bluuebunny/crossref_metadata_2025_split huggingface dataset:
Liquid Weight Material for Drilling & Completion Fluids
Authors: Al-Bagoury Mohamed , Steele Christopher 
Published: January 2016

Abstract
For decades, non-aqueous drilling fluids (NADF's) have been the fluid of choice to drill challenging wells. This is because they possesses high robustness, high rate of penetration (ROP) and high thermal stability. However, there is a growing interest in developing alternative fluids to replace non-aqueous drilling fluids, because they are expensive to dispose of, environmentally unfriendly, and may cause formation damage. Alternative fluids should have a better HSE profile and have an equivalent, or even better performance compared to the non-aqueous fluid. In addition, due to the increase of drilling costs, a substitute for expensive brines such as Cs formate for completion fluids is sought.
Recently the use of potassium formate brine (KFo), weighted with manganese tetraoxide (Mn3O4) as a drilling & completion fluid, has grown rapidly, particularly for sensitive formations such as shale and other clay-containing formations. In addition, being environmentally friendly, the KFo / Mn3O4 fluid has excellent performance for shale stability, high thermal stability and has less potential for formation damage compared to non-aqueous fluids. This fluid is very stable and is usable over a long period.
This paper will discuss the development of a novel, stable slurry of Mn3O4 in KFo with a high density of 2.3-2.5sg. The properties of the slurry were optimized to ensure easy flow and long-term storage stability. The stability of this slurry was monitored for a period of 6 months. The use of such slurry in preparing drilling fluids will be illustrated. The new liquid weight material simplifies the fluid mixing significantly. It can be used on its own or diluted back with water or KFo brine and the addition of other additives, such as fluid-loss agent, dispersant, viscosifier, etc., to convert it into a drilling or completion fluid. As a liquid additive, it is easy & safe to handle. The use of liquid chemicals eliminates any dust issues which may be encountered with powder handling.
In addition, the paper will show the design of a new high-density fluid 2.62sg (22ppg) and testing at temperatures of 200°C for ultra HPHT drilling. The new fluid has a low plastic viscosity of 48cp, and low fluid loss of &lt;15 ml on 5µm ceramic disc at 150°C. It has a low dynamic sag of 0.16lb/100ft2.
This is the first time to develop such a high-density aqueous weight material (2.5sg) for drilling & completion fluids. It is also the first time to design environmentally friendly & high-density fluids (2.6sg) for ultra HPHT drilling.
Modeling and Control of Stick Slip and Bit Bounce in Oil Well Drill Strings
Authors: Al Sairafi F. A. , Al Ajmi K. E. , Yigit A. S. , Christoforou A. P. 
Published: January 2016

Abstract
Stick slip and bit bounce are common problems while drilling the production sections of oil wells with Polycrystalline Diamond Compact (PDC) bits. The production section often encounters different lithology including highly fractured limestone, sand/sandstone and reactive shale. In some cases, vibrations are so severe that they cause failure in drill string components, loss of expensive tools in the hole; such as bit and logging sources/equipment, bit damage, wellbore instability and reduction in the Rate of Penetration (ROP).
The current paper presents a dynamic model and an active control strategy for reducing stick slip and bit bounce of a drill string with a top drive system. The model includes complete drive systems for both rotational and axial motions, as well as the hoisting system. Also included is the bit/formation interaction, which facilitates the inclusion of the effects of formation characteristics. First, the equations of axial and torsional motions are derived and solved numerically. The numerical results are validated with real data logs recorded while drilling the production sections in Kuwait fields. Second, feedback controllers are designed and incorporated into the model.
Simulation results show that in certain conditions the drill string may experience high values of TOB (Torque on Bit) and WOB (Weight on Bit), which can damage sensitive tools within the drill string, such as, LWD (Logging While Drilling) tools and RSS (Rotary Steerable System). It is demonstrated that implementing only a torsional controller in the system is not effective in mitigating bit bounce phenomena, and an axial controller should be designed and implemented as well. Simulation results show that it is possible to minimize both stick slip and bit bounce and maintain desired drilling conditions with the axial and torsional controllers.
It is expected that, the insight gained by the proposed model will be instrumental for determining and realizing optimal drilling conditions. Therefore, the cost related to drilling a specific well will be reduced, and the life of equipment used to drill the well, such as bit, motor, stabilizer, and drill collars, will be increased.
Lost Circulation Management in Naturally Fractured Reservoirs
Authors: Savari Sharath , Whitfill Donald L. , Walker Jonathan 
Published: January 2016

