bluuebunny/crossref_metadata_2025_split huggingface dataset:
Torque Simulation in the Well Planning Process
Authors: Boonsri K. 
Published: August 2014

Abstract
As the hydrocarbon reserves are progressively depleted, the way to find hydrocarbon is much more complicated than ever by having a number of restrictions such as environmental issues, surface location, well proximity, and so forth. It is no surprise that the well planning process nowadays is very challenging. The torque limitation of the equipment is one of the constraints. During well planning, a prediction by sophisticated engineering software is required to ensure that the drilling torque would be within the limit. However, many wells drilled in the past have suffered with excessive torque, causing unusable wells or eventually unfeasible projects. This raises a disconcerting question whether the root cause originated from the software or the engineers. No matter what the answer is, the key is to understand the root cause and how to prevent it.
Therefore, first and foremost, this project will address the nature of the torque in the drilling operation in cooperation with a mathematical approach to describe torque behaviour. Secondly, torque simulation is very useful but also perilous. The difficulties lie in how much insight the engineers have into which software modelling or input is crucial in which circumstances. For this, a study of well design parameters including well architecture, drill pipe selection, BHA type, drilling fluid and tortuosity, will elaborate the extent to which these variables have influences on the torque by utilizing torque and drag software in a controlled environment together with an analysis of the actual field data. Last but not least, well planning optimization and external resources are also integrated as a guideline for future usages.
Lessons Learned from Over 20 Historical Years of Completion Practices in the Cuu Long Basin Offshore Southern Vietnam
Authors: Vu Hao Manh , Lu Vi Dinh , Le Quan Vu , Nguyen Vu Minh , Le Trung Quoc , Emiliani Gianni 
Published: August 2014

ABSTRACT
Cuu Long basin is the major hydrocarbon producing basin in Vietnam with several discoveries of oil and gas in both Oligocene-Miocene and fractured basement reservoir such as H, D, A and R field in 1990s. Overall, the geological characterization to apply the well completions in the area is not too complex. However, as operation and production have caused damage, especially, the migration of reservoir sand and fines into wellbore, water breakthrough, and paraffin deposition which might shorten lifetime of wells, increase operating costs and might decrease well profitability.
The purpose of this paper will review, discuss and evaluate the well completion technologies current application in the Cuu Long basin, the methodology starts with approximately 350 wells on a total of more than 430 production and injection wells are collected. Then, the focus on case by case of the field studies cover completion design, well performance evaluation, completion improvement, completion failure diagnostics, and so on. Finally, the main target for this study is to share some lessons learned and experiences gained from the past more than 20 historical years a worthy case study for both current and future development of the fields not only in the Cuu Long basin but also in the continental shelf of Vietnam and the world.
Best Practices for Logging While Drilling Fluid Sampling of Deviated Wells in Deepwater Applications
Authors: Martin Stephen J. , Tran Pei-Chea , Marshall Steven 
Published: August 2014

Abstract
A deepwater operator in Asia Pacific required a large volume fluid sample from a gas reservoir in the northwest shelf of Australia for accurate non-hydrocarbon gas content analysis. This paper highlights pre-job planning and operational considerations for running logging while drilling (LWD) fluid sampling and formation pressure testing devices in two highly deviated 8 ½-in wellbores. These include risk mitigation techniques to avoid stuck pipe, accommodating rig heave associated with deepwater drill ships, oil-based mud (OBM) gas sampling issues and the prevention of geo-chemical absorption.
Because the wells reached more than 80°inclination, traditional, wireline fluid sampling required a pipe-conveyed or tractor mechanism, increasing the AFE, rig time and operational risks. To make sampling feasible required the use of a unique LWD solution. Furthermore, the planning, mobilization, and deployments were accomplished in less than six weeks by seamless cooperation between the operator and service partner.
In two runs, 26 samples were acquired containing more than 19 liters of fluid. During the pre-sample cleanup, a high- speed telemetry system provided 25 bits per second of real-time fluid analysis data to ensure the fluid properties were stabilized. Because of the improved operational efficiency of logging while drilling technology, the operator estimated savings of approximately USD10 million dollars in rig and operating costs and potentially millions more in reduced retrofitting costs of the production facility.
Fluid sampling while drilling technology represents a major change in deepwater formation evaluation capabilities. By utilizing the techniques presented in this paper, operators can collect large volumes of fluid samples in deviated wells while reducing operational risks and minimizing costs. A recap of the two wells presents best practices for prejob planning, risk mitigation and overcoming mobilization challenges in short call-out scenarios. These high-quality development well samples enable a properly designed production facility, thereby preventing costly post-production modifications.
Best Practice in the First Wireline Retrievable ESP Pilot Job in Kuwait
Authors: Bouhanna Mahfoud , Al-Shammari Menwer , Al-Fadli Ali , Mali Prasanna Vasant , Al-Jasmi Ahmad 
Published: August 2014

