bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Art of Short Radius Drilling – Best Practices to Consistently Deliver Wells
Authors: Baig Farooq Anwar , Alhasawi Ali , Perez Marco Aburto 
Published: May 2021

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Summary
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.