bluuebunny/crossref_metadata_2025_split huggingface dataset:
Parameter Optimization and Application Evaluation of Rotary Percussion Drilling
Authors: Li Bodong , Tu Yulin , Zhan Guodong David , Aljohar Abdulwahab , Sehsah Ossama , Ke Ke 
Published: March 2021

Abstract
Rotary percussion drilling has gained increasing interest in the oil and gas industries because of its high drilling efficiency and good deviation control [1, 2]. In this work, a rotary percussion-based drilling tool is successfully deployed in a test well, and demonstrates a convincing enhancement of the rate of penetration (ROP).
In the test, the rotary percussion tool drilled through a 12 1/4″ hole section with excellent ROP, under a high mud weight (MW) condition of 120 pcf (Pound per cubic feet). The result shows a 22% enhancement on average ROP, and 31% enhancement on instantaneous ROP comparing to the best performing offset well offset well drilled in the same condition.
This paper covers the principle of a rotary percussion-based hammer tool, details in rotary percussion drilling parameters design and bit selection considerations for the effective coupling with the hammer tool. In addition, the paper uses an example of a high MW application to evaluate the overall performance of the tool in ROP enhancement.
Revitalizing Seismic Beyond Geometry Limitations: A Case Study of OBN Survey in Offshore Sabah
Authors: Ngo Lee Sii , Cheah Wai Leng , Sazykin Artem , Menzel-Jones Gavin , Wong Joyce Li , Rong Evonne Yu , B. Muhamad A. Aziz , Supardy M. Iqbal , B. Hashim M. Hakimey , B. Mokhtar M. Afiq , Tee Wei Yong , Shankar Das Prabal , Bt. Bahadon Ima Nazmi , B Harun M. Faeez , Jeevachandran Laletha 
Published: March 2021

Abstract
Ocean-bottom node (OBN) surveys are an increasingly common choice of method for marine seismic acquisition and offer several key advantages. These include recording wide-azimuth data and reliable low-frequency information. Since the start of OBN acquisition almost two decades ago, key challenges remain, not only on equipment handling and data management, but also on the data processing and imaging methodologies as these multicomponent workflows continue to evolve. We present a case study of an OBN survey acquired in offshore Sabah with a cross-spread geometry, in an ultra-shallow-water environment. This study discusses a few key processing challenges encountered due to this sparse acquisition including noise and multiple energy contamination and aliasing on data. We explain the challenges, how these were overcome, and the methodologies we used to enhance the data quality. As the main product for this project is a depth-imaged seismic volume, we also describe the earth model building workflow and imaging tools we used to leverage the advantage of full-azimuth data and multidirectional wavefield recorded in this survey. This includes full-waveform inversion, multi-azimuth tomography, and imaging with multiple.
The Concept of Need for a Downhole Scale Inspection Tool: An Appraisal for an Emerging Technology in Scale Management
Authors: Zoveidavianpoor Mansoor , Rosland Eadie Azahar , Laakkonen Pasi , Aryana Saman , Jaafar Mohd Zaidi , Ibrahim Jamal Mohamad , Kolivand Hoshang , Tewari Raj Deo , Johar Razman Marsoff , Mohamed Zaidi Awang , Salleh Intan Khalida 
Published: March 2021

