bluuebunny/crossref_metadata_2025_split huggingface dataset:
BHA Modeling and Application of Bi-Center Bit with Unique Vibration Dampening Tool to Improve Hole Opening Performance in Offshore HTHP Exploratory Well in Krishna Godavari Basin, India
Authors: Lobo Monali , Agarwal Chakshu , Sharma Deepak , Lang Clifford , Brickell Nigel , Pathak Mandar , Chakraborty Biswajit 
Published: August 2016

Abstract
In a technically challenging & high cost environment such as HTHP wells, careful selection and adoption of advanced technologies for the successful completion of the well is paramount. As per the original well design of the subject well, it was planned to drill with a bit & under reamer which was actuated by a ball drop mechanism. This led to the restriction of placing the under reamer close to the bit as MWD/LWD had limited pass through & hence the under reamer had to be run above the tools leaving approximately 25-30 m of rat hole un-opened along with inability to retrieve radioactive source in an event the BHA was lost in hole. This required two separate BHA runs to open the rat hole in order to place the casing shoe as deep as possible. The additional hole opening trip would have resulted in extra time and hence additional cost, moreover it was prudent in HTHP well to place the casing shoe exactly at right depth to achieve well objectives. Hence, use of Bi-center bit to simultaneously drill & under ream without any pass through restriction was evaluated.
Several critical issues, related to application and BHA design, were faced by the Well Engineering team. Reaming while Drilling (RWD) with bi-center bits has always been challenging in terms of vibration-related inefficiencies. Due to the asymmetrical geometry of the bit, imbalances in force and mass have been responsible for the vibration related problems. Secondly, due to the minimum pass through requirements, these assemblies are virtually always run with under-gauged stabilizers as it allows a certain degree of lateral movement within the constraints of the enlarged hole.
All of these issues could have caused the pilot-bit drilling an over-gauged hole along its axis which results in the bit drilling off center giving an overall under-gauged hole as the pilot of the bit is not centralizing the reamer. A unique eccentric vibration dampening tool (ideally located in the string) was used to mitigate the drillstring vibration & bit whirl. This paper describes the well specific BHA design & placement of the vibration dampening tool used to improve hole opening performance. A total of 4 bi-center bit runs over three hole sections & different sizes i.e.12.¼″× 14.¾″, 10.3/8″ × 12.¼″ & 5.7/8″ × 6.¾″ are also discussed in the paper.
Unusual problems were encountered while drilling shoe track & landing collar for liners in 10.3/8″ × 12.¼″ and 5.7/8″ × 6.¾″ hole section. Lessons learnt, recommendations & contingencies to be planned for successful application of bi-center bit are discussed.
Dare to Change: An Approach to Implement Enterprise Level of Real Time Well Solution for Collaborative Working Environment
Authors: Mohamad Azlan , Yusoff Noorazmah , Aris Sazalee , Bismo Dismas , Regan Matt 
Published: August 2016

Abstract
Petroliam Nasional Berhad (PETRONAS) has long realized the importance of real-time drilling data. The company utilizes the technology to monitor rig site operations. An in-house real-time surveillance-monitoring centre, called the Smart Drilling Optimization Monitoring Centre (Smart DOMC), was established in 2010 within the company’s headquarters. The centre’s real-time environment was fully managed by a single service-company: data aggregated on the rig site was kept in the service company’s server, in the service company’s proprietary format, and only accessible to the drilling engineering team via the service company’s web-based application. This approach forced PETRONAS to be wholly reliant on the service-company’s own technical application and service, with no ownership or control of (the company’s) real-time data architectures, and only nominal visibility of dataflow and management.
In line with the company’s Integrated Operations (IO) initiative and driven by the company’s increasing amount of operations, the availability of a standardized independent real-time data management infrastructure became a critical component in order to facilitate seamless flow of real-time technical data transparently throughout the organization, particularly within the Smart DOMC and the operation team’s disbursed workplaces.
Thus, in 2014, the Real Time Well Solution was implemented. The new solution is an enterprise real-time data management solution with web-based delivery, which leverages the Wellsite Information Transfer Standard Markup Language (WITSML) as the standard format for the exchange of data. It is a secure infrastructure wholly resident within PETRONAS IT environment, which consists of clustered database servers with load balancing and failover backup servers ensuring high-availability, and capable of facilitating the flow of real-time drilling data from multiple rig sites, for the company’s domestic and international operations. It offers advanced customizable web-based features for domain experts to view real-time drilling data, through the standard web-browser and mobile devices.
This paper will describe PETRONAS Real Time Well Solution and the three main challenges faced in implementing the new solution. Four case histories detailing the utilization of the WITSML infrastructure during critical well construction operations will also be reviewed. With the new System, PETRONAS is able to implement industry-accepted and non-proprietary standard in accessing real-time information, take immediate ownership and better control of data aggregated on rig sites, and integrate real-time information with existing corporate third-party applications.
Risk Impact Analysis Maximises Safety, Efficiency & Drilling Cost Effectiveness: Vital in Today's Oil Price Era
Authors: Gibson Michael 
Published: August 2016

