for estimating Pb. Moreover, the feature importance for predicting Pb is discussed. The datasets used in building the predictive model are experimentally derived from 117 oil samples. Results show that the developed predictive model with the presence of missing data, outperforms the most commonly used empirical correlations in predicting Pb in terms of the average absolute percent relative error. Moreover, the built predictive model can be applied towards predicting other oil and gas properties by retraining the model with a new set of features, such as in the gas-liquid multiphase flow pattern identification. In addition, the predictive model can be integrated into simulators. In addition to the heuristic feature importance which can be determined by the decision tree regression model, this model has shown a significant predictive power with the presence of missing data in the input features. Furthermore, the dataset used in this study is novel and it represents oil wells of the Greater Burgan oil fields, in the State of Kuwait.
Extending the Application of Classical Conformance Plot to Assess the Water Flooding Plan
Authors: Haryanto Elin , Yersaiyn Saltanat , Khattak Iftikhar Ahmad , Shah Abdur Rahman 
Published: November 2019

Abstract
The use of Recovery-factor (RF) versus Pore Volumes Injected (PVI) plot to assess historical and ongoing water flooding strategy and its conformance is a common practice. However, this technique is rarely utilized to guide the future water flooding plan that are often assessed by dynamic modelling. The objective of this paper is to demonstrate an extended application of classical conformance plot not only for the typical use of historical and on-going water flooding performance evaluation but also as a tool to guide the future water flooding strategy.
A collaborative effort between different reservoir management team members were required to obtain the input parameters. This new workflow starts by applying the classic conformance plot technique on prediction scenario of production and injection data from numerical model. In this study, the water flooding conformance plot at layer level is presented. The plot was complemented by the theoretical recovery factor as reference of an ideal water flooding scenario. Subsequently, various injection prediction scenarios from dynamic model were added to the conformance plot template for detailed evaluation. The assessment includes evaluation of water injection rate, timing of water flooding development strategy application, location of injectors and various sensitivity analysis on the injection rates.
Some distinct shapes of conformance plots were recognized during the study. Views and opinion are gathered based on this study to identify the new use of conformance plot as a tool to assess the efficiency of different water flooding strategies. The lesson learnt from this study and the identified conformance plot shape can be beneficial to guide the direction of water injection plan to improve the overall field development plan.
Multi-Measurement Logging-While-Drilling Imager: New Enabler for Wide-Scale Comprehensive Geosciences Applications in Oil-Base Mud
Authors: Shrivastava Chandramani , Maeso Carlos , Wibowo Vera , Amir Irlan , Auchere Jean-Christophe , Maggs David , A Adrian 
Published: November 2019

Abstract
Borehole images have been widely used in industry for almost three decades for different geological and petrophysical applications; though these logs were often limited in application in the wells drilled with oil-base mud (OBM) due to resolution and coverage constraints against the downhole environment. Recent advances in technology helped address this issue with wireline logging; however, the logging-while-drilling (LWD) capabilities for high resolution borehole images in OBM remained limited thereby limiting any real-time applications of this data. The new innovative multi-measurement LWD imager provides game-changing enabler for wide-scale comprehensive solutions from drilling-efficiency till field development.
Singular image acquisition for subtle features at high resolution could often miss out on a lot of important events, thereby constraining the optimal characterization of sub-surface and downhole conditions. To properly understand, characterize and demystify the sub-surface, Industry's first multi-measurement imager was developed with high resolution capabilities in OBM; with ultrasonic and electromagnetic measurements physics.
Ultrasonic and Electromagnetic measurements are made at multiple frequencies by multiple sensors to ensure that the features on borehole wall are observed and resolved, both. The complementing nature of these technologies provide far better application capabilities, with multiple full-bore images being acquired simultaneously for apparent resistivity, amplitude and transit time by multiple sensors to overcome downhole operational challenges and variability of formation response without introducing complexity to the drilling bottom-hole assembly (BHA). The apparent resistivity images from electromagnetic measurements provide rich information of the sedimentological, diagenetic and structural features while the ultrasonic images are more sensitive to the near wellbore fracture, drilling induced features and borehole conditions.
Availability of the multiple measurements in real-time and relevant time lends the borehole image data for various applications, enabling drilling optimization, smoother and efficient operations and detailed geological characterization. Such comprehensive applications were not available earlier for wells drilled with OBM or any non-conductive mud.
Improving Cementing Success with Better QC: Field Case Studies of using a World-First Quantifiable Mix-Water Analysis Technique
Authors: Mahavadi Sharath Chandra , Curtis Nathan , Taoutaou Salim 
Published: November 2019