Abstract
Monitoring techniques in oilfield scale management are expensive, susceptible to error, are not conducted in real-time, and they are non-in situ. Most scale prediction tools (i.e., water analysis and computer-based algorithms) have their deficiency and the need for accurately correlate calculated scaling tendencies with actual field data is evident. Lack of info about type, severity and location of scale deposits can lead to the failure of well intervention jobs. This work aims to serve as an opportunity to provide fertile ground and basis for utilizing new emerging technology for scale management in downhole application.
Research into utilizing sensors along with an advanced computerized imaging procedure in the downhole application has not been explored to the same extent as other applications, such as scale monitoring in pipelines and surface facilities. Downhole Scale Inspection Tool (DSIT) is a new emerging technology which promises to enhance considerably our ability to detect deposits and scale with the aim of sensors and tomography technology. DSIT has enormous potential for application in downhole condition as it uses slickline unit alongside with routine well intervention jobs. The acquired data by DSIT such as temperature, pressure, depth, deposition thickness and permittivity are utilized for downhole scale analysis, monitoring and detection.
When the type of scale is known, it is easier to take the correct steps in preventive maintenance or a cleaning process. Using DSIT, the trend of deposition thickness can be detected and immediately known if it is growing or shrinking. This will help to optimize any chemical feed and also generate substantial savings over time. This paper gives an overview of developing cutting-edge technology in downhole applications for scale management and possible barriers to new technology implementation. Using DSIT can lead to better data acquisition from downhole and contribute to a higher success rate of scale removal in downhole. This technique offers many benefits for scale treatment, monitoring and prediction when filed data is necessary for validation of scaling tendencies.
Research on Intelligent Production Technology of Intermittent Gas Wells in Sulige Gas Field
Authors: Chen Yong , Xie Yonggang , Tian Wei , Wang Xiongxiong , Zhao Zhengyan , Xiao Shuqin 
Published: March 2021

Abstract
An intermittent gas well intelligent production technology is presented that use intelligent methods to determine and optimize the intermittent system of intermittent gas wells and use newly developed remote pressure-controlled well opening equipment that can simulate manual operations and corresponding intelligent control systems. This new approach is based on the research and application of intelligent technology in the production of intermittent gas wells. By establishing the models of gas flow in different types of gas wells, combined with the historical data of typical gas wells, the optimal pen and shut-in well time chart is finally formed. A series of remote pressure-controlled well opening equipment have been developed to replace manual pressure-controlled open well operations at the well site. Through intelligent integration of well site equipment and remote control platforms, an ntermittent gas well intelligent production management system is established. The quantitative determination of the intermittent system of different types of gas wells is realized. The effectiveness of gas well intermittent measures has increased from 72% to 90%. Electromagnetic remote-controlled open well equipment with adaptive decompression and full-open cylinder structure is developed, and can meet the requirements for rapid opening of type Il intermittent gas wells. Needle-valve type remote-controlled open well equipment embedded with intelligent well drilling algorithm is developed, and the fine well opening of class I and Il intermittent gas wells is realized. Hands-free operation is realized, and the workload of operating staff on the well site is reduced by more than 15%. On-site diagnosis of gas well production status, intelligent generation of systems, intelligent analysis and optimization are realized, and intermittent gas wells are transformed from manual management to intelligent management. An intermittent gas well intelligent production management system is established to achieve intelligent management of intermittent gas wells. Complete intermittent gas well intelligent production technology for low ermeability gas fields is described in detail to permit global similar gas field reference. The novelty of the technology lies in the use of intelligent methods to solve the production problems of intermittent gas wells, including reducing the labor intensity ofemployees, improving production efficiency, improving the fine management level of tight gas field gas wells, and reducing the impact of human activities on the natural environment.
Anisotropic Geomechanical Rock Properties Modelling for Unconventional Shale Gas Formation
Authors: Musa Ikhwanul Hafizi , Tan Chee Phuat , Leem Junghun , Altaf Iftikhar , Md Zain Zahidah , Adams Matthew 
Published: March 2021