Abstract
Managing severe-to-total lost circulation can be especially challenging in naturally fractured formations. This situation becomes further complicated if it is a producing formation. Particulate lost circulation materials (LCM) have been used to manage lost circulation for many years. However, current LCMs are not efficient in terms of size and application methods to cure severe-to-total losses, such as highly fractured reservoirs.
In the present paper, a novel acid-soluble combination in the form of an engineered composite LCM solution (ECS) with a multi-modal particle size distribution (PSD) has the potential to manage severe-to-total loss circulation situations in naturally fractured reservoir formations. The multi-modal PSD and unique combination of particles will help manage any uncertainties in fracture sizes, and the larger particles present will aid in plugging large fractures. The results of a laboratory investigation will be presented, highlighting the potential benefits of this solution.
When managing severe-to-total losses in highly fractured reservoir formations, particulates alone may not be effective, thus the LCM should preferably be acid soluble. The combination of a large multi-modal PSD LCM containing a fibrous material along with platelet particles was designed as a candidate for dealing with these extreme losses. The solution developed is capable of plugging laboratory-simulated fracture sizes in the range of 5,000 μm. It was further demonstrated that supplementing with another larger LCM platelet materials enhanced its capability to seal 0.5 in. (12.5 mm) in the lab. A significant determination in the solution developed is up to 96% soluble in 15% HCl and organic acids. This paper will discuss in detail the product concentration, testing methodology, and results. In addition, the strategy to apply these materials in the field will be discussed.
The large PSD, acid-soluble LCM solution can help manage uncertainties in fracture sizes and allow for curing severe-to-total losses in naturally fractured reservoir formations.
Optimizing Multistage Hydraulic-Fracturing Design Based on 3D Continuum Damage Mechanics
Authors: Shen Xinpu , Standifird William , Evans Scott 
Published: January 2016

Abstract
The purpose of this work is to build a real three-dimensional (3D) method for optimizing the design of stage intervals in multistage hydraulic fracturing and design of horizontal well spacing in unconventional oil and gas resources. The method proposed in this paper uses continuum damage mechanics as its basis for modeling fractures and their propagation under stimulation injection. The volumetric density of cracks created by injection fluid is represented by a set of two scalar-damage variables. This method can provide a solution for fracture propagation in two horizontal directions. This solution is used for the optimized design of stage intervals for multistage hydraulic fracturing and for the optimized design for well spacing in parallel horizontal wells. The determination of optimized stage intervals considers the overlapping effect of two nearby stimulation stages. A validation example of a design for the hydraulic fracturing of a set of parallel horizontal wells in a tight-sand oil formation is presented. A 3D numerical model was built for this purpose. A numerical solution for the distribution of continuum damage variables under stimulation-injection loads is obtained with a poro-elastoplastic damage model by using the finite element method. The effective fracture length with the critical value of synthetic damage variable (DV) is determined. The optimized stage interval and well spacing are determined, respectively, with reference to numerical results of continuum damage distribution generated by stimulation. The critical value for the synthetic DV is the value of the DV that can represent the opening of an effective fracture. The distribution of synthetic DVs generated by stimulation injection was calculated and analyzed. The stage interval along the well trajectory and the well spacing are determined by using the numerical results of continuum damage distribution. This method can provide a fracture propagation solution in three directions of a 3D volume, which creates a real 3D method for fracturing analysis.
Multilateral TAML-4 and -5 Junctions Provide Consistent Results for Arabian Gulf Operator
Authors: Glaser Mark , Rosas Eulalio , Rivero Gilberto J 
Published: January 2016

Abstract
Since 1999, more than 120 wells in Saudi Arabia have been completed using multilateral technology (MLT). This paper will discuss case histories, associated technology improvements, and best practices in which dual-lateral completions, with and without pressure-isolated junctions (Technical Advancement of Multilaterals (TAML) levels 4 and 5), were developed and used to help ensure that each installation met the operator's objectives.
Advancements and improvements in multilateral technology has led to reduced risk and enhanced well production, while addressing the operator's well challenges of maximizing reservoir exposure and increasing the use of existing slots. This paper uses end-of-well and incident reports to identify areas for improvement, the subsequent implementation, and the results of system modifications. Focused planning of drilling operations, wellbore preparations, installation procedures, and development of contingency methods led to the success of the installations. The operator's commitment to using this technology has reduced non-productive time and provided incremental cost savings as process improvements were implemented over the 15-year period.
Multilateral technology in Arabian Gulf offshore fields has enhanced productivity using innovative techniques to fulfill the completion and intervention requirements of dual-lateral wells, with and without pressure-isolated junctions. Collaborative multidisciplinary teams comprised of engineers from the operator and multilateral service provider were assigned to help ensure the successful implementation of the technology. The system modification goals of improving consistency and enhancing the surface indications of downhole progress during the junction construction were met, thereby increasing the reliability and overall confidence in this technology. The multilateral systems were run in both new and existing wells, and the operator's objectives were met in each case. The successful implementation of this technology has expanded the use of multilateral completions in the Middle East.
This paper provides an overview of the evolution of advanced multilateral technology well-construction techniques and describes how overcoming challenges became a catalyst for innovation. This technology is now routinely applied to increase reservoir exposure and meet development and production goals.
Application of MWD Survey Corrections in Real Time
Authors: Marr Tyler , Schiermeier Pete 
Published: January 2016

