bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Review of the Theory and Practice of Two-Phase Flow in Gas-Liquid Transmission Systems
Authors: Brookbank M.R. , Fagiano P.M.J. 
Published: December 2007

American Institute of Mining, Metallurgical, and Petroleum Engineers, Inc.

Abstract
The development of frictional pressure drop correlations for two phase flow is reviewed covering the contributions of Lockhart and Martinelli, Baker and Duckler. A new equation is presented for prediction of the multiplying factor () for frictional pressure drop in two phase flow which gives pressure drop in two phase flow which gives results very similar to those predicted by Duckler's case 2 method.
1.82 V (1-Rl) 1 x2= {1 + l} x +g --- ------- ----- ----Vg Rl (1-Rl)2.4 Rl 1.8
The effect of vertical rises and undulations on the overall pipeline pressure drop is discussed. A hypothesis is presented for the mechanism of massive liquid and gas surges which have sometimes been observed at reception terminals for two phase pipelines. pipelines

Introduction
Although there are now many two-phase gas-liquid transmission pipelines in use, some of which have been in operation for many years, and although a number of research projects have been initiated on the subject projects have been initiated on the subject over the last three decades, there still remains much to be learned about the various phenomena occurring in two phase flow. The phenomena occurring in two phase flow. The present paper reviews some of the criteria present paper reviews some of the criteria which are used in designing two phase transmission systems and contributes some new thoughts on the subject.

THE DEVELOPMENT OF TWO-PHASE FRICTIONAL PRESSURE DROP CORRELATIONS PRESSURE DROP CORRELATIONS
For many years since its development in. the late 1940's the Lockhart - Martinelli correlation represented the most accurate and most widely used method for the calculation of frictional pressure drop in two phase flow. This correlation was based on experiments using air and various liquids in pipes of 1" diameter and less. It expresses a multiplying factor (2) as a function of the ratio of the pressure drops for the liquid phase flowing on its own and the gas phase flowing on its own (X2). The product of this multiplying factor and the product of this multiplying factor and the pressure drop for one of the phases flowing pressure drop for one of the phases flowing on its own is then the friction pressure drop for two phase flow.
Lockhart and Martinelli identified four types of flow which depend on whether the flow is viscous or turbulent for each of the phases. phases.
Cuttings Flux Measurement and Analysis for Extended-Reach Wells
Authors: Thonhauser Gerhard , Millheim Keith K. , Martins Andre L. 
Published: December 2007

Abstract
Cuttings transport efficiency is one the most critical issues, to be considered, for drilling a successful extended reach well. Recent efforts to develop transient models to simulate cuttings flux in extended reach wells let to the conclusion to develop a tool to measure cuttings flux over the shale shakers to determine hole cleaning performance. Standard rig procedures did not prove to be sufficient to monitor the cuttings transport efficiency and provide data as basis for such a simulation.
A mechanical device was built to measure the amount of cuttings "produced" from the wellbore. The combination of this information with the real time data acquisition of other drilling parameters was used to analyse the hole cleaning behaviour of the wellbore.
Hardware was built to fit multiple situations on- and offshore to be as flexible as possible. The major part of the development was to provide the means to interpret the collected data and retrieve valuable information to evaluate hole cleaning performance of the system. The measurement system was designed to satisfy two different objectives for data collection.
First to provide the basis for real-time interpretation to optimise circulating strategy, and schedule, based on the information retrieved. The quantitative measurement of the cuttings flux allows to compare generated versus "produced" cuttings. The comparison enables the driller to determine when to circulate to clean the annulus, thus avoiding unnecessary circulating time – meaning cost. Furthermore it was tried to correlate measured cuttings flux with wellbore stability problems, as well as overall drilling performance.
Second to provide the basis for drilling data post analysis. This includes representative data sets for a sequence of wells, accessible for the drilling engineer to optimise well planning. Such a data set could also be used to feed a learning hole cleaning simulation.
Slimwells Without the Pain
Authors: Head P. , Turner D. , Hanson T. , Al Rawahi S. , Cameron G. 
Published: December 2007

