bluuebunny/crossref_metadata_2025_split huggingface dataset:
Coiled-Tubing Wiper Trip Hole Cleaning in Highly Deviated Wellbores
Authors: Walker S. , Li J. 
Published: December 2007

Abstract
Wiper trips are the current field practice to clean the hole for coiled tubing drilling or sand clean out operations. A wiper trip can be defined as the movement of the end of the coiled tubing in and out of the hole, a certain distance. In order to clean the solids out of the wellbore, a proper wiper trip speed should be selected based on the operational conditions. There is no previously published information related to the selection of the wiper trip speed. In this study, numerous laboratory tests were conducted to investigate wiper trip hole cleaning and how the hole cleaning efficiency is influenced by solids transport parameters such as; a) Nozzle Type, b) particle size, c) fluid type, d) deviation angle, e) multi-phase flow effect. The results indicate the following: Compared with stationary circulation hole cleaning, the use of the wiper trip produces a more efficient clean out.For a given operational condition, there is an optimum wiper trip speed at which the solids can be completely removed.Nozzles with a correctly selected jet arrangement yield a higher optimum wiper trip speed and provide a more efficient clean out.The hole cleaning efficiency is dependent on the deviation angle, fluid type, particle size, and nozzle type.
Correlation's have been developed that predict the optimum wiper trip speed and the quantity of solids removed from and remaining in the wellbore for given operating conditions. The wiper trip provides an advantage for hole cleaning and can be modeled to provide efficient operations.
Development of Computer-Controlled Hybrid CT Drilling Units
Authors: Ewen Robert , Mackay Kevin , Shepard Frank 
Published: December 2007

Abstract
This paper describes the development and design of a computer controlled hybrid coiled tubing unit used for workover, re-entries, casing exits, coiled tubing under-balanced drilling, running & cementing liners and logging & perforating. Key components of the unit were a purpose-built bottom hole assembly and a companion control cabin.
The goal was a "fly by wire" control cabin with no hydraulic lines and a minimum number of hydraulic hoses linking the equipment. All equipment on site was to be controlled from a central location. The focus was to construct an environmentally friendly unit requiring minimum crew size but without impacting safety.
Risk-Based Well Control Planning: The Integration of Random and Known Quantities in a Computerized Risk Management Tool
Authors: Nilsen Thomas , Sandøy Malene , Rommetveit Rolv , Guarneri Alberto 
Published: December 2007

Abstract
Site-specific challenges related to water depth, geological and environmental conditions, rapid technological development and increased demands with respect to cost effectiveness and environmental consciousness are all factors that impact the uncertainty picture related to drilling and well operations. Thus risks related to undesirable outcomes such as kick and blowout are also influenced. It is however questionable whether the ruling practices for use of quantitative risk analyses in planning of the operations keep up with this development. As the nature of the operations change drastically, use of overall statistics from earlier incidents hardly provides a satisfactory basis for decision making. Such statistics does not reflect the exposure of the specific well to the various kick and blowout mechanisms or the effect of measures introduced to reduce the probability of these mechanisms to occur. KickRisk, a new risk analysis tool with focus on kick and blowout is developed in order to improve the basis for risk-based well control planning. The idea behind this tool is a more detailed system modeling, which enables the planning to include more well- and operation-specific information in the analyses and to obtain a more differentiated risk description. Uncertainty is expressed through probabilities related to factors at a detailed system level and is propagated in kick and blowout probabilities through the logic of the model structure. The intention of this paper is to discuss the requirements for risk analysis methods with respect to kick and blowout in well planning and how these can be met in practice. The principles of the new tool KickRisk are described and the experiences from case studies on real wells are presented.
Use of Flow-Pattern-Based Models for Interpreting Oil-Water Flow in Production Logging
Authors: Kabir C. S. , Hoadley S. F. , Kamal D. 
Published: December 2007

Abstract
Production logs (PL) are often run to diagnose unwanted water production before seeking remedial actions. The diagnosis, involving accurate estimation of slip velocity during two-phase oil-water flow, is a precursor to taking successful corrective measures.
This study entails finding the most reliable holdup or slip-velocity model by examining 78 production logs, run in Kuwait’s Greater Burgan field. We observed that most models provided the desired level of accuracy when the downhole results were compared with those measured at surface. The notion of direct use of flow-pattern maps in PL interpretation is introduced in this work.
Underbalanced Operations Continue Offshore Movement
Authors: Hannegan Don M. 
Published: December 2007

