bluuebunny/crossref_metadata_2025 huggingface dataset:
Automation of Formation Tops Estimation Dramatically Reduces Well Planning Process Duration
Authors: Salimov Rail , Torres Javier , Al Katheeri Yousif , Alhammadi Yousef , Abdelrahman Ahmed
Published: May 2021

Aiming to make the well planning process leaner and agile focusing on duration reduction without compromising quality of deliverables, automation opportunities have been identified within the multi-discipline iterations. The two key criteria considered for the selection of the automation project were: Minimum deployment effort and Maximum value added in efficiency.

The initial project objective was to calculate formation tops for a well engineer without requiring the intervention of a geoscientist using commercial software. The methodology utilized is the following: 1. Inputs: Well trajectory and Surfaces. 2. Process: The algorithm finds intersections between surfaces and well trajectory. Surfaces and trajectory are represented as a set of XYZ points. To find the intersection, the software iterates through each point of the trajectory from the top, comparing the depth of the projection to the target surface. The projected depth to the surface is found by 2D interpolation of the surface. Once the trajectory point becomes deeper than the surface projection, the intersection is estimated using geometrical considerations of similar triangles. 3. Deliverables: Estimated formation tops for the given trajectory. 4. Results: Simple in-house developed software enhanced well planning workflow in an Offshore Green Field. The software converted to single executable file and can be run on any device without the open-source software installed. Very accurate results achieved with proposed algorithm with a negligible difference of 0.5 feet with the geoscience traditional software.

Well planning duration reduced from average 1 week to 1 or 2 days. The workload for well engineers and the asset team has been dramatically reduced. Reduction of the number of commercial geoscience software licenses required.

Way forward: A test with a slightly modified code was used to generate formation tops for more than 400 well in a Long-Term Field Development Plan project for a Brown Field during feasibility study. Upscale to all the Fields within the organization. Improve User Interface for better adoption. Include more formats for both, trajectories, and surfaces. Reduce computing time.

This project represents the first initiative in the organization aiming to automate the well planning process.

Overall, it represents the beginning of a journey where multiple opportunities for automation can be achieved using an open-source coding software that allows any engineer with little to no experience coding to being able to generate solutions to address daily challenges.
Novel Solution For Curing Total Losses in Highly Fractured Reservoir Formation on a Major Oil Producing Field in the Middle East
Authors: Ovwigho Efe Mulumba
Published: May 2021

The reservoir formation in a major oilfield in South of Iraq is highly fractured. The operator has set as requirement that any losses had to be cured before drilling ahead. Whenever losses are encountered, drilling is stopped to cure the losses, most of the times spotting at least four cement plugs before drilling ahead are required. The current process leaves the well in an underbalanced condition for a long time posing well control risk. It was necessary to come up with an optimized solution that reduces this exposure.

Drilling the entire reservoir formation to expose all loss zones before spotting cement plugs to cure all the losses was the first step taken. Secondly, since encountering total losses across the reservoir formation was inevitable, redesigning the cement slurry formulation was an objective. Many alternative designs were proposed but were disqualified as some of the chemicals or fibers were not bio-degradable causing some damage to the reservoir. After a consensus between all parties, it was proposed to introduce temperature-degradable fibers into the cement slurry. Pilot tests were performed at maximum anticipated downhole temperature which proved successful.

The analysis results from the lab were approved and one well was assigned for the field test of the proposed solution. The selected well was drilled to expose all the loss zones, losses were encountered as expected, cement slurry incorporated with temperature degradable fibers was spotted which resulted in all the losses getting cured at the first attempt. This solution was tested in all subsequent wells drilled on the field achieving the same successful result. This solution has since been adopted for curing total losses encountered across the reservoir formation in this field as it ensures that less time is spent on curing losses, less cement material is consumed and those wells are delivered quicker and at reduced cost. This solution has led to average savings of approximately 5 days per well drilled subsequently on this field. Previously it took an average of 166 hours to restore fluid well control barrier (see wells 1 and 2 in figure 2), these days in 52 hours fluid well control barrier is fully restored barrier (see wells 3 and 4 in the attached image). Well control risk is greatly reduced.

This paper will show how minor changes to operational procedure and improvement to conventional solutions can greatly impact well control and the quick restoration of well barrier element when drilling across highly fractured reservoir formation. It will also discuss the comprehensive analysis of the loss zones, the cement laboratory analysis, the trial jobs, the measures that were put in place to reduce operational risks in order to ensure that the job was executed successfully.
A Gas Kick Model that Uses the Thermodynamic Approach to Account for Gas Solubility in Synthetic-based Mud
Authors: Manikonda Kaushik , Hasan Abu Rashid , Rahmani Nazmul H. , Kaldirim Omer , Obi Chinemerem Edmond , Schubert Jerome J. , Rahman Mohammad Azizur
Published: May 2021

This paper presents a rigorous, mechanistic model for simulating a gas kick, that uses the thermodynamic approach to account for gas solubility. This thermodynamic solubility model uses the pressure and temperature data from the kick simulations and estimates the mole fraction of various gas components in the liquid phase. We validated these gas solubility results using Aspen HYSYS, a commercial chemical process simulation software.