Abstract
Cementing is one of the most important steps in preparing a well for production. Critical parameters influencing the success of a cementing job are the concentration and the types of additives present in a mix fluid to prepare the cement slurry. However, it is extremely challenging to analyze water-soluble organics under oilfield operational conditions. In addition, with the complexity in chemistry of additives and mix fluids, it is also an analytical challenge to experimentally determine the quality of mix fluid and the slurry with standard analytical techniques such as high-pressure liquid chromatography (HPLC) or inductively coupled plasma spectroscopy (ICP). In addition to the general business need to verify chemical addition accuracy, in the field, the current practice to prepare mix fluid entails the addition of different additives either manually or using specialized liquid additive systems (LAS). Any human error in programming the LAS or manually adding the products yielding poor or no traceability for QA/QC could fail the cement job. This warrants the need for a reliable and field-robust method of quantifying additive concentrations in the mix fluid.
To address this challenge, we developed a workflow using electrophoresis to address this issue to support operations. Electrophoresis uses an electric field to separate and quantify the components of a single fluid or a mix-fluid additive system. More importantly, we can simultaneously detect and quantify multiple chemistries in a single run. We have developed methods to analyze and quantify all the ingredients in an aqueous fluid system. This includes organics such as surfactants, natural and synthetic polymers, organic acid, and the inorganic ions that are common in seawater and most base fluids in the additive system.
In the first step, we developed a method to analyze a single additive. This method addressed the issue of analyzing organics in aqueous fluid and demonstrated the applicability of this technology in determining the quality of the additives in terms of contamination. In later steps, the method was expanded to analyze and quantify dispersants, multicomponent retarders, and antifoaming agents individually as well together in a single run. Our study clearly demonstrated the electrophoresis technique can quantitatively differentiate multiple additives in a mix-fluid system while simultaneously estimating their respective ratios in the system. The developed method was applied to a mix-fluid system to identify a missing additive that led to the failure of a critical job.
Overall, a simple and reliable technique is introduced to determine the quality and composition of additives and the mix-fluid system composition to enhance the reliability of existing processes and thereby improve the success rate of cementing jobs. Examples from the field will be presented.
Autonomous Tracking Performance Analysis of Hierarchical Controller on Various Laying Conditions of Buried Oil and Gas Pipelines
Authors: Sudevan Vidya , Shukla Amit , Sharma Arjun , Bhadran Vishnu , Karki Hamad 
Published: November 2019

Abstract
Middle Eastern countries have the most complex and extensive oil and gas pipeline network in the world and are expected to have a total length of 24066.9km of pipelines by 2022. Routine inspection and active maintenance of these structures thus have high priority in the oil and gas operations. Pigging, the commonly used internal inspection method is expensive and the need for pre-installation procedures for flawless pig operations makes it time-consuming. The external inspection is currently done manually by a group of operators who either drives or walks over the buried pipeline structures. The visual/sensor data collected using various handheld devices are then analyzed manually to identify/locate the possible anomalies. The accuracy of data collected and their analysis highly depends upon the experience of the operators. Also, the extreme environmental conditions like high temperature and uneven terrain make the manual inspection a tedious task. The challenges in the current manual inspection methods can be tackled by using a robotic platform equipped with various sensors that can detect, navigate and tag the buried oil and gas pipelines.
In UAE, the oil and gas pipelines are mostly buried under a berm, a raised trapezoidal structure made up of sand over the buried pipeline structure. The pipelines are buried under the berm either as (i) single pipeline buried in the middle of the berm or as (ii) two pipelines buried on the two edges of the berm. To conduct any external inspection of buried pipelines using a robotic platform, the accurate location of the buried pipeline has to be known beforehand. The proposed Autonomous Robotic Inspection System (ARIS) should have the capability to precisely locate the buried pipeline structure and navigate along with these structures without any fail/skid. A novel hierarchical controller based on a pipe-locator and ultrasonic sensor data is developed for ARIS for detection and navigation over the buried pipeline structures. The hierarchical controller consists of two modules: (i) pipe-locator based tracking controller, that allows the vehicle to autonomously navigate over the buried pipeline and (ii) a sonar-based anti-topple controller which provides an extra layer of protection for vehicle navigation under extreme conditions. An experimental setup, similar to the real buried pipeline condition was built in a lab environment. The autonomous tracking performance of ARIS was tested under various buried pipeline laying conditions. The results obtained show the ability of ARIS to track and navigate along the buried pipeline even in extreme conditions without any fall/skid.
Evolution of Khuff Tight Gas Reservoir Understanding for a Field in Offshore Abu Dhabi
Authors: Menon Pradeep , Anurag Atul , Mills Carey , Basioni Mahmoud , Steiner Stefan , AlBlooshi Mohammed , Dasgupta Suvodip , Guerra Julian , Shasmal Sudipan , Adil Suliman Salim Israa 
Published: November 2019