Abstract
The application of measurement-while-drilling (MWD) survey corrections is a critical step to ensure that the required service level is met and that definitive surveys are accurate, secure, and delivered in real time. Over the complex life of a directional survey, it is critical that these corrections are applied in the correct sequence and that the final survey is delivered to the directional driller within a time frame that avoids delays for critical decisions.
Past methods of supplying survey corrections to the wellsite vary greatly in terms of both methodology and speed. Techniques that are commonly deployed include file transfer, email, and online file sharing. Although there are benefits of using these methods, each falls short in one or more areas; these areas can include speed, security, or accuracy. Because of the need for one or more specialists to analyze the data, large amounts of data are often imported and exported. This process is not only laborious, but can also introduce opportunities for error.
To overcome these challenges associated with supplying the survey corrections to the wellsite, a new survey correction platform and associated workflows were developed. The new platform takes advantage of modern advances in software development and infrastructure along with the lessons learned from previous generations of software. The use of the new survey correction platform and application enables a database-to-database solution that streamlines multiple areas of survey handling. These areas include the application of in-field referencing (IFR1), interpolated in-field referencing (IFR2), multi-station analysis (MSA), and MWD survey quality control. The most significant improvement, however, is the removal of manual survey entry and extraction from the survey processing database and field MWD database.
This paper outlines advancements made at multiple steps in the lifespan of a directional survey to increase the speed, reliability, and accuracy associated with supplying survey corrections to the wellsite. It also describes the applications of this process in a real-time environment.
MWCNT for Enhancing Mechanical Properties of Oil Well Cement for HPHT Applications
Authors: Khan W. A. , Rahman M. K. , Mahmoud M. A. , Sarmah P. 
Published: January 2016

Abstract
Growing demand to drill High Pressure High Temperature (HPHT) wells requires improved technology to overcome the HPHT challenges. Oil well cementing has a greater impact on the production potential of a well as compared to other operational actions. A successful cementing job is dependent on how quickly and efficiently cement achieves strength. Achieving desired mechanical properties of cement becomes harder and complex at HPHT conditions.
A wide variety of admixtures are commonly mixed with the oil well cement slurries to deal with the extensive range of pressure and temperature to acquire enhanced mechanical properties depending on the combination of admixture used. Carbon Nanotubes (CNT), declared as "Miracle Material", have been one of the most recent admixtures being used to achieve the desired mechanical properties of cement slurries. This paper highlights the study carried out to examine the mechanical properties comprising compressive strength of oil well cement slurries integrating chemical additives and CNT under high pressure high temperature (HPHT) conditions.
Three different percentages of functionalized multi-walled CNT's (MWCNT), at 0.1%, 0.25% and 0.5% bwoc, were mixed with Type-G oil well cement together with other additives used in HPHT applications. Compressive strength investigations (Destructive and UCA) were carried out on those slurries. SEM investigations were also conducted on selected MWCNT mixes. The study indicated that incorporation of MWCNT, at a very small percentage, in cement slurries resulted in a significant increase in the compressive strength values.
Case Study for Real Time Stick/Slip Mitigation to Improve Drilling Performance
Authors: Vogel Stephen K. , Creegan Andrew P. 
Published: January 2016

