bluuebunny/crossref_metadata_2025_split huggingface dataset:
Bearing Wear Model for Roller Cone Bits
Authors: Hareland G. , Wu A. , James J. 
Published: October 2009

Abstract
Bearing failure of roller cone bits may result in a time-consuming fishing job, and lead to significant increase in drilling costs. The bearing failure generally comes from over wear of frictional pairs (surfaces between the journal and bearing of the cone). A bearing wear model has been developed to predict the wear status through multi-variable nonlinear regression analysis based on field data. The wear model considers four variables including weight on bit (WOB), revolution per minute (RPM), diameter of bit and hours drilled as a function of IADC bit bearing wear. Some abnormal bit run field reported bearing failures were removed in order to acquire the best regression of the field data. A bearing failure probability model is then introduced to predict the survival probability of the bit, the parameter of which is obtained through statistics of more than 500 bit runs.
The wear status, including instantaneous and cumulative wear, for different roller cone bits and different wells drilled in Western Canada is simulated respectively with the wear model.
A good correlation coefficient was obtained for different IADC bit types including both milled tooth and insert roller cone bits. The cumulative wear values from the model match close those from the field.
The wear model and the failure probability model can help drilling engineers evaluate bearing wear status during real time drilling operations through simulation, and make a decision on when to pull out the bit in time to avoid bearing failures and the possibly lost cones. Better bearing wear predictability will result in better drilling results and effect the total drilling cost.
Hydraulic Workover Unit is Drilling Shallow Offshore Gas Wells
Authors: Huesecken T. , Al Balushi H. A. 
Published: October 2009

Abstract
In early 2007 the operator was looking at options to drill additional gas wells. A hydraulic workover unit (HWU) had been used to previously sidetrack a number of wells offshore Dubai and a decision was taken to investigate this option further.
The goal was to drill the same well profile as a jack-up did on a previous campaign but at lower costs.
The work scope for the HWU campaign would include the retrieval of the existing completion, setting a whipstock, milling through two casing strings, drilling 8-1/2″ build-up section into the top of the reservoir, lining off with a 7″ liner, horizontally drilling the reservoir section in 6-1/8″ hole and finally completing with a 5-1/2″ completion. Due to time constraints all planning including contracting was performed in a two months window prior spud.
The operator selected three mother wells on a platform connected to the main field facilities, which included accommodation and logistical support.
With the reservoir being at around 3,300 feet TVD, a total of 4,285 feet were drilled in the three sidetrack wells. A regional first achieved is the drilling of 1,500 ft of 8-1/2″ and running of a 7″ liner with a HWU.
This paper will describe the planning, challenges, limitations, learnings from the campaign and the resulting innovations for future HWU projects, which includes the concept of ‘using self-elevating-workover-platform’ or ‘lift boat’ and purpose built, minimized footprint tank farms for standalone production platforms.
Solving Bore Hole Instability Problem of Underbalanced Drilling in Several Wells of an Iranian Oil Field
Authors: Bakhtiarizadeh Samad , Asadi Iman , Sadat Ali Yousefi 
Published: October 2009

Abstract
Under-Balanced Drilling (UBD) practice is an optimized drilling approach, aiding in more reservoir recovery, too. Considering long-period production from some of Iranian oilfields and their correspondent pressure decline, it seems more necessary to replace UBD with the Conventional Overbalanced Drilling (OBD). Utilizing UBD in one of Iranian low-pressure fields named here "S" field however improves Productivity Index (PI) of the wells drilled besides minimizing drilling challenges and increasing Rate-of-Penetration (ROP) but extremely increasing risk of wellbore instability. This paper presents wellbore stability assessment of three layers of Mishrif reservoir using common reservoir data, correlated in-situ stress regimes and rock mechanics parameters based on its lithology & regional data. By employing a computer modeling software, stability limitations of the borehole as optimized Equivalent Circulating Density (ECD) were specified through the Finite Difference Method (FDM) and Mohr-Coulomb criteria. By applying the results of this modeling, about 6000 ft of 5 wells in "S" field was drilled with good hole condition and negligible instability problems while mentioned benefits of UBD was preserved.
Case Study Using Hollow Glass Microspheres to Reduce the Density of Drilling Fluids in the Mumbai High, India and Subsequent Field Trial at GTI Catoosa Test Facility
Authors: Thyagaraju B. A. , Pratap K. Krishna , Pangtey K. S. , Trivedi Y. N. , Garg S. , Georges Gilles P. , Goff David A. , Devadass Melvin 
Published: October 2009