Abstract
Slimming down the well geometry to reduce the cost of well construction has been an economic goal of operators for many years 1,2,3,4. Historically, this has resulted in small diameter holes across the reservoir with the associated problems of specialised equipment requirements, reduced drilling rates, complicated well evaluation and reduced flow path. In addition, systems to date have also introduced severe operational drawbacks such as high surge and swabbing pressures during casing installation and high circulation pressures while cementing.
This paper will present the results from a joint industry project (JIP) the object of which was to address these issues, and provide an effective solution to overcome these drawbacks. The common approach throughout all of the well construction processes described in this paper is a series of liners, with tiebacks to previous liner tops as required. Finally the well is completed with a monobore tieback to surface.
The main technical challenges to overcome were:
- How to terminate each liner hanger with so little annular space while still retaining the same tensile load capacity as the virgin pipe. This was achieved by engineering a unique liner hanger system which requires no moving components, and which forms a metal to metal seal with the previous liner.
- To prevent the open hole being exposed to excessive pressures during liner installation, and while cementing. This was resolved by a novel conveyance system which allows for two modes of fluid circulation while the liner is being deployed and landed in the well, with a third conventional mode for circulating and cementing operations.
With the current trend towards deepwater operations smaller riser and casing configurations offer significant advantage over conventional well architecture. Figure 1 shows two potential casing configurations using this technology. The first illustrates the application of a taut leg moored 4th generation rig employing a 16" riser (the limit of its capability in great water depths). The second and slightly more radical application of this technology illustrates an 8" reeled riser from a DSV deploying the coiled casing option. Both these examples illustrate how this innovative project has broadened the range of options for well architects/engineers.
Rig Floor Accidents: Who, When and Why? - An Analysis of UK Offshore Accident Data.
Authors: Dobson J. D. 
Published: December 2007

Abstract
Rig floor accidents and dangerous occurrences account for almost 30 % of all reported accidents offshore on the UK Continental Shelf. They include fatalities and serious injuries. It is an imperative of both industry and regulators that the frequency of these accidents is reduced significantly.
Analysis of accident data held by HSE, the UK regulator, has identified the most frequent types of accident, the most common injuries, when accidents are most likely to occur and who is most likely to be injured. Analysis of the data has also been carried out to determine the impact of rig mechanisation on accident frequency. While many of the findings are as one would expect, there are also some surprising features. The analysis reveals that accidents are most frequent at the beginning of shifts and when shift pattems change. Personnel most at risk are floormen and roustabouts, especially those new to the industry and those with around 7 years’ experience; they occur most frequently in the age range 26 to 30. Most common injuries are those to hands. Mechanisation of rig floors makes a small but significant improvement to rig floor safety, mosl notably by the installation of top drives.
Earlier project work by HSE looked at the steps the industry was taking to reduce injury from dropped objects in drilling derricks and from manual handling accidents. Current projects sponsored by HSE include develop:nent of guidance to help assess rig floor design and layout to minimise human factors in the cause of accidents.
Virtual Experience Simulation for Drilling - The Concept
Authors: Millheim Keith K. , Gaebler Thomas 
Published: December 2007

Abstract
Future management of drilling operations will face new hurdles to reduce overall costs, increase performance; and to do this with possibly less retained experience and organizational drilling capacity.
Over the past fifteen years huge drilling data accumulations evolved as part of the drilling process. Although unused these inert data accumulations offer the new possibility to create what will be called a Virtual Experience Simulation (VES) for drilling.
This paper presents a new concept based on heuristics. Unused data accumulations are processed (or activated) using a technique cited in the paper. An example, using a 22 well data accumulation is processed into specific data sets for geology, tripping, cementing, logging, penetration rate, and unscheduled events. These new data sets now have a value added by retaining the field drilling experience and knowledge.
The last part of the paper explains one type of heuristic computer simulation engine (using system dynamics) that gives the user access to this virtual drilling experience and knowledge.
It is believed the work in this paper offers evidence that the VES is a new way to retain field drilling experience in a way it can be learned by others as virtual experience.
Dynamic Behaviour of a Bit-Motor-Thruster Assembly
Authors: Schmalhorst Bernd 
Published: December 2007