The thermodynamic solubility model presented in this paper assumes a pure-methane kick and applies the concepts of phase-equilibrium and fugacity to estimate the amount of dissolved gas in the drilling fluid. Application of fugacity equilibrium between the gas and liquid phases, in conjunction with the Peng-Robinson equation, gives the liquid phase mole fraction of methane. The analytical kick model uses the Hasan-Kabir two-phase flow modeling approach to describes the changes in pressure during kick migration, at various points in the annulus. Since the expansion of the gas bubbles depends on the variation in pressure, these studies also lead to pit gain estimates.

A comparison between our model results and HYSYS values for methane liquid-phase mole fraction showed a maximum 8% deviation with complete agreement on bubble point (Pb) pressure and location estimates. Similarly, our model calculated the solution gas-oil ratio (Rs), with a maximum divergence of 3% from HYSYS estimates. From the comparison studies with other empirical Bo & Rs correlations, we note that the estimates of our model agreed best with those of O’Bryan’s (O'Bryan 1988) correlations.

Many numerical kick simulators exist today, but they are notoriously time-consuming, limiting their on-field utility. Our kick simulator’s simplicity makes it potentially useful for on-field well control decisions. Most of these existing numerical simulators ignore the effects of kick solubility in synthetic-based muds. In the few models that do not ignore solubility, the approach to accounting for gas solubility and mud swelling is empirical, limiting their usage under conditions beyond the range of the source data used in developing these correlations. The mud swelling calculation approach we developed does not have these pressure and temperature range limitations.
New Approach for Abandon and Side Track Cement Plugs in Long & High Deviated Wells
Authors: Kassem Youssef Ali , Hassan Mahmoud Mohamed , El-Atrache Bassam Jamal , Ahmad Moustafa Ahmad , Al Kindi Rashid Khudaim , Alwahedi Khalid Ahmad , Al Marzooqi Abdul Mohsen Mohamed , Hammadi Majed Ismail
Published: May 2021

One of the biggest challenges in Oil and gas industries is placing a proper abandonment and sidetrack cement plugs in long and highly deviated wells like ERD wells.

As per ADNOC offshore strategy for introducing new technology and practices to overcome operation challenges. ADNOC offshore drilling team worked together with one of the oil and gas services provider and came up with an innovative idea and technique by using available equipment and implementing a new procedures and practices to ensure well integrity by placing a long abandon cement plug in highly deviated well across hydrocarbon bearing reservoir.

The new tools and technique implemented successfully in two wells X01 and X02 in one of ADNOC offshore fields.

The new idea started from planning phase by working together with Services Company, where the assigned team went through all required job planning and check the proper tools to use with the best procedures. The team faced some challenges in relation to tools and equipment availability, which affected the first trial job. However, these challenges mitigated in the next job. The new technique proved advantageous by avoiding cement plug failures during abandon and sidetrack cement plug placements jobs, in optimum time and efficient way while reducing cost. This technique subsequently introduced to all ADNOC Offshore drilling teams and to be implemented in future wells.
Enhancing the Drilling Performance Management on a Large Drilling Operation
Authors: Handoko Alvin Ivan , Khella Henry Edward , Couzigou Erwan , Al-Marzouqi Adel Abdulrahman
Published: May 2021

Since the implementation of the Drilling Performance Department in late 2017, ADNOC Offshore has been able to develop a company performance-oriented culture among the drilling teams. This performance culture is reflected in 25% ILT reduction in 2018 and 12% in 2019. Furthermore, 37 NPT RCA cases were investigated and concluded in 2019, which resulted in 57 actions for tracking and closure.

With 5 (five) concessions, 9 (nine) different shareholders, and 39 (thirty-nine) rigs, drilling performance management is challenging. ADNOC Offshore created a centralized Drilling Performance Team to capitalize on this diversity as an opportunity to improve the traditional drilling performance role. This paper describes the team's approach on Drilling Performance and the consecutive result.

The team enhances the typical drilling performance role of Key Performance Indicator (KPI) management and reporting by adopting the Performance Opportunity Time (POT) and Root Cause Analysis (RCA) Process. At the same time, the Drilling Performance Team facilitates the flow of information between teams to ensure effective knowledge transfer within such a large organization.

The POT concept tackles the well duration reduction through the reduction of Invisible Lost Time (ILT) and Non-Productive Time (NPT).

To reduce the ILT, the team took advantage of the extensive technical background in the various drilling teams. Performance improvement initiatives were proposed by taking references from different teams within ADNOC Offshore and evaluating the application in other concession. Other approach is to compare with out-of-company references.