Abstract
About 20% of the world's known offshore reserves of natural gas and oil are economically undrillable with today's conventional tools and technology. Major barriers to conventional methods and equipment must be overcome to economically drill for these vast reserves. The barriers to conventional deepwater drilling methods are: Narrow margin between the formation fracture and pore pressures requiring excessive casing programs and larger, more expensive rigs to drill.Depleted reservoirs relative to water depth where hydrostatic head of conventional mud and cuttings cause gross overbalanced and resulting damage to well productivity.Shallow water flow hazards.Limited ability to adjust equivalent circulating density while drilling ahead.
The tools and technology associated with underbalanced (UB) drilling are seen as key to economically and safely drilling into these reserves. Further, it is expected that by the end of this first decade of this millennium, offshore applications of underbalanced drilling tools and technology will play a profound role in the industry, particularly in deeper waters.
For example, to deal with the conventional drilling barrier described in Item 1., above: The ability to drill offshore with lightweight fluids, perhaps while incurring annulus pressure at the surface in the marine riser (if drilling from a floating rig) or surface BOP stack (if drilling from a jack up), is seen as a viable and attractive method for overcoming this conventional overbalanced drilling barrier. The objective in many cases may not be to achieve true underbalance, but to drill nearer balanced than one would wish to do if drilling conventionally.
For dealing with the barrier described in Item 2., above: Dual density (aka dual gradient) deepwater drilling methods provide an additional attractive option. In the application of this technology, a state of underbalanced is not achieved or desired, but the tools and technology one normally associated with underbalanced drilling are required to practice this technology.
For dealing with the barrier described in Item 3., above: Use of a subsea rotating control head is an option. In this case, one considers shallow water flow hazards as a well control issue and tools up to deal with it accordingly.
For dealing with conventional drilling barrier described in Item 4., above: Underbalanced operations require specialized surface equipment. In the case of dual density drilling, specialized subsea equipment. E.g., Rotating diverter control head, choke manifold, fluids separation and a means of dealing with produced hydrocarbons. The addition of this equipment usually provides at least one and sometimes several additional methods of adjusting equivalent circulating density while drilling ahead.
Jet Drilling Tool: Cost-Effective Lateral Drilling Technology for Enhanced Oil Recovery
Authors: Buset P. , Riiber M. , Eek Arne 
Published: December 2007

Abstract
The paper describes a new coiled tubing conveyed drilling technique, were several new well bores are jet-drilled perpendicular from the mother well and into the reservoir formation. This technology is targeted for Enhanced Oil Recovery (EOR) in both existing and new field developments. The objective is to improve the production profile around the mother well, by penetrating the damaged skin zone, and connecting to possible hydrocarbon pockets left behind in the reservoir.
The Bottom Hole Assembly (BHA) is configured to jetdrill several slim laterals, all in one coiled tubing (CT) run. This through tubing operation has the potential to create up to ten, 50 m long, and 1–2 in. diameter laterals at the exact desired depth in the mother well. The BHA consists of two main parts; a casing drilling machine and a high-pressure hose and jet-nozzle. The hose is spooled from the BHA as the lateral is drilled into the formation.
The main issues presented in the paper are: The new jet tool functional characteristicsThe theoretical aspects of jet drilling; penetration mechanisms and self-induced nozzle pull forceLaboratory experiments (confirmation of theoretical models)The jet drilling effect on improved well production (production simulations).
The technology is an attractive substitute or supplement to acid and proppant fracturing, perforating services and conventional sidetrack drilling.
Practical Methods to High-Grade Infill Opportunities Applied to the Mesaverde, Morrow, and Cotton Valley Formations
Authors: Hudson J. W. , Jochen J. E. , Spivey J. P. 
Published: December 2007

Abstract
Several gas basins within North America are under-going a period of infill drilling in order to supply the increasing demand for natural gas. It is not uncommon for an operator to have hundreds, if not thousands of infill candidates from which to choose. Is there a practical way to high-grade infill locations within a particular basin or field? This paper presents several practical techniques to high-grade infill drilling opportunities when faced with large data sets and little time. We will present results for the Mesaverde in the San Juan Basin, the Morrow in the Permian Basin, and the Cotton Valley in east Texas.
We calculated the infill potential for each of the three example formations. Based on our experience, we have found that comparisons between actual and predicted individual infill well performance can vary significantly. Therefore, ranking infill candidates on predicted individual well performance may not necessarily yield the best overall results. Poor wells, predicted to be good wells, may still be drilled and good wells, predicted to be poor wells, may not be drilled at all.
Alternatively, when considering an infill drilling program as a whole, we have found that the predicted performance for the group can be quite accurate. In this paper, we will present a method to divide a basin or field into smaller areas and predict the distributions of infill performance as a group for the smaller areas, rather than individual wells. We will then present two methods to rank the small areas to achieve the most economic results. The first method ranks the areas based on the average of the distribution. The second method uses decision tree analysis to calculate a typical infill well in an area using the P10, P50, and P90 values from the distribution.
We considered actual recent drilling programs in each of the three formations, used the above techniques to eliminate predicted uneconomic wells, and compared the actual to predicted drilling program results. We found that the finding and development costs were lower, return on investment was higher, and the success ratio was higher when the techniques presented in this paper were used to high-grade drilling opportunities.
The results of a study applying this analysis technique can be used when budgeting and planning near- and long-term drilling programs.
Produce or Plug? a Summary of Idle and Orphan Well Statistics and Regulatory Approaches
Authors: Thomas Keith T. 
Published: December 2007