Abstract
Geomechanical rock properties correlations and modeling approach for conventional reservoirs are inappropriate and unsuitable for unconventional shale gas reservoirs where the shale formation is strong and has very low porosity. These correlations are critical in the development of 1D and 3D geomechanical models which are used for various field applications including drilling optimization, hydraulic fracturing design and operation, and field management. The study investigates various geomechanical rock properties and their relationships to one another using data extracted from rock mechanics testing conducted on shale core samples. For rock elastic properties correlations, dynamic elastic properties determined from compressional sonic velocity, shear sonic velocity and density are plotted against laboratory-measured static elastic properties obtained from triaxial tests. Steps were taken to further refine the properties correlations by separating the data from vertical and horizontal core samples, using data from tests conducted at in-situ confining stress condition, and focusing on data only taken from Field A and nearby fields. Similar steps were also taken to develop the correlations for rock strength properties. Correlations for the shale anisotropic elastic properties were also developed based on ratio of horizontal and vertical elastic properties. Blind tests were conducted on three wells in Field A using the new rock properties correlations which showed good matching of the predicted geomechanical properties with the new correlations and core measured test data.
Prevent Barite Static Sag of Oil-Based Completion Fluid in Ultra-Deep Wells
Authors: Wang Jianhua , Zhang Jiaqi , Yan Lili , Cheng Rongchao , Ni Xiaoxiao , Yang Haijun 
Published: March 2021

Abstract
Oil-based mud (OBM) is the first choice for complex deep wells due to its advantages of high-temperature resistance, good lubrication and borehole stability. But barite sagging under ultra-high temperature during the long-time stationary completion operation may lead to serious problems in ultra-deep wells, for instance, pipe sticking, density variation and well control problems.
In this paper, the influence of high-temperature and high-pressure (HTHP) on the performance of oil-based completion fluid was studied, and a model of rheological parameters was established with HTHP static sag law. The barite sagging stability was evaluated by a high temperature (220°C) and high pressure (100MPa) sag instrument. The results indicated that RM6 value and static shearing force were the main factors of affecting the settlement stability. The viscosity of the completion fluid significantly decreased with the increase of temperature, but increased with the increase of pressure. In addition, the relationship was also studied between HTHP rheology and atmospheric pressure rheology at 50°C. The results showed that when RM6 value was kept above 10, the sag stability factor (SF) of oil-based completion fluid was less than 0.52 at 190°C for 10 days, which proved a good high-temperature sag stability.
Furthermore, the anti-high temperature property of oil-based completion fluid was improved through enhancing the temperature-resistance of the additives. And the high-temperature-resistant organic soil was introduced to raise the RM6 value and the static shearing force. Based on these solutions, the barite sag under high temperature of the oil-based completion fluid was prevented during drilling and completion operation in ultra-high temperature wells.
The oil-based completion fluid was successfully used in Well Keshen 17 (175°C,7475 m) in Kuche piedmont structure and TT 1 well (210°C,6500 m) in Sichuan basin. The casing run smoothly, the oil-test operation was completed smoothly for 15 days, and no barite sag happened. It testified that the oil-based completion fluid had excellent of high-temperature sag stability. Therefore, this oil-based completion fluid is expected to be used widely in ultra-deep wells.
Drilling in the Digital Age: Machine Learning Assisted Bit Selection and Optimization
Authors: Batruny Peter , Zubir Hafiz , Slagel Pete , Yahya Hanif , Zakaria Zahid , Ahmad Alaa 
Published: March 2021

Abstract
Conventionally, a bit is selected from offset well bit run summaries. This method of selection is not always accurate since each bit is run under different conditions which might not be reflected in an offset study analysis.
The large quantities of data generated from real time measurements in offset wells makes machine learning the ideal tool for analysis and comparison. Artificial Neural Network (ANN) is a relatively simple machine learning tool that combines inputs and calculation layers to compute a specified output layer. The ANN is fed over thousands of data points from 17-1/2 in hole sections across multiple wells. A specific model is then trained for every bit with weight on bit (WOB), rotary speed (RPM), bit hydraulics, and lithological properties as inputs and rate of penetration (ROP) as output. The model is finalized when a satisfactory statistical set of KPI's are achieved. Using a combination of Monte-Carlo analysis and sensitivity analysis, different bits are compared by varying parameters for the same bit and varying the bit under the same parameters.
A bit and its optimized parameters are proposed, resulting in an average instantaneous ROP improvement of 32%. Performance benchmarked with individual drilling parameters shows improved ROP response to WOB, RPM, and bit hydraulics in the optimized run.
This project solidifies machine learning as a powerful tool for bit selection and parameter optimization to improve drilling performance. Machine learning will become a significant part of well planning, design, and operations in the future. This study demonstrates how ANN's can be used to learn from previous operations and influence planning decisions to improve bit performance.
Application of Innovative Extended Reach Well Operation Technology in Nanhai East
Authors: Zhang Qiang , Zhang Weiguo , Qin Shili , Wei Yusen , Tian Bo , Jin Yong 
Published: March 2021