For NPT reduction, the innovative approach was to use the HSE Root Cause Analysis (RCA) concept. This RCA process led by the Drilling Performance Team was implemented to standardize the approach and have a systematic investigation analysis. This process resulted in identifying root causes and effective corrective action plans. As per HSE, addressing the root causes of incidents would result in the most significant impact in NPT.

This approach also allows an independent and more detailed look on the subjects, where commonly these tasks are done in a limited manner by drilling teams alone with their ongoing operational workload. Finally, results are communicated to the drilling organization through lessons learned portal and technical bulletins.
Improving Rate of Penetration in High Pressure High Temperature Gas Wells by Utilization of Managed Pressure Drilling and Artificial Intelligence
Authors: Ghamdi Ahmed , Saihati Ahmed , Abdelrahman Mohamed , Omar Mahmoud , Abdulraheem Abdulazeez
Published: May 2021

Drilling in deep high-pressure high-temperature (HPHT) abrasive sandstone pose significant challenges: low rate of penetration (ROP), bit wear, differential sticking, and wellbore instability issues. These issues are magnified when attempting to drill long laterals in the direction of minimum stress.

This paper focuses on the use of Managed Pressure Drilling (MPD) and Artificial Intelligence (AI) analytics to improve ROP.

MPD is normally used to help drilling in formations with narrow mud weight window, it achieves this by controlling the surface backpressure to keep the annular pressure in the wellbore above the pore pressure and below the fracture gradient. One key benefit of using MPD is that high mud weight is no longer required, since the Equivalent Circulating Density (ECD) is going to be managed to maintain the overbalance. An example of a well that was drilled using MPD solely for ROP improvement is presented in this paper. This well achieved almost double the ROP of a control well, which was drilled in the same formation with no MPD.

Essentially most of the drilling parameters used, which include, pump rate, revolution per minute (RPM), weight on bit (WOB), and other drilling practices, are controlled by the people on the rig. Incorporating AI analytics in the equation, help minimizes human intervention and could achieve further improvement in ROP. After the ROP improvement observed while using MPD, both technologies were combined in a well drilling the same formation. An example is presented for the well drilled using both technologies.
The Art of Short Radius Drilling – Best Practices to Consistently Deliver Wells
Authors: Baig Farooq Anwar , Alhasawi Ali , Perez Marco Aburto
Published: May 2021

Short radius wells typically incorporate build rates between 35deg per 100ft and 70deg per 100ft. These wells are typically drilled to minimize exposure of a problematic zone above the target or to reduce geological uncertainty. This paper will discuss best practices and equipment developed specifically for delivering these wells in the Middle East. Case histories will illustrate the close collaboration with the operator resulting in performance step change for short radius drilling.

The approach is based on a rigorous Drilling Engineering process. Such process is divided in four major steps; design, execute, evaluate and optimize. One of the first key steps is to perform a diligent risk assessment ensuring the customer objectives are achieved. This resulted in the development and implementation of technological innovations on downhole motors and Measurements While Drilling (MWD) tools to achieve the required high build rates safely and consistently. Proper communication was crucial for flawless execution, and meticulous documentation enabled proper evaluation and optimization of the art of short radius drilling.

For over 10 years, multiple short radius wells have been consistently delivered meeting their objectives; from successful sidetracking operations, accurate curve landing, optimum geo-steering, valuable Logging While Drilling (LWD) data collection, to extending the life of the wells by maximizing their production. The last two steps of the Drilling Engineering cycle (evaluate and optimize) have been the foundation of the continuous improvement process; targeting adequate equipment maintenance, Bottom Hole Assembly (BHA) design and operational practices to ensure consistent results. The paper will recap the drilling engineering cycle for wells drilled recently. The discussed best practices have enabled master the art of short radius drilling. Such distinctive knowledge should be shared with the entire oil and gas industry.

The paper captures the engineering approach to tackle the traditional challenges of drilling short radius wells. It also discusses the reliable solution for drilling short radius wells in Middle East which are planned to access new reserves from an existing infrastructure, while minimizing drilling and geological risks.
Successful CRI Project for Offshore Abu Dhabi Field: 3 Million Barrels Injected with ZERO Subsurface Failures
Authors: EL Helali Osama , Haddad Mohamed , Gumarov Salamat , Benelkadi Said , Bianco Eduardo , Mitchel Craig
Published: May 2021

Cuttings reinjection (CRI) project at OFFSHORE ABU DHABI field achieved successful operation with three million barrels injected to date with zero subsurface failures setting up an environmentally friendly and cost-effective waste management success story that complies with zero discharge requirements.

The project exceeded initial expectations by accommodating non-aqueous drilling waste from jack-up drilling rigs in addition to artificial islands own rigs. Subsurface assurance and engineering workflows proved to be effective in ensuring subsurface containment of drilling waste in challenging environment while ensuring efficiency of operation to meet demanding drilling schedules.