Abstract
Case studies show that the use of a thruster in the bottomhole assembly of a drillstring is beneficial for the operator because of a considerably improved rate of penetration and smooth drilling conditions. From a dynamics standpoint, the axial and torsional vibrations of the drillstring are improved by the use of a simple thruster device. The thruster acts like an ‘anti-vibration’ tool. Laboratory measurements of a full scale assembly containing a bit, a downhole mud motor and a thruster were carried out to quantify the forces, accelerations and dynamic pressures. Measurements were made at a 6kHz sampling rate and under various operating conditions. The signals were analysed by digital signal processing techniques to determine dynamic characteristics. The dynamics of the considered systems were then described by transfer functions. In these tests, the measured vibration response was used to calibrate the unknown parameters of a bit-motor-thruster dynamics time domain model that includes mud flow forcing effects. The computer application then predicts the dynamic behaviour of a complete drillstring while drilling.
Well Engineering Aspects of a 2 7/8in Ultraslim Lined Well Campaign
Authors: Saville P. , Hoorn F. Van , Edbury D. 
Published: December 2007

Abstract
This paper presents the well engineering aspects of a 2 7/8in Ultraslim lined Well Campaign. The application of this technology is seen as an essential capability for development of some mature fields. The 2 7/8in wells are sidetracked from existing 4 ½in horizontal liners. After milling a window in the horizontal liner, a 3 3/4in hole is drilled utilizing logging while drilling tools. The 2 7/8in liner is run, cemented, perforated and acidised. Operations are conducted through the existing 4 ½in Gas Lift completions or 4 ½in parasitic strings.
Lessons Learned During Deepwater Drilling Operations West of Shetland
Authors: Lesiuk Joseph , Rennie Andrew , MacPhail Ian , Cummins Ian 
Published: December 2007

Abstract
The frontiers of drilling in harsh environments are continually being pushed back. Since 1994, drilling rigs have successfully operated at all times of the year in the deep waters of the Northeast Atlantic Margin. Lessons learned from experience in these hostile waters are guiding rig development.
The Sovereign Explorer, a GVA 4000 design, was the first rig to operate around the year in the area and in water depths greater than 1500 ft during 1994 and 1995. As a result of this experience, extensive rig riser modifications were made to facilitate operation in the stronger-than-expected currents before a second round of drilling. A riser recoil system was installed to allow a controlled retraction of the slip joint during disconnection of the lower marine riser package (LMRP), and additional riser tensioners were fitted to reduce tensioning system operating stress levels.
Further modifications are planned, including active heave compensation and an improved BOP control system. Heave compensation will allow the Lower Marine Riser Package (LMRP) to be re-latched in 8- to 12-ft heave conditions rather than 4- to 6-ft heave, with an estimated saving of seven rig days per year. Improved BOP control, together with other modifications, will extend the rig's water depth limit to 4500 ft.
The challenges set by the difficult operating conditions encountered in the Northeast Atlantic Margin are discussed, together with some of the solutions already tested and other developments proposed.
Application of Digital Technology Optimizes Bit Selection to Cut Drilling Costs in Torrente Cigno Field-Italy
Authors: Clark Anthony , Aliko Enis , Scott Dan , Cooley Craig , Vedovato Alberto 
Published: December 2007