Abstract
With most of the world’s ‘easy play’ oil and gas fields having been found and now being produced, Operators have little choice in many cases but to drill in more and more difficult conditions in order to produce the oil and gas which the world demands. This increase in difficulty is further compounded by a very low oil price these past 18 months (2014 – 2016) which means that every effort must be made to reduce not only the cost of drilling itself but also to ensure that no untoward event occurs such as a blowout.
This paper describes a very significant drilling success story completed in Europe (UK North Sea) which has direct applicability to South East Asian Operators & Drilling Contractors. By carrying-out effective Risk Analysis this difficult well was drilled successfully & economically.
A Coupled Model for Predicting Flowing Temperature and Pressure Distribution in Drilling Ultra-Short Radius Radial Wells
Authors: Li Xiaojiang , Li Gensheng , Wang Haizhu , Lu Peiqing , Tian Shouceng , Yang Ruiyue , Wang Meng 
Published: August 2016

Abstract
Ultra-short radius radial well (URRW) drilling is one of the crucial ways to improve the recovery efficiency and rejuvenate mature oilfields. However, due to the lagging development in drilling theory and related facilities, the technology is still encountering various bottlenecks such as high pressure loss, low rock breaking efficiency and low penetration rate, etc. Supercritical carbon dioxide (SC-CO2) jet has a low specific energy and high rock breaking efficiency when is used in drilling. Besides, the hydraulic power can be lowered due to its lower threshold pressure and viscosity compared with water. Thus it can be used in URRW underbalanced drilling and is expected to solve problems above. But properties of CO2, such as density and viscosity, are very sensitive to temperature and pressure, which makes prediction of flowing temperature and pressure distribution in wellbore very complicated.
In this paper, a theoretical temperature and pressure prediction model was developed based on conservation laws of mass, momentum and energy balance. The state-of-the-art equation of state for carbon dioxide proposed by Span and Wagner (1996) was adopted to calculate the in-situ density and isobaric specific heat for a certain segment of wellbore. Besides, the model of Vesovic et al. (1990) was adopted to calculate the viscosity and thermal conductivity of SC-CO2. Temperature and pressure were coupled during calculation by using an iteration scheme.
The results indicate that supercritical state of carbon dioxide, that is SC-CO2, can be reached at a relatively shallow depth. The temperature and pressure distributions of URRW drilling are quite different from those of conventional drilling. And temperature and pressure change dramatically due to the special structure of drillstring and narrow radial laterals. Finally, parameter analysis was conducted by calculating the influences of circulation rate, inlet fluid temperature, casing pressure and circulation time, well depth and borehole geometry on temperature and pressure of drilling fluid.
The novelty of this research is that the flowing temperature and pressure distribution in wellbore during drilling a URRW is studied accurately for the first time. Besides, the feasibility of drilling a URRW with SC-CO2 is validated from the aspect of temperature and pressure. This calculation model can be used to help design wellbore structure and operation parameters.
New Concentric Dual Diameter Fixed Cutter Technology Bit Drills 100% Faster and Saves Operator Drilling Time Through Challenging Abrasive Sandstone in One of the Largest Reservoirs in the Middle East
Authors: Al-Ajmi Khaled , Al-Hamadi Ebrahim , Baqer Yousef , Al-Suliman Mishari , Al-Mutairi Abdulwahab , Singh Anilkumar , Al-Sarraf Abdullah Baqer , Al-Sairafi Fatma Abdulatif , Fayed Moustafa , Khalil Karim , Khalil Ahmed 
Published: August 2016

