bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Consolidated Method for Selecting Drilling Parameters
Authors: Suryadi Hendrik 
Published: April 2019

Abstract
Over the years, considerable research has been conducted and the results of numerous studies have been published about optimizing drilling operations that maximize the footage drilled and minimize drilling costs. One of the optimization aspects studied is determining which drilling parameters improve drilling efficiency. Many drilling application software packages exist to help engineers simulate the drilling process. These software packages might include the capability to evaluate drilling parameters’ sensitivity; however, many of the software programs only focus on a specific engineering area and rely on the engineer to evaluate the relation between the results of an engineering analysis and deciding. A new approach has been developed that consolidates various engineering analyses into a single workflow to automatically define the optimum drilling parameters. The application provides a drilling parameters roadmap consisting of weight on bit (WOB), surface rpm, and flow rate for efficient drilling execution.
This application uses the knowledge of offset wells as a starting point to define the WOB and RPM ranges. Those values are represented as a drilling parameter matrix for input into the model. Then, by using static and dynamic bottomhole assembly (BHA) modeling and hydraulics modeling in addition to predicted rate of penetration (ROP), the application runs various sensitivity analyses to obtain the optimum drilling parameters within rig and downhole equipment specifications. The sensitivity analysis with static BHA modeling provides the buckling check to the maximum WOB proposed while the dynamic BHA modeling provides downhole vibration analysis and predicts the drilling ROP, which is compared with downhole tool specifications. Then, the hydraulic modeling provides validation of hole-cleaning quality for the relation between flow rate and ROP, without exceeding rig pump and circulating system pressure specifications. The application also implements a smart learning process to reduce the number of iterations and computation time.
The results of this approach were tested on a field project where implementing the roadmap computed from the application showed excellent results for improving drilling performance.
Chan Plot Signature Identification as a Practical Machine Learning Classification Problem
Authors: Garcia Carlos A. , Mukhanov Akhan , Torres Henry 
Published: April 2019

Abstract
Creating Chan water control diagnostic plots is a common well surveillance activity to search for signatures that distinguish and explain mechanisms behind excessive water production in oil wells. The technique involves an engineer who visually classifies patterns or signatures related to a water production mechanism. This study shows how the Chan plot signature identification can be approached as a machine learning (ML) classification problem, where a well can be characterized by the slopes of water-oil ratio (WOR) and WOR time derivative (WOR’) curves. A model tries to find the pattern category to which that well belongs. Having ML models that can predict whether a well belongs to a specific Chan plot signature, or pattern, would be valuable as a well surveillance tool, especially in high-well-count fields.
Our previous work focused on using the shape of the Chan plot as features for a radial basis function (RBF) support vector machines (SVM) model. In this study, we examine how features to identify Chan plot signatures can be simplified and how different ML models compare in accuracy. ML models used in this study were: nearest neighbor, SVM, decision tree, random forest, logistic regression, and Naive Bayes. In this study, we use the slopes of WOR and WOR’ as features. As a result, we observed an increase in the accuracy of the ML models that we used. By performing the quality check on the data set after selecting slopes as features, we identified that the dataset contained several incorrectly labeled examples, which we adjusted before we trained the ML models. By comparing the models’ metrics in the context of the test set, we identified that the ML model with the highest f1-score was nearest neighbor at 0.93, whereas the RBF SVM model achieved a value of 0.90. We also compared models’ decision boundaries to find how they differ among all ML models.
We obtained an improved accuracy of an ML model by simplifying features as well as raising the quality of data used in the Chan plot signature identification problem. These ML models could be useful in automatic classification whether a well exhibits a specific Chan plot signature, to flag it for a review within a broader petroleum engineering decision framework.
Sustaining Production in a Prolific Gas Well Using Storm Choke in Place of Failed TRSCSSV
Authors: Zaidil Hanani 
Published: April 2019