Abstract
The practice of using hollow glass microspheres to reduce the density of drilling fluids and cement slurries has become more prevalent in recent years due to increasing demand for "hydrostatic pressure management" with high performance low density cement and fluids. The use of hollow glass microspheres in drilling fluids presents unique benefits and challenges. This paper addresses a case study of a recent offshore managed pressure drilling project which ONGC conducted using glass bubbles in the Mumbai High. The study demonstrated the value of bubbles as a mud density reducer in a challenging drilling environment and also showed the importance of specific operational parameters in the project's success. A subsequent field study was conducted to quantify, under controlled conditions, the impact of these parameters on the bubbles performance while drilling. Mud density and mud solids content were monitored as flow rate (FR), weight on bit (WOB) and drill string rotation speed (RPM) were changed. The tests were conducted at the GTI Catoosa Test Facility rig under the co-direction of 3M and Newpark Drilling Fluids. A new generation of glass bubble, with a density of 0.42 g/cm3, an isostatic compressive strength of 8000 psi, and a smaller particle size was selected for this work. Solids control equipment settings were shown to be one of the key components to success in this experiment. A comprehensive mud sample collection plan enabled the monitoring of mud density, solids content and rheology parameters versus time. This study confirmed that glass bubbles can be used to satisfactorily maintain the mud density within an acceptable range in an economical way. The glass bubbles, specifically the new generation with a higher strength to density ratio, were shown to be an efficient, convenient, and sustainable way to reduce the density of a drilling fluid.
New PDC Technologies Utilized to Improve Performance in Deep Khuff Gas Wells for Offshore Operator in Abu Dhab
Authors: Mohamed Ehab , Alvarez Octavio , Gomaa Gamal Galal 
Published: October 2009

Abstract
The process of drilling the 12 ¼-in. section in the deep Khuff field offshore Abu Dhabi is challenging because of an intricate geological sequence. This sequence consists of carbonates (limestone and dolomite) and anhydrite that are interbedded with shale and sandstone.
In the past, the operator, ADMA, has attempted to efficiently drill the section by using roller cone tungsten carbide (TCI) and polycrystalline compact (PDC) technology. PDC bits yielded a better performance in terms of penetration rate and durability in comparison to the TCI bits. However, because several PDC bits were required to drill the section, the amount of time required for drilling and tripping at a relatively deep interval increased. The increased time exposes the well to many risks that could occur as a result of tripping in a long open hole interval. To reduce the time and risk factors, additional analyses were performed that led to the creation of an optimum PDC design and established new benchmarks in the field at the first trial.
The objective of the study was to minimize the number of bit trips by enhancing the PDC bit performance and bit durability to drill longer intervals with a higher rate of penetration (ROP). Meeting this objective required a new PDC technology in conjunction with optimized motor drive. To address the challenge, ADMA, the bit vendor, and other service companies worked together to seek an optimized solution to drill this section efficiently.
This paper reviews the findings of the detailed study in drilling the 12 ¼-in. section in typical deep Khuff wells. The study shows that PDC damage from encountering harder stringers was the primary impediment to achieving better performance. The challenge was overcome by implementing a new cutter technology and drilling simulation software to optimize the cutting structure design.
The improvement that occurred in Umm Al-Shaif field is demonstrated by comparing the performance of the most recent well, in which the new technologies have been implemented, to the performance of earlier wells to illustrate the significant savings in time and eventual drilling cost.
Case Study of Performance Improvements Offshore Drilling Carbonates Using Specially Designed PDC Bits
Authors: Al Ramahi Basil , Diab Emad 
Published: October 2009

Abstract
In the 12 ¼-in. section of an Abu Dhabi offshore company's wells, complex directional well profiles and varied formation characteristics create a challenging drilling environment. Outcomes of the drilling efforts in this environment include non-productive time (NPT) as a result of tripping, as well as lower rates of penetration (ROP) as a result of vibration. Conventional positive displacement motors (PDM) were typically used in this offshore application. Polycrystalline diamond compact (PDC) bits were run with the PDMs because of their longer life and increased ROP through the varied formations; the particular designs used had provided good steerability in previous applications. The conventional PDM-PDC system, however, often creates high vibrations that reduce overall performance. In addition, the section has always required two runs so that the bent housing could be changed in the second run, which resulted in lost time for tripping.
To address these issues, a new system was designed that provides significant advantages over conventional steerable assemblies. This system includes a specially designed long-gauge PDC bit run on a point-the-bit rotary steerable tool, both of which were designed and modeled together. The advantages observed using this system in the field includes improved hole quality and increased ROP, as well as reduced hole spiraling and tortuosity, reduced vibration, better steerability and hole cleaning, increased bit life, and reduced tripping time.
This paper provides three case studies of the use of this system in which one of Abu Dhabi offshore operators achieved the objective of drilling the 12 ¼-in. interval, which averaged more than 2,500 ft, in a single run, and optimized the ROP without compromising hole quality or cleaning efficiency. A summary of results indicates the effectiveness of design improvements, with the new bits achieving the highest single run ROP in history for this particular operator and longest footage achieved in a single run.
These benefits are expected to have considerable implications on future drilling operations.
Well Casing Integrity Excellence: A Case History of Evaluating Casing Integrity Using Modern Imaging and Corrosion Tool Logs in Ghawar Field in Saudi Aramco
Authors: Al-Shuwaikhat Hisham I. , Al-Driweesh Saad M. , Al-Zain Ahmed K. , Al-BuHassan Shaker A. , El-Zefzafy Ibrahim M. , Al-Tammar Hasan I. 
Published: October 2009