Injection schedules and procedures were based on results of thorough subsurface FEED study and global best practices. Slurry fluid quality requirements were verified thru extensive laboratory tests. Throughout injection operation downhole pressure and temperature of the injection well was vigilantly monitored and analyzed along with well temperature survey and periodic fracture modeling updates of the fracture waste domain to ensure seamless fracturing of formation and containment of waste domain within selected formation.

More than 3 million barrels of drill cuttings and associated drilling waste have been safely and successfully disposed of into a single injection zone of two cuttings reinjection wells over five years of project operation to date. No downtime was experienced and no impact to drilling schedule was induced demonstrating high capability of technology when designed and executed in right way. Results of actual injections showed accuracy and robustness of the engineering workflow implemented from Job design, planning and execution

The paper presents unique and knowledge-based steps that contributed to success of project and set high bar for region for the drilling waste management.
Innovative Approach to Drilling Across Highly Fractured Formation in the Biggest Deep Gas Field in the Middle East
Authors: Ovwigho Efe Mulumba
Published: May 2021

On a Deep Gas Field in the Middle East, it is required to drill across a highly fractured and faulted carbonate formation. In most wells drilled across the flank of this field, it is impossible to cure the encountered losses with conventional or engineered solutions. Average time to cure losses is 20 days. With the current drive for cost optimization, it has become necessary to eliminate the NPT associated with curing the losses.

A thorough risk assessment was conducted for wells drilled on the flank of this field, it was established that the risk of encountering total losses was very high. Seismic studies were performed and it was observed it would be impossible to eliminate total losses as fractures were propagated in all directions. It was proposed to run a sacrificial open hole bridge plug above the loss zone and sidetrack the well instead of performing extensive remedial operations. The proposed solution would help eliminate the well control and HSE risks associated with drilling blindly ahead with the reservoir formation exposed.

Applied the proposed solution on the next well that was drilled on the flank of the field, encountered total losses, spotted eight LCM pills, unable to cure the losses, ran sacrificial open hole bridge plug and sidetracked the well. The entire process was completed in 30 hours. Sidetracked the well in adjacent direction to the initial planned well trajectory based on further seismic data analysis and no losses was encountered. Recovered full mud column to surface thus ensuring the restoration of all well barrier elements. This solution has since been adopted as best practice for wells drilled on the flank of the field where there is high probability of encountering total losses. The average time saving per well due to this optimized solution is 450 hours for wells where total losses are encountered.

This engineered solution has made drilling wells on the flank of the field in a timely manner possible and at optimized costs. This has resulted in: –The elimination of Non-Productive Time,–Quick delivery of the well to production,–Reduced HSE risk,–Reduced well control risk as loss zone is quickly isolated before drilling ahead.

This paper will explain why running sacrificial open hole bridge plugs and sidetracking the well is a more effective solution compared to extended remedial operations when total losses are encountered while drilling across highly fractured / faulted formation. It will discuss the extensive risk assessment conducted, the mitigation and prevention measures that were put in place in order to ensure successful implementation on trial well.
Exploitation of Field Drilling Data with an Innovative Drilling Simulator: Highly Effective Simulation of Rotating and Sliding Mode
Authors: Koulidis Alexis , Kelessidis Vassilios , Ahmed Shehab
Published: May 2021

Drilling challenging wells requires a combination of drilling analytics and comprehensive simulation to prevent poor drilling performance and avoid drilling issues for the upcoming drilling campaign. This work focuses on the capabilities of a drilling simulator that can simulate the directional drilling process with the use of actual field data for the training of students and professionals. This paper presents the results of simulating both rotating and sliding modes and successfully matching the rate of penetration and the trajectory of an S-type well.

Monitored drilling data from the well were used to simulate the drilling process. These included weight on bit, revolutions per minute, flow rate, bit type, inclination and drilling fluid properties. The well was an S-type well with maximum inclination of 16 degrees. There were continuous variations from rotating to sliding mode, and the challenge was approached by classifying drilling data into intervals of 20 feet to obtain an appropriate resolution and efficient simulation. The simulator requires formation strength, pore and fracture pressures, and details of well lithology, thus simulating the actual drilling environment. The uniaxial compressive strength of the rock layer is calculated from p–wave velocity data from an offset field. Rock drillability is finally estimated as a function of the rock properties of the drilled layer, bit type and the values of the drilling parameters. It is then converted to rate of penetration and matched to actual data.

Changes in the drilling parameters were followed as per the field data. The simulator reproduces the drilling process in real-time and allows the driller to make instantaneous changes to all drilling parameters. The simulator provides the rate of penetration, torque, standpipe pressure, and trajectory as output. This enables the user to have on-the-fly interference with the drilling process and allows him/her to modify any of the important drilling parameters. Thus, the user can determine the effect of such changes on the effectiveness of drilling, which can lead to effective drilling optimization.

Certain intervals were investigated independently to give a more detailed analysis of the simulation outcome. Additional drilling data such as hook load and standpipe pressure were analyzed to determine and evaluate the drilling performance of a particular interval and to consider them in the optimization process.