Abstract
This paper will discuss the deployment of the concentric dual diameter fixed cutter bit technology which was introduced in January 2015. The bit was deployed and tested four times in a vertical application and S-shape wells in Burgan Field, South of Kuwait and achieved the fastest penetration rate in the application.
The concentric dual diameter bit is composed of a smaller pilot and a larger reamer section, where the reamer section dictates the final drill size. Conventional fixed cutter bits take very little advantage of stress relieving the rock, as it only affects the borehole wall. Concentric dual diameter technology bits are able to initially drill with a leading smaller pilot section efficiently to relieve the stress of the rocks. Subsequently, the reamer section removes the stress relieved rock with lower mechanical specific energy compared to regular fixed cutter bits, giving it the advantage to generate higher penetration rates. Another advantage of the concentric dual diameter technology bits is the stability of the bit, since two gauge sections are available to be in constant contact with the borehole while drilling.
The first 12 ¼ in. concentric dual diameter technology bit in conjunction with a packed rotary BHA was tested in a vertical application in the Burgan Field, South of Kuwait. The bit was able to deliver improved performance by drilling two wells from shoe-to-shoe to section TD of 1372 ft with an ROP of 152.4 ft/hr where the lithology consisted of shale and sandstone.
The performance capability was confirmed when the second bit drilled two wells shoe-to-shoe to sections to a TD of 2263 ft with ROP of 161.6 ft/hr. and achieved top record runs in south Kuwait for vertical applications and S-shape wells and consisted of similar lithology of shale and sandstone.
The 12 ¼ in. concentric dual diameter was able to surpass the average rate of penetration for the same application in the Burgan Field by 100% saving the operator drilling time and making the concentric dual diameter bit design the top performing drill bit in the field.
Implementation of an Engineered, Fiber-Based Spacer Solution for Improved Mud Removal -Thailand Case History
Authors: Olutimehin K. , Taoutaou S. , Pasteris M. , Wuttikamonchai P. , Vargas Bermea J. A. , Ashraf S. , Kaotun K. K , Phonpuntin V. 
Published: August 2016

Abstract
The optimization of spacer fluid properties is very critical for achieving good mud removal in primary cementing. A new, laminar spacer fluid formulation using surfactant/solvents based on engineered-chemistry approach and incorporating high-temperature mud removal (HTMR) fibers was introduced to improve cementing placement results for a major operator in the Gulf of Thailand. The successful implementation of this technology has been accomplished in the field through the application of the Design-Execution-Evaluation workflow best practices.
The team carried out extensive laboratory testing to validate placement efficiency at conditions representative of high-temperature production tubing jobs. A detailed analysis was carried out to compare performance (with fibers) with the legacy system (without fibers) from the same field. The testing results showed significant improvement in the stability of the new system at high temperature and a much higher cleaning efficiency attained using a proprietary test method. Repeat tests were conducted in different laboratories to ensure reliability and robustness against minor changes in downhole temperature.
In order to achieve complete tubing annulus integrity the design workflow required mandatory mitigations for 4 main phenomena (i.e. microannulus, channeling, gas migration and set cement delamination) which, based on detailed analysis of actual data from treated wells, were the main risk factors that could cause integrity issues. This thesis is consistent with indepth analysis of previous wells and therefore supported the introduction of a more technically robust spacer in the production string cementation fluids train to eliminate the risk of channeling.
Prior to actual field implementation of the system on the first well, a dummy "yard" test was carried out onshore to validate mixability and pumpability under simulated field conditions. For operation integrity, a pre-job quality checklist system plus technical co-ordination was implemented between operator fluids team, service company technical engineers and rig-based personnel - this included use of standardized peer review, risk assessments, materials preparation & logistics workflows, plus the application of ISO-certified quality assurance procedures. Three case histories from numerous successful jobs will be presented in this paper.
Cementing Across 30 Varying Pressure Zones: A Case History of Overcoming Engineering Challenges
Authors: Saeed Y. , El-Sayed I. Fouad 
Published: August 2016

Abstract
After drilling a 3,200-m exploration well, an operator in the United Arab Emirates faced a considerable cementing challenge: 30 producing reservoirs with multiple different pressure properties. For example, several injector wells surround the new well, which created a highpressure zone with an equivalent pore pressure of 11.97 ppg. A nearby zone, however, had an overbalance of 2,448 psi and a high potential for significant losses.
The pressure conditions left almost no room between equivalent circulating density and the fracture pressure, so the spacer and lead cement were designed with the same density as the mud. To ensure good hole-cleaning without a clear density hierarchy, engineers analyzed the well conditions using a novel fluid displacement software model to assess effective laminar flow, a functional alternative to turbulent flow when properly implemented. Furthermore, a specialized lost-circulation spacer was designed to mitigate expected losses while cementing. Finally, gastight, lightweight lead cement with high-performance microspheres was designed to cover the upper section of the well, followed by a heavy expandable cement to ensure zonal isolation. The cementing operation was pumped successfully, with cement returns to surface after successful displacement. A successful Shoe Bond Test followed after 96 hours, and drilling resumed.
This paper will describe the technical evaluation, risk assessment, and operational execution of the job, with details of the lost-circulation spacer, as well as the lightweight lead and expandable tail slurries. Modeling simulation of the ECD, centralization, and fluid displacement will also be shared.
Numerical Analysis of Bottomhole Velocity and Pressure Distributions of High Pressure High Temperature Hydrothermal Jet
Authors: Hu Xiaodong , Song Xianzhi , Li Gensheng , Shen Zhonghou , Cui Liu , Lv Zehao , Shi Yu , Peng Chi 
Published: August 2016