Abstract
Well 1A is a prolific, big bore dry gas well that has been installed with storm choke due to failure of the well's hydraulic control line. Because of its pilot implementation, a one-year trial period was enforced as part of the valve's endurance and reliability test. The objective of this paper is to show findings from a root cause analysis on valve inadvertent closure (trip at FTHP above valve setting pressure) observed after the conclusion of the one-year trial period which had already indicated positive results with 98% reliability.
Physical inspection of three separate sets of storm choke that had premature closure issues within a duration of five months were analyzed to find a common root cause. The well parameters were studied versus the known operating envelope to narrow down possibilities that were either naturally occurring or externally induced within the well that could have caused the inadvertent closures. Based on the available data, the root cause remained tentative triggering the need for downhole pressure and temperature data acquisition.
Inspections of the retrieved valves revealed common damaged element; the piston O-ring. The O-rings were found to be either leaking, broken or flattened. When analyzing the well parameters, the only significant change detected since the valve installation was the wellhead temperature which had shown increase of 6 degrees Celsius. However, this increase in temperature should not have impacted O-ring's operating envelope.
The well was designed to be completed with downhole gauge at approximately 2000 feet above top of perforations to eliminate need for wireline surveys. This limits the ability to verify predicted temperature profile in the tubing. Suspecting the inadvertent closures to be related to temperature, downhole temperature survey was launched to investigate its impact on the valve.
Based on the survey, a much higher temperature was recorded at the storm choke valve depth compared to model estimation. This provided the key to provide a conclusive narrative to the storm chokes’ premature closure issues. The higher temperature had inadvertently increased the storm choke's dome charging pressure resulting in physical throttling of the valve when in operation and thus resulting in damaged seals. With the higher temperature being taken into consideration for new dome setting pressure, inadvertent closures of the same nature were no longer observed.
This experience will be able to provide a guideline on best practices in managing wells with storm chokes in the future and outline recommendations for parameters to monitor, surveillance requirements, pressure setting determination practices, procedures for valve function testing and valve handling the well and at the yard.
Connected Reservoir Regions Map Created From Time-Lapse Pressure Data Shows Similarity to Other Reservoir Quality Maps in a Heterogeneous Carbonate Reservoir
Authors: Kayode Babatope , Yaacob Mohd Raji , Abdullah Faisal A. 
Published: April 2019

Abstract
The purpose of this paper is to highlight the similarity between Connected Reservoir Regions (CRR)map created using time-lapse pressure groups (Kayode et.al 2018)and other reservoir quality maps like Seismic Acoustic Impedance (SAI) map and petro-physical rock quality map.
Time-lapse average reservoir pressure from producers and injectors spanning several years of field production were sorted into groups of similar pressure trends. Wells that show similar pressure trend were classified into same CRR, while wells that show different pressure trends were classified into different CRRs. Only wells operating within the same reservoir zone have been used in the pressure grouping in order to ensure that the observed pressure trend differences are only due to lateral variations of reservoir quality and not due to vertical zonation. A geo-modelling software was used to create connected reservoir regions map in which all wells within the same pressure group are identified with a unique colour code and polygons are drawn to delineate the spatial limits of wells within each pressure group. The CRR map thus obtained, was then compared with SAI map and permeability quality map.
Similarity was observed between the CRR map, SAI map and petro-physical rock quality map. Areas indicated as poor quality (high impedance) on the SAI map and indicated as low permeability on petro-physical map were consistent with CRR regions that are characterized by high injection pressure and poor pressure support. Areas indicated as good quality (low impedance) on SAI map and high permeability on petro-physical rock quality map were consistent with CRR regions that are characterized by low injection pressure and excellent producer-injector communication. In addition, a particular well was sidetracked in order to improve reservoir sweep, this producer whose pressure had been historically fairly steady, experienced a sudden increase of time-lapse average reservoir pressure. When the pre and post sidetrack locations of this well were plotted on CRR map, the reason for the sudden pressure increase became obvious; well was sidetracked across CRR boundary, from a poor reservoir quality to a good reservoir quality CRR.
In certain cases, oil and gas fields may not have seismic data, in other cases the resolution of the returned seismic signal may be weak. In such cases, CRR maps created using time-lapse average reservoir pressure groups could be used during geo-modelling,for controlling the distribution of 3-D properties away from well control points, instead of seismic acoustic impedance reservoir quality map.
Case Stories of Horizontal Wells in Offshore Fluvial Oil Reservoir
Authors: Shi Hongfu , Hu Yong , He Yifan , Sun Qiang , Zhao Junshou 
Published: April 2019

Abstract
Fluvial facies reservoirs account for 60% of the reserves in Bohai oilfield. The effective development of such reservoirs plays a very important role in long-term stable production of Bohai oilfield. There are many challenges including: poor reserve, large well spacing, large lateral changes, poor connectivity, heterogeneity, unfavorable viscosity, low structure amplitude and strong bottom water. Horizontal wells are widely used in these reservoirs, especially in the edge or bottom water reservoir and the narrow channel reservoir in Bonan area. Many cases of horizontal wells design, implementation, well pattern optimization and water flooding management were presented to improve the recovery rate of fluvial oil reservoirs. The technique has been widely used in ten fluvial oil fields in Bohai, and has enhanced the recovery rate of by 3% and achieved remarkable technical and economic effects.
Improved Seismic Imaging with Multi-Azimuth PSDM Processing: A Case History South China Sea
Authors: Liu Jinpeng , Zhong Mingrui , Fang Zhongyu , Dan Zhiwei , Sun Leiming 
Published: April 2019