Abstract
This paper describes how digital technology was used to make a landmark bit selection decision that significantly reduced drilling costs in Torrente Cigno field of central Italy.
The operator used a new computer program that converted open-hole log data from an offsetting well into a digital format to select an appropriate bit for the expected drilling conditions. This new tool analyzed rock mechanics and helped the operator determine that a particular limestone section in the field traditionally drilled with roller cone bits fell within the limits of new polycrystalline diamond compact (PDC) bit technology. A medium set bit was selected with polished cutters and sufficient face volume and junk slot area to allow efficient drilling through shale. The bit also incorporated a newly developed high impact strength cutter with a highly stabilized layout to resist premature damage while drilling the limestone section. The bit drilled the lime faster than planned and also maintained a good rate of penetration through the shale section under controlled parameters. The bit came out of the hole in excellent condition.
The authors will discuss how the software program unraveled the complex problems associated with calculating rock strengths of the Miocene allochthonous and Pliocene formations. The output of the program, which uses empirical formulas derived from statistical observations and tests, gave the operator the confidence to run a PDC bit for the first time in the lime/shale sequence. This combination of new bit and cutter technology along with the innovative log analysis techniques allowed the 8 ½" section of the well to be drilled with one bit for a savings of $423,000 US compared to the offset well.
Improving Transient Testing Results Using Data Management
Authors: El-Hawary A. M. , Mahgoub I. S. , Sayyouh M. H. 
Published: December 2007

Abstract
The prime objective of data management is the economic optimization of data resources to achieve common goals. Data management is very important to project success, and Data Collection should be carefully planned and carried out. Justification, priority, timelines, Quality, Quantity, and cost-effectiveness should be the guiding factors in data collection and analysis. Each data project should be screened by a cost-benefit analysis.
A clear understanding of the purpose and application of information obtained from well tests is mandatory if this information is to be used properly in managing the reservoir. For instance, skin values calculated from well tests are used to determine the need for workover or stimulation of the wells. Another example is identification of the presence of boundaries. Defining boundaries is particularly important when testing appraisal wells. Occasionally, more work is needed before using the results of the "Well Testing" analysis to identify the reservoir model. Several factors affect the type of information obtained from well tests should be considered.
The input data used in well test interpretations is inevitably subject to measurement or estimation error. Therefore, each of input data type such as net pay, porosity, compressibility, and formation volume factor is subject to its own source of errors. Knowing the effect of these errors on the obtained results helps the engineer to identify the input data that have the most impact on the key reservoir parameters. The challenge for the engineer is to define the level of certainty that should take place, the cost of additional information and the economic benefits of reducing the uncertainty in the data. Reducing the uncertainty for the sake of accuracy should be avoided. The economic benefits of refined well testing results should be justified. On the other hand, Even if the data is perfect, data in isolation from other data may have no value, but when integrated with other data may have significant value. For instance, because transient testing is an inverse problem, more than one model may match the test data. Hence, results should be integrated with those from other methods to select the most likely reservoir model. By crossing the traditional boundaries and integrating the work of geoscientists and engineers, data resources are better utilized. It will be able to correct contradictions, to validate the well test interpretations, and consequently, minimizing costly errors.
In this paper an overview of the practical aspects of data management approaches being used today is provided. It discusses in details the application of the data management in transient testing. The application explores the source of input data errors; their effects on the results of well test interpretation and how these results can be integrated with other methods to obtain reservoir descriptions. Field examples are presented illustrating the effectiveness of this approach.
Integrated Characterization of Complex Khuff-C Carbonate Reservoir in Ghawar Field
Authors: Dasgupta S. N. , Hong M. R. , Al-Nasser M. T. 
Published: December 2007

