bluuebunny/crossref_metadata_2025_split huggingface dataset:
Comprehensive Transient Modeling of Sand Production in Horizontal Wellbores
Authors: Nouri Alireza , Vaziri Hans , Belhaj Hadi , Islam M. Rafiqul 
Published: January 2008

Summary
Installing sand control in long horizontal wells is difficult and particularly challenging in offshore fields. It is, therefore, imperative to make decisions with regard to the most optimum completion type objectively and based on reliable assessment of the sanding potential and its severity over the life of the well for the intended production target. This paper introduces a predictive tool that forecasts not only the initiation of sanding, but also its rate and severity in real time.
A series of well-documented experiments on a large-size horizontal wellbore was simulated using a finite difference numerical model. The model accounts for the interaction between fluid flow and mechanical deformation of the medium, capturing various mechanisms of failure. The model allows capturing the episodic nature of sanding and the resulting changes in the geometry and formation consistency and behavior within the sand impacted regions. Sand detachment is simulated by removal of the elements that are deemed to have satisfied the criteria for sanding based on considerations of physics, material behaviour and laws of mechanics. The proposed numerical model is designed to account for many of the factors and mechanisms that are known to influence sanding in the field and as such can be used as a practical tool for predicting the frequency and severity of sand bursts and changes in operating conditions that can be considered for mitigating or managing such problems.
The model shows reasonable agreement with the experimental results in terms of borehole deformation and sanding rates. The model correctly predicted initiation of shear failure from the sides of the borehole and its propagation to the boundaries of the sample. It was further seen that the propagation of the shear failed zone resulting from sand production agreed well with the numerical pattern of failure growth upon removal of elements satisfying the sanding criteria. The approach and concepts used are considered suitable for application to field problems involving horizontal wells.
Analyses and Procedures for Kick Detection in Subsea Mudlift Drilling
Authors: Choe Jonggeun , Schubert Jerome J. , Juvkam-Wold Hans C. 
Published: January 2008

SummaryIn deepwater drilling, a conventional large-diameter riser requires drilling vessels with large weight and space capacities, large mud volume to circulate through a riser, and many casing points because of narrow gaps between pore and fracture pressures. A large number of casing points also require a larger wellhead and a larger marine riser. These problems are inter-related and intensify as the water depth increases. Although there are some successes to set a new drilling record on water depth, it is impractical to extrapolate current technology with a marine riser to 10,000 ft water depth.Subsea mudlift drilling (SMD) is a term used to describe an unconventional technique using a relatively small diameter pipe as a mud-return line from the seafloor instead of a large-diameter marine riser. The scheme also balances internal and external pressures at the seafloor by reducing the internal pressure to make a dual pressure gradient possible. It has potential advantages of cost and time savings and rig upgrades for deepwater applications.Kick detection and well control will not be hurdles for field applications of SMD. If the circulation rate is less than the maximum free-fall rate, there will be a time delay in kick detection. In this case, the circulation rate may need to be increased or a drill-string valve that provides a positive surface-pump pressure should be used. In case of transient U-tubing or fill up, other operations should be avoided for easy kick detection and well control, unless there is an accurate prediction and monitoring tool available.
Drilling Technology Mastery - Complementing Drilling Engineers' Knowledge Acquiring Process
Authors: Ismail Zulkarnain , Yusoff Noorazmah , Jusoh Kamri , Yakob Razak 
Published: January 2008