Abstract
It is an obvious statement of fact that every well drilled will reach the end of its productive life. When the well reaches that point, plugging is the appropriate and environmentally sound solution. Unfortunately, there are a large percentage of wells which are idle, not because their resources have been depleted, but because they have become unprofitable due to low product prices or high production and environmental compliance costs. At this time the latter two are more likely. Most idle wells do not pose an environmental threat. Idle wells could potentially provide the states and the nation with much needed domestic production. It is in the best interest of the oil and gas states to insure that no well is prematurely plugged. The states recognize the economic potential of idle wells, but also realize that many of these wells represent potential liability. The responsibility of plugging orphan wells -- those where the operator has gone out of business or is insolvent -- falls on the states. For some states this is a large burden. Though orphan wells are the greatest burden, the states are usually responsible for monitoring the status of all idle wells. Facing this challenge, the oil and gas states have developed some effective solutions.
Simulation of Naturally Fractured Reservoirs with Effective Permeability
Authors: Sutopo Sutopo , Arihara N. , Sato K. 
Published: December 2007

Abstract
Proper modeling and simualtion of naturally fractured reservoirs is one ofthe most important and challenging issues in reservoir engineering. A dualporosity or dual permeability approach is applied in simulation when fracturesform a flow network. On the other hand, single continuum model, where thefracture system is represented by effective permeability, is commonly used iffractures are discrete or disconnected. Focusing on the letter case, this paperpresents a numerical model that incorporates full tensor permeability in eachgrid block to accurately simulate behaviors of discretely fractured media.
We formulate a flux continuous model using the mixed finite volume elementmethod where the pressure equations, expressed as two coupled first-orderpartial differential equations for pressure and velocity, are solvedsimultaneously. This minimizes the numerical errors occurring in standardmethods caused by differentiation of pressure and then multiplication by roughcoefficients. The saturation equation is to be solved by an implicit pressureexplicit saturation approach.
Numerical examples of simulating flow in fractured reservoirs are presentedto demonstrate the performance of the proposed simulator. The reservoir modelsfor simulation are two-dimensional and include regularly or stochasticallydistributed discrete fractures. Effective permeabilities calculated by thecomplex variable boundary element method are assigned to grid blocks. The samemethod is used to obtain reference solutions of the tracer propagationperformance in the five-spot pattern. The examples validate importance ofaccurate representation of the full tensor permeability for simulation ofnaturally fractured reservoirs.
Optical Fiber Logging System for Multiphase Profile Analysis in Steam Injection Wells
Authors: Ruan Hang , Chen Yaosheng , Liu Yanjing , Jiang Liping , Claus Richard O. 
Published: December 2007

Abstract
In a steam injection well, the downhole parameters such as temperature, pressure, steam quality and steam flow indicate an accurate multiphase profile, which is important for oil acquistion and reservoir management. The downhole logging systems based on optical fiber sensors for simultaneously measuring the four parameters of steam are reported in this paper. The constructive details and procedure for sensors alignment are described. Few examples of logging applications are discussed.
Petroleum Engineering Professional Registration into the 21st Century
Authors: Wines G. Bing 
Published: December 2007

Abstract
Professional Registration in the United States is continuing to become more important for Petroleum Engineers. It has seen some drastic changes since its implementation unto the national scene in 1973. The requirements to become registered have gradually become stiffer. An engineering, math or science degree is fast becoming the norm to be a licensing engineer. Continuing Education requirements are also being implemented.
The Petroleum Professional Registration Exam is changing. As we enter the 21st Century, the PE Exam is being offered as a full multiple choice exam. The format of the exam is evolving towards an exam that can be administered eventually via the computer. Tomorrows average Petroleum PE examinees will be better qualified than their counterparts of previous years. Projections are made for the next century.
Continuously Tapered Coiled Tubing
Authors: Stanley Roderic K. , Martin John R. 
Published: December 2007

Abstract
Coiled Oilfield Tubing (CT) continually finds new markets, and has experienced continued growth in extended reach wells and high-pressure service. One major improvement is in the quality possible at skelp end welds, when continuously tapered strip1 is employed to join strip of the same thickness. In this paper, the following are discussed: Tapered strip and tubing dimensional specifications at all points along the tubing.Design of CT employing continuously tapered strips.Effect of tapered wall thickness on theoretical fatigue life.Effect of skelp-end welds of the same thickness, as compared with those of conventional tapering, on overall string life.Suggested amount of tubing to be removed if needed during servicing operations.
Propellant Assisted Perforating -- An Effective Method for Reducing Formation Damage When Perforating
Authors: Cuthill David A. 
Published: December 2007

