bluuebunny/crossref_metadata_2025_split huggingface dataset:
A New Generation of Steerable Drilling Motor is Born - Understand the Unique Geometry, Drilling Benefits and Performance Gains
Authors: Jones Steve , Sugiura Junichi 
Published: September 2021

Abstract
Steerable drilling motors still dominate US shale drilling applications. Shale well construction is commonly planned with monobore vertical, high dogleg-severity (DLS) curve and lateral sections. Limitations arise in each portion of the wellbore because one single bottomhole assembly (BHA) does not provide optimal results; hence, trips are required to optimize the BHA.
The main disadvantage with existing steerable drilling motors is the requirement for high bend-angle settings to drill the high DLS curve portion of the wellbore. The geometry of a high bend-angle motor is only optimal for slide drilling the curve, it is not optimal for drilling the vertical and lateral portions of the wellbore. While drilling the vertical and lateral portions of the well, surface RPM (revolutions per minute) must be limited to reduce the cyclic bending fatigue on the large external bend. Not to mention poor wellbore quality while rotary drilling with a large external bend.
To overcome this issue, a new geometry design was required. The new-generation motor uses a tilted internal drive mandrel aligned with a small external bend. This combination delivers the best of both worlds, providing high DLS capability while slide drilling and high surface-RPM capability while rotary drilling (because of the small external bend).
Compact embedded drilling dynamics data recorders were used to validate the dynamic improvement of the new steerable-drilling-motor geometry versus older-style geometry with large external bend. The embedded sensors recorded at-point dynamics of shock and torsional response providing detailed comparative data sets during the development phase.
The new-generation steerable-drilling-motor technology utilizes point-the-bit rotary-steerable-system (RSS) methods (for example, a tilted mandrel) with conventional steerable-motor methods (for example, an external bend). The combination of the internal tilt and external bend (aligned together) provides a completely new geometry for a steerable motor. This new geometry is beneficial for high DLS sliding capability, high surface-RPM rotary drilling and improved borehole quality (slide/rotate transition and rotary mode).
This new steerable drilling motor with enhanced geometry was utilized to prove delivery of vertical/curve/lateral in one run, consistent DLS through the curve and improved tracking in the lateral. The results from development testing (comparing to older-geometry motors) will be described in this paper.
Direct Visualization and Quantification of NCF-Strengthened CO2 Foam Generation, Propagation and Sweep in a 2D Heterogeneous Fracture Network Model
Authors: Wei Bing , Yang Qiong , Mao Runxue , Tian Qingtao , Wang Dianlin , Lu Jun 
Published: September 2021

Abstract
CO2 foam holds promising potential for conformance improvement and mobility reduction of CO2 injection in fractured systems. However, there still exists two main issues hampering its wide application and development, 1. Instability of CO2 foam lamellae under reservoir conditions, and 2. Uncertainties of foam flow in fracture systems. To address these two issues, we previously developed a series of functional nanocellulose materials to stabilize the CO2 foam (referred to NCF-st-CO2 foam), while the primary goal of this paper is to thoroughly elucidate foam generation, propagation and sweep of NCF-st-CO2 foam in fractured systems by using a self-designed visual heterogeneous fracture network. We found that NCF-st-CO2 foam produced noticeably greater pressure drop (ΔP) than CO2 foam during either co-injection (COI) or surfactant solution-alternating-gas (SAG) injection, and the threshold foam quality (fg*) was approximately 0.67. Foam generation was increased with total flow rate for CO2 foam and stayed constant for NCF-st-CO2 foam in fracture during COI. CO2 breakthrough occurred at high flow rates (&gt;8 cm3/min). For SAG, large surfactant slug could prevent CO2 from early breakthrough and facilitate foaming in-situ. The increase in sweep efficiency by NCF-st-CO2 foam was observed near the producer for both COI and WAG, which was attributed to its better foaming capacity. Film division and behind mainly led to foam generation in the fracture model. Gravity segregation and override was insignificant during COI but became noticeable during SAG, which caused the sweep efficiency decreased by 3~9% at 1.0 fracture volume (FV) injected. Due to the enhanced foam film, the NCF-st-CO2 foam was able to mitigate gravitational effect, especially in the vicinity of producer.
The Role of CO2 in Carbonate Acidizing at the Field Scale – A Multi-Phase Perspective
Authors: Kumar Harish , Muhemmed Sajjaat , Nasr-El-Din Hisham 
Published: September 2021