The resulting rate of penetration and well trajectory simulation results show an excellent match with field data. The simulation illustrates the continuous change between rotating and sliding mode as well as the accurate synchronous matching of the rate of penetration and trajectory. The results prove that the simulator is an excellent tool for students and professionals to simulate the drilling process prior to actual drilling of the next inclined well.
Preventing Drilling Fluid Induced Reservoir Formation Damage
Authors: Klungtvedt Karl Ronny , Khalifeh Mahmoud , Saasen Arild , Berglind Bjørn , Vasshus Jan Kristian
Published: May 2021

During drilling of permeable reservoirs, drilling fluid may penetrate the formation and induce damage to the reservoir rock. Specifically, solids present in the drilling fluid may enter the formation and cause subsequent reduction in reservoir permeability in the area near the wellbore.

When drilling with a water-based drilling fluid in a reservoir, various polymer-based additives are normally applied to reduce the filtration loss. These additives, such as Xanthan Gum, Poly Anionic Cellulose (PAC) and Starch may help in reducing losses to the formation in presence of small pore-throats and low differential pressures. If the pore throats exceed e.g. 20μm and differential pressures reach 500psi, these additives have little effect on reducing loss of drilling fluid to the formation and thereby little effect in preventing solids from entering the formation.

Lost circulation is particularly challenging when losses occur in the reservoir section. This is because LCM treatment may create formation damages. Green et al. (SPE-185889) showed the nature of drilling fluid invasion, clean-up, and retention during reservoir formation drilling. They also showed the lack of direct relation between fluid loss and formation damage. In light of such ideas, a development of new Non-Invasive Fluid (NIF) additives was conducted. These additives were able to handle downhole pressure differences and create a preventative sealing of a permeable formation when applied into a solids-free drilling fluid.

Ceramic discs of various permeability and mean pore-throat size were installed into a HTHP pressure cell. Drilling fluid was pumped through the cell and a filter cake was formed across the ceramic disc. A pressure of 500psi was applied and filtration loss was measured over a 30-minute period.

Examples are herein presented showing how filter cake materials were applied into the drilling fluid and effectively sealing the permeable surface of the ceramic disc. Also, it will be shown how the filter cake was effectively removed from the discs using a breaker solution. Furthermore, a selection of experiments is presented, showing the possibility to heal lost circulation in permeable reservoirs without the presence of weighing materials, clays or drill-solids in the drilling fluid. A test was also conducted in such a way that the disc was fractured inside the test cell to investigate the impact on fluid loss.
An Engineering Centric Plan to Standardise and Optimise Completions in Order to Reduce Phase Duration and Non Productive Time
Authors: Wagstaff Scott , Beaman Daniel James , Torres Javier Ernesto , Al Katheeri Yousif Saleh , Alhammadi Yousef Ahmed , Abdelrahman Ahmed Abdelrahim
Published: May 2021

For several decades, completion design has been performed by the Field Development (FD) Team of several offshore fields in Abu Dhabi and installed with minimal Completion Engineering Team contribution. The demand of lower completion requirement has being increased to maximize well portfolio and enhance well life. The completion design is becoming more challenging and import for key to success. Since a companywide re-organisation occurred a dedicated Completion Engineering Department has been formed to develop a plan to standardise & optimise completions in order to reduce phase duration and NPT.

A plan was approved that involved the hiring of a complete engineering department with expertise in many different types of completion and workover operations from all over the globe. This engineering team was brought together from other oil companies and service providers, and tasked with reviewing all current and future completion designs, operations procedures and completion equipment. This was done in order to identify suitability and gaps that were the cause of well construction NPT and identify processes that could be used to reduce or eliminate possible future Well Integrity problems.

When the new organisation was formed completion phase NPT reached over 20%, however three month after the NPT had dropped to 11.1%. Within six months of the engineering team starting to be formed, completion phase duration has reduced by 20% and NPT has reduced by almost 50%. These results have been achieved with a concerted effort to maximize understanding of the equipment available to be deployed and develop standardized completion designs that meet the functional requirements of the Field Development Department. As the department has grown and moves forward, a greater involvement in the development of documents such as but not limited to: scope of work and technical requirements for procurement; further deepens the engineering-centric approach that will continue reducing completion phase duration contributing to the operator strategic goals.

This paper will show how the newly formed engineering team has managed a complex change from a previous organisation to a new one. Whilst the previous completion design and execution methodology was seen to be successful in other operating companies, the successful engineering-centric approach has been proven within other national operator offshore concessions to reduce phase duration and NPT.
Evolution of Dynamic Sag Testing Methods
Authors: Miller JJ , Jamison Dale E.
Published: May 2021

Maintaining the integrity of the drilling-fluid column is vital for safety and operational efficiency. Stable, controlled fluid density provides a primary pressure barrier during the drilling phase. Non-aqueous fluids (NAFs) provide huge benefits for nearly all aspects of difficult drilling situations, yet still can have challenges related to weight suspension. The geometry and annular restrictions of modern well designs often demand low fluid rheology parameters to avoid excessive circulating pressures, and this unsurprisingly increases the risks of sagging weight material. Given the importance of understanding the fluid behaviors in these situations, operators and service companies have made significant efforts to develop reliable sag testing methods.