Abstract

Proposal
PCSB’s Drilling Technology Mastery program was initiated in August 2002. Conceptually, it was designed as a total competency development model for PCSB’s Drilling Engineering Department. The Program is built around a modular delivery format, and takes Engineers from a Foundation Level Certification, through an Advanced Certification, and finally Expert Level. The program combines core technical skills development, along with soft skills development. The result of this program delivers certified resources, delivering technical analysis and results in a more accurate and time-efficient manner. This allows for a greater confidence to PCSB in managing drilling risks, thus helping to manage the improvement overall safety of a project and also contributes to substantial reduction of overall project cost.
This paper takes as its example, the Foundation Level Certification process, and illustrates the roadmap that a Drilling Engineer follows in terms of a structured modular training program, supplemented with mentoring sessions and, finally challenged by the sitting of a certification. The certification has been jointly developed by PCSB and Landmark, and allows PCSB’s Drilling Engineers to be ranked against standard benchmarks which have been based upon a competency set required for the successful completion of PCSB’s standard operational process. While the objective of the program has been to accelerate the engineers’ development process, the Certification process ensures a measurable and guaranteed capability from a Drilling Engineer on successful completion of this program.
The program is complemented with an online skill matrix database; which allows management access a dashboard of their current resource pool, to allow more objective evaluation candidates for particular assignments. It also allows both managers and the resource pool a real time competency and tracking tool for developing career development plans.
This program is greatly supported by the implementation of an Integrated Well Planning Workflow. This defines the process of completing Drilling Engineering analyses from the planning stage to daily surveillance routines.
Thru-Tubing Zonal Isolation and Water Shut-Off Utilizing Coiled Tubing in the Java Sea: Operational Challenge & Treatment Strategy
Authors: Susilo Yoliandri , Wibowo Wahju , Tobing Budhira L. , Arbai Imam , Hendra Yasri S. 
Published: January 2008

Abstract
Almost all the wells in the Offshore North West Java (ONWJ) field penetrate multi-layer reservoirs. To accommodate reservoir management issues, most of these wells were therefore completed in multiple packer completions (dual or single string with multiple packer). As the field is getting mature, more wells are becoming wet and consequently more wells are dying due to water encroachment. Therefore, remedial actions to revive dead wells play an important role to maximize the revenue. To address this issue, thru-tubing cement squeeze and polymer squeeze using coiled tubing have proved to be efficient methods to reduce water production by isolating watered out zones in the ONWJ field.
However, the operation of this job can be more complicated when done in multiple packer completion or in dual completion cases, especially when the tubing has leaks in order to avoid the cement or polymer from penetrating other places or productive zones. In several cases, the condition of old tubing that has experienced deformation (buckling/ collapse) has made the task even more challenging. Therefore, treatment strategies must be designed carefully for successful cement/polymer placements into the target zone without affecting production from the other string or zones.
From 1999 to 2003, a total of 36 thru-tubing zonal isolation & water shut-off jobs utilizing coiled tubing were done with a high degree of success, although in many cases the tubing had leaks and mechanical problems. Several methods were used and modified to ensure proper cement or polymer placement. Through the use of the innovative "cement packer" technique and inflatable packer, the jobs were accomplished successfully. The coiled tubing has proven to be an effective solution to deal with well conditions in the ONWJ field.
This paper will also discuss three case histories, with each case representing different operational challenges.
Hydrajet-Fracturing Stimulation Process Proves Effective for Offshore Brazil Horizontal Wells
Authors: Surjaatmadja Jim B. , Willett Ron , McDaniel B. W. , Rosolen Marcos A. , Franco Marcus L.A. , dos Santos (ret) Fernando Canavarro Rodrigues , Fernandes Paulo Dore , Carneiro Fernando A.S. , De Lima Bonifacio B. , Cortes Mauricio 
Published: January 2008