Abstract
Extended reach well (ERW) can be extremely drilled to distant reservoirs to reduce the infrastructure and operational footprint. Drilling ERW and extending their reach to greater depths requires both improved equivalent circulating density (ECD) and frictional resistance due to large horizontal displacement, long open hole and borehole unstability.
ECD is one of the keys to safe and efficient drilling, especially in complex formations with narrow pressure profile, and wellbore frictional resistance appreciably influences drilling torque and drag, as well as casing running. This paper presents several methods, including continuous circulating valve(CCV) drilling technology, cuttings bed removal technology and chemical friction reduction technology, to promote the success of ERW drilling. The applications are realized by means of adding CCV, cuttings bed cleaner to the drill string and chemical friction reducer into the drilling fluid.
Respectively the CCV drilling technology realizes the continuous circulation of drilling flooding, and cuttings bed removal technique utilize integrated design of hydraulic machinery with hydraulic parameter adjustment and flow passage design, to enhance turbulence velocity and strength of drilling fluid flow field, which both can effectively improve the efficiency of carrying bit cuttings, and reduce the fluctuation of ECD. Chemical friction reduction technology is mainly composed of chemical frictional drag reduction agent which belongs to organic anion compound products, and has excellent super anti-wear lubrication. Results show that the fluctuation of ECD in the high-risk well section with well loss was controlled within 2.5%, and narrow density window formation (0.18g/cm3) was drilled safely without any caving and leakage. The friction coefficient ranged from 0.4 to 0.25, with 40% decrease compared with previous wells in Huizhou Oilfield. And also the ROP increased by 45% due to effective transmission of WOB.
The technologies shown in this paper comprise key innovative technologies in ERW operation in Nanhai East. Less time is occupied in equipment installation, as well as simple operation flow, however with improved stability and remarkable performance. It lays a foundation for further study of ultra extended reach wells with greater difficulty and challenge.
Digital Oil Model Development and Verification
Authors: Hon Vai Yee , Mohd Saaid Ismail , Ivy Chai Ching Hsia , M. Fauzi Noor 'Aliaa , Deguillard Estelle , Male Jan van , Handgraaf Jan-Willem 
Published: March 2021

Abstract
Advances in digital technologies have the potential to enhance model predictive capability and redefine its boundaries at various scale. Digital oil with accurate representation of atomistic components is a powerful tool to analyze both macroscopic properties and microscopic phenomena of crude oil under any thermodynamic conditions. Digital oil model presented in this paper is the key input in molecular chemistry modeling for designing chemical enhanced oil recovery formulation. Hence, it is constructed based on a fit-for purpose strategy focusing in oil components that have large contribution to microemulsion stability.
Complete crude oil composition could comprise over 100,000 components. Lengthy simulation time is required to simulate all crude oil components which is impratical, despite the challenges to identify all crude oil components experimentally. Therefore, we established a practical experimental strategy to identify key crude oil components and constructed the digital oil model based on surrogate components. The surrogate components are representative molecules of the volatiles, saturates, aromatics and resins. Two-dimensional digital oil model, with aromaticity on one axis, and the size of the molecules on the other axis was constructed. We developed algorithm to integrate nuclear magnetic resonance response with architecture of the molecular structure. A group contribution method was implemented to ensure reliable representation of the molecular structure.
We constructed the digital oil models for a field in Malaysia Basin. We validated the physical properties of the digital oil model with properties measured from experiment, predicted from molecular dynamics simulation and calculated from quantitative property-property relationship method. Good agreement was obtained from the validation, with less than 5% and 13% variance in crude density and Equivalent Alkane Carbon Number respectively, indicating that the molecular characteristic of the digital oil model was captured correctly. We adopted the digital oil model in molecular chemistry modeling to gain insights into microemulsion formation in chemical enhanced oil recovery formulation design. Digital oil is a robust tool to make predictions when information cannot be extracted from experimental data alone. It can be extended for engineering applications involving processing, safety, hazard, and environmental considerations.
Rotary Steerable System Design Optimisation with Roller Reamers Prevents Stuck Pipe Events
Authors: Yadav Anurag , Abdelazeem Omar , Chebab Mohamed , Shata Atef , Al-Othman Ahmad , Al-Mulaify Mohammad 
Published: March 2021