Abstract
Most lab-scale acidizing experiments are performed in core samples with 100% water saturation conditions and at pore pressures around 1100 psi. However, this is seldom the case on the field, where different saturation conditions exist with high temperature and pressure conditions. Carbon-di-Oxide (CO2), a by-product evolved during the acidizing process, is long thought to behave inertly during the acidizing process. Recent investigations reveal that the presence of CO2 dynamically changes the behavior of wormhole patterns and acid efficiency.
A compositional simulation technique was adopted to understand the process thoroughly. A validated compositional numerical model capable of replicating acidizing experiments at the core-scale level, in fully aqueous environments described in published literature was utilized in this study. The numerical model was extended to a three-phase environment and applied at the field scale level to monitor and evaluate the impacts of evolved CO2 during the carbonate acidizing processes. Lessons learned from the lab-scale were tested at the field-scale scenario via a numerical model with radial coordinates.
Contrary to popular belief, high pore pressures of 1,000 psi and above are not sufficient to keep all the evolved CO2 in solution. The presence of CO2 as a separate phase hinders acid efficiency. The reach or extent of the evolved CO2 is shown to exist only near the damage zone and seldom penetrates the reservoir matrix. Based on the field scale model's predictions, this study warrants conducting acidizing experiments at the laboratory level, at precisely similar pressure, temperature, and salinity conditions faced in the near-wellbore region, and urges the application of compositional modeling techniques to account for CO2 evolution, while studying and predicting matrix acidizing jobs.
Development of a System for Remote Control and Monitoring of Wellheads
Authors: Kiplimo Elijah , Oyoo Daniel , Tapia Antonio , Jepng’etich Marseline 
Published: September 2021

Abstract
Wellheads have a major role in ensuring well integrity, providing access to the wellbore and flow control. It is vital to constantly monitor the wellhead fluid pressure and temperature effectively in order to maintain the full control of wellbore fluids. Over the years, wellheads have remained purely mechanical and have heavily relied on physical on-site monitoring. There is need to develop a reliable and accessible monitoring solutions for the wellheads in order to increase the effectiveness of the well integrity management systems and to get the full benefits of the wellhead data by incorporating the emerging data analytics technologies.
This project details the development of a system that gathers wellhead temperature, pressure and the accurate valve position at any given time. The data gathering systems used in this project entail smart sensor technology capable of withstanding the wellbore pressures and temperatures. The system transmits the data securely, using blockchain, to an online platform where advanced data analytics using MATLAB and machine learning algorithms are used for visual data representation. The online platform additionally provides a means of real-time valve position control and takes into account the exact revolutions required for the opening and closure of the valve hence keeping a record for maintenance purposes. The innovative use and analysis of the data gathered form the wellhead provides insights for the operators and service companies and gives a way for setting ang thresholds in order to get alerts based in their custom specifications. This paper documents the development of a system that gathers wellhead data and provides a means of remote control of the wellhead valves. It covers the design phase, selection of appropriate sensor placement locations on the wellhead, the design of valve actuators, offline data gathering systems and the online data analysis and valve control platform. The project also pays a key attention towards the secure data transmission techniques and highlights the benefits of incorporating such a system in the oil and gas upstream sector.
Rotary Fatigue Testing Device for Determining Drilling Fluid Compatibility in A Pdm Stator
Authors: McCalip Jonathan , Bohmer Bob , Daechsel Dustin , Zovko Andrea 
Published: September 2021

Abstract
The purpose of this study was to evolve the understanding between mud motor power section reliability and oil-based drilling fluid chemistry, using novel laboratory data recorded from a proprietary test apparatus and instrumentation. The underlying objective is driven by operator's desire to maximize drilling performance by extending the operating envelope of the PDM/drilling fluid system, beyond what is possible using legacy ASTM immersion testing.
This paper describes a new test method and machine, intended to complement currently existing test methodologies, that incorporates multiple interplaying downhole conditions. Twelve fluids were analyzed using the novel test machine and the results compared to data obtained from conventional ASTM immersion testing; The fluids varied with respect to base oil type, as well as concentrations of emulsifier, and wetting agent. The goal of testing was to determine if positive displacement motor (PDMs) elastomer failure mechanisms (abrasion, cracking, chunking) could be replicated in a controlled environment, and if doing so could improve the data and understanding of its lifespan in a PDM. The result of testing provided evidence of two and three body abrasion, compression set, chunking, and chemical swell. It was found that concentrations of additives, as well as base oil type significantly affect runtime in the novel test machine, even if the differences in conventional testing were inconclusive. The novel test machine demonstrated that concentrations of key additives, as well as base oil type significantly affect elastomer runtime, even if conventional testing showed inconclusive results.
Compressed Dimension of Reservoir Models Uncertainty Parameters for Optimized Model Calibration and History Matching Process
Authors: Al-Turki Ali , Alnajjar Obai , Baddourah Majdi , Moriwawon Babatunde 
Published: September 2021