Abstract
Ensuring good casing integrity is very important to prolong well life. Cement quality is a major element for ensuring casing integrity. Well casing integrity excellence is the key aspect that makes a well in good condition and keeps the well completion suitable to produce crude oil from an oil producer or inject water in an injector.
Recently, advances in cement and well completion practices have significantly improved the quality of wells and extended their operating life. Also, the installation of a Cathodic Protection System (CPS) on every well, and tubing packer completion in some wells, prevented external corrosion and consequently casing failure. However, casing integrity problems were discovered in three isolated cases. This paper will discuss issues related to three wells where casing leaks or behind casing channeling were detected across a high-pressure zone located above the main reservoir. A team, consisting of professionals from various engineering departments, was formed to explore remedial options and techniques, as well as employ tools and new technologies that assess well casing integrity excellence. Implementing the recommendations and findings of this team have improved well casing integrity.
As well casing is an important asset to ensure well safety, continuous operation and environmental protection; there is an ever increasing need for tools that verify wells with suspect casing integrity problems. These tools are the Cathodic Protection Evaluation Tool (CPET), Ultrasonic Inspection Tool (USIT), Ultrasonic Corrosion Inspection Tool (UCIT) and the Electro-Magnetic Imaging Tool (EMIT). The EMIT provides real images of the multiple casing strings.
CPET, USIT, UCIT and EMIT were selected and run on three wells Well-A10, Well-A20 (oil producers) and Well-B1 (water injector) with suspected casing integrity problems. These logs detected and imaged the corroded, scaled and cracked intervals before performing remedial actions to return the wells to an operating status by renovating casing integrity.
World-Class Organizations/World Class Safety—How the Best Oil and Gas Companies Achieve and Sustain Outstanding Safety Performance
Authors: Matthews Teg 
Published: October 2009

Abstract
Oil and gas organisations face a number of EHS challenges in today's business landscape. Fatality prevention, the changing role of safety professionals, managing behavioural reliability among increasingly globalization operations, and maintaining a focus on process and personal safety are some of the most common issues we hear about. The key to responding to these challenges is to approach safety performance systemtically. The key to creating world-class safety is understanding safety and its context with the organization.
Implementation of Real-Time Tubing Inspection in PDO's South Oman Fields Results in Reduced Costs and HSE Risks
Authors: Sharma Anurag , Al Ruqaishi Mohammed , Al Asmy Moghrob , Mahrooqi Salim , Shibu John 
Published: October 2009

Abstract
Real time tubing inspection during hoist interventions was implemented in South Oman in late 2007. It utilizes the principle of electromagnetic pipe inspection. The technique is similar to conventional yard based electro magnetic tubing inspection, the difference being that yard inspection is performed on the ground whereas real time tubing inspection is performed on the well. It provides scientific assessment of tubing condition in real time.
The purpose was to provide a quick, reliable and an objective method of evaluating the tubing condition. The past practice of visual inspection of pulled tubing by hoist crew often resulted in misjudgment of tubing condition. This led to either re-running flawed tubing or wholesale rejection of good tubing. The obvious consequences were premature well failures due to loss of completion integrity or unnecessary tubing transportation costs and associated HSE risks. It also strained the conventional system of yard inspection, which was unable to cope up with the huge work volume as a consequence of excessive tubing rejection by the hoists.
The technique was utilized during 130 hoist interventions in 2008 across the fields of South Oman. This represents approximately 10% of total hoist interventions in South Oman wells annually. Immediate gains were realized in terms of reduction in tubing consumption volume, reduction in yard inspection volume, prevention of pre-mature well failures due to loss of tubing integrity, reduction in transportation costs and HSE risks.
Above all it helped in collating tubing failure data in a systematic manner, which was not possible with centralized yard inspection as keeping track of rejected joints on well wise basis was not possible. The database allows segregation and analysis of tubing failure data based on field, age & failure depth basis. With sufficient data availability, it has potential to enable better understanding of pipe failure mechanisms and allow implementation of prevention steps.
Real-Time 3D Modeling and Geosteering in a Heterogeneous Carbonate Reservoir
Authors: Al-Jaberi Salem , Dama Saeed , Al-Rayaisah Jasim , Said Saad A. H. , Lakhlifi Assia 
Published: October 2009