Older methods of testing neglected movement and instead centered on mimicking the downhole conditions such as temperature and hydrostatic pressure. Variations of this static aging method addressed the critical angle where Boycott settling accelerates the sag. More complex, dynamic methods were devised later in time to provide greater insight on sag behaviors.

Although engineers and scientists have made numerous strides to create a definitive sag test, the current tests have limited capabilities. Very few are capable of working in an offshore environment. Sag events continue to be costly and problematic to operators’ main objectives of drilling and completing their wells safely and efficiently. The authors address results from the current state of the art in sag testing and compare these to a proprietary dynamic procedure created in 2019. While the method is still in development, its capabilities have been well defined. Fluid samples are kept in constant motion at low-ranging shear rates and elevated temperatures to simulate sag-prone conditions downhole. Results indicate a high degree of correlation to the expected sag with different sizes of barite in low-ECD fluids.
Introduction of Smart Circulating Sub in Offshore Abu Dhabi
Authors: Biyanni Hanifan Mayo , Al Ameri Suhail Mohammed , Couzigou Erwan , Alwahedi Khalid Ahmed , Al Marzouqi Adel , Al Ameri Fahed Salem , Tahoun Ahmed , Liang Lucian , Mohamad Fairuz
Published: May 2021

The paper describes deployment phase of a smart circulating sub in offshore Abu Dhabi field as an effort to improve efficiency and flexibility in tackling operational drilling risk and minimize associated NPT. It will describe the pre-campaign technical assessment and preparation, the field operation summary, the detail activation record, and the trial statistics including the activation success ratio including also some reliability milestones that will beneficial to be reference in term of tool functionality and reliability.

The smart sub offers practicality to select three different flow path mode on top of the isolation mode without any necessity to pull out of hole nor to disconnect the pipe at surface. Different from any other conventional tool, the command to change the flow path mode is fully achieved only by manipulating absolute pressure or pipe rotation speed. Thus, it will save time, lower the operational risk as well as increase flexibility. As part of new technology implementation, a set of factory test and field trial run were conducted to evaluate its operability, reliability, and also to define its technical limit.

A total of 8 field trial runs with 38 activation in more than 800 running hours has proved the system's the reliability through the field trial. And through the paper, some feedback from the field trial runs that is aimed to raise a design and operational improvement towards a more robust tool functionality.
Rapid Development of Multi-Source Heterogeneous Drilling Data Service System
Authors: Cheng Zhong , Xu Rongqiang , Chen Jianbing , Li Ning , Yu Xiaolong , Ding Xiangxiang , Cao Jie
Published: May 2021

Digital oil and gas field is an overly complex integrated information system, and with the continuous expansion of business scale and needs, oil companies will constantly raise more new and higher requirements for digital transformation. In the previous system construction, we adopted multi-phase, multi-vendor, multi-technology and multi-method, resulting in the problem of data silos and fragmentation. The result of the data management problems is that decisions are often made using incomplete information. Even when the desired data is accessible, requirements for gathering and formatting it may limit the amount of analysis performed before a timely decision must be made. Therefore, through the use of advanced computer technologies such as big data, cloud computing and IOT (internet of things), it has become our current goal to build an integrated data integration platform and provide unified data services to improve the company's bottom line.

As part of the digital oilfield, offshore drilling operations is one of the potential areas where data processing and advanced analytics technology can be used to increase revenue, lower costs, and reduce risks. Building a data mining and analytics engine that uses multiple drilling data is a difficult challenge. The workflow of data processing and the timeliness of the analysis are major considerations for developing a data service solution. Most of the current analytical engines require more than one tool to have a complete system. Therefore, adopting an integrated system that combines all required tools will significantly help an organization to address the above challenges in a timely manner.

This paper serves to provide a technical overview of the offshore drilling data service system currently developed and deployed. The data service system consists of four subsystems. They are the static data management system including structured data (job report) and unstructured data (design documentation and research report), the real-time data management system, the third-party software data management system integrating major industry software databases, and the cloud-based data visual application system providing dynamic analysis results to achieve timely optimization of the operations. Through a unified logical data model, it can realize the quick access to the third-party software data and application support;

These subsystems are fully integrated and interact with each other to function as microservices, providing a one-stop solution for real-time drilling optimization and monitoring. This data service system has become a powerful decision support tool for the drilling operations team. The learned lessons and gained experiences from the system services presented here provide valuable guidance for future demands E&P and the industrial revolution.
Simple and Robust Algorithm for Multiphase Equilibrium Computations at Temperature and Volume Specifications
Authors: Lu Chang , Jin Zhehui , Li Huazhou , Xu Lingfei
Published: May 2021