Abstract
Integration of 3D seismic analyses with petrophysical and other well data has improved the reservoir characterization and reduced the drilling risk for the Permian Khuff-C carbonate reservoir in the Uthmaniyah area of Ghawar Field. The reservoir is heterogeneous, complex and influenced by syndepositional diagenesis. The Khuff-C reservoir rocks were deposited in a peritidal setting where slight changes in sea level created local islands that were sub-areally exposed. This exposure in an extremely arid climate resulted in porosity occlusion by evaporite cements. The occurrences of these tight islands within the Khuff-C reservoir interval are sporadic and randomly distributed.
Recently acquired 3D seismic data in the area, calibrated with borehole information, has permitted the prediction of these local tight Khuff-C porosity areas.
Inverse modeling of amplitude was performed on the 3D seismic data using an initial acoustic impedance (velocity x density) model developed from sonic and density logs from nearby wells. The amplitude inversion technique employed on the 3D seismic volume was target oriented, iterative, and constrained by acoustic impedance computed at the wells. The initial model assigns an impedance log for every trace in the seismic volume by interpolating between the well control points. The inversion process updated the initial model to match the amplitudes for each trace in the seismic volume time window. Six deep wells were drilled based on the 3D seismic inversion results in the Uthmaniyah area of Ghawar Field. As predicted from this inversion model, wells that were located over areas of low impedance penetrated porous Khuff-C gas reservoir. Prior to the seismic modeling some of the deep gas wells drilled in the Uthmaniyah area had encountered poorly developed Khuff-C reservoir.
In this reservoir study the integration of observations from various disciplines has resulted in a synergy that has reduced the ambiguity in the interpretation of results from each individual discipline. Improved characterization of the reservoir resulted in the optimization of each drilling location, reducing the drilling risk of developing the Khuff-C reservoir. A similar approach is being applied to the Khuff-C reservoir in other areas of Ghawar Field.
History Matching of Gas Simulation Models Using Optimal Control Theory
Authors: Dougherty E.L. , Khairkhah D. 
Published: December 2007

American Institute of Mining, Metallurgical, and Petroleum Engineers, Inc.
This paper was prepared for the 45th Annual California Regional Meeting of the Society of Petroleum Engineers of AIME, held in Ventura, Calif., April 2–4, 1975. Permission to copy is restricted to an abstract of not more than 300 words. Illustrations may not be copied. The abstract should contain conspicuous acknowledgment of where and by whom the paper is presented. Publication elsewhere after publication in the JOURNAL OF PETROLEUM TECHNOLOGY or the SOCIETY OF PETROLEUM ENGINEERS JOURNAL is usually granted upon request to the Editor of the appropriate journal provided agreement to give proper credit is made.
Discussion of this paper is invited. Three copies of any discussion should be sent to the Society of Petroleum Engineers office. Such discussion may be presented at the above meeting and, with the paper, may be considered for publication in one of the two SPE magazines.

Abstract
Two papers presented at the 1973 Las Vegas meeting showed how to use optimal control theory to history match reservoir simulation models. Distributions of kh and h which minimize mean square pressure error at reservoir control points are thereby determined. In this paper the method is applied to real-gas systems with closed outer boundaries in which pseudogas potential is calculated by pseudogas potential is calculated by the simulation model. Results obtained with three gas models are shown: a nine-cell model, a 36-cell model, and a 51-cell model; the latter is a hypothetical but realistic gas field model. It was concluded that this method satisfactorily generates kh and h distributions for real-gas systems which result in small pressure errors if sufficient control points are provided. The kh and h distributions provided. The kh and h distributions obtained depend upon starting distributions used; however, total pore volume is accurately estimated.

Introduction
Performance (history) matching is the process of varying values of reservoir parameters in a numerical reservoir simulator until acceptable agreement between performance predicted by the simulator and the predicted by the simulator and the observed data is reached. Parameter values must satisfy some criterion of reasonableness. The simplest approach to history matching is the trial-and-error procedure of visually examining simulator procedure of visually examining simulator results and adjusting parameter values by intuition or experience. This procedure is often slow and costly, and is frequently ineffective as well.
In an attempt to overcome these deficiencies of the trial-and-error approach, automatic history matching techniques have been developed. Many authors have investigated the subject of history matching.