Abstract
Stick-slip oscillation is a recognized and documented drilling dysfunction that reduces drilling performance and increase well costs. Stick-slip is a drilling phenomenon associated with the use of fixed cutter bits that use a shear cutting mode and exacerbated by non-optimal weight on bit (WOB) and rotations per minute (RPM) settings. The bit speed can vary drastically from fully stopped to twice the RPM setting (0-200%) during periods of stick-slip oscillation. This case study details the benefits of an automated stick-slip identification and mitigation system and service using surface measurements for an Operator drilling in a geographically diverse area. The stick-slip mitigation service was successfully used to increase ROP, reduce the drilling time, and improve bit performance.
Traditional methods of reducing stick-slip include varying the WOB and RPM set points by the driller, which requires the driller to identify the stick-slip occurrences and manually manipulate both settings. Inefficiencies are inherent to this process as the driller is unable to accurately quantify the magnitude of the stick-slip period and set the optimal drilling parameters. Additional inefficiencies are associated with this method relative to how quickly the driller reacts to the onset of stick-slip and the frequency these changes are made while drilling.
An automated system was added to identify and quantify the stick-slip severity and to manipulate the top drive RPM speed to mitigate the stick-slip in real time. A real-time service complimented the automated system through the delivery of specialized training, remote settings maintenance, performance monitoring, and streamlining knowledge transfer.
A Case Study:Impact of Completion on Multi-Stage Fracturing Performance of a Horizontal Well in a Thin-Interbed Reservoir, Tarim Basin, China
Authors: Liu Huifeng , Yang Xiangtong , Yuan Xuefang , Liu Jiangyu , Chen Zhaowei , Tian Shouceng 
Published: January 2016

Abstract
Silurian reservoir in Ta-zhong Oilfield, western china, is a thin-interbed, low-permeability reservoir with buried depth from 4000 to 4500m. The sand distribution in this reservoir is heterogeneous both vertically and horizontally. Horizontal well with segregated completion and multi-stage fracturing is taken as an efficient technology to exploit this kind of reservoir. However, the existence of many mudstone interlayers makes the design of completion and fracturing difficult.
This paper will provide a case study on design and operation of multi-stage fracturing of a horizontal well in Ta-zhong Silurian reservoir. This well was fractured twice using two different technologies, firstly hydraulic jetting fracturing and then packer-segregated fracturing. Both the two operations encountered abnormal pumping pressure and sand out. The design and implementation process of both technologies will be introduced in this paper, and the challenges facing the completion and fracturing design will be highlighted. The causes to the abnormal pumping pressure and sand out will be analyzed comprehensively through numerical modeling and comparative calculation.
The results show that the defective completion design is the main cause of the failures of the two operations. For hydraulic jetting fracturing, the ill-considered jetting points and improper jetting space cause the difficulties for fracture initiation and propagation and therefore the sand out. For packer-segregated fracturing, the inappropriate perforating interval leads to simultaneous initiation of multiple fractures in each stage. These fractures interfere with each other during propagation, leading to great near-wellbore pressure loss and width reduction for each fracture, therefore the abnormal high pumping pressure and sand out were encountered. The acting mechanism of induced stress and fracture interaction and reorientation are illuminated in this paper. A bunch of ways to avoid these problems during multi-stage fracturing of a thin-interbed sandstone reservoir is also proposed from both designing aspect and operating aspect.
Nowadays, horizontal well with multi-stage fracturing is a common-used technique in tight thin-interbed formations. However, the design of a segregated completion and multi-stage fracturing is still a nodus for such formations. This paper gives a detailed introduction of a failure case and comprehensively analyzes the causes of these failures from geology to engineering, therefore gives a lesson for avoiding this kind of failures and optimizing a staged fracturing design in tight thin-interbed reservoirs.
Modern Jack-up Design Solutions for Mature Markets
Authors: Baan Rutger , Remco van der 
Published: January 2016

Abstract
In mature oil and gas fields particularly in the Middle East, India, Gulf of Mexico, West Africa and Asia, a specific footprint is required due to earlier campaigns. The key reference is the LeTourneau-116 design. With its specific footprint, it is the most widely used jack-up design in these regions. The CJ43 drilling jack-up, based on its successful predecessors, is the modern replacement and sets a new standard for jack-up drilling rigs used in mature oil and gas fields.
Drilling technology has evolved over the years. The focus has been on drilling equipment reliability, mechanization, partial automation and advanced well control. However, when reviewing the overall jack-up technology – excluding the drilling related equipment – a large part of what has been ordered recently resembles the same design philosophy of thirty to forty years ago. No significant changes on the jack-up design to improve its capabilities in terms of uptime, efficiency, material handling, maintenance, redundancy of critical systems and elements to improve human life on board.
But, when applying innovative technology, a more modern jack-up design such as the CJ43 can be shaped which delivers operational benefits to owners and operators in terms of lower OPEX and higher operational flexibility.