Two-phase and three-phase equilibria are frequently encountered in a variety of industrial processes, such as carbon dioxide (CO2) injection for enhanced oil recovery in oil reservoirs, multiphase separation in surface separators, and multiphase flow in wellbores and pipelines. Simulation and engineering design of these processes using isothermal/isochoric (VT) multiphase equilibrium algorithms are sometimes more convenient than that using the conventional isothermal/isobaric (PT) algorithms. This work develops a robust algorithm for VT multiphase equilibrium calculations using a nested approach. The proposed algorithm is simple because a robust PT multiphase equilibrium algorithm is used in the inner loop without any further modifications, while an effective equation-solving method (i.e., Brent’s method; Brent 1971) is applied in the outer loop to solve the pressure corresponding to a given volume/temperature specification. The robustness of the VT algorithm is safeguarded by using a highly efficient trust-region-method-based PT algorithm. We demonstrate the good performance of the newly developed algorithm by applying it to calculate the isochores of fluid mixtures that exhibit both two-phase and three-phaseequilibria.
A 3D system to model human pancreas development and its reference single-cell transcriptome atlas identify signaling pathways required for progenitor expansion
Authors: Gonçalves Carla A. , Larsen Michael , Jung Sascha , Stratmann Johannes , Nakamura Akiko , Leuschner Marit , Hersemann Lena , Keshara Rashmiparvathi , Perlman Signe , Lundvall Lene , Thuesen Lea Langhoff , Hare Kristine Juul , Amit Ido , Jørgensen Anne , Kim Yung Hae , Sol Antonio del , Grapin-Botton Anne
Published: May 2021

Human organogenesis remains relatively unexplored for ethical and practical reasons. Here we report the establishment of a single cell transcriptome atlas of the human fetal pancreas between 7 and 10 post-conceptional weeks of development. To interrogate cell-cell interactions we developed InterCom, an R-Package for identifying receptors-ligand pairs and their downstream effects. We further report the establishment of a human pancreas culture system starting from fetal tissue or human pluripotent stem cells, enabling the long-term maintenance of pancreas progenitors in a minimal, defined medium in three-dimensions. Benchmarking the cells produced in 2D and those expanded in 3D to fetal tissue reveals that progenitors expanded in 3D are transcriptionally closer to the fetal pancreas. We further demonstrate the potential of this system as a screening platform and identify the importance of the EGF and FGF pathways controlling human pancreas progenitor expansion.
Contact Force Estimation for Serial Manipulator Based on Weighted Moving Average with Variable Span and Standard Kalman Filter with Automatic Tuning
Authors: Cao Feng , Docherty Paul D. , Chen XiaoQi
Published: May 2021

Sensorless contact force estimation methods facilitate the application of the serial manipulators to manufacturing as they enable robots to interact with unexpected collisions at low cost. In this paper, an external force estimation approach with no embedded sensors is proposed. The approach combines a Weighted Moving Average (WMA) with variable span, the standard Kalman filter (SKF), and its tuning routines. Improved confidence in the motor output torque is achieved due to the reduction of the measurement noise in the motor current by the WMA. The span of the filter adapts continuously to achieve optimal tradeoff between response time and precision of estimation in real-time. With the comprehensive information of uncertainty in motor current noise and measurement errors of individual joints speed, an automatic tuning algorithm of the SKF is presented. Validation of the presented estimation approach in terms of estimation accuracy and response time was conducted on the Universal Robot 5 manipulator with differing end effector loads. It was found that the combined force estimation method leads to a reduction of the root-mean-square error and response time by 55.2% and 20.8% in comparison with the established method. The proposed method can be applied to any robotic manipulators as long as the motor information (current, joint position, and joint velocities) are available. Consequently, the cost of collision recognition could be reduced dramatically.
Identification of lncRNA–mRNA Regulatory Network Associated With Isolated Systolic Hypertension And Atherosclerotic Cerebral Infarction
Authors: Yang Jie , Tao Yan-Nan , Hu Fang-Xiao , Chen Yong-Zhi , Yang Xue-Song , Zhuang Xin , Cui Ming-Ling , Li Guan-lan , Li Chao , Yang Chuan-Hua , Jiang Yue-Hua
Published: May 2021