Abstract
Hydrothermal spallation drilling (HSD) is a new method, especially suitable for drilling hard brittle rocks. HSD is promising for drilling deep hard formations. Recent studies of HSD have mainly focused on the effect of non-uniform thermal stresses during rock-breaking processes, with a nozzle exit velocity of usually less than 20 m/s. Inspired by high-pressure water jet technology, a new technology is proposed for HSD in this study. The technology, named hydrothermal jet spallation drilling (HJSD), which refers to a high-speed jet with high temperature at the nozzle outlet, should be more efficient for rock-breaking because the rock breaks due to not only thermal spallation but also the impact force of the jet. In this paper, numerical simulation of the high pressure high temperature jet in HJSD (hereafter referred to as the hydrothermal jet) is performed to analyze the distributions of impact pressure and cross-flow velocity of the bottom-hole flow field. The influence of the inlet temperature and pressure on the flow field is also analyzed. In addition, sensitivity analysis is performed to determine which parameter is more influential on the impact pressure and drag force. The results show that compared with the conventional water jet, under conditions of the same nozzle structure and pressure difference, the hydrothermal jet can generate higher impact velocity, cross-flow velocity and impact pressure; however, its attenuation is less obvious. Impact pressure, cross-flow velocity and drag force increase with the inlet pressure. With increasing temperature, the impact pressure and drag force remain almost constant, whereas the cross-flow velocity increases. In terms of the impact effect, a higher pressure in the chamber is preferred.
Successful PMCD Application Significantly Improved Drilling Efficiency on Carbonate Drilling
Authors: Houng N. H. , Rubianto I. , Abuelaish A. R. , Abdullah Mohd Aimran 
Published: August 2016

Abstract
Two offset wells were drilled in a field in East Malaysia, the original well and a sidetrack from the original well. Both wells experienced total lost circulation and Pressurized Mud Cap Drilling (PMCD) was attempted, but was not successful. A total of 55 days were spent drilling both offset wells, without achieving the primary well objectives.
After a 4-year gap, a re-drill well was planned and a specialist PMCD service provider was approached to drill the well. The PMCD team worked closely with the Operator's drilling team through the early stages of planning including well design, completions, fluids, logistics, BHA design, mud pit arrangements and drilling procedures. The lessons learnt from the previous wells were analyzed and precautionary steps were taken to avoid similar mistakes in the planned re-drill well. Field proven PMCD operational procedures were provided and experienced field personnel were assigned for on-site execution.
The re-drill well hit total losses and was converted to PMCD after evaluating the characteristics of the well. The section was drilled to the planned Total Depth (TD) in one run, a section length of 430m. A Composite Bridge Plug (CBP) was stripped in hole and set in the previous casing to isolate the carbonate section. The 7″ liner was made up with a drill shoe and run in hole, and the CBP was drilled out. The well went back on losses after drilling the CBP and PMCD mode was re-established and the 7″ liner was stripped in to TD. The liner was then set and cemented at the shoe.
The well primary objectives were achieved successfully. This paper elaborates on the planning, drilling and completion phases of a successful PMCD operation, with relevant lessons learned and recommendations for future solutions.
Experimental Investigation of Self-Repeating Effect of Different Nanoparticles on Internal Mud Cake Formation by Water-Based Drilling Fluid in Directional Wells
Authors: Sedaghatzadeh M. , Shahbazi K. , Ghazanfari M.H. , Zargar G. 
Published: August 2016

Abstract
In this paper, the impact of three parameters including nanoparticles geometry, particles aggregation and borehole inclination on induced formation damage from water based drilling fluids were investigated by means of experimental studies. Accordingly, we designed a dynamic filtration setup capable to rotate and change well inclination. Nano-based drilling fluids consisting of spherical, cubical and tubular shapes nanoparticles as fluid loss additives were used. Mud cake quality, core permeability impairment and degree of formation damage at various well inclinations were examined. The cluster structure of aggregated particles were determined using fractal theory and applying dynamic light scattering technique. For this purpose, drilling fluids were circulated at different well inclinations and at a constant differential pressure against a synthetic core. Field emission scanning electronic microscopy images taken from mud cakes confirmed the proposed cluster structures of nanoparticles. The experimental results show that the mud cake quality and degree of damage are functions of produced structure of aggregated particles. Moreover, by increasing the well inclination, the skin factor increases. However, this trend is intensively depended on particle geometry. Real time analysis of pore throat size to particle size ratio during mud circulation shows the tendency of particles to create external/internal filter cake is mainly related to well inclination and particle shape. The results can be used to optimize the size and shape of selected macro/nanoparticles as additives in drilling fluids to reduce formation damage in directional and horizontal wells during drilling operation.