Abstract
An increasing deployment of rotary steerable system to drill through complex reservoirs demands considerable gains in operating efficiency. It is a known fact that one of the main drilling challenges faced by oil & gas industry is stuck pipe. The risk of stuck pipe is particularly elevated when using a rotary steerable system tool to drill through formations having geo-mechanical instability and alternating hard-soft interbedded layers. This elevated risk is due to the pivot stabilizers, typically used on such tools which have a limited flow by-pass area and high side loads at the contact points with formation. This study showcases how in geo-mechanically unstable formations, a stabilizer in a rotary steerable system tool can be replaced with a roller reamer technology to reduce stuck pipe events while still delivering steerability objectives.
Roller reamers are known to deliver reduced contact forces and torque. The analysis focuses on how roller reamer technology was used to prevent rotary stalling of a drill string while drilling, which inadvertently had been a root cause in most stuck events. It also describes how BHA was optimized to achieve directional objective. Further, it discusses how drilling execution and monitoring procedures were modified to ensure stuck pipe is avoided without compromising directional yield of the BHA.
Results are presented from actual wells, demonstrating an outstanding achievement of no stuck events on 4 back to back wells after multiple incidents of stuck pipe and lost in hole on previous wells. The best practices followed to ensure safe drilling are explored to highlight roles played by roller reamer replacement of pivot stabilizer in rotary steerable system tool, BHA optimization and real time drilling monitoring. Results prove that an engineered application of proper BHA design and effective drilling execution & monitoring can deliver efficient operations, even in most complex drilling environments.
An Innovative and Transparent Negotiation Mechanism for the Petroleum Contracts to Develop Marginal Oil Fields
Authors: Shiaoi Tsung-Wen 
Published: March 2021

Abstract
This study is to propose a transparent mechanism among host governments and international oil companies (or IOCs) so an amicable "win-win" situation can be achieved on the negotiation of the petroleum contracts for the development of marginal fields.
Marginal field has various definitions. It can be a field with recoverable reserve not exceeding 30 million barrels of oil or 500 billion standard cubic feet of natural gas (Abdul Razak 2011, Malaysian Petroleum Income Tax Act 1967). It also can be a field, somehow "stranded", needs an oil price of US$60/bbl to be commercial (Aziz 2019). Or as simpe as it can be, a marginal field in Nigeria is any field being left unattended for more than ten years from the date of discovery (Auwalu 2020). In this paper, the author recommends that a marginal field be difined as any undeveloped field with a zero present value at 10% discount rate (or PV10 Value = 0) based on the average commodity price of previous 12 months’ first-day-of-the-month prices. This definition is conformable to the SEC pricing guidelines for publicly traded IOCs in the U.S.A. (Scheig n.d.).
Host governments endeavor to bring foreign fund and technology to develop their hydrocarbon resources effectively for the benefit of national welfare. IOCs are eager to expand into other promising areas for more hydrocarbon reserves in order to strengthen the balance sheets. A well-designed petroleum fiscal regime can thus achieve the balance between host governments and IOCs (Tordo 2007).