Abstract
The algorithms and workflows have been developed to couple efficient model parameterization with stochastic, global optimization using a Multi-Objective Genetic Algorithm (MOGA) for global history matching, and coupled with an advanced workflow for streamline sensitivity-based inversion for fine-tuning. During parameterization the low-rank subsets of most influencing reservoir parameters are identified and propagated to MOGA to perform the field-level history match. Data misfits between the field historical data and simulation data are calculated with multiple realizations of reservoir models that quantify and capture reservoir uncertainty. Each generation of the optimization algorithms reduces the data misfit relative to the previous iteration. This iterative process continues until a satisfactory field-level history match is reached or there are no further improvements. The fine-tuning process of well-connectivity calibration is then performed with a streamlined sensitivity-based inversion algorithm to locally update the model to reduce well-level mismatch.
In this study, an application of the proposed algorithms and workflow is demonstrated for model calibration and history matching. The synthetic reservoir model used in this study is discretized into millions of grid cells with hundreds of producer and injector wells. It is designed to generate several decades of production and injection history to evaluate and demonstrate the workflow. In field-level history matching, reservoir rock properties (e.g., permeability, fault transmissibility, etc.) are parameterized to conduct the global match of pressure and production rates. Grid Connectivity Transform (GCT) was used and assessed to parameterize the reservoir properties. In addition, the convergence rate and history match quality of MOGA was assessed during the field (global) history matching. Also, the effectiveness of the streamline-based inversion was evaluated by quantifying the additional improvement in history matching quality per well.
The developed parametrization and optimization algorithms and workflows revealed the unique features of each of the algorithms for model calibration and history matching. This integrated workflow has successfully defined and carried uncertainty throughout the history matching process. Following the successful field-level history match, the well-level history matching was conducted using streamline sensitivity-based inversion, which further improved the history match quality and conditioned the model to historical production and injection data. In general, the workflow results in enhanced history match quality in a shorter turnaround time. The geological realism of the model is retained for robust prediction and development planning.
A Regression Model to Determine Pressure Ratings of Slotted Tubular Components With Imperfections
Authors: Remma Shravan Kumar , B.B. Devaiah , Deng Guijun 
Published: September 2021

Abstract
The objective of the present work is to develop a prediction model to predict the pressure rating accounting for the imperfections using Design of Experiments (DoE) approach. Each imperfection is modelled in terms of a design parameter and bounded by a certain realistic variation. The DoE approach aids in identifying the most influencing imperfections and in further developing an approximate model that relates the input design parameters to the maximum radial deformation. Furthermore, the regression model is built to obtain the pressure rating of the component accounting for the imperfections.
The study identifies that ovality and its orientation are by far the most influential imperfections when compared to others and provides the designer the effects of imperfection parameters on the component. The prediction model developed, serves as a ready reckoner to obtain the pressure rating of the component within the design space without any exclusive analysis. This approach leads to effective design and saves computational time.
Asphaltenes: Fundamental Principles to Oilfield Applications
Authors: Mullins Oliver , Pomerantz Andrew , Zhang Yunlong 
Published: September 2021

Abstract
The sophisticated molecular imaging methods, atomic force microscopy (AFM) and scanning tunneling microscopy (STM), have been utilized to image individual asphaltene molecules, both their atoms and bonds, and their electronic structure. The stunning images have confirmed previous results and have all but resolved the long-standing uncertainties regarding asphaltene molecular architecture. Asphaltenes are also known to have a strong propensity to aggregate. The dominante asphaltene molecular structure and hierarchical nanocolloidal structures have been resolved and codified in the Yen-Mullins model. Use of this model in a simple polymer solution theory has given the first equation of state (EoS) for asphaltene gradients in oilfield reservoirs, the Flory-Huggins-Zuo EoS. With this EoS it is now possible to address reservoir connectivity in new ways; equilibrated asphaltenes imply reservoir connectivity. For reservoirs with disequilibrium of contained fluids, there is often a fluid process occurring in geologic time that precludes equilibrium. The collection of processes leading to equilibrium and those that preclude equilibrium constitute a new technical discipline, reservoir fluid geodynamics (RFG). Several reservoirs are reviewed employing RFG evaluation of connectivity via asphaltene thermodynamics. RFG processes in reservoris often include diffusion, RFG models incorporating simple solution to the diffusion equation coupled with quasi-equilibrium with the FHZ EoS are shown to apply for timelines up to 50 million years, the age of charge in a reservoir. When gas (or condensates) diffuse into oil, the asphaltenes are destabilized and can convect to the base of the reservoir. Increasing asphaltene onset pressure as well as viscous oil and tar mats can be consequences. Depending on specifics of the process, either gooey tar or coal-like asphaltene deposits can form. In addition, the asphaltene structures illuminated by AFM are now being used to account for interfacial properties using simple thermodynamics. At long last, asphaltenes are no longer the enigmatic component of crude oil, instead the resolution of asphaltene structures and dynamics has led to new thermodynamic applications in reservoirs, the new discipline RFG, and a new understanding of tar mats.
Adaptation of Technologies Making Clean out Operations Environment Friendly and Cost Effective - Converting Failure into Success Using New Type of Fluidic Oscillator
Authors: Ahmed Barzan , Khoshnaw Farhad Abdulrahman , Raza Mustansar , Elmoneim Hossam , Shehzad Kamil , Sarbast Mustafa , Zanaty Omar El , Yousif Serwer 
Published: September 2021