Background: Increasing evidences uncover that lncRNAs play an important role in Isolated systolic hypertension (ISH). However, a systematic lncRNA-mRNA regulatory network is still absent in isolated systolic hypertension and atherosclerotic cerebral infarction patients (ISH & ACI).Aim:This research aims to establish a lncRNA-mRNA co-expression network in patients with ISH & ACI, to probe into the potential functions of lncRNA in those patients.Design and Setting:Expression profiles of lncRNA and mRNAs are collected and compared respectively from 8 patients with ISH and 8 patients with ISH & ACI by RNA-seq data.Methods: Differentially expressed lncRNAs and mRNAs were screened out via high-throughput sequencing in the plasma of ISH/ACI patients and control ISH patients. Then, a lncRNA-mRNA interaction network was built using the Pearson correlation coefficient by Cytoscape software. The expression levels of the hub genes and lncRNAs were verified by qRT-PCR in another 10 ISH/ACI patients and 10 control patients. Results: 2768 differentially expressed lncRNAs and 747 differentially expressed mRNAs were identified. 2 hub genes (CD226 and PARVB) and 11 lncRNAs were identified in the lncRNA-mRNA interaction network. qRT-PCR and cell assay results verified that lncRNAs ENST00000590604 and CD226 are highly expressed in patients of ISH & ACI. CD226 was associated with vascular endothelial cells growth and stability through platelet activation and focal adhesion pathway.Conclusion: We established a novel mRNA-lncRNA interaction network. lncRNAs ENST00000590604 and CD226 might be the potential biomarkers of ISH & ACI.
Photocatalytic Degradation of Norfloxacin By Magnetic Molecularly Imprinted Polymers: Influencing Factors And Mechanisms
Authors: Fang Lei , Tang Kaijie , Wei Dong , Zhang Yan , Zhou Yongchao
Published: May 2021

Novel magnetic molecularly imprinted polymers (MMIP) were prepared for selective removal of norfloxacin from ambient water by effectively utilizing photocatalytic degradation and magnetic separation techniques. The imprinted materials with titanium layer and multihole surface showed excellent photocatalytic property. In this paper, the kinetics of photocatalytic degradation of norfloxacin by MMIP was explored, and the influences of environmental factors, including solution pH, humic acid, common ions and water media on photocatalytic performance of the materials were elucidated. The results showed that MMIP had good adaptability and could degrade norfloxacin within 60 min, but the degradation rate constant decreased by 40.3% and 66.4% in tap water and surface water, respectively. According to the intermediates, the possible degradation pathways of norfloxacin were analyzed, speculating that norfloxacin might be degraded into small molecules after de-piperazine ring, de-carboxyl group and de-fluorine. Moreover, the mineralization ratio of norfloxacin could reach 84.2% after ultraviolet irradiation for 150 min. In the study of photocatalytic in-situ regeneration and recovery performance of MMIP, the total removal efficiency of norfloxacin was still 99.0% after seven cycles of adsorption-degradation tests. And the low cobalt release of MMIP by molecular imprinting technology enhanced the security of the materials.
Investigation of the Biological Treatability of Pistachio Processing Industry Wastewaters in a Batch-operated Aerobic Bioreactor
Authors: Tırınk Sevtap , Nuhoğlu Alper , Kul Sinan
Published: May 2021

This study encompasses investigation of treatment of pistachio processing industry wastewaters in a batch reactor under aerobic conditions, calculation of kinetic parameters and comparison of different inhibition models. The mixed microorganism culture used in the study was adapted to pistachio processing industry wastewaters for nearly one month and then concentrations from 50-1000 mg L− 1 of pistachio processing industry wastewaters were added to the medium and treatment was investigated in batch experiments. The Andrews, Han-Levenspiel, Luong and Aiba biokinetic equations were chosen for the correlations between the concentration of pistachio processing industry wastewaters and specific growth rates, and the kinetic parameters in these biokinetic equations were calculated. The µmax, Ks and Ki parameters, included in the Aiba biokinetic equation providing best fit among the other equations, had values calculated as 0.25 h− 1, 19 mg L− 1, and 516 mg L− 1, respectively.
Dynamic Environmental Regulation Threshold Effect of Technical Progress on Green Total Factor Energy Efficiency:Evidence from China
Authors: Li Ge , Gao Da , Li Yi
Published: May 2021

Sustainability is a strategic choice for the transition to a green economy in China. Improving green total factor energy efficiency (GTFEE) is the key to realizing the dual targets of energy saving and economic growth. This paper assesses the nonlinear influence of environmental regulation (ER) on technical innovation (TI) affecting GTFEE by establishing a dynamic panel threshold model using panel data of 271 prefecture-level cities in China from 2004–2016. Meanwhile, a system GMM approach is used to verify the channels through which TI affects GTFEE. Finally, the spatial and temporal characteristics of TI affecting GTFEE are analyzed from the perspective of ER. The empirical results are as follows: (1) TI can significantly improve GTFEE, and there is a threshold characteristic of this improvement effect, when ER is above the threshold value, TI has a greater improvement effect on GTFEE. (2) Besides directly influencing GTFEE through green technical innovation effect, TI can also indirectly influence GTFEE via channels such as economic growth effect, industrial structure upgrading effect and foreign investment effect, and the indirect influence channels show ER heterogeneity. (3) The number of cities crossing the threshold of ER in China increases year by year, which helps TI play a role in improving GTFEE, but there are still a small number of cities that do not cross the threshold during the sample period, which should attract the attention of local governments.