Abstract
This paper presents a workflow method that has been designed to improve well placement accuracy, enhance decision-making and decrease cycle time through rapid geologic model updates. This workflow was applied successfully to a horizontal well located in a giant oil and gas field offshore Abu Dhabi, United Arab Emirates.
This workflow involves geomodeling, well design, synthetic log creation, real-time geosteering, and updating the geological model while drilling.
Drilling a horizontal well in this environment presents several challenges due to complex geology, heterogenous carbonate reservoir and layer thickness. In addition, there are many uncertainties reflected in the 3D geological model and while drilling.
The primary aim of this workflow is to minimize drilling time with maximum efficiency and optimum well placement. This is achieved through designing the well in the same model centric environment where the geological model was built allowing access to all available data and information for accurate well placement. Secondly, to reduce non-visible loss time and take faster decisions using real-time information. Thirdly, to evaluate associated geological uncertainties in 3D models. Finally, the use of the latest technology available in the market to meet field development requirements.
Great value was added when a 3D model was generated and updated in real time, in addition to the forward-modeling technique that assists the operation geologist to geosteer within the thin layer of the heterogeneous carbonate reservoir in order to achieve the optimum well placement in the minimum amount of time.
Successful Introduction of Next Generation - Reactive Liner Perforating Technology in Pakistan
Authors: Qayyum T. , Khattak K. , Qureshi I. , Aizad T. , Hameed S. , Akhtar S. 
Published: October 2009

Abstract
Maximizing productivity from every well has always been the ultimate objective of industry experts. Connecting the wellbore with the reservoir is a key element towards meeting this challenge. In the case of perforated completions, techniques like static and dynamic underbalance are used to try and remove the crushed zone caused by the perforation process. In marginal reservoirs, poor connectivity can be the difference between a commercial discovery and a dry well.
Reactive liner perforation technology is a new technique which removes the crushed zone using a highly exothermic reaction, providing a step-change improvement in perforation geometry and performance. The reaction breaks up and expels debris to leave a clean, undamaged tunnel, even in variable or low quality rock. This process is independent of lithology and wellbore conditions. This next generation perforating technique has recently been launched in Pakistan with exceptional results.
This paper describes these successes in greater detail. When compared with offset wells with identical parameters, perforated using relatively new techniques, the superiority of the reactive technique was proven. Significant rate improvements and very low (negative in some cases) values of total skin were measured. When applied prior to hydraulic fracturing, significantly reduced initiation pressures and lower horsepower requirement added significant value through optimized fracturing treatment, reduced risk of screen-out, and reduced expenditure.
Results in-hand prove the superiority of this technology in improving well connectivity, particularly in tight gas reservoirs. The independency from rock properties and wellbore conditions are truly added advantages of the reactive liner technology. This is a technically viable and cost efficient option for ensuring operators achieves their production objectives.
Dynamic Test Evaluates the Effectiveness of Self-Healing Cement Systems in the Downhole Environment
Authors: Darbe Robert , Pewitt Keith , Karcher Jeffery 
Published: October 2009

Abstract
Cement sheath is a critical piece when constructing a well for long-term competence. The ability of the cement to block annular fluid flow has both economical and environmental implications. Examples of uncontrolled movement of formation fluids through a leaking cement sheath include unwanted water migrating to the perforations, hydrocarbons escaping to a lower-pressure reservoir, and hydrocarbon-based fluids flowing to environmentally sensitive water zones or to the surface.
Throughout the years, several advances in cement technology have been introduced to help ensure zonal isolation is maintained throughout the operational life of the well. Such advances include the design of cement with mechanical modifiers tailored for a specific well type and anticipated loads on the cement. Today, a new cement system is being introduced. This system aims to help assure zonal isolation, even if the cement is loaded beyond its capacity resulting in cracks, micro-annuli, or pathways for wellbore fluids to migrate. The new system works on the premise that the migrating fluids react with the damaged cement system resulting in the cement automatically sealing the cracks to help prevent further fluid migration.
The purpose of this paper is to illustrate simple evaluation techniques that allow for quantification of auto-sealing cements in a simulated static or dynamic-downhole environment. Experimental apparatus used consist of a standard annular ring mold used for expansion/shrinkage measurements as well as a cement fluid-loss test apparatus with a specialized insert designed for continuous flow past the cement test specimen. The capability of the cement system to react to the flowing fluid and ultimately reduce the flow is monitored. Results of various cement systems reacting with fluids under a range of simulated downhole conditions are presented.