Abstract
Electrical Submersible Pump is an artificial lift method which consists of lowering a pump system on tubing string during rig workover where the power cable is clamped externally along with the tubing.
Because of the significant rig workover cost, the ESP is usually run until failure.
Wireline Retrievable ESP (WRESP) is a step change in ESP method, where the pump without electrical cable can be retrieved and reinstalled with a wireline method (as a rigless job) at any time of ESP life cycle.
A Wireline Retrievable ESP system consists of two main parts:
Permanent part: Docking station with a male connector, attached to a large bore tubing string with a power cable clamped on it and lowered in the well bore during a rig work-over job Retrievable part: Standard ESP string with a seal assembly on top and motor connector on the lower end, lowered and retrieved with Wireline inside the large bore tubing.
This technology was implemented as a trial jobs in Oman, Ecuador and Nigeria. Challenges faced during implementation were as follow:
➢ Considerable seals friction of seal assembly, resulting in a serious damage and stuck in tubing wall during pulling out of hole. ➢ Difficulties to retrieve remaining pieces of damaged seals from the docking station. ➢ Swap to CT conveyance. ➢ Swabbing effect.
During the first implementation in Kuwait, similar challenges were faced.
An Innovative Idea was designed, implemented and succeeded to overcome the above challenges. It was about adding a circulating device (operated by a slickline method) to the seal assembly configuration part, which was resulting first time (in Kuwait and worldwide) in completing a trial project smoothly and successfully.
This paper will describe the innovative idea, experience and best practices of the first WRESP application in Kuwait oilfield.
Lessons Learned from DAS and DTS in MultiCluster, MultiStage Horizontal Well Fracturing: Interpretation of Hydraulic Fracture Initiation and Propagation through Diagnostics
Authors: Sookprasong P. A. , Gill C. C. , Hurt R. S. 
Published: August 2014

Abstract
Fiber optic distributed temperature sensing (DTS) and distributed acoustic sensing (DAS) have been used to monitor and diagnose the integrity of wellbores (leak detection, gravel-pack screen damage, formation subsidence, etc.), the performance of reservoirs and wells (production profile, injection profile, etc.), used for surveillance and other applications for quite some time. The application of high resolution fiber optic DAS and DTS during multi-stage hydraulic fracturing has increased in recent years.
In this horizontal tight-gas well, the fiber optic filaments were placed in a small stainless steel tube which was clamped to the casing while running in hole, and the casing was then cemented in place. Perforations had to be oriented to avoid damage to the fiber optic. In this case, perforations were place at the topside of the casing, zero degree phasing, at 5 shots per foot (1 foot per cluster).
This paper shares results from DAS and DTS techniques that allow for interpretation of fracturing treatments in multi-cluster (each stage), multi-stage horizontal well with cemented casing and ‘plug and perf’ completion process. The images illustrate the dynamics pertaining to initiation, propagation and arrest of hydraulic fractures during simultaneous stimulation of multiple clusters. First, fracture initiation appears not only during early time, as expected, but late time initiation events may develop in seemingly dormant clusters. Second, propagation of multiple fractures can occur randomly within a cluster array. Third, dominate clusters are often observed during stimulation. Further, during the treatment cycle, the position of dominate cluster(s), within a given stage, may actually change.
Case Study: High-Strength Disintegrable Tripping Balls in Hydraulic Fracturing System Application
Authors: Wibowo H. , Carrejo N. , Gaudette S. L. , Kitzman J. D. 
Published: August 2014

Abstract
High-strength disintegrable frac balls have provided successful isolation in multi-stage completion systems during hydraulic fracturing treatments in thousands of wells throughout North America. The multi-stage hydraulic fracturing is enabled through one avenue with the utilization of a ball-activated frac sleeves to fracture each stage. Advancements in technology permit over 40 individual stages in one wellbore. This puts a critical emphasis in the reliability of the frac ball as an integral part to the success of each treatment. The High-Strength Disintegrable (HSD) frac balls must exceed the pressures required in hydraulic fracturing, while avoiding the risk of remaining stuck on seat or collecting in the lateral. This break-thru-material is engineered to disintegrate in typical downhole brines. The combination of this unique characteristic and its high strength enables the material to actuate frac sleeves and provide flow assurance by optimizing the flow area after fracturing a stage. More than 30, 000 HSD tripping balls have been deployed downhole. This paper presents a case study on fracturing pressure requirements using this new, innovative technology, and the reliability of the tripping balls' ability to disintegrate while being exposed to downhole brines.
Elastic-Plastic Behavior and Limit Load Analysis of Casings
Authors: Morita Nobuo 
Published: August 2014