Abstract
During the completion of a well the utilization of a propellant stimulation system immediately after or at the time of perforating has been demonstrated to provide sufficient stimulation energy to cleanup formation damage in the near wellbore region while remaining within the desired zone of interest. The focussed and virtually instantaneous nature of this technique means that it can be used in applications where more aggressive stimulation techniques may result in the increase of undesirable fluid production due to stimulation extension into adjoining regions. Propellant stimulation devices provide an inexpensive and effective method of dealing with near wellbore damage due to drilling, completion, or perforating in both producing and injecting environments.
Standalone propellant stimulation techniques have been successfully utilized for a number of years in various areas of the world. The recent development of a propellant assisted perforating system means that the perforations and near wellbore region can be effectively stimulated at the instance of perforating. This advanced perforating system fuses perforating and propellant stimulation devices into a hybrid system - the well can be perforated and the near wellbore region stimulated all with one run in the hole. The development of propellant stimulation modeling software and high-speed electronic pressure recording devices has assisted in the development and verification of the technique's effectiveness in removing or reducing near wellbore damage.
This paper will discuss the development history of this unique perforating and stimulation technique and the new analytical tools used in its advancement and ongoing application. A number of case histories are presented documenting the use and effectiveness of the stimulation method in a variety of environments and applications.
Fracture Propagation in Drill Cuttings Re-Injection: An Investigation Using Analytical Modelling
Authors: Deloge P-A. , Bouteca M. J. 
Published: December 2007

Abstract
Re-injection of drill cuttings is considered in several areas as a mean of disposing solid wastes. Injection in sands or in shales has been considered. In sands, fracture mechanics as used in hydraulic fracturing should apply. A new problem arises in shales where the stress contrast no more contains the fracture and a vertical propagation is expected. In this paper, we derive analytical solutions of the vertical propagation problem in order to better analyze the stability/unstability of fracture propagation. The shape of the fracture is assumed to be elliptical in the propagation plane and the ellipticity is obtained as a solution of the mechanical problem. The case of a circular fracture is firstly considered in order to analyze and illustrate the implication of the evolution of the minor horizontal stress as a function of depth. Considerations on the influence of the spatial discretization in numerical modelling are derived. The elliptical fracture is then dealt with. Finally, the case of a variable Young modulus is considered and the analytical solution is compared with numerical results obtained in the literature with the Terrafrac model. The analytical solution and the numerical one are similar for the case considered by BP.
Possible Use of Bacteria/Steam to Treat Asphaltene Deposition in Carbonate Rocks
Authors: Almehaideb Reyadh A. , Zekri Abdulrazag Y. 
Published: December 2007

Abstract
In this project bacteria and steam were tested to stimulate limestone cores damaged by asphaltene deposition. Several dynamic experiments were conducted to determine the effect of asphaltene on the permeability of limestone cores. Plugging effects due to asphaltene deposition were evaluated through a comparison between permeability measurements after oil flow and the reference permeability measured prior to oil flow. Damaged cores were subjected to bacteria and/or steam and the permeability of the cores was measured after each treatment. Core impairment resulting from in-situ asphaltene deposition was found to cause a 56 to 89% loss of initial oil permeability depending on rock permeability and injection rate. Core stimulation results from direct bacteria treatment, was found to cause a 3 to 105% improvement on the damaged core permeability depending on core permeability and the extent of the damage. Bacteria treatment results were compared to steam treatment of the damaged cores.
How Good Are Your Horizontal Wells?
Authors: Levitan M. M. , Clay P. L. , Gilchrist J. M. 
Published: December 2007

Abstract
This paper presents results of comprehensive analysis of BP horizontal well productivity and completion performance data. The study was performed to benchmark performance of existing horizontal wells with a view of developing simple empirical techniques that could be used for predicting performance of future wells. The developed correlation predicts a range of expected well productivity for future wells. This prediction reflects limitations of current completion technology and possible reservoir heterogeneities. The analysis method is based on presenting the existing well productivity data in the form of dimensionless parameters: the well productivity coefficient and the normalized productivity improvement factor. The results of this study can be used to: sense check estimate of theoretical well performance for undeveloped discoveries with historical performance for similar type reservoirsprovide quality control for newly commissioned wells to see if performance is as expectedhelp optimize development well design (i.e. high angle vs. conventional) to optimize reservoir exploitationoffer a means to rank well surveillance work based on where initial well performance lay with respect to global historic experience.