Abstract
With the deepening of exploration and development, exploration in the south China sea is faced with increasingly complex geological targets, including complex fault blocks, lithological targets, middle and deep strata, small scales and more subtle and complex exploration targets. At present, the internationally recognized best seismic solution is "two wide and one high" acquisition and processing, namely wide azimuth, broadband, high-density field observation system and targeted processing. In the aspect of wide azimuth acquisition and processing, domestic land acquisition has also developed greatly, and in the past few years, there has also been a heated debate on the advantages and disadvantages of wide and narrow azimuth acquisition in complex areas. However, in the aspect of offshore acquisition, wide-azimuth acquisition is rarely carried out. The main reason is that the construction cost and difficulty are higher. With the primary 3d coverage of some mature areas on the sea, it is still unable to meet the exploration needs. In the past, the seismic observation system design was mostly based on the seismic acquisition and survey lines in accordance with the direction of vertical structure strike, so as to facilitate the accurate imaging of the main structure or the construction along the long axis of the work area according to the cost of offshore acquisition. However, in fact, the fault strike in the tectonic development area is complex and changeable, and there is no uniform rule. Some small faults that control the trap are completely perpendicular to the large structural strike, so the old 3d will lead to some poor fault imaging. According to the practical test data analysis, found that the different line direction observed data imaging effect is different, therefore some recently in the south China sea area for the secondary multi-dimensional three-dimensional attempt at sea to achieve multiple acquisition costs are relatively low, and the construction is convenient, but if you want to achieve benefit maximization, must consider the joint use of composite materials. Compared with the factors that need to be considered in collection and processing, it is much more complex, and the development of processing is relatively lagging behind. The main anisotropy is not fully considered, and relatively simple superposition is often difficult to reflect the effect of multi-direction.
Exploring Opportunities for Capacity Enhancement in Sour Gas Treatment Unit
Authors: Deshpande Sunil , Sukanandan Jangumiah , Sengupta Partha 
Published: April 2019

Abstract
Methyl Di-ethanol Amine (MDEA) based Gas Sweetening Process is an established process for treatment of sour gases to meet pipeline specifications with regards to H2S contents. One of the Gas Sweeting Unit (GSU) has been designed with generic MDEA solvent to selectively remove H2S along with 32% Co-absorption of CO2. It was observed that because of higher receipt of sour gas, all GSU trains were operating with higher feed gas throughput resulting in higher H2S content in sweet gas & higher quantity of acid gas generation. A detailed study was carried out to explore the possibilities for maintaining sweet gas quality with increased sour gas throughput.
Detailed simulation studies on "HYSYS" process simulator revealed, that using generic MDEA it was difficult to increase the operating capacity of the GSU while maintaining H2S content in sweet gas & acid gas quantity generation within acceptable limits. Hence opportunities for speciality amines were explored.
Case studies revealed successful use of specialty amines for capacity enhancement and improved performance in the existing system. With the targeted sweet gas quality, the capacity can be enhanced up to 30% with minor modifications in the existing set up. This also resulted in significant reduction in consumption of utilities like steam, power and cooling water.
Increasing Efficiency of a Gas Processing Plant-A Case Study
Authors: Sengupta Partha , Deshpande Sunil , G. Sharmila , Das Barnali , Pawar Anil 
Published: April 2019

Abstract
LPG production from a gas processing plant was experiencing gradually decreasing LPG production in spite of having feed gas rich in heavier hydrocarbons. The process involves dehydration of feed gas, cooling the gas in a propane based chiller to condense heavier hydrocarbons, processing the liquid in a De-ethanizer column to separate C3+ components and further separate the C3/C4 (LPG) and C5+ components in a De-butanizer column.
To understand the above phenomenon, a steady state model of the plant was developed using licensed commercial process simulation software. The crucial process parameters required for efficient recovery of LPG are then identified and their optimum values established through simulations. Further experiments were carried out during plant operation to identify the bottlenecks in maintaining the parameters at optimum levels.
From simulations it was observed that De-ethanizer pressure, De-butanizer reflux condenser outlet temperature and De-butanizer reboiler temperature have the major effect on LPG components loss. From real time monitoring of operations, it was observed that there was difficulty in maintaining De-ethanizer pressure and De-butanizer temperature profiles at the optimum levels. It was concluded that an ineffective air cooled condenser, a passing manual valve and an improperly tuned temperature controller were the root causes behind sub-optimal operation. Accordingly, recommendations were made for rectifying the problems and the same have been accepted by the plant engineers for implementation which will result in LPG production gain by 20 %.
Novel Methods to Prolong the Life of Mature Offshore Oilfield Under Low Oil Price Condition
Authors: Su Yanchun 
Published: April 2019