Abstract
A case study is presented detailing the methodology used to perform the clean-out operation in a water disposal well of Khurmala Field, Kurdistan Region of Iraq. Untreated disposed water caused scaling and plugging in perforated liner and in the open hole that eventually ceased injection. Multiple attempts and investments were made in recent years to resume access to the injection zone using high-pressure hydro-jetting tools coupled with acid treatments. However, these attempts yielded futile efforts. Before proceeding with the decision of workover, it was decided to go for one final attempt to regain wellbore access using Fluidic Oscillator (SFO).
Fluidic Oscillator (SFO) having pulsing, cavitation and helix jetting action was used in combination with a train of fluids consisting of diesel, 28% HCl and gel. The clean out was performed in stages of 10m, to clean the fill from 1091m to 1170m. Since the well bore was initially isolated from the injection zone, the cleanout was conducted with non-nitrified fluids. As the cleanout progressed and access to the liner and open hole was regained, the circulation of insoluble fill to surface required a lighter carrying fluid. Nitrification, volume of the fluids, batch cycling, and ROP were designed considering the downhole dynamic changes expected during each stage of the operation.
The combination of SFO, the thorough selection of treatment fluids and the accurate downhole hydraulics simulations pertaining to different stages of the operation offered an effective solution and regained the connectivity between the wellbore and the injection zone. The injection rate of water increased from 0 bpm at 700 psi to 15 bpm at 200 psi. Throughout this operation, the SFO helix, cavitation, and acoustic pulse (alike) jetting proved to be more effective than other single acting rotating jetting tools. Also, Environmental impact was reduced by eliminating the need for a rig workover operation. The matching of the injection pressure when the well was first completed and the post job value indicated that the complete zone was exposed and scale deposits were removed from the critical matrix or bypassed.
SFO has an effective jetting near wellbore region, while the kinetic energy transferred via fluid makes the impact stronger in the deeper region. Internal mechanism of the tool allows it to handle high pumping rate and pressures, external finishing offer multi-port orientation of outflow that allows targeting the fill in desired directions. Presently the SFO used in the case study is the only technology that has pulse, cavitation, and helix jetting structure. Also, since the tool does not require redressing, it proves to be an efficient, safe and cost effective alternative
Incremental Method vs Split Conditions: Discussing the Similarities Between Reserves Evaluation and a Madoff Scheme
Authors: Salacz Dominique , Allam Farid , Szilagyi Imre , Mansoori Yousof Al 
Published: September 2021

Abstract
After the oil price crashes in 2014 & 2020 several M&A deals ended up in legal debates because operators cancelled major projects or infills wells that were booked in the "probable" reserves only. This document challenges the compatibility between the deterministic incremental reserve assessment method (PRMS2018, chapter 4.2.1.3), and the concept of split condition (PRMS2018 chapter 2.2.0.3), which is not allowed for reserves booking under PRMS. With a few examples, we explain why the incremental method may be misleading investors, if used wrongly.
Policies, stock market requirements, or simply the understanding of reserves guidelines may differ from one company to another. Many filers and auditors are still keen on using the deterministic incremental approach. This method consists in "defining discrete parts or segments of the accumulation that reflect high, best, and low confidence regarding the estimates of recoverable quantities under the defined development plan". In principle, this should give similar result to the widely accepted scenario method (PRMS2018, chapter 4.2.1.3) but in reality, major discrepancies are observed. Some reserve evaluation may also become misleading for banks, investors, or even for good asset management. I many cases, the estimation of recoverable volumes is reasonable, but it does not match the company CAPEX requirements, affecting corporate cash flow as well as potential Reserves Based Lending (RBL) requirements. In another case, the 1P case will be robust, but the 2P may be grossly overestimated, affecting M&A or share price.
"Reserves guidelines are principle based" this has recently become a very fashionable statement in the context of SEC bookings. Similar discussions will also occur when reviewing PRMS reports. However, different interpretations for keywords such as "Project", "Spit condition", or "FID" should not prevent the evaluator to provide a reliable reserves estimation to investor or company management.
This document questions the threshold where ethics disappears, and a Madoff scheme may become legal.