Abstract
The Khuff Formation is a Permo-Triassic aged carbonate unit which reservoirs a highly economic gas resource in several countries within the Middle East. The appraisal and development of Khuff Formation tight gas resources is the subject of increased focus in the offshore UAE. This case study focuses on the appraisal of a particular field in offshore Abu Dhabi and summarizes how the understanding of this complex reservoir has evolved over time.
The oldest well penetrating the Khuff Formation in this field was drilled almost 3 decades ago. This well tested gas within the Upper Khuff however appraisal of this resource had to wait until 2017-18 when two appraisal wells were drilled on the discovery. These appraisal wells included a complete suite of wireline logs, image log data, formation pressure measurements and well tests to give a clearer picture of the formation and fluid saturations. Subsequent to the drilling of the recent appraisal wells an integrated study was completed integrating all the processed and advanced answer products in order to determine the key elements controlling gas productivity. This knowledge were subsequently applied to optimise a well drilled and production tested in late 2018.
Understanding the production behavior of the Khuff Formation reservoirs intervals has been one of the most critical factors behind the decision to develop this complex reservoir. Certain key answer products are considered critical for identification of completion intervals. These products include; sonic imaging (looking for fractures away from the wellbore), advanced textural analysis from borehole images (porosity classification) and critically stressed fracture analysis from geomechanics. This study led to the conclusion that critically stressed fractures and/or connected pores from images are the best indicators of high gas flow potential, while this flow can become exponentially higher when fractures at the wellbore connect to fractures away from the wellbore. This workflow has now been applied to the most recently drilled well and to other Khuff Formation appraisal projects across the off shore of Abu Dhabi.
This is an illustration of how in-depth analysis of all the acquired data in an integrated manner can help in understanding a complex reservoir and lead to better decision-making for the future wells and offset appraisal projects. Lessons are hidden in both success and failure and as long as these lessons are analyzed properly, they can lead to long-term success.
Practicing Sustainability in Remote Location
Authors: Al Awadhi Ibrahim , Sharma Ashok , Karim Twana 
Published: November 2019

Abstract

Objective/Scope
Effective electrical and instrument control system is required for efficient operation of pipeline network. These equipment are kept in unmanned shelter with necessary cooling, as ambient temperature can go upto 54°C vs designed of 40°C. Pipelines and supply network often run through remote areas where usually no power supply is available. This puts heavy challenges to cooling inside shelters. This paper presents a unique approach adopted to enhance the shelter cooling performance in remote locations.

Methods, Procedures, Process
Conventionally shelter in remote area are Passive cooled shelter (PCS) where water in the exchanger is cooled by using lowest night ambient air. This water is circulated inside the shelter in closed circuit which cools the space by natural convection. High inside temperature (45ºC) was recorded in some existing PCS. To assess reasons for high temperature, performance of PCS and heat dissipations of installed equipment against design values were evaluated. Furthermore, survey was performed for ambient and inside temperature during summer peak time instead of assuming ambient temperature of 54°C. Accordingly, the impact of maximum temperature on instrument was evaluated.

Results, Observations & Conclusions
Study concluded high inside temperature in PCS was due to high heat dissipation and external opening for ventilation in battery room.
Conventionally reduction in maximum temperature inside PCS can be carried out by increasing the capacity of installed external exchangers from existing 300 W/C to 600 W/C. Further benefits can be achieved by installing small fans next to the internal water tank and installing breather diaphragms with filter in external openings to reduce the heat input from outside. However, study concluded that with all this, minimum temperature inside PCS can be reduced to 42ºC vs required 40ºC as all installed equipment are designed to operate at max 40ºC . This is due to high lowest ambient temperature during peak summer (36ºC)
Due to remote location and non-availability of electric power, unique approach of additional cooling using Solar Hybrid A/C system was proposed without battery charger. Study concluded installing Hybrid Solar A/C system without battery charger can be operated during the summer peak time for period of 6 hours per day can bring down the inside temperature below 35°C throughout the year. Proposed solution is now successfully implemented in existing PCS and performance is found satisfactory during peak summer condition.