Abstract
Most companies producing from high compaction reservoirs continue using casings even if they find that these casings have been elongated or compressed exceeding the yield stress (Furui, et al., 2011). The magnitude of elongation and compression of these casings are often 3 to 5% while the strains at the yield strength are supposed to be 0.3–0.5%. Since casings are actually used beyond casing yield strength, field engineers should take into account the casing properties during plastic deformation. In this study, extension, compression and radial loading tests were conducted from H-40 to V-150 casings up to failure. The tests gave the following results:
Under extension tests, the casings were uniformly deformed beyond the yield strength. The uniform deformation continued while the casings were stretched by 4 to 25% until non-uniform deformation was induced. The constitutive relations were constructed simulating the elastic and plastic deformations up to the failure. The radial compression tests showed stability of casings was maintained until the stresses at four cross-points of the stress concentration areas exceeded the yield strength. The higher grade casings did not significantly increase the maximum strength after yielding while lower grade casings significantly increased the strength while being stretched or compressed uniformly after yielding.
The analyses show that the casings were uniformly deformed until the maximum strength so that they were usable. The peak load of the uniform deformation is the limit load since they rupture after the uniform deformation. When casings are compressed or extended by geo-technical loadings, thicker casings with a lower grade prevent rupture and kinks while higher grade casings tend to rupture with a large formation deformation. When casings are compressed by directional geo-technical load, the casings start losing the load-support capability after the stresses at four cross-points of the casings exceed the yield stress. Selecting a proper grade and thickness of casings are the key for mitigating casing failure where the data of casing deformation beyond the yield strength are essential information for casing designing using geomechanical models.
Improving Drilling Economics Through Drilling Fluids and Solids Control in the Eagle Ford - Case Examples and Results
Authors: Guo Quanxin , Wang Youyou , Deplaude Oriane , Fout Gary 
Published: August 2014

Abstract
Drilling of shale oil and gas presents a unique opportunity for improvement. Since many similar wells are drilled during the life of a basin, even a small improvement can produce invaluable economic benefits. Drilling data of Eagle Ford wells were collected and analyzed to identify and rank major factors affecting drilling performance and economics. Solutions were developed and applied to Eagle Ford wells, resulting in savings in both drilling fluids cost and drilling days.
Drilling data of 965 horizontal Eagle Ford shale wells drilled between 2010 and 2013 by nearly 40 operators were collected and analyzed. Well drilling history was recreated from drilling data and reports. By analyzing this large number of wells with regard to well design, drilling procedures, drilling fluids, and solids-control methods, we confirmed the significant progress made in reducing drilling days and cost while increasing the lateral length over the years. The analysis also confirmed the detrimental effects of low gravity solids (LGS) on drilling operations. By comparing drilling fluids with high and low LGS concentration, it was found that high LGS concentration (&gt; 9 or 10%, depending on the operator and data set) were associated with about 20% higher drilling fluids cost and an additional 2 to 3 drilling days per well. LGS are known for resulting in slower drilling, more non-productive-time (NPT) events, and downhole tool failures. By focusing the analysis on the most troublesome wells, it was found that the top NPT events were tools failure, wellbore instability, lost circulation, and stuck pipe.
This paper also presents an advanced solids-control solution and the early results of applying it in the Eagle Ford basin. This improved solids-control system is based on batch processing and staged centrifugation, used in tandem with chemically enhanced flocculation. It removes the ultrafine particles that cannot be removed with a conventional dual-centrifuge system. A comparison has been made between wells drilled by the same operator and drilling rig. Although the sample size in this comparison analysis may be too small to yield meaningful statistic results, the limited data showed a drilling-fluids cost saving (including solids-control costs) of 4.2 USD/ft by decreasing dilution and chemical additions, and an average drilling-time savings of 4.4 days per well.
Designing and Running a Special Oil-Based Mud for a North Sea HPHT Campaign
Authors: Kabanov Maxim , Telford Elizabeth , Gray Chris 
Published: August 2014