Abstract
The oil price has fallen off dramatically since 2014 which quenched the oil company's enthusiasm to develop new oil fields, especially those with low quality reservoir. For Bohai oilfield, its work is mainly focused on the mature oilfield development in view of its huge reservoir potential, convenient existing facilities and quick fund turnover period. Bohai oilfield has carried out several projects to keep production steady at 3000×104m3 for eight years. In the paper, several methods including high resolution seismic acquisition, potential sands tracking, improving oil recovery (IOR) by water flooding and nanoparticle profile controlling are presented.
Predictive Monitoring of Acid Gas Membrane Performance
Authors: Rossi Marcus , Jariwala Ankur , Pan Shu , Medvedev Oleg , Booth Richard 
Published: April 2019

Abstract
We present a new digital solution based on a novel technique to predict acid gas membranes remaining performance based on the field data. Gas membranes are widely used onshore and offshore for acid gas removal from natural gas due to their efficiency and compactness. These systems are proven and well accepted, however their performance is highly dependent on field operations practices and conditions of the natural gas stream that feeds the system. If operating conditions are not controlled, the system performance can deteriorate. The weakened performance can lead to undesirable product gas specifications, contractual penalties, unexpected downtime, and ultimately the risk of environmental impact. On the other hand, maintenance anxiety and uncertainty can lead to overspend on membrane elements replacements; increasing overall operating expenditures. We developed the new technique during the past two years to allow the system operator to anticipate performance upsets by predictive monitoring and active machine learning using field operations data of gas membrane systems. This technique has adopted one of recursive Bayesian estimation techniques, linear Kalman filtering, and allows operators to predict and manage remaining membrane performance in the field proactively thereby optimize the membrane replacement expenditure.
Production Liner Cementing Practices in Challenging Horizontal Wellbores
Authors: Al-Baiyat Islam , Khalil Mohamed , Heinold Thomas , Porter Dean 
Published: April 2019

Abstract
Providing competent hydraulic isolation between multiple reservoir sections in horizontal wellbores represents a difficult industry challenge. This paper will discuss some of the practices and tools used for cementing production liners in critical horizontal wells.
Issues with bore hole conditioning, ovality, effective solids removal, and hole collapse are more problematic in horizontal wells. Historically issues occurred while running and cementing highly deviated liners. This was true before and after the cement placement including the premature setting of cement, an inability to run the liner to bottom, difficulties in setting the hanger assembly, pressure in the tubing-casing annulus, and cement channeling. Proper pre-job preparedness including pilot testing of the fluid systems, mud conditioning practices, centralization, cement placement simulations, and well site execution procedures for cementing these liners will be discussed.
The practices to be presented have been executed for horizontal as well as deep vertical gas well applications. Scorecards were developed to measure and assess the processes used. This work explains how this effort as well as the cementing service delivery practices have led to successful jobs. The recommended practices have a positive business impact by minimizing or mitigating operational complications, saving rig time, and reducing the need for remedial work due to poor primary cementing operations.
The paper highlights how the combination of enhanced cementing practices in conjunction with new cementing tools and technologies made important contributions to delivering effective zonal isolation in a highly challenging wellbore environment.
Numerical and Analytical Waterflood Evaluation of North Kuwait Giant Carbonate Reservoir
Authors: Alotaibi Basel , Lamine Sadok 
Published: April 2019

AbstractWaterflood (WF) is the main drive mechanism of North Kuwait reservoirs. Different development strategies has been adopted to develop a giant carbonate reservoir in the asset. Irregular scheme of WF has been implemented in the last 5 years which made it challenging to properly evaluate the WF performance. This paper presents both numerical and analytical approaches to assess the current performance of the waterflood in this reservoir.The first method uses actual production and injection data to generate traditional waterflood plots such WOR vs. Np, injection throughput, VRR and other diagnostics.The second approach uses the numerical model to understand the fluid movements in terms of production and water injection. A high resolution model is used to know about the horizontal producers and injectors WF scheme. Streamline model tool is used to understand how the injectors impact their surrounding producers. Injector's efficiency, allocation factors and reservoir sweep efficiency are calculated using the simulation model.Both approaches are compared to have a better evaluation of the waterflood.When the waterflood started, a regular i-9 spot patterns was the way to develop the reservoir. The heterogeneity of the reservoir was observed clearly in the different performance of each pattern. Also, high permeability layer (thief zone) has adversely affected the reservoir performance during WF.The sharp increase of water cut with very low corresponding recovery factor triggered a paradigm shift in developing this waterflooded reservoir. Injecting in lower layers and producing in upper layers (horizontal wells) was the next stage. This brought a great challenge to assess the performance of this WF scheme. Evaluating such a development strategy remains a achallenge.