Novel/Additive Information
There is several PCS with similar issues and this unique approach of installing 24V DC Hybrid Solar A/C system is now being adopted in other PCS shelter which will support ADNOC Way by sustaining safe network operation and 100% HSE. There are large network of pipeline running in remote locations across the world where power availability is a concern and limit were above approach can be followed to realize larger benefits.
Research on Gas Stringer Automatic Deliquification in Sulige Gas Field
Authors: Chen Yong , Gui Jie , Liu Shuangquan , Zhao Zhengyan , Xu Wenlong , Xiao Shuqin 
Published: November 2019

Abstract
Managing numerous gas stringers reasonably and effectively is an arduous work. A system of gas stringer automatic deliquification is presented that uses simulation of opening wells manually and automatic liquid loading identification as its basis for control logic. Technical effects of automatic deliquification in field test are compared to the operations of manual intermittent production and using foam. The new approaches are based on the research on the intermittency of the gas stringer. It considers the factors of tubing pressure, casing pressure, gas production rate, liquid producing, etc. Three algorithms are provided to reach a better effect of deliquification including operation of intermittency, operation of using foam, and operation of combination. Accordingly, reasonable intermittent rules can be set according to the characteristics of pressure and production rate. Simultaneously, fair concentration and amount can be determined as well. Furthermore, the mode of self-diagnosis of upper computer is described. Hardware and software for automatic opening well and automatic injecting foam are development, as well as remote control platform. The effects of using system of gas stringer automatic deliquification are compared to manual intermittent production and manual foam that have been traditionally applied. Four field case studies are presented. Field test in Sulige gas field shows that the average difference between tubing pressure and casing pressure decrease by 0.8MPa and gas production rate increase by 0.2×104m3/d. Meanwhile, the effects of liquid loading are reduced. The most significant effect is that automatic deliquification can make the operations timely and even finely. This is important because in some cases the proper rules are hard to execute for manpower. Besides, costs and labor intensity are reduced. The novelty of system of gas stringer automatic deliquification is in the ability to improve the accuracy and timeliness of operations. Through the research of gas stringer automatic deliquification, fine management of the gas well could be achieved, and the automation level of the gas field could be promoted. It will benefit tens of thousands of gas stringers in the world.
Improved Massive Dolomite Mapping by Integrated Forward Diagenetic and Geological Modeling
Authors: Xu Yin , Lu Peng 
Published: November 2019

Abstract
Stratigraphically discordant massive dolomite bodies of the Upper Jurassic have long been documented because they strongly affect reservoir quality. Dolomitization is affected by varies factors such as original depositional texture, dolomitizing fluid, dolomitization timing and types, and previous diagenetic stages, which can make dolomite bodies either flow conduits or barriers. Therefore, understanding the complex diagenetic system and the distribution of the massive dolomite are extremely important.
In this study, we integrated forward diagenetic and geological modeling following 4-step approach: (1) detailed 3D geologic modeling to delineate the spatial distribution of the massive dolomite; (2) calculation of the effects of dolomitization on reservoir quality; (3) property modeling to predict the spatial distribution of reservoir quality; (4) integrate geological and diagenetic forward modeling to improve the understanding of the dolomitization system and its impact on reservoir quality.
Modeling results indicate that: (1) In general, dolomitization can be divided into two phases, replacement and pore-filling. During the replacement phase, porosity preservation is the dominant process, while during the pore-filling phase porosity decreases sharply with the increase of dolomite volume fraction. Overall, the replacement phase improves reservoir quality, while the pore-filling destroys it; (2) The massive dolomite is heterogeneously distributed with an overall regional trend of decreasing dolomite content southwards; (3) two episodes of dolomitization are likely to occur, supported by multiple types of data, the first is driven by the tectonic compression and developed adjacent to salt basins, whereas the second is related to late hydrothermal dolomitization overprinting the early dolomite.
This integrated forward diagenetic and geological modeling approach helps to better understand the dolomitization mechanisms and regional diagenetic system, by improving the mapping of the massive dolomite and the prediction of reservoir quality.