Abstract
A major operator in the North Sea had a requirement for a special fluid system to drill a series of HPHT exploration and appraisal wells. The operations had to overcome substantial technical challenges, with an expected bottom hole temperature near 400°F, anticipated reservoir pressures around 17,000 psi and narrow margins between formation pore pressure and fracture pressure. The oil-based mud had to fulfill a number of requirements, including thermal stability, consistent properties and predictable density behaviour, especially given the extensive wireline programme. The first part of this paper discusses the approach taken to the initial laboratory design work, with special consideration given to selection of weighting agent and HPHT testing regimes. With a suitable, environmentally acceptable fluid formulated, the second part of the paper deals with operational considerations given to wellsite maintenance and testing that allowed the three-well campaign to be completed successfully. Careful monitoring ensured that fluid properties remained stable throughout the drilling phase, and enabled a sustained, balanced rheological profile. This was necessary to minimize effective circulating density in the narrow drilling window, and to prevent sag during drilling and lengthy logging periods. The successful use of this special fluid contributed to the success of the wells. The fluid achieved excellent hole conditions, removing the need for costly wiper trips and delivering excellent wireline logs. Furthermore, the fluid's stability facilitated the resolution of well-control situations that often required slow, controlled circulation.
Optimization of the Emergency Glass Plugs Opening with Technology of Riserless Light Well Intervention
Authors: Tepka Piotr 
Published: August 2014

Abstract
Glass plugs technology was initially installed on Skarv field in Norwegian Continental Shelf. In partnership with technology provider, the new concept of completion barrier plugs was dynamically implemented. Its purpose was to close the lower formations of reservoir until the time the well was ready to proceed with production from those zones. The early years showed that even if this technology is forward-looking, the risk of failure and intervention still exists.
According to the operator's data three out of ten wells demanded the emergency glass plug opening and in the rest of cases the small complications occurred. Emergency breaking of the glass plug involves renting a unit and running the wireline with a tractor. It is an additional cost that can be optimized by understanding the challenge and proposing the accurate approach. Base of this research is the analysis of failure cases, activities that have been taken up by an operator and final outcomes from the operations. It is supplemented by the analysis of the optimal intervention concept according to economic calculations and market availability. The aim of the research is to transfer the knowledge acquired from failure cases into the recommendation for running such interventions and provide criteria for the final assessment of available solutions.
Self-Powered Intelligent Data Retrieval Gauge for Unconventional Well Testing Using DFIT Technology
Authors: Karaman Turker , Waldman Nathan , Tompkins Darryl , Swartley Adam , Redman Michael 
Published: August 2014

Abstract
Pressure transient testing has been the standard method used to obtain well information such as reservoir pressure, permeability, and skin in conventional reservoirs. However, with the shift towards unconventional, ultra-low permeability reservoirs, the only type of test that is economically practical for operators to use to determine reservoir and fracture properties is a diagnostic fracture injection test (DFIT). The DFIT provides a simple, cost-effective method for identifying fracture design parameters and essential reservoir properties in a relatively short period of time. Both fracturing and reservoir properties are critical inputs for proper fracture design, optimization, and reservoir characterization.
When performing a DFIT, it is critical to use a high-quality pressure gauge that is thermally compensated, capable of one-second sampling and with a resolution of 0.01 psi. Detection of subtle pressure changes over a short period of time is essential in analyzing the fall-off data to determine reservoir characteristics accurately.
The recently developed Self-Powered Intelligent Data Retriever system (SPIDR®) is an option for capturing accurate pressure data from the surface for use in DFIT analysis. This system provides a lower cost alternative that allows operators to view and download the data periodically during the fall-off without data interruption and without erasing the data. The downloads can then be reviewed to provide near real-time analysis, and also, will help determine when the test has been completed.
A case study will be discussed that will show how data from a high-quality surface gauge mirrors that of bottomhole pressure gauges and can provide accurate DFIT analytical results more economically.
Bayesian Inversion of Rate of Penetration (ROP) Data and Sonic Logging Data for Estimation of Unconfined Compressive Strength and Pore Pressure
Authors: Wu Zhan , Suryanarayana P. V. , Vasantharajan Sriram , Whitney Bill 
Published: August 2014

Abstract
In this paper, we propose an innovative use of MWD and Sonic logging data for better estimation of UCS. Sonic logging data and real-time ROP measurements are integrated into a Bayesian inference framework, employing empirical sonic correlations and an ROP model. Combining the two types of data sets under a single inference scheme can help reduce the uncertainty in UCS estimation and in prediction of ROP.
The prior mean of the parameters employed in the sonic correlations is interpreted from sonic logging in offset or analog well(s). The UCS estimation for the target well is inferred by application of the least square minimization approach to yield approximations for the maximum a posteriori (MAP) estimation. Verification of the inference procedure is demonstrated on actual MWD data and Sonic datasets. The results show that the UCS generated from the empirical correlation of sonic travel time slowness still contains large uncertainty. Joint inversions of ROP data and sonic velocity measurement reduce the uncertainty in the UCS estimation. The results indicate that the calibration of ROP data is critical before use of empirical correlations to estimate UCS. This paper also addresses the possibility of deriving the pore pressure and UCS simultaneously with quality MWD and sonic data.