Abstract
Cased cemented completions have not been the preferred horizontal well completion method in offshore Brazil. Lower-cost solutions such as uncemented, preperforated liners are often used in completing horizontal wells offshore and are usually very effective. Often, however, low producing rates necessitate stimulation treatments for many wells. For some wells, this was the case at initial completion, and for others would be after a year or more of production. Application of conventional stimulation technology has generally been either ineffective or not cost-effective for these lower-producing completions. This situation poses a challenge for the operator to find more effective solutions to continue developing some parts of these fields. Efforts to find a solution have included the re-evaluation of the more expensive cased cemented completion method to provide more effective options for stimulation treatments and attempts to find newer stimulation techniques that can be more effective with the lower-cost completion method using noncemented liners.
In the attempt to find an economical yet effective stimulation solution, the operator chose to implement a newly emerging technology: the hydrajet-fracturing process. Although this stimulation technique has a proven success rate in onshore applications, this was the first offshore application. The technique can be applied in either sandstone or carbonate formations, which are both commonplace in offshore Brazil fields. Therefore, stimulation plans in this field include fracture acidizing and propped fracture stimulations with high concentration of proppants [ceramic and/or curable resin-coated proppants (RCPs)].
This paper discusses results from the first few wells in the investigation.Additionally, comparison wells that were completed and evaluated with differentcompletion schemes are reviewed in depth.
Indonesia: Coalbed Methane Indicators and Basin Evaluation
Authors: Stevens Scott H. , Hadiyanto Hadiyanto 
Published: January 2008

Abstract
Indonesia has thick, low-rank coal deposits that are prospective for coalbedmethane (CBM) development but remain untested. Conventional oil and gas wellsthat drill through these coal seams experience gas kicks and blow outs, goodCBM indicators. We analyzed petroleum and coal mining data to perform acomprehensive assessment of Indonesia's CBM resources. We identified 12.7trillion m3 (450 Tcf) of prospective CBM resources within eleven onshore coalbasins. Full-cycle development costs in high-graded areas are estimated at$0.70/Mcf. These potential CBM reservoirs could be tested at low cost usingcoreholes or production "wells of opportunity."
Selective Placement of Fractures in Horizontal Wells in Offshore Brazil Demonstrates Effectiveness of Hydrajet Stimulation Process
Authors: Surjaatmadja Jim B. , Willett Ron , McDaniel B. W. , Rosolen Marcos Antonio , Franco Marcus Luis de A. , dos Santos Fernando Canavarro Rodrigues , Fernandes Paulo Dore , Carneiro Fernando A. S. , de Lima Bonifacio Bezerra , Cortes Mauricio 
Published: January 2008

Abstract
Cased cemented completions have not been the preferred horizontal-well completion method in offshore Brazil. Lower-cost solutions such as uncemented preperforated liners were often used in completing horizontal wells offshore and are usually very effective. Often, however, low producing rates mean stimulation treatments become necessary for many wells. The use of conventional stimulation technology has generally been ineffective for these completions, which posed a challenge for the operator to find an effective solution for continuing developments in some fields. These challenges included re-evaluating the more expensive cased cemented completions to allow more effective options for future stimulation, as well as trying to find newer stimulation techniques that can be effective with lower-cost completions (noncemented liners).
In the attempt to find an economical yet effective stimulation solution, the operator chose to implement a unique and relatively new hydrajet stimulation technique that has a proven success rate in onshore applications. The technique can be applied in either sandstone or carbonate formations, which are commonplace in this field; therefore, stimulation plans in this area will include fracture acidizing as well as propped fracture stimulations that use a high concentration of proppants or curable resin-coated proppants (RCP).
This paper discusses the early results of this investigation. Wells that were completed and evaluated using different completion schemes are reviewed.
Optimization of Riser Design and Drill Centers with a Coupled Reservoir and Facility Network Model for Deepwater Agbami
Authors: Narahara G. M. , Holbrook J. A. , Shippen M. , Erkal A. 
Published: January 2008

Abstract
The utilization of multiple wells connected at a subsea manifold provides the opportunity to reduce the number of risers and to reduce capital expense. The problem is the proper modeling of the reservoir well flow coupled with the combined flow into the facility network (manifolds, flowlines and risers), which is necessary to prevent under design resulting in flow rate bottlenecks or over design resulting in extra expenditures. This paper presents a tool and methodology for better modeling of the well to riser flow and the optimization of riser count and configuration.
Although reservoir models coupled with facility networks is not new, software enhancements provided the capability of including operation logic that could duplicate operations in the field. The reservoir model coupled with the facility network provided more reasonable and accurate modeling of multiphase rates and pressures as wells were combined into a single riser.
To optimize the riser count, operation logic was applied to maximize rate in the riser at all times against the erosional velocity limit. This in turn prevented over designing by placing more risers than needed to obtain the field facility capacities.
The utilization of the coupled model and operation logic allowed the optimization of the riser count for any particular reservoir model. The optimum riser count was then determined for 3 earth (geologic) models.
Application of Tracers in Oil-Based Drilling Mud for Obtaining High Quality Reservoir Fluid Samples
Authors: Gozalpour F. , Danesh A. , Todd A. C. , Tohidi B. 
Published: January 2008

AbstractOil-based drilling fluids are extensively used in drilling activities world-wide. During the drilling process, due to over-balance pressure in the mud column, the filtrate of oil-based mud invades the formation. This hydrocarbon-based filtrate mixes with the formation hydrocarbon, which can cause major difficulties in obtaining representative reservoir fluid sample. Despite the recent improvements in sampling, obtaining a contamination-free formation fluid is a major challenge, particularly in open hole wells.Depending on the type and conditions of the reservoir, the oil-based mud filtrate is totally or partially miscible with the formation fluid. Oil-based mud filtrate completely dissolves in reservoir oil, therefore the captured sample contains the true reservoir oil with added filtrate. Gas condensate (lean gas condensate in particular) is often not fully miscible with mud filtrate. In this case, the mass exchange between gas condensate and mud filtrate makes the sample unrepresentative of the reservoir fluid.In this study the impact of sample contamination with oil-based mud filtrate on different types of reservoir fluids, including gas condensate and volatile oil samples, is investigated. Two simple methods are suggested to retrieve the uncontaminated composition from a contaminated sample where mud filtrate is totally dissolved in the formation fluid (i.e. reservoir oil samples). A tracer-based technique is also developed to determine the composition of uncontaminated reservoir fluid sample from a sample contaminated with oil-based mud filtrate, particularly for those cases where the two fluids are partially miscible. The tracers are added to the drilling fluid with the additional cost to the drilling mud preparation being negligible. The capability of the developed techniques has been examined against deliberately contaminated samples under controlled conditions and contaminated field samples. The results indicate the reliability of the proposed methods.
Gel-Volume Optimization in Water Conformance Applying Risk and Uncertainty Analysis
Authors: Caicedo S. , Del Conte B. , Prado M. 
Published: January 2008

Abstract
Gels have been used successfully in water conformance. One of the keyfactors in the application of this technology is the volume of gel, which hasbeen estimated by several techniques: a) using a relationship between thevolume and the water rate, b) calculating it given a fixed volume per feet, orc) invading a chosen penetration radius.The present work shows a newapproach to estimate the optimum volume of gel considering uncertainties andrisks. The proposed approach considers a model for the expected water and oilproductivity indexes integrated with nodal and economical analysis. Clearly allthese three major steps depend on the volume of gel, whose optimum value is thegoal of this research, then an iterative method is required. Besides theproposed method used should consider the lack of accuracy in the inputparameters, some of them highly sensitive.Three real cases are analyzedin order to show the potential of this approach. The results aid to establishpriorities to answer the following questions: Where to focus the efforts inField data and research?, What is the accuracy required in the inputparameters?, How much would an activity improve the profit of the treatment?Even though the methodology and the software prototype considered only threewater production problems, the general idea can be easily applied in othercases such as channeling in water injection wells.
Challenges in Drilling in Campos Basin
Authors: Paes P. , Ajikobi F. , Chen D. C. -K. 
Published: January 2008

Abstract
Brazil's Campos Basin, home of several fields in water depth ranging from 100 m to more than 2000 m, is one of the most important deepwater developments in the world. Campos Basin also accounts for nearly 80 percent of Brazil's overall crude output. Drilling in Campos Basin, however, has been quite challenging due to difficult pore pressure prediction and close margin between pore pressure and fracture gradient. In addition, poor hole cleaning and high drilling vibrations have also resulted in substantial non-productive time (NPT) and related costs. To improve drilling performance, Petrobras has employed a new drilling optimization operation focused on optimization specialists with state-of-the-art technologies such as real-time modeling and LWD/MWD tools. Over the past three years, over sixty drilling optimization operations were completed in the Campos Basin area. Those fit-for-purpose optimization operations have substantially reduced the drilling cost, reduced NPT, and increased drilling efficiency. This paper will discuss the drilling problems and the technologies used to solve these problems.
Waste Management Strategy Decision Matrix is Crucial to Compliant and Economical Waste Treatment and Disposal
Authors: Collins R. , Stanley A. 
Published: January 2008

Abstract
To help assure the successful development and implementation of the most appropriate waste management strategy, should be thoroughly considered all variables which may affect the operation. These factors may come from any number of areas, including but not limited to operations, logistics, regulatory policies, internal company strategy or equipment availability. As the cost for waste management approaches and surpasses the cost of the actual fluid services, the importance of the development of the proper response to the challenge only increases.
An environmental management strategy should address every portion of the fluid systems. Drilling fluid, completion fluid, production fluid, stimulation fluid and cement slurries can all have different residual effects which must be considered. Coupled with generated solids such as drilled cuttings and produced sands, the task of deciding on the correct disposal option becomes critical. By understanding the factors that effect each individual operation and area and utilizing correct management practices and procedures, a purpose-designed, compliant option should be identified and implemented. This strategy, backed with proper monitoring and documentation, can provide the operator with a sustainable environmentally responsible and compliant solution.
Environmental legislation varies from country to country, and even specific region to region within a country, and the legislation may be subject to frequent changes. Another critical component is the operator's own corporate standards. These can often be more stringent than regulatory limits, which can help prevent future liability for actions taken today. Therefore, proper comprehension of all applicable legislation and the operator's internal standards is critical. The costs, both direct and in-direct, of non-compliance should be considered.
The minimization and control of waste which develops from the strategy can also have the beneficial effect of reducing the number of health-related issues by minimizing or mitigating effluent discharge through air, water and soil releases. The benefits realized through proper handling and disposal of waste materials can have a correlation with reduction of occupational hazards.
Deepwater Horizontal Openhole Gravel Packing in Marlim Sul Field, Campos Basin, Brazil—Completion Project Learning Curve and Optimization
Authors: Acosta Marco , Farias Rodrigo , Vilela Álvaro , Mendez Alfredo , Pineda Francisco , Montanha Roberto , Garcia Eduardo , Calderon Agostinho , Magno Carlos , Germino Mário 
Published: January 2008

Summary
Most of the deepwater Campos Basin reservoirs, offshore Brazil, have unconsolidated formations that require sand control. Openhole gravel packing has proven to be the effective completion method of choice. The main objectives were to achieve low damage ratios, maximize completion efficiencies and reduce completion time.
The project was conducted in one of the largest deepwater offshore fields in Brazil, Marlim Sul. This paper describes the learning curve and completion optimization obtained during planning, execution, and post-job analysis of six horizontal wells campaign with five water injectors and one oil producer.
A combination of integrated service lines and experienced personnel were important to achieve excellent injectivity and productivity ratios. Several key operations from drilling to completion contributed to successfully complete these wells: openhole stability, drilling practices, drill-in fluids (DIFs), wellbore clean-up, filtration, completion fluids, completion tools, sand control, gravel-pack software simulator, and job execution.
The efficiency of the service company was measured with a system of penalties and rewards allowing the operator to monitor and measure the progress of the learning curve on completion. As a final result, the partnership between the operator and the service companies contributed to a more economic completion cost by reducing